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Nicaragua Pueblo ProjectIssue #65 Fall 2014

Saving The World With Clay Plasters Hempcrete, Part 2 - How To Build A WallGetting Dirty At WorkshopsKyomigaki Earth-Clay Finish Adobe Floors

PUBLISHER

EDITOR

ISSUE LAYOUT

WEB HOST

GRAPHICS

PRINTER

Odisea LLCJeff RuppertSatomi LanderSustainable SourcesMorninglori Graphic DesignPublication Printers

On the cover:

Submission GuidelinesCopy should be created using Times New Roman font, 11 pt, no bold, no colors, no underlining except for web sites, and no indentations for paragraphs. Don’t take time to reformat copy you receive from others; we can do that here. We’ve set up some format, spelling and other rules we could share upon request.

Word Count – with 30 pt heading• 900 words fills one page• 500 words with two photos fills one page• 700 words with one photo fills one page• 1000 words with two photos fills two pages

If several photos are used in an article and captions are added to the photos, the space for text will be reduced accordingly.

Submission DeadlinesDecember 1, March 1, June 1 and September 1. Please note that the story deadlines are important to our production schedule. Text and photos may be sent by surface mail or electronically to the TLS editorial office. For complete submission guidelines for articles and photos, see our web site at thelaststraw.org.

Contact the editorial office for information and input regarding issue topics and content development, ideas for articles and issue design and other advice, encouragement, complaint or controversy.

The Last Straw is printed entirely on recycled content paper, using soy-based inks.

The Last Straw is a quarterly journal documenting the natural building world. It was formed in 1993 to address the lack of public information about straw bale construction and has grown to cover all related topics. We are reader-supported, meaning we rely on raw stories from the field.

The Last Straw is produced quarterly. For subscriptions and address changes, back issue orders, printing and distribution, promotion, classified advertising and the calendar of events please visit our website at thelaststraw.org.

Donated articles and photographs are always and sincerely welcome on any topic relating to straw-bale and natural building. Letters to the Editor are also encouraged. Remember, your input is what keeps TLS up-to-date, functional and relevant! We work with offerings respectfully, though we may have to edit, postpone or decline their use. The Last Straw team reserves editorial responsibility for the content of the journal.

TLS Editorial Office Jeff RuppertEditorPO Box 1809 Paonia CO 81428(970) 704-5828TLSEditor@thelaststraw.org

© The Last StrawISSN# 1077-997332.

Children and Decorative Clay Plaster in NicaraguaPhoto by Liz Johndrow

The Last Straw • No. 65 Fall 2014 5

Editor’s NoteC O N T E N T S

Editor’s Note

Brewing a Brewery by Lydia Doleman

Getting Grounded on an Adobe Floor by Sigi Koko

Building with Hempcrete (hemp-lime): Essential Tips for the Beginner (Part 2) by Alex Sparrow

Natural Building in Nicaragua by Liz Johndrow

I Love My House by Katherine Gould-Martin

Kyomigaki / Otsumigaki Polished Earth-Lime Finish by Kyle Holzhueter

Why Workshops Work by Andrew Morrison

How Clay Plaster Might Save the World by Chris Magwood

Book Review: Shelter

Classifieds

Events and Human Resources on the back cover

Inside

The views expressed by our authors do not necessarily represent our own. We retain the right to edit, change or refuse to print submitted content. All submissions become the property of The Last Straw. And remember, safety is of the highest priority on construction projects.

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The Building Season is winding down for us in the Northern Hemisphere and just getting started for those below the equator. If you have a project wrapping up, we hope you’ll be moving in soon, firing up the heating system and testing it out with the well-insulated walls. It is fun to learn how a new building actually works. Does it feel like you expected? You begin to determine what small things could have been done differently. But for the most part it’s downright nice to start that long relationship with your latest friend.

In this issue we hope to share a good bit of knowledge that will help those of you who have yet to begin your project. From floors and walls to finishes and even workshops, this issue of TLS continues series of how-to articles and begins new ones. The owner-builder will find much to like in the feature project and the book review. Our own Satomi Lander helped Katherine Gould-Martin build a beautifully simple house in New Mexico, while Wayne Bingham shares his experience on his own home in his own book.

Reflecting the natural building world itself, our contributors in this issue are split evenly by gender. We start two new series and hopefully begin more contributions from a third person, all of whom are arguably a few of the most respected natural builders today - Lydia Doleman, Sigi Koko and Liz Johndrow. To say we are excited to have these women share their knowledge would be an understatement. The experience they share in this issue highlights their ongoing work to better the world around them, which is nothing short of inspiring and heartening.

Lydia shares her recent project, the Yale Creek Brewery in southern Oregon, which uses straw-clay walls in what could be the tastiest project this year. Sigi begins a two-part series on adobe floors, introducing us to them in this issue and walking us through installation in Issue #66. Finally, Liz tells us about her ongoing experience in Nicaragua and her passion to help those in need through simple, local building materials, techniques and community building.

To top off what we think is the best issue of TLS since our revival there are a few more in-depth and valuable contributions we think you’ll really enjoy.

Bringing home the value of TLS, Chris Magwood convinces us not only that can we save the world, but it is as simple as the dirt in our yards. In all seriousness, Chris walks us

through the obvious and perfectly logical reasons why clay plaster is your top choice for finishing walls. If you have ever wondered why you would use earthen plaster, here it is. It is difficult to deny the reasoning Chris uses.

Alex Sparrow continues his in-depth look at Hempcrete. He walks us through the basic steps to pouring hempcrete walls and other steps in the process. He answers basic questions and shows us, literally in pictures, what it takes to build these types of walls. This is the type of article we really like here at TLS. You won’t find much of this information on the web, and you’ll need to buy a book to learn more. In fact, at the end of the article Alex has shared a link to order his new book on the subject. You will also find Alex’s fellow TLS author and hempcrete guru, Tom Woolley, teaching what he knows at an upcoming workshop at Endeavor (details on the back cover).

Once again astounding us with his attention to detail, our regular contributor Kyle Holzhueter steps us through the process of Kyomigaki earth-lime finish. If you recall our coverage of Tadelakt in Issue #63, Kyomigaki is similar, but different. It is a mixture of both earth and lime, which, for those of you with knowledge of the two materials know, they don’t always mix well. But the results are stunning and also resistant to moisture. This article is by far the most in-depth how-to contribution we have ever had in this publication, and we think you will appreciate how much Kyle is sharing.

There is even more in this issue to enjoy, but we want to remind you of two things before we run out of space. New Zealand is hosting the next international conference on bale construction in 2016. Make sure to keep the dates open; you can find information on the back cover and on our website. Also, you’ll find an advertisement on page 37 for the upcoming CASBA annual conference in April near Sonoma, California. Sounds like a good place to enjoy Spring next year.

That wraps it up for us here until next year when we begin our second as a new publication. Remember, we couldn’t do it without you, so please renew your subscriptions and consider advertising with us. Our readership steadily grows and therefore so does your target audience if you are a professional or material supplier.

Happy baling and mudding! -Jeff Ruppert

6 The Last Straw • No. 65 Fall 2014 The Last Straw • No. 65 Fall 2014 7

Materials Materials

Yale Creek Brewery is a micro-brewery located in the Little Applegate Valley, the heart of southern Oregon’s wine country,. The brewery was founded in 2013 by Abbot Koehler, Jared Smith, Spencer Middleton, three early-twenties beer and self-sufficiency enthusiasts who met while attending Evergreen State College in Washington.

The brewers deep commitment to localization and sustainability is embodied in the significant amount of the ingredients in their beer they grow on site with plans to cultivate more on their 40 acre farm and education center. The 2,500 square foot brewery (formerly a horse barn) is powered by solar power and has been built with mostly local crafts people. In an effort to create a deeper sense of community ownership they opted to construct the walls of the tasting room area using 8” thick straw-clay walls that would be installed during a week long work party.

Joseph Becker of ION Eco-building (from Olympia, Washington) and I, Lydia Doleman of Flying Hammer Productions, teamed up to co-facilitate the infill of the tasting room’s epic seven-day work party.

Joseph drove 9 hours with Rumpelstiltskin, the straw-clay mixing machine, equipped with a 300 gallon slip/dunk tank to facilitate the mixing of an estimated 11 cubic yards of material.

Rumplestiltskin the straw-clay tumbler

Having much more experience with straw bale and my only straw-clay experience was on much smaller projects in which all the material was mixed by hand, I was eager to see how much more efficient the use of Joseph’s giant straw-clay tumbler would be.

We purchased 10 yards of pre-sifted clay/dirt from a local source and soaked it in ratios of 1:2 water to clay/dirt in 35-gallon garbage cans. We also opted to add borax and sodium silicate to ideally minimize the amount of water used to hydrate the clay to hopefully facilitate a quicker dry time. What the borax and sodium silicate (added in 1 cup borax per and 2 oz. sodium silicate per 20 gallons slip) did was precipitate out all the silt from our mix, resulting in a higher clay content in our slip. But consequently we had a lot of silt and gravel to remove from the bottom of the buckets.

Once our 6 containers of slip were prepared we used a diaphragm pump to send the slip up into the elevated 300-gallon tank that would gravity feed into the tumbler.

We ordered 30 two-string rice straw bales for the project, assuming we would use some for scaffolding and have plenty left over for mulch. Rice straw is oddly more available in southern Oregon than wheat or barley! We did incorporate some barley straw from the brewery’s barley harvest during the

work party.The rice straw was baled in such a way that it was a bit of

a process to unfurl all the flakes into a massive pile of loose straw that could be fed into the ever hungry Rumplestiltskin. Joseph Becker, gem of a human being, with the help of his sweet son Noah, led the loading of the tumbler and the mixing of slip, while I worked on the interior guiding people in the delicate balance of tamping straw clay enough to get it to adhere to itself but not so much that the insulation value was compromised from over tamping.

The walls were split stud 2x4’s with a minor amount of wiring and plumbing to work around. We opted for curved window openings, which were achieved by using Sonotube concrete forms cut into quarters length wise for a controlled radius around the openings. Electrical boxes were placed flush with the studs to keep the form work flow streamlined. We used 5/8” cdx plywood with strong-backs placed at the top of the 24” high forms and deck screws to avoid screw breakage and stripping. At the tops of the stud cavities and where a 2x8 marked the end of a framing section we nailed on ‘keys’ to help hold the straw-clay in the event there was any shrinkage after drying.

The first days of the work party we started in the loft and used a pulley system to hoist our materials up. Each day averaged about 10-15 volunteers and we completed the straw clay in 7 long but fun filled days. The work party culminated in a large BBQ and brew work party on the last Saturday. The

carrot on the stick was the impending keg that would be tapped on site once we reached a particular point. Incentive!

In a ceremony celebrating the connection of place the brewery is intended to foster, the brewers, builders and volunteers mixed a batch of straw-clay from barley grown on the farm with the slip infused with some of Yale Creek Brewery’s Yale Creek Pale Ale (aka YPA), toasted the beauty of the people, the planet and place, and how tasty the brew was! Here’s to straw-clay ale!

Lessons learned and critiquesWith a strong straw bale

construction background I found myself at times thinking ‘we would be done by now if we had opted for straw bale!’ However, we wouldn’t have had a quiet worksite (how many hours of chainsaw notching would have been involved!?), and I was drooling over getting to plaster perfectly flat walls of straw and clay. I have to say, straw-clay trumps straw bale in-terms of inclusivity as we had lots of little ones on our mostly quiet and dangerous-power-tool-free site. However, with a crew of 5 we could have stacked, trimmed and applied a scratch coat of plaster on the same space. It’s a testament to how

no natural wall system is perfect!I do think if I were to do it again, I might have skipped on

the borax and sodium silicate. As the walls dry I am noticing ‘blooms’ from the borax and have had issues in the past with borax blooms bleeding thru the to the next layers. If I had thought to do it, I would have done a wall section without the

by Lydia Doleman

Straw breakers

Brewing a BreweryStraw Clay Brewery

8 The Last Straw • No. 65 Fall 2014 The Last Straw • No. 65 Fall 2014 9

Materials Materials

This is the first article in a two-part series on adobe floors. In the next issue Sigi will walk us through the installation process of an adobe floor.

Why Would You Want A “Dirt” Floor?The truth is, you probably wouldn’t want to live on a dirt

floor. A dirt floor implies the lack of any finished floor…where the unrefined ground acts as your floor. Plain dirt is difficult, if not impossible to clean, and persistent dampness is likely (due to moisture rising from the ground below). Chronically damp surfaces can pose a host of health issues, including toxic forms of mold. A dirt floor has a connotation of poverty or is used purely for utilitarian (not living) spaces.

But this article is not about dirt floors.

additives to compare the dry times and see if there was indeed a difference. In addition to that, It might have been more efficient in time and money to have used bagged clay as the 10 yards of sifted clay ($1200!). We could have mixed it all in the 300-gallon trough and by passed the pump rental, and the silt relocation and sifting, but then we would be taking larger and larger steps away from localized and more meaningful materials.

If I had a time machine I would have used 55-gallon drums in lieu of the garbage cans and I would have been more diligent about installing the keys. Now that the walls have dried there are minor gaps where the straw clay has pulled away from the un-keyed areas and we have one spot where we have a bulge that will have to be mended with plumbers tape. I would have also like to have inspected the framing prior to the installation of the plumbing and electrical and removed a lot of unnecessary 2x4’s on the interior portion of the walls.

One challenge the rice straw presented was that without seed heads that germinate at lower temperatures there was no obvious way to determine when the wall was dry. I attempted to use my Delhorst Straw/Hay moisture meter, but it was obviously not calibrated for straw that was so intensely mineralized. Probing it into seemingly bone dry powdered clay on a hot, dry windy Southern Oregon August day was giving me readings of above 30%. So we gave our 8” thick walls 5 weeks of dry time with full southern exposure and two monster fans going 24/7. Next wall with rice straw I will buy a bag of wheat

seed and sprinkle it in the mix as we go. The walls are now dry and amazingly solid. As we are

prepping for plaster it is interesting to note how many gaps there are in the framing where the wood has shrunk away from itself (in the case of sistered vertical members) and how there are very few gaps in the straw-clay; another virtue of the continuous insulation.

I would not have changed the forms and totally recommend spending the extra money on good deck-screws. We had ZERO screw breakage, which paid for itself in spades!

Over all it was a wonderful experience only to get more wonderful as the Brewers and the builders are dedicated to making a beautiful space to match the rather heavenly place they live.

Lydia Doleman is a natural builder and activist currently practicing in Southern OR. She has been building since she first stole her sister’s legos at the age of three. For the last thirteen years her work has been a culminating point for ecology, art and social justice.

Flying Hammer Productions is her natural building construction company focused on pushing the bounds of affordable and energy efficient housing, training people and communities in various building skills and infusing the dreary urban fabric with structures that reflect beauty, sustainability and community. You can usually

find her in the mud, wrestling straw bales, laughing or just flying around by the seat of her pants….www.theflyinghammer.com (503) 975-4232

Straw clay at the top

Curved openings

GETTING GROUNDED ON AN ADOBE FLOOR by Sigi Koko

What we’re talking about here, is an adobe floor system…made from earth, but with specific material ratios and with controlled installation processes. And the difference is not nuanced. An adobe floor, also called an earthen floor, is lusciously beautiful, completely non-toxic, and quite durable. The floor is easily maintained, cleanable, and promotes a healthy indoor space. And best of all, in many regions adobe floors can be made using local clay soil. (Which makes them dirt cheap...sorry, I couldn’t resist!)

What exactly is an adobe floor?An adobe floor uses the same materials as its namesake

“adobe”: clay, sand, and fiber (most commonly, straw). The integrity of the floor relies on the sticky binding properties of clay...one of the most versatile building materials I know of.

Adobe floor in a strawbale cottage in West Virginia.

10 The Last Straw • No. 65 Fall 2014 The Last Straw • No. 65 Fall 2014 11

Materials MaterialsClay expands when wet, creating fat, sticky platelet particles, that act like suction cups. As the clay dries, those suction cups stay connected, creating a strong bonded material. But, if you use pure clay for a surface as big as a floor, the clay shrinks significantly as it dries, which means it cracks everywhere.

To control the shrinkage and cracking as the clay dries we add lots of sand to the mix. The sand does not expand when wet or shrink when dry, so it reduces the total amount the adobe will change in volume, wet versus dry. The sand also increases compressive strength, which means the floor is stronger. The sand should be angular in shape (not smooth) and should include a variety of sizes, up to ¼-inch across and down to fine particles. This way all of the sand interlocks, with the clay in between to bind it all together.

Finally, we add some fiber, such as chopped straw. The fiber knits everything together…similar to reinforcing bars in concrete. Alternatives to straw include dried grasses, horse or cow manure, and even recycled paper pulp. Anything that will give your floor additional tensile strength…which is the ability to withstand movement and internal pulling forces without cracking.

The finish mix is essentially the same as adobe or cob.

The difference between adobe bricks (or cob) and an earthen floor, becomes clear when it comes to processing and installation. Cob involves using the adobe mixture to sculpt thick walls. Adobe bricks are prepared by pouring the mixture into oversized brick forms, baking the blocks in the sun, and then building a masonry wall using the bricks and adobe mortar. For a floor, we use essentially the same adobe mixture, but pouring and floating it to form a thick, monolithic slab.

The installation of an adobe floor applies the same skillset used to pour a concrete slab. The wet adobe is poured in place and leveled. As it begins to dry, you “float” (smooth) the surface, creating a continuous floor slab. The “curing” process is just evaporation of the moisture. As the floor dries, you can burnish the surface as smooth as you like. Once the floor is completely dry, you seal the adobe to densify the finish surface and ensure that it’s easy to clean.

Since there is no cement in the adobe floor, you avoid the environmental impacts and cold nature of cement. Instead, you have a warm, grounding floor, with a super low eco-footprint…that begs you to walk barefoot.

What it looks like…What the actual finished adobe floor feels like depends

on how much you trowel and burnish the surface as it dries.

Burnishing tightens the particles together, reducing the micro-pores in the surface. The tighter the pores, the smoother the finish feels. You can make your floor feel smooth like leather with modest skill and a bit of patience. (I recommend practicing on smaller test panels to get your technique down, before committing to an entire floor.)

The color possibilities are as expansive as your imagination. A basic adobe mixture takes it’s pigmentation from clay soil, which means color ranges from red to brown, green to yellow, purple to gray. You can enhance or change the color by adding

pigments to the mix or staining the surface when your floor is dry. The sky’s the limit for color possibilities.

You can also embed stone or tile into the surface to create additional patterns. Just be sure to finish the surfaces flush, so you don’t stub any toes.

Where (and where not) to install an adobe floor

An adobe floor can suit nearly any use…and yes, that includes kitchens and bathrooms. Contrary to intuition, adobe floors can get wet…they just can’t stay wet for prolonged periods of time. Wet materials deteriorate faster, harbor pests, and promote mold growth. Areas prone to surface spills are no problem, because a spill is easy to wipe up. What you want to avoid is consistent moisture over time. This

means a floor poured directly on the ground needs to include a capillary break and a vapor barrier, to keep out rising ground moisture. (More on this in the next issue…)

Don’t install an adobe floor if you are in a hurry. The thicker the floor, the longer it takes to dry…which can be anywhere from 2 to 8 weeks. Additionally, the sub-surface under an adobe floor needs to have very little flex. Any movement can cause the finish floor to crack. If you plan to install an adobe floor over framing, I recommend stiffening the floor joists to minimize flex.

Do install an adobe floor if you are looking for a non-toxic floor option that is do-it-yourself friendly, breathtakingly beautiful, and sensuous to walk on. And stay tuned…in the next issue we’ll cover a step-by-step “how to” for installing your own adobe floor.

Sigi Koko founded Down to Earth Design, an architectural design firm that specializes in durable strawbale buildings for wet climates. Her projects use natural materials that ensure healthy indoor spaces, super energy efficiency, and minimal environmental impact. She teaches a wide variety of natural building techniques that empower her clients to contribute meaningfully during the construction of their home.

In the previous issue of The Last Straw (#64) I began to outline some key “dos and don’ts” for people wanting to build with hempcrete (hemp-lime composite). My business partner William Stanwix and I, along with the rest of our team at Hemp-LimeConstruct, have been building commercially with hempcrete in the UK for 6 years now, and have learned a lot of tricks along the way which we’re happy to share with TLS readers. For those wanting more in-depth information details of our forthcoming book The Hempcrete Book: Designing and building with hemp-lime can be found at the bottom of this article.

In the last issue we covered the nomenclature of hemp building, the basics of using hemp in construction (including different methods for applying it on site), and the first steps for building a hempcrete wall. Having looked at the plinth, the structural timber frame, fixings, and how services are brought into the building, we will now move on to discuss the method of mixing and applying the hempcrete itself.

Building with hempcrete (hemp-lime): Essential tips for the beginner (Part 2) by Alex Sparrow

Building with hempcrete (hemp-lime): Essential tips for the beginner (Part 2) by Alex Sparrow

Disclaimer: The author provides this overview of hempcrete construction in the spirit of advancing the knowledge and skills of people wanting to use the material. This article does not constitute a full training programme in the use of hempcrete and it remains the responsibility of designers and builders to detail and specify materials for their own buildings, and to ensure that contractors are fully trained. The author can accept no liability for the actions of his readers.

Shuttering under construction for a hempcrete wall.

The finished floor

12 The Last Straw • No. 65 Fall 2014 The Last Straw • No. 65 Fall 2014 13

Materials MaterialsShutteringTemporary shuttering (formwork) is constructed around the timber

frame to form the void which will be filled with the freshly mixed hempcrete. In our own practice we use OSB (oriented strand board) as we find it hard wearing and flexible (it can be cut to form unusual shapes). It can also be recycled into a roof deck or garden shed at the end of the build. Curved walls can be formed using flexible plywood as the shuttering. Commercial plastic or metal formwork systems can also be used which speed up the work considerably on a large square building, but these are costly and somewhat less flexible on smaller, or more individualised, buildings.

When erecting the shuttering, care must be taken to ensure that it is straight (true) and plumb, so that the eventual face of the hempcrete wall is also straight. This is presuming that you want a straight, plumb wall – they are not to everyone’s taste! Angled window reveals are attractive and help to maximise natural light in a building with thick hempcrete walls. These can be formed in the shuttering, or the reveals can be formed square and scratched back after casting with a nail float. This technique is also used to soften external corners after casting, for aesthetic reasons and to eliminate the need for corner beads in the plaster.

Mixing hempcreteHempcrete is usually mixed in a large (180 gallon) forced action pan

mixer. It can be done in a conventional drum cement mixer, but it is more difficult to ensure an even mix and in a new build the quantities needed for anything other than the smallest extension preclude this as a viable method. At a push, once you have mastered the technique, one person can run two cement mixers at a time which doubles the output, but really a big pan mixer is the thing for larger buildings.

The critical thing to remember when mixing hempcrete is to use the exact proportions of hemp shiv, binder and water, as specified by the binder manufacturer. Especially critical is the amount of water added, which should be no less and no more than what is required. This is because the dry hemp immediately sucks up some of the water in the mix and, because the binder needs water to achieve its hydraulic set, the amount of water specified includes extra water for the hemp, to ensure the binder gets all the water it needs. This extra water added at the mixing stage is what needs to dry out of the wall after the shuttering is removed. This drying (to the point where wet finishes can be applied) normally takes around 8 weeks, depending on the thickness of the wall, contractor skill during placing, and local weather conditions. As discussed in the last issue, long drying times are the main cause of problems with the build schedule, so it is vital to add enough water without adding too much, which will extend drying times.

The hemp, binder and water should be mixed for the minimum time possible to ensure a consistent mixture with the binder evenly distributed and coating all of the hemp. Mixing for longer than necessary (especially in a drum mixer) causes the mix to start “balling”; small balls of binder start forming in the mixture. The readiness of a hempcrete mixture is tested by taking a handful out of the mixer and squeezing it into a ball between your hands. Push a finger into the ball. It should break cleanly into two or three pieces; if it crumbles it’s too dry, if it’s squidgy it’s too wet. Once mixed, hempcrete should be used promptly before it starts going off, and buckets waiting to go into the wall should be protected from rain (adding more water) or direct sunlight (drying the material out).

Placing hempcreteTubs of freshly mixed hempcrete are ferried to the shuttering and tipped into the

void in layers of no more than 100-150mm (4-6 inches) at a time. The mixture is then spread around with a gloved hand to ensure that it is evenly distributed around the void, taking special care in hard-to-access corners, and around frame timbers to ensure that the material is making good contact with the timber. The top of the layer is then patted down firmly with the palm of your gloved hand. No other “tamping” is required, since over compressing the material has unwanted effects. Firstly you are reducing the amount of air trapped in the material (reducing the insulation value of the finished wall). Secondly your wall will be more expensive, as you will have put more material into it. Lastly you are closing up the matrix structure and reducing the size of the thousands of tiny air tunnels running through the finished wall. This restricts air flow and so further extends the drying time, causing delays in the application of finishes.

For this reason we never use “tamping sticks”; we find that people are more sensitive to the amount of compression required when their gloved hand is in contact with the material. Give someone a stick, and they immediately lose touch with the material and the tendency is then to over-compact. We use sticks only to reach inaccessible areas, and teach people to use them as an extension of what they are doing with their hand. Some areas, e.g. where the coverage of hempcrete over a frame timber is not very deep (the minimum is 50mm or 2 inches), may require more compression, to ensure the structural integrity of the finished material. Additionally it is good practice to give extra compression, with the tips of your gloved fingers, along the sides of the void to consolidate the face of the wall. How much compression is needed here is largely a matter of experience, and there is a balance between a wall face which is too “open” - potentially friable and swallowing up too much plaster in the base-coat, increasing the finish costs - and too “closed” - with insufficient air holes, thus reducing the surface area of the material at the face of the wall, slowing the evaporation of excess water out of the wall and extending the drying time.

Move around the building, placing hempcrete in the shuttering as described until it is all full and ready for the next lift. You can fix more shuttering boards to create the next lift, leaving the ones below in place. Once the hempcrete has taken its initial set, boards can be removed, but always keep a board in place below the lift you are currently casting. There is no set “maximum lift” in a day, this depends on the materials you are using, but in practice, unless you are casting a very small shed, you are unlikely to run into trouble as long as you always cast a whole lift before moving up. If you have to stop for the day with shuttering half full, taper the last few mixes down into a gradual slope, so that the next day your first hempcrete is building on top of what is already there. This is better than leaving “vertical day joints” which form a weak spot in the finished material.

When casting spans across windows and doors, cast the whole ‘lintel’ section in one go, extending at least 300mm (12 inches) over the wall on each side, to ensure the integrity of the spanning section. Small section timbers, such as roofing battens, can be cast into the ‘lintel’ hempcrete on either side of the frame to provide extra support to it as it dries. For longer spans, more substantial timbers may be required to provide additional support. At the bottom of openings in the wall (e.g. windows) where the hempcrete stops, cast the hempcrete approximately 25mm (an inch) higher than the eventual desired level, and cut it back afterwards with an old hand saw. This is so that the top layer (always loose and friable when dry) can be cut back to solid hempcrete.

wTop: Joining two shuttering boards together for the next lift.Bottom: A hempcrete wall with shuttering partially removed.

The constituents of hempcrete; hemp shiv, lime binder and water.

Mixing hempcrete in a large pan mixer. This is the usual method since large quantities are easily mixed.

Mixing hempcrete in a drum mixer is more difficult, but it’s possible if you don’t need large quantities.

Tipping hempcrete into the shuttering.

14 The Last Straw • No. 65 Fall 2014 The Last Straw • No. 65 Fall 2014 15

Materials MaterialsAfter castingOne or two weeks after casting, once the hempcrete has hardened

sufficiently (but before it goes too hard!) use a nail float to shape the hempcrete as required, and an old saw to cut back to level at the openings.

Use good drying management to speed up the drying time. The key here is to get as much heat and airflow to the surface of the wall. A “good washing day” is good for hempcrete drying. Organise the site so that materials are not left leaning against the wall or standing in front of it to block light and airflow. Ensure the building is well ventilated and if doors and windows are fitted, make sure these are left open as much as possible. If a wood burner is fitted ensure the door is left open when not in use, to provide passive ventilation of the building. If you are casting at colder times of the year (which is not recommended), heat the building when you are there and, as soon as the heat source is turned off, open all the doors and windows to vent away any moisture that has evaporated into the heated room.

FinishesAll finishes for a hempcrete wall must be vapour permeable to ensure the

continued health of the fabric of the wall, which contains untreated timber and a plant aggregate. The usual finish is a two coat lime plaster, and lime render externally. Clay plasters can be used internally. All paints must be vapour permeable, and lime or clay paints, and limewash are often used. Other finishes include timber or hung tile cladding with a vented air gap, or stone or brick cladding with lime mortars. For a cladded wall, an external, or double, frame design is required so that there is something to tie the cladding back to. A

vented air gap can be used behind the masonry cladding, or the masonry can be constructed first and the hempcrete cast against it, as long as consideration is given to a) the ability of the hempcrete to dry out after casting, and b) the exposure of the wall to driven rain. In situations where the wall is frequently exposed to severe weather a vented cavity is preferable.

Wet finishes can be applied as soon as a dry crust of around 40mm (1 ½ inches) is present below the wall’s surface. Dry means below approximately 23% WME (wood moisture equivalent) as tested with a protimeter (moisture meter) with long probes to get inside the wall. A dry crust indicates that moisture is now leaving the wall as vapour rather than liquid water, and so cannot carry tannins (present in the hemp) through to the surface of the wall. Plastering too early can cause cosmetic staining of the plaster due to these tannins being deposited on the surface. Plastering also closes up the surface of the wall, reducing the surface area for evaporation and slowing the drying of the wall, meaning that it will take longer to reach its optimum thermal performance, so it’s important not to apply wet finishes too early.

Final thoughtsCast in situ hempcrete is a low tech, sustainable and very enjoyable material

with which to build. It offers a flexible construction method, suitable for all types of construction (with the exception of underground or underwater applications!).

Hempcrete is truly zero carbon, since it acts as a carbon sink for the lifetime of the building. Tom Woolley is correct in saying that once people have experienced this

way of building, they rarely go back to using any other method.The main drawback is the drying time on site, which as described above can be extended considerably by weather conditions,

sloppy practices and contractor error, and so for larger builds pre-cast hempcrete blocks or panels are probably more suitable options. Contractor technique on site can also have an effect on the thermal performance of the finished hempcrete, so it’s important for those building with hempcrete to understand the issues involved to ensure a successful and smoothly run project.

Currently, due to supply-demand issues and the consequent price of binder materials, the cost of building with hempcrete (in the UK at least) is broadly the same as the equivalent brick and block construction with a high spec insulation. However, hempcrete - while “light work” - is a pretty labour intensive way of building, and due to the low-tech, hands-on method it is very easy for self-builders to do much, if not all, of the work themselves, dramatically reducing costs.

Using a nail float to soften a hempcrete corner 10 days after casting.

The effect of plastering too early; tanin stains on the plaster.

New build hempcrete housing in Swindon, UK (built by Haboakus).

Hung tile cladding on a hempcrete gable.

A self-built hempcrete house, combining timber cladding and lime render finishes.

The issues and methods outlined above are discussed in more detail in William Stanwix and Alex Sparrow’s forthcoming book The Hempcrete Book: Designing and building with hemp-lime. The book is in three parts: a discussion of the underlying principles of hempcrete building; a full practical construction manual; and a section on detailing and wider design considerations for architects and other building designers.

The publication dates are 9th October (UK) and 1st November (USA). More information can be found at http://www.greenbooks.co.uk/the-hempcrete-book

Hemp-LimeConstruct can be contacted through their website at www.ukhempcrete.com, or via twitter:

@UKHempcrete and @hempcretebook.

A video showing hempcrete being mixed in a drum mixer is available at: http://www.youtube.com/watch?v=w1FupaK-rvM

See also: Allin, S. (2005) Building with hemp. Seed Press: Rusheens

Co. Kerry

Bevan, R. and Woolley, T. (2008) Hemp Lime Construction: A guide to building with hemp lime composites. IHS BRE Press: Bracknell

Daly, P., Ronchetti, P. and Woolley, T. (2013) Hemp Lime Bio-composite as a Building Material in Irish Construction. Environmental Protection Agency Ireland: online only. http://erc.epa.ie/safer/iso19115/displayISO19115.jsp?isoID=202

Woolley, T. (2006) Natural Building: A guide to materials and techniques. The Crowood Press: Marlborough

Although currently in its infancy due to the developing supply chain for industrial hemp and certified binder materials, this is a method which can, and will, increasingly be used around the world to provide low impact homes and take us towards a serious reduction in carbon emissions associated with the built environment.

w

16 The Last Straw • No. 65 Fall 2014 The Last Straw • No. 65 Fall 2014 17

Nicaragua Nicaragua

This is an overview of the natural building work I am doing in rural Nicaragua, primarily with women and young people. This article shares the conditions, existing infrastructures and materials available, and some of the successes. Nothing has proven to be a failure, though the path has taken some turns! I will follow up with a series of articles deepening the exploration of each of these points.

I am preparing for my fourth building/teaching season in Nicaragua, working in rural communities. Spending most of my time in the northern region near the Honduran border. I am inspired by both the simple earthen adobe style houses and the warmth and generosity of the people I have met. In my time volunteering, and then being asked

back as an instructor, I have worked with some great grassroots organizations doing important work, including Grupo Fenix of

Sabana Grande and AMCC of Condega. Both of these groups champion for women’s advancement in non-traditional roles and practices that support both human potential and environmental awareness. They welcome building techniques that care for the environment and empower women and young people to create, participate and improve their homes. You can learn more about them at the links at the end of the article.

My focus over the last few years, under the guidance of these organizations who have already identified the needs the communities, has been hands-on earthen building training for women and youth, while offering the exposure and opportunity to men in the engineering, building, and architectural fields as well. I often joke about welcoming the men as long as they are willing to be overwhelmed by the number of women. I believe it’s good for the men in a machisimo culture to be exposed to women finding their power, seeing them work outside the box of tortilla making and water hauling. The men also have some great wisdom of techniques from the past and memories of their fathers and grandfathers employing natural materials.

Here, as is seen throughout the world, earthen structures can be given a bad name in the face of modern building practices. In my opinion, the logical choice for building the world round is using local, plentiful, raw materials with sensible and improved techniques to adjust to the challenges of modern impact. A logical choice for a gringa (me in this case) visiting a place such as Nicaragua is to celebrate traditional wisdom and bring in some useful, modern adaptations. This article is an overview of my personal service and experience as a women’s rights activist and natural builder to the growing of an organization, Nicaragua Pueblo Project, with a mission guided to help secure resiliency in these vulnerable communities.

I am committed to growing the opportunity for women and young people to help them continue to strengthen their experience of improving the quality of their lives, while choosing to live within the present limitations of their environment. We overdeveloped country dwellers often have the blind and dangerous luxury of living beyond our means and our appropriate ecological footprint, and often inserted buffers to serious climate change impact without even realizing it. These communities don’t have such “luxuries.”

To paint a socio-political snapshot here are a few statistics that impact the rural communities of Nicaragua, particularly in the north. Three out of four teenage girls are pregnant or already have children. One out of three girls don’t complete primary education. In recent history,

Natural Building in Nicaraguaby Liz Johndrow

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Nicaragua Nicaraguaheavy clear-cutting of forests to raise cattle for US beef export has led to serious land erosion and loss of topsoil. This in turn led to blights, droughts, crop failures and malnutrition. Land mines left behind from the CIA led war in the 80’s devastated many families in these rural farming communities. These communities are 100% underemployed and most are living a subsistence lifestyle under $1 per day. There is an identified housing deficit of nearly 1,000,000 homes in a country of 6,000,000 people and the number of the housing deficit rises 30,000 per year (Habitat for Humanity - www.habitatnicaragua.org)

Obviously housing is critical and necessary. In these regions homes are over crowded with several generations packed into a small abode. Traditionally floors

are dirt and adobe walls aren’t plastered. In many communities families haul their water and many don’t yet have electricity. It can often be a breeding ground for disease carrying insects as the homes are often difficult to clean. Cement is appealing and encouraged for home improvement but many can’t afford such luxuries. And adobe homes in fact have better thermal cooling capacity and are naturally more comfortable than the modern cement block home, encouraged for it’s standardization and safety record in seismic regions. But statistics and time have shown that concrete buildings are often poorly built in these underdeveloped regions, which can create a deadly scenario during seismic activity.

The materials most readily available in this heavily deforested region is a beautiful varied red clay soil, river sand, stone from the mountains and riverbeds, small amounts of immature timber, rice straw, hydrated lime, cactus and bark additives, horse and cow manures, and grasses. There are also deposits of beautiful colored clays. I will share more about the local techniques and materials another time!

Many of my efforts have been to pass on skills and information, celebrate traditional adobe and other vernacular building styles that bring comfort and deservedly should bring pride, offer opportunity for often sorely missing creative expression, and create opportunity for necessary home improvements.

Over 50 women and young people have received training in workshops over the last three years. We have created three community centers and begun a model adobe home.

An initiative was born this past season in Sabana Grande to improve old adobe structures with earthen plaster and simultaneously create a canvas for community storytelling through mud art.

This past season, with Grupo Fenix, we began our first home improvement exchange with some families in the community to help each other achieve necessary home improvements of oil stabilized earthen floors and wall plasters, with a result to eliminate nooks and crannies for disease carrying insects to inhabit. They are also beautiful, offer a deep sense of pride, and are easily maintained by the homeowners who participate in the process of their homes and others, using locally sourced materials.

The community centers are now a source of community pride and offer educational and even economic opportunity.

Some participants have gained the confidence in these natural building

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Nicaragua Projects

PART 1. The BackgroundI recently found in my files a 1960 article from New

Mexico Magazine on how to build an adobe house. That same year my family had moved away from New Mexico, from the adobe house I had grown up in. I loved New Mexico and my life there. I was determined to return and build myself an adobe house.

50 years passed before I could begin. In 2010, I retired from Bard College and began the activities that would lead me to my house: reading, volunteering, taking workshops, finding professional help, and consulting my Gila Valley neighbors.

Reading: Build It with Bales by Matts Myhrman and S. O. MacDonald (my neighbor on the Gila River); A Pattern Language by Christopher Alexander, Sara Ishikawa and Murray Silverstein; Building a Straw Bale House: The Red Feather Construction Handbook by Nathaniel Corum; Building with Awareness (DVD and guidebook) by Ted Owens; the videos of Andrew Morrison; and the gorgeous picture books of Athena and Bill Steen and David Bainbridge.

Volunteering: building energy efficient houses with the Hudson, NY, chapter of Habitat for Humanity; and finishing

up a straw bale house on the Hopi Reservation in Arizona with Red Feather Development Corporation.

Taking workshops: five weekends at a Green Phoenix-sponsored Permaculture design certification course in High Falls, NY; a week-long straw bale and clay plaster workshop with Bill and Athena Steen at the Canelo Project, AZ; a weekend of clay plaster training at Tom and Satomi Landerʼs LanderLand in Kingston, NM; and a week of carpentry at the Heartwood School in Massachusetts (hard to remember because I had walking pneumonia).

Finding the professionals: Steven Shelendich, architect, and Rich Bigelow, contractor, both of Silver City, NM. Since they hadnʼt built with straw bale or clay plaster before, I recruited Tom and Satomi Lander as advisors and builders. (Their advice was needed on crucial design elements, starting with the foundation; you canʼt just throw straw bales into a stick-built house as if they were dry wall!) Steven and Rich introduced me to the solar electrician, Craig Wentz, and the woodworker, John Owen, and recruited all the other necessary professionals. The daily crew, truly excellent human beings

workshops to move on to other community initiatives and do things they hadn’t previously thought possible.

This coming season I will lead three workshops in three communities with different women’s cooperatives. And Nicaragua Pueblo Project plans to support a team of volunteers to come and participate in the home improvements. We will build composting latrines, raised beds for strengthening the bee population, and continue to teach about improved adobe techniques and natural plasters.

Now that I’ve painted a picture of the impact of this region on my life and what Nicaragua Pueblo project has and hopes to continue accomplishing, I will share some specific techniques and processes in future articles. Stay tuned for more in depth look at improved adobe building techniques.

To learn more about my work and Nicaragua Pueblo project: www.nicaraguapuebloproject.org www.earthenendeavors.com

and to learn more about the local groups in Nicaragua:www.grupofenix.orgwww.mujeresconstructoras.org

I Love My Houseby Katherine Gould-Martin

Beautiful earth plaster and earthen floor.

Liz has always enjoyed spaces that bring her in touch with the natural surroundings. As a builder, she was thrilled to discover she could bring that contact deeper into structures through the choice of building materials. Since that discovery, she has been exploring the world of cob, strawbale, adobe, earthbag, earthen plasters and floor systems, and timber framing. The simplicity of these systems and materials allow for people of all ages and abilities to participate in the creation. The past few years have taken her further into the role of teacher, facilitator, instructor and co-conspirator. She is increasingly passionate about helping others learn these skills so they in turn can share their vision of beautiful, sustainable, and socially just structures. Her more recent work has been in Nicaragua with the women and youth in the northern pueblos and with Red Feather Development Group in the Hopi Reservation in AZ. These projects have been the most challenging and rewarding work for her thus far. She is founder of the natural building firm Earthen Endeavors and of the organization Nicaragua Pueblo Project.

22 The Last Straw • No. 65 Fall 2014 The Last Straw • No. 65 Fall 2014 23

Projectsand builders, consisted of Wayne Bunker, Danny Ryan, and, for some phases, Mike Fugagli.

Consulting the neighbors: I spent time with my neighbors, visiting their houses and talking about houses, floods, fires, vermin and every other related issue. What worked and didnʼt work? What would they have done differently? (It was my good fortune, though not theirs, that a hard freeze struck before my house was underway, thus prompting us to put considerable effort into protecting the water pipes.) I was concerned most of all with whether I felt comfortable, safe, and happy in the houses I visited and what physical features contributed to those feelings.

I wanted a “green” house, one that worked, took care of itself, would last my family for generations, and would be a model of sustainability and energy efficiency. It should rely on local labor and local materials, and employ a wise and sparing use of the earthʼs resources. It should be as small as possible, while being handicapped accessible and roomy enough to hold most of my children and grandchildren. It should provide space for all our usual activities, but have no wasted space and certainly not room to encourage the clutter that drains our energies. The outdoor space and out buildings were important in the planned use of the place.

I wanted the house to fit nicely into the local natural environment and human community. And I wanted my family to feel as if the house really belonged to them by incorporating their participation. That became part of its story.

Part 2. The ProductI love my house. It is restful, comfortable, efficient, and

perfectly suits our needs. Built in the local style - an expanded rectangle with metal Dutch hip roof - it nestles easily under

cottonwoods, walnuts and a sycamore tree, backed by the irrigation ditch and looking out at the river valley and the mountains.

The house is deeply beautiful. My designs, much improved and transformed by the architect and realized by the contractor, give the house its proportions, lines, and useful spaces. Moreover, every surface of the house is beautiful. The walls are softly rounded and appealingly, very subtly, uneven. Made by the Landers of pinkish brown clay from my neighborʼs natural clay mountain, they glimmer softly with bits of golden straw. The inner walls and ceiling are local wood with color variations and knots and intricacies of grain. My ideas for cupboards, counter, desk, and Murphy and bunk beds were refined by the architect; the woodworker, using contrasting juniper and ponderosa, turned them into works of art. There is no place that does not delight the eye. It is a landscape I never tire of viewing.

The clay floor, darker than the walls due to the linseed oil finish, delights both the eye and the foot. Warmer than tile or concrete and softer than either, it collects sunlight to warm the house in winter and holds the nightʼs coolness in summer. The southern half of the floor is clay; the northern half, which includes kitchen and bath and hence water use, is cork - also a pleasure to the feet and eye.

The house works! It received a five star rating for energy efficiency. More to the point, it remains in the 70ʼs in the summer when the outside temperature is in the 90ʼs and above, and in winter the temperature does not dip below 60, even when it may be 20 outside. For heat it has four systems. The big south-facing windows with their well designed overhang allow the winter sun deep into the house, while keeping out the summer sun. The clay floor absorbs and returns the warmth. A

Projects

trombe wall, that is, a masonry column, painted black, stands just inside the center window and warms the air long after the sun has set. A soapstone wood stove heats the house and the trombe wall retains the heat. Lastly, a propane stove, currently set to 52 degrees, ensures that the pipes donʼt freeze if no one is there during cold, cloudy days and bitter nights. The heater can be turned up if the occupants are cold and do not want to build a fire. For coolness, there are the thick straw bale walls, covered with stucco outside and adobe inside. There are windows to the east and north, but none to the west, protecting the house from the afternoon sun. A ceiling fan moves the air when people are home and a ventilator fan keeps the air fresh.

Part 3. The ProcessThe foundation, posts, window frames, door frames, and

roof were ready in November, 2012, when the straw bales were delivered out on the highway and ferried in. The contractor, his crew, and the architect were there to receive them and to learn from the Landers how to “infill” with them. A mountain of bales arose under the roof, leaving space only around the edges of the foundation. It was hard to imagine living in the house from that narrow peripheral pathway!

New Mexico building code calls for “internal pinning” - large amounts of rebar stuck through all the bales to hold them together. The Landers secure the bales more effectively

with an alternative method. They bolted a series of boards, called “curbs” or “toe ups”, onto the foundation. The boards had rows of nails hammered into them, but only partway hammered down. The first row of bales was settled down onto these nails and could not move in any direction. All the other bales were securely tied with baling twine to the bales below, above and next to them. And lastly, using bale needles, bamboo was tied on either side of the wall and connected through the walls. Since the bales are just giant bricks, the main part of the walls was quite simple. Around the window and door frames and especially up by the ceiling, the work was very difficult, as the bales had to be retied and trimmed into a variety of smaller sizes.

I was not strong enough to lift the bales or even to tie them, but I swept up and bagged all the loose straw - an important job as loose straw can burn. The bags of straw have gone to my

Passive solar designed house - south side.

Katherine carrying a big bag of loose straw.

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Projects Japan

Kyomigaki, also known as Otsumigaki, is a polished earthen-lime finish often used in entrance ways and stair wells, that is, anywhere a more durable finish is desired. In pre-industrial Japan, due to its energy intensive nature, hydrated lime was a valuable commodity and was used sparingly. Kyomigaki uses roughly the minimum amount of lime needed to polish an earthen plaster, which provides a more durable surface than mizugone or nori-tsuchi, other popular earth based Japanese finishes. The following describes the preparation and application of Kyomigaki. My gratitude to the Kyoto masters for sharing their tradition.

Preparation of Materials:Haitsuchi Brown CoatClay : Fine Straw Fibers : Hydrated Lime :: 1:1:0.4

neighbors for their gardens and animals, and Iʼm using them in composting.

Most importantly, they were used in the clay of the next stage.

Four months later, in March, 2013, it was mud time! For the initial clay plastering of the straw walls, I recruited my brother, my sons, and my grandsons, who could show up during their spring vacation week from schools in Maryland and Sweden. Tom and Satomi Lander assembled the equipment and supplies. The crew, the contractor and the architect were present. My contractorʼs brother-in-law, retired superintendent of a construction company in Pennsylvania, worked for free while visiting New Mexico from France!

The first job was to turn the chunks of my neighborʼs clay mountain into powder that could be sifted, then mixed with water and with sifted sand and cut straw. The 5- and 8-year-old grandsons delighted in the mixing process and covered themselves with mud.

Besides helping us, they built a small house of their own out of boards, rocks and mud.

In the evening they built another out of graham crackers, marshmallows, and chocolate frosting!

In the beginning, the straw seemed to repel the mud slip we were applying; straw and vmud kept falling to the ground. But once we all got the hang of it, the slip held, and a thick layer of clay plaster could be applied. Then it was scratched to help the much later second coat to hold. The most difficult areas, such as over the windows and doors, were done by the Landers. We were a jolly crew, noisy with conversation and laughter and a pizza party at the end. We finished in about five days. March is cold for this work; weeks passed while that first thick coat dried.

I was not around for the second coat done by the whole crew, and Tom and Satomi did all the careful work of the final and beautiful third coat. They also constructed the earthen floor by themselves. I was more relieved than disappointed not to participate, as I wanted a floor that held, that would not crack or crumble or trip people with its bumps.

Meanwhile, the contractorʼs crew, the woodworker, electrician, plumber, stucco folks and other specialists continued their work. My husband and I did the tiling of kitchen and bathroom back splashes and toilet and shower floors with Talavera tiles. The neutral color scheme of wood and clay is brightened by the many colors of the tiles and the Talavera ceramic drawer pulls. Each grandchild chose his or her favorite drawer pulls from the website, mexicantiles.com.

The house was finished by Christmas 2013. We celebrated with our children, grandchildren, the neighbors, and as many of the people who had worked on the house as could come. Each subsequent stay increases our pleasure in it. The house is perfect!

Those who so generously worked on it with an unstinting devotion to detail and effect have our deep and everlasting gratitude.

Katherine Gould-Martin spent the formative years of her childhood in northern New Mexico. Educated as an anthropologist with research in rural Taiwan, she has had a checkered career in anthropology, epidemiology, urban forestry, the Park Service, and odd jobs, most recently working in Asian Studies at Bard College, Annandale, New York. Her husband, Robert Martin, is a cellist and analytic philosopher who teaches at Bard and founded and directs the Bard Conservatory of Music. They have four grown children and four young grandchildren.

Check out www.LanderLand.com for their basic earth plaster recipe and step by step earthen floor article.

Katherine, her son and grandsons playing with mud.

Katherine and her husband Bob tiling their new kitchen walls.

Kyomigaki / Otsumigaki Polished Earth-Lime Finish

by Kyle Holzhueter

A combination of native Kyoto soils, white clay and Juraku soil 1:1 to 3:1.

All clay is sifted through a 1.5mm sieve.

Fine Straw Fibers

Mijin fine straw fibers are sifted through a 1mm screen. The powder that falls through the sieve is saved for Mizugone, a different finish, and not used for Kyomigaki’s Haitsuchi brown coat. If the straw fibers are rather large, they should be

separated again with a 5mm sieve. The fibers that do not pass through the 5mm sieve are too large for Haitsuchi and should be saved for a different purpose. In other words, the fibers should be between 1-5mm in length.

26 The Last Straw • No. 65 Fall 2014 The Last Straw • No. 65 Fall 2014 27

Japan

Dry mix the Juraku soil and white soil and then mix with water.

Japan

The dry clay is mixed with water, and then the straw fibers are added. To ensure full saturation of the clay and straw fibers, this mix should sit hydrated for one week.

Clay mixed with fine straw fibers and allowed to ferment for one week. Due to the fine nature of the clay and fibers, this mixing trough of materials is valued at over $1,000USD.

To reduce the cost, Hidashi straw fibers

can be used in place of the fine mijin straw fibers. However, after the finish has completely dried, the outline of the Hidashi straw fibers in the sub-layer may be visible.

Hydrated lime:

Sift hydrated lime through a 1mm sieve.

On the day of applying the finish plaster, mix hydrated lime with some water, then add the mix to the fine earth-straw fiber mix.

Hikitushi (Noro) Finish CoatThe top coat (noro) consists of fine clay and Washi paper fibers, and is mixed with hydrated lime immediately before use.

Sheets of Washi paper, approximately 500g/sheet, which will cover 35m2/sheet.

Completely dry the colored clay before soaking. Preferably the clay is crushed after thorough drying. If placed in water while the clay still contains moisture, the clumps of clay may be difficult to break apart.

Soak colored clay and paper fibers in water for 1-2 weeks.

Mix clay with a hand mixer.

Sift clay through a 100-150 mesh

Wash sieve regularly.

After soaking, tear apart Washi paper fibers.

Remove paper fibers from the soaking bucket and pound the saturated fibers on a flat stone with split bamboo. The pounding softens the fibers and breaks them apart.

After pounding, put a handful of fibers in a bucket of water and stir vigorously to unwind the fibers. Remove any unbroken paper fibers, which appear as white clumps in the water.

Strain the paper fibers through a sieve and collect the prepared fibers into a separate bucket.

Prepared paper fibers

Mix the strained colored clay and paper fibers. Approximately one tennis ball/baseball size of straw fibers per 4-5 liters of sifted and hydrated colored clay.

After mixing the clay and paper fibers, stick your hand into the mix and pull it out. You should see the paper fibers like a web between your fingers.

Allow the color clay and paper fiber mix to sit for at least 24 hours and up to one week.On the day of application, remove the standing water over the settled clay and paper fibers and mix with a hand mixer.

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Japan JapanBefore mixing with sifted hydrated lime, check to ensure that washi paper fibers have broken apart.

Hydrated Lime

Sift hydrated lime through a 100-150 mesh.

On the day of applying the finish plaster add the sifted hydrated lime to the clay and paper fiber mix at a ratio of approximately 1 part hydrated lime to 3 parts clay and paper fibers.

ToolsA number of trowels are used throughout application and polishing. The most important trowels are (1), either (3) or (4), and (5).

1. Jigane application trowelWhereas a steel trowel will tend to slide over plaster, iron Jigane trowels will naturally push and pull material, evening the plaster.

Well worn Jigane trowel

Jigane trowels available at Japanese Plastering.

2. Fusekomu Jigane Trowel:

Significantly worn, narrow Jigane TrowelThe purpose of the Fusekomu Jigane trowel, as will be explained below, is to drive the fibers back into the wall after rewetting. To ensure that the trowel doesn’t catch and damage the wall, a worn, narrow Jigane trowel is used. If this trowel is unavailable, a polished Jigane trowel can be used for the same purpose.

3. Polished Jigane trowel for evening and compression.

After application, the polished Jigane trowel is used to even the surface and for deep compression. Whereas a steel trowel will tend to only compress or polish the surface, the Jigane trowel compresses the entire thickness of the plaster, resulting in a deeper compression and fuller polish. This trowel must not be used for any other purpose, and especially not with plasters containing sand aggregates, which would scratch the trowel. The edges of the trowel must be polished with 1000 grit sand paper or higher. Any micro scratches in the trowelmight scratch the surface of the finish.

4. Konashi Trowel

Almost any trowel can be used as a Konashi trowel for compression as long as the plate of the trowel is meticulously polished. Yamanishi-san’s Blue Paper no. 1 Honyaki trowel is an excellent choice.

5. Honyaki polishing trowel

Traditional Kyoto Polishing trowel.

Yamanishi-san Ultimate Finishing Trowel In addition to being meticulously polished, the polishing trowel consists of the hardest honyaki steel, the same steels used in Japanese sword making.

Application:

Apply an even Haitsuchi with a Jigane application trowel and compress with a polished Jigane trowel.

After the mix has stiffened, and will draw moisture, apply the Hikitsuchi/noro.

Apply and compress with a Jigane application trowel. As the mix stiffens, compress with a polished Jigane trowel.

When there is too much friction for the polished Jigane trowel, compress with a polished Konashi trowel.When the surface can no longer be polished due to friction, re-wet the surface with a cloth. Quickly drive the loose paper fibers back into plaster with a worn, narrow Jigane trowel. The narrow, worn nature of the trowels allows for quick, easy movement.

Compress with the polished Jigane trowel, and then with the polished Konashi trowel. If you have a uniform texture and color, you may then move on to polishing with a honyaki polishing trowel when the konashi trowel can no longer be used due to friction. If there are some variations in color or texture, re-wet the plaster again and repeat the previous steps.

Slowly polish the surface with a polished Honyaki polishing trowel, covering the wall 2-5 times. Be careful not to scratch the surface. When there is too much friction, move on to the next harder trowel. When there is too much friction for the polishing trowel, clean and organize the work-site, return home and have a beer.

Kyle works as a builder, consultant, researcher and educator specializing in natural building materials such as straw bale, light straw clay and natural plasters. He has a PhD in Bioresource Sciences from Nihon University where he researched the hygrothermal environment of straw bale walls in Japan and building practices to control moisture. Apart from academia, Kyle has studied natural farming in Japan, permaculture in Australia, and organic and biodynamic farming in the US. Further details can be found at the following links: http://holzhueter.blogspot.comhttp://japaneseplastering.blogspot.com

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Community Community

There’s something special about the connections that happen when people work together towards a common goal. I see this at every workshop I teach. Without fail, there are people who share with me that the weeklong workshop has been the best experience of their lives. I used to joke with people that they “need to get out more,” but I no longer see it that way. Instead, I have come to recognize the beautiful community experience that people share at events such as a seven-day, hands-on straw bale workshop. I’ve seen it happen enough now that I felt it was time to dig a little deeper into why people have such powerful experiences. I have been grateful for the opportunity to ask this question of my workshop participants and of myself as well. Here are five things that I have learned.

1. Adults are kids too. Most adults have a hard time being a kid once they become adults. In general, adults are more concerned about looking and acting a certain way than they are about being goofy and having fun for fun’s sake alone. Here’s an easy example: If you, as an adult, get together with a bunch of friends, do you a) have conversations about fun times you have previously had in your life, b) have a few drinks to loosen up and then…have conversations about old times, or c) run around in the street screaming and

laughing with minimal clothes on? Not to say that we run around screaming and laughing with minimal clothes on in my workshops, but we do have a lot of fun. One woman shared with me that she had not sat around a campfire with friends telling jokes and playing music since she was a kid. She hadn’t realized just how much she was missing out on until she had the chance to experience it again. Another man shared with me that he hadn’t laughed so hard, so often, and for so long in about 60 years as he did at the workshop.

2. When we work together, we connect. I mentioned in the introduction that there is something about working together towards a common goal. When we spend seven days working hard at each other’s sides a certain bond is made. Keep in mind that many of the people attending the workshops are not used to doing seven days of hard labor in a row. Although some are contractors and builders, others are architects, engineers, CPAs, parents, and people from many other trades. Those who are not used to the labor, feel it right away. Working side by side with others with that common goal helps people to not only persevere and keep working, but also connect at a deeper level with those around them.

3. Common Visions. Everyone who comes to one of my straw bale workshops has something in common: a desire to learn about straw bale construction. This is just the beginning

though. Many have beliefs around living a sustainable lifestyle and minimizing their impact on the planet. Others believe in the importance of knowing where their food comes from and ensuring it is healthy and organic. Still others love the opportunity to meet new people and to work and play within a group dynamic. What’s more, people don’t have to have the same belief systems to connect at a deeper level. It doesn’t matter how you vote, where you live, or what (if any) religion you practice as long as you come with an open heart and a willingness to share an experience with others. No matter how people see the world they find ways in the seven days to come to places of common ground. The best example I have of this is my friend Cal who I met when he first attended one of my workshops several years ago (he has been to several since). He and I have perhaps the most opposite beliefs when it comes to politics. He said it best: “we live in different worlds” as he is from a relatively conservative part of North Carolina and I live in a very progressive town in Oregon. Even though we couldn’t disagree more on politics and many other topics, we have found a great friendship from our time together at workshops. We respect each other for our differences and care about who we are inside: kind people doing our best to bring something positive to the world.

4. Coming back for more. My friend Gretchen has been to several of my workshops. She even flew down to Australia a few years ago to be part of my first class down under. I asked her one day why she keeps coming back, adding (tongue in cheek) that I hope it wasn’t because I was doing a bad job teaching her! She told me that she just loves the time with other people from different backgrounds who are all in the same boat for a week. She loves the friendships she has made and she loves the opportunity to spend a week doing something positive. There was no other reason. She doesn’t plan to build her own straw bale house (she will hire it out). She doesn’t need to brush up on her plastering techniques. She just wants to spend the week with amazing people doing something good for the world. I can’t argue with that.

5. So much more than a straw bale workshop. What I have truly come to embrace is that the week of baling is so very much more than simply building. We come together, a group of 35 or so people (most of which don’t know each other), and LIVE together. We bring positive, fun energy to everything we do…even when things go wrong along the way (hey, it’s a construction site and things are never perfect!). We help each other. We help the hosts by building their house. The hosts help us by feeding us and nurturing us for the whole week. It is truly a win-win situation. The hours before, during, and after the work on the job site are all equally as important. We have had “joke-fests” go on until the early morning hours (and yes, we still got work done the next day!). We have played music together and sang around a fire. I have worked one on one with participants who were having personal struggles in their lives late into the evening. These moments of “personal growth work,” for lack of a better term, have deepened the group dynamic immensely. The participant’s willingness to be real, to be honest, and to

be vulnerable in front of people they have just met shows how incredible the workshop experience can be. We have literally laughed, cried, and shared our truths with each other time and again. The experience is so much more than just a construction workshop.

I have toyed with the idea of changing the name to a straw bale funshop, because “workshop” seems too serious for the amount of fun we have. The truth is, we do work and we work hard; however, we also play hard and share ourselves at a deeper level as a result. Just how the perfect recipe comes together, I cannot say. What I can say is that it always seems to be the same result: a week of incredible people coming together to do incredible things and all the while, connecting and creating friendships that last. I can’t think of a better job to have and I am incredibly grateful for it.

Andrew has a passion for straw bale construction that is matched only by his desire to teach his knowledge to others. With nearly 20 years of building and contracting experience, he has now moved his practice entirely to consulting and teaching. He shares his knowledge with thousands of people via his DVD series, blog, and hands on workshops. www.StrawBale.com.

Why Workshops Work by Andrew Morrison

Montana 2013 Group Photo

Notching Lesson

32 The Last Straw • No. 65 Fall 2014 The Last Straw • No. 65 Fall 2014 33

Materials MaterialsIf one scratches the surface of most of the environmental

claims made by manufacturers of green building products, chances are high that any particular material offers only a modest reduction in environmental impacts and can often come with high impacts when the product’s full life cycle is taken into account. In general, I tend to dismiss grand claims such as the one made in the title of this article.

While clay plaster probably won’t save the world, I do believe that it has a remarkable potential to dramatically lower the environmental impact of our buildings while simultaneously helping to achieve very high levels of energy efficiency in a way that is unique among our material palette for the sheathing of walls.

The low environmental impacts aren’t difficult to assess. Amongst the embodied energy figures for different wall sheathing materials, clay plaster is clearly the low-impact winner by an order of several magnitudes:

• Clay plaster – 113 MJ• Wood plank – 3,890 MJ• Plywood/OSB – 15,450 MJ• Gypsum board – 6,800-9,942 MJ• Magnesium oxide board – 4,672 MJ• Fired clay brick – 82,260 MJ• Lime and lime-cement plaster – 10,864 MJ(All figures for a sample building of 1,000 square feet with

1750 sf of wall area, taken from Making Better Buildings, New Society Publishers, 2014)

Clay plaster has several advantages over all other materials when it comes to energy input during manufacturing. The processing of local clay soils into viable plaster requires only low-grade mechanical action. In the form of diesel powered excavators and electric or gas powered mixers, the amount of energy required to dig up and mix up a clay plaster is very small, and it’s also possible to do it with no fossil fuel input.

How Clay Plaster Might Save the World by Chris Magwood

Artistic exterior clay plaster in an exterior application, using silicate mineral paints for weather protection

No heat or multi-step mechanical processes are needed, and transportation distances are often negligible compared to all the other materials.

Environmental impacts extend beyond embodied energy, and here too clay plaster takes a markedly lower toll on the environment. No deep mining is required, nor do trees or other natural ecosystems need to be disturbed. Even if thousands of homes were to be built using clay plasters, the majority of the clay soil can come from excavations for those homes and other public works where the soil would already be disturbed and removed. The abundance of clay soils in many regions would make it possible to keep supply and production on a very local scale.

Clay plaster can be used on a wide variety of wall types. While we typically associate clay plaster with “alternative” building types like straw bale and cob, there is no reason conventional frame buildings cannot use clay plaster as a combination of structural sheathing and finished wall surface on the interior and exterior. Depending on climate, exterior clay plaster can be protected by a rain screen cladding of another material, or used in conjunction with protective mineral paints or other coatings.

The use of clay plaster on more conventional buildings could radically change the nature of these buildings without needing a radical change in building design. Currently, conventional approaches to wall systems incorporate various sheet barriers to help ensure that buildings are airtight and do not experience moisture issues. These barriers are all derived from petrochemicals, and don’t just add greatly to the environmental impacts of a new building but also ensure that buildings are reliant on the kinds of industries that make these products. A properly applied clay plaster could transform a plastic-barriered, non-permeable wall system that relies on the petrochemical industry into a permeable, healthy and locally-

Artistic possibilities abound, sculpting around a truth window by Jen Feigin (CJ Johnston).

Basic tools turn dirt into plaster 1. A roto tiller is used to break up site soil prior to mixing.

34 The Last Straw • No. 65 Fall 2014 The Last Straw • No. 65 Fall 2014 35

Materials Materials

sourced building that is much more resilient to changes in the availability of oil and remote production facilities.

The clay plaster, if well-detailed, could provide a high degree of air tightness that can easily surpass current building code requirements and can even reach the targets of ambitious standards such as Passive House. This is not just a theoretical possibility, as several real-world projects have managed to reach impressive air tightness figures while relying on clay plaster as the main air barrier of the wall system.

Natural builders know that clay plasters work well with a number of natural wall insulation types, but they can be equally well matched to more conventional insulation materials as well. Cellulose insulation, in particular, is widely available, and within a conventional frame wall can be an integral component of an air tight, high performance, permeable wall system. Combined with wooden lath or other low-tech meshing strategies, clay plaster and frame walls mesh well together.

While many people question the long-term durability of clay plasters, many buildings are now entering their second decade in fairly harsh northern climates without requiring much, if any, maintenance or repair. Given that many of these pioneering buildings came early in terms of the modern revival of clay plastering, it is likely that formulations and applications will only improve the overall

The cost of clay plasters is low, making them accessible to anybody attempting to build any kind of structure. The sculpt-able nature of the plaster means any kind of finished appearance can be achieved, from the straight and square look of conventional western building to free-flowing curves and unique hand-sculpted elements. Whereas manufactured sheathing materials dictate an aesthetic by their very nature, clay plasters have no inherent aesthetic and leave all choices regarding finished surfaces, textures and shapes to the builder.

Clay plasters have terrific moisture handling capabilities, helping to balance humidity levels in buildings by freely absorbing excess moisture when interior air is overloaded, and releasing stored moisture when interior conditions are dry. In most current practice, buildings rely on mechanical ventilation to assist with moisture handling, but a generous amount of clay plaster could go a long way to reducing or eliminating the need for mechanical means of balancing moisture.

While there have yet to be definitive studies performed on clay plaster walls, small scale testing (particularly at the University of Kassel’s Research Laboratory for Experimental Building in Germany under Gernot Minke) indicate that clay plaster can have positive affects on indoor air quality. At the very least, they tend to have no negative affects as long as the soils they are made from are not contaminated.

To date, most of the work to prepare clay soils into viable

durability. And where clay plaster can really exceed all other sheathing materials is in repair ability. Unlike any other material, a clay plaster can be re-wet and re-worked back into a monolithic whole. New clay can be added to existing walls with solid results for hundreds, even thousands of years, and achieve the same levels of performance as when they were first applied. Even “durable” materials like brick and stone can have shorter lives and experience more compromises as time marches on. The “vulnerability” of clay plasters is also, from this perspective, one of their greatest strengths.

Blower door test seams in clay plaster. Seams in clay plaster can be points of air leakage, but are easy to seal with more clay. The home in this picture reached Passive House level of air tightness after sealing seams with clay.

plasters has been done by motivated individuals operating on a small scale and with little documented research. There is no

doubt that if clay plasters were to be taken seriously, advancements would be made regarding formulations, mixing strategies, admixtures and application techniques. Several European manufacturers offer clay plasterboards that are a manufactured wallboard much like drywall but using raw clay and natural reinforcing fibers, and such products could be made in

Basic tools turn dirt into plaster 2. Manual screening of clay soil if rock needs to be removed.

Basic tools turn dirt into plaster. An electric mortar mixer is run by solar power for fossil fuel free mixing.

Blower door test. A blower door is used to find points of air leakage into a building.

Clay plaster over lath. Clay plasters are easily applied to conventional frame walls with the use of wood lath, allowing the plaster to become an integrated element of an otherwise conventional building. (Kelley Jacobson).

Exterior clay plaster under a rain screen. In climates where it may not be appropriate to have clay plaster as the exposed finish, it can still be used to provide all the properties of a good sheathing under a rain screen.

Simple ball of dirt. A simple ball of mud could revolutionize the building world. (Daniel Earle).

Small amounts of clay soil. Large quantities of clay soil suitable for plasters are already being excavated for other purposes and could easily be put to use for making plasters.

Continue on bottom of page 36...

36 The Last Straw • No. 65 Fall 2014 The Last Straw • No. 65 Fall 2014 37

Book ReviewsShelterReviewed by Jeff Ruppert

... Continued from page 35

Many of us dream of having a natural home in the country, away from the city and built from materials close at hand. Few of us are lucky enough to experience such a gift, and the rest of us continue to dream.

Wayne Bingham is a dreamer, an architect, and one of the lucky few to live his dream. He now has a beautiful straw bale home in Idaho that is shared with his wife and family and friends. However, this book is not just about the home or the dream. It is primarily about the journey. The gift of this story is that it is real. It is a story one can relate to and it is spoken as one man’s truth during a journey over many years.

The book covers many years of Wayne’s life, but the thought of “walking the talk” emerged in 2001 after he had designed a few bale homes and felt a deeper connection with what was to become an odyssey into natural building.

The story is predictable and honest, but it is also full of timeless wisdom in the form of “Tips” that are captioned. Each one of these are gems that those of us who design and build natural homes know well. As an engineer and contractor I felt a connection to Wayne’s story, and must admit, also felt jealous

small factories throughout North America.While clay plasters probably won’t change the world,

they could go a long way to improving the overall quality of almost any building, reducing environmental impacts greatly while improving the health and performance of the building. It seems far-fetched to imagine mainstream acceptance of clay plasters, but as the cost of conventional building materials continues to rise and the complexity of using conventional strategies to achieve both air tightness and proper air quality continues to plague attempts to raise performance levels, clay plaster offers all of us – natural and conventional builders alike – a simple step toward large improvements.

Chris Magwood is the Founder and Executive Director of The Endeavour Centre, a not-for-profit sustainable building school based in Peterborough, Canada. His new book, Making Better Buildings was reviewed in Issue #62 and is on bookshelves at your favorite book store.

as I have not lived my dream just yet. This book is a must-have for all owner-

builders. It gives a perspective on costs and why various decisions were made, but most importantly the time-scale of building your own home with limited help is an eye-opener. As an owner-builder it is important to understand the scale of building a home. It is immense and requires patience, perseverance and lots of love of your partner, if you have one. This story shows how one couple was able to successfully navigate those rough waters and come out happy, but not unscathed.

Shelter is an inspiration that we recommend as a quick read for both the owner-builder and seasoned pro alike, especially if you are new to natural building. There are lots of images that

successfully convey the scope of the project and we’re pretty sure you won’t be disappointed with the ending.

At the time of publication Shelter is available for pre-order $16.95 USD from Familius. It appears it will be available both in paperback and digitally. Print ISBN 978-1-939629-25-8, Digital ISBN 978-1-939629-84-5

38 The Last Straw • No. 65 Fall 2014 The Last Straw • No. 65 Fall 2014 39

TLS Human Resource ListThe Human Resource List, or HRL, is a resource for professionals who want to share their products or services with the TLS audience.

In the past TLS printed an annual Human Resource Issue. To save printing and overhead costs we are keeping the HRL web-based for the most part.

However, during our start-up period, while the number of listings is relatively few, we will include those listing in the printed issues, free of charge.

When you enter a listing you are given the option to make it a “Featured Listing.” This means it will be at the top of every search and listing of services on our site, rotated with other Featured Listings. In addition to being featured on our website, Featured Listings will also be printed in each issue of TLS as an incentive to get you to use the service.

A basic listing is $15/year per category with a maximum of 2 images. A Featured Listing is an additional $50/year to be at the top of searches.

These costs, when spread out over one year, are very reasonable considering that thousands of people visit our site who are looking for resources to use on their next project.

The best thing is, you are supporting your favorite natural building journal!

List your Stuff in the TLS ClassifiedsClassifieds in the print publication are still free, but you must also list your goods or services on our website. Any listing added prior to our deadline date for publication will be included in the print version of the next issue. Thousands of visitors are viewing TLS website pages each month, which makes the online Classifieds the most valuable tool for reaching your target audience.

For your listing to be included in the print version of each issue we will need a compact version with a maximum of 40 words. The online limit for your classified listing is 750 words and six images.

PricesOne month $ 9.99Two Months $17.99Three Months $26.99

DeadlinesApril Issue March 1July Issue June 1October Issue September 1January Issue December 1

ClassifiedsStraw Bale House for Sale in Southern Colorado$239,0001824 Sq. Ft., 5.63 acres, open floor plan, tile floors, infloor heat throughout, custom kitchen, attached heated oversized 2-car garage with workshop, great well, master bedroom, bath & huge walk-in closet, upstairs bedroom 15x30 with full bath, large living room with stove, 1/2 bath in hall, large mud/laundry area off garage, covered front porch, breathtaking views of the Sangre de Christo and Wet Mountains, year-round access, pictures at MLS#: 2509189. 141 Navaro Road, Westcliffe, Colorado 81252 Call (417) 224-5369

Upcoming issues will include articles on:• Pre-Fabricated Bale Panels• Hemp Lime, or Hempcrete• Large Buildings with Bale Walls• Plastering Techniques and Materials• Regional Associations• Details (Send yours in today!)• And more…

Please tell us what you want to see and send us your articles.

To make sure your work is shared among the best of natural building, send us your articles.

Plaster Pump and Power Trowel Apparatus for Sale$750Location: Guelph, Ontario, CanadaVisit http://harvesthomes.caThompson Plaster Pump – pumps mortar & cement-lime plaster over long distances. Upgrades include: Honda motor complete with external throttle control & clutch, custom-fabricated “power trowel” to apply material directly to wall (no messy spraying), several lengths of 2” hose with quick connects; many spare parts. Thompson piston type pumps were built to last. We’ve invested $3500+ in upgrades &components. Stored idle for 5 years, so will likely need some work to make serviceable. Sold as is. $750 OBO

2 Power Trowels – as described in TLS issue #42. Built by the author.

To read the entire listing and view product photos, visit the TLS website.

How Can You Help TLS?Publishing a magazine like TLS usually requires a little more income than we receive through subscriptions.

The best way for you to support us is to make a donation or advertise with us. Our website is growing daily and is a great place to gain exposure with your target audience.

If you are a professional organization please visit our website and look at our Media Guide. It’s a great way to increase business and keep TLS going.

Upcoming Natural Building Events20 Oct Solar Power International Expo & Conference Las Vegas, NV22 Oct GreenBuild 2014 New Orleans, LA24 Oct Rainwater Harvesting 101 Austin, TX1 Nov Hempcrete Workshop Ontario, Canada3 Nov Sustainable Brands ‘14 London Lancaster, London7 Nov French National Meeting of Straw Construction Correze, Limousin8 Nov Design-Build Workshop in Ghana Ashanti, Ghana12 Nov Cities Alive: Annual Green Roof & Wall Conference Nashville, TN13 Nov 2 Day Solar Course for Appraisers Tempe, AZ22 Nov 7-Day Straw Bale Design & Construction Workshop Geraldine, New Zealand23 Nov 15th International Conference on Non-conventional Materials and Technologies São Paulo, Brazil28 Nov EcoXpo Sustainable Eco Living Surry Hills, NSW19 Apr 2015 Permaculture Design Certification Course Mastatal, Costa Rica3 Mar 2016 2016 International Straw Building Conference Methven, New Zealand Please visit our website for a full listing and description of these events.

The Last Straw JournalPO Box 1809Paonia CO 81428(970) 704-5828TLSEditor@thelaststraw.org

Human ResourcesTransMineral USAProvider of Saint-Astier Natural Hydraulic Limes, Lime Mortars, Lime Putty and Lime Paintswww.limes.us(707) 769-0661

Henderson ClayworksHenderson Clayworks is a General Contracting business specializing in Earth and Natural Building. Rediscovering and Refining the worlds great Earth Building Traditions. Earth based and Lime based plasters are used on all projects. On site testing and blending of clay soils is James’ specialty. If you can dream it, we can build it out of sand, straw and clay.Licensed General Contactor in Washington State, USA.http://www.facebook.com/HendersonClayworks(360) 460-3484

SolarWiseFor the last decade, Solarwise has specialized in energy and resource efficient straw bale design and construction. We combine a lifetime of conventional construction knowledge with the specific skills needed for effective straw bale construction. We design and build beautiful and healthy homes with exceptional

attention to detail, quality and craftsmanship. Our projects incorporate passive solar and site appropriate design, local/natural/green/recycled materials, non-toxic finishes and renewable energy systems to create an attractive and nourishing home that is both socially and environmentally responsible.(970) 376-3495 or (719) 539-9160

Dan DorseyDesigned and drawn plans for 85+ straw bale projects, know the SB codes, built first permitted SB single family residence in Pima County, AZ, in 1991. Consult and Design on Straw Bale and other natural building projects, do workshops, wall raisings.www.sonoranpermaculture.org/teaching-team-members/dan-dorsey(520) 624-8030

MG ArchitectsFull architectural design services including: conceptual design, construction and permit documents, and construction phase administration. Can assist owner/builder with getting approval for construction from local building inspector/department.www.mgarchitects.ne