Hempcrete A beginners guide to this up-and-coming - building technique

French 8-Story Bale Colorado Light -Straw More Japanese Mesh - How And Why We Use It On Bale Structures

$10.00 USD Issue #64 Summer 2014 On the cover:

PUBLISHER Odisea LLC EDITOR Jeff Ruppert ISSUE LAYOUT Satomi Lander WEB HOST Sustainable Sources GRAPHICS Morninglori Graphic Design PRINTER Publication Printers

A new-build hempcrete house under construction Photo by Alex Sparrow

The Last Straw is a quarterly journal documenting Submission Guidelines the natural building world. It was formed in 1993 to Copy should be created using Times New Roman address the lack of public information about straw font, 11 pt, no bold, no colors, no underlining except bale construction and has grown to cover all related for web sites, and no indentations for paragraphs. topics. We are reader-supported, meaning we rely Don’t take time to reformat copy you receive from on raw stories from the field. others; we can do that here. We’ve set up some format, spelling and other rules we could share upon request. The Last Straw is produced quarterly. For subscriptions and address changes, back issue Word Count – with 30 pt heading orders, printing and distribution, promotion, • 900 words fills one page classified advertising and the calendar of events • 500 words with two photos fills one page please visit our website at thelaststraw.org. • 700 words with one photo fills one page • 1000 words with two photos fills two pages Donated articles and photographs are always and sincerely welcome on any topic relating to straw- If several photos are used in an article and captions are bale and natural building. Letters to the Editor are added to the photos, the space for text will be reduced also encouraged. Remember, your input is what accordingly. keeps TLS up-to-date, functional and relevant! We work with offerings respectfully, though we may Submission Deadlines have to edit, postpone or decline their use. The Last December 1, March 1, June 1 and September 1. Please Straw team reserves editorial responsibility for the note that the story deadlines are important to our content of the journal. production schedule. Text and photos may be sent by surface mail or electronically to the TLS editorial TLS Editorial Office office. For complete submission guidelines for articles Jeff Ruppert and photos, see our web site at thelaststraw.org. Editor PO Box 1809 Contact the editorial office for information and input Paonia CO 81428 regarding issue topics and content development, (970) 704-5828 ideas for articles and issue design and other advice, [email protected] encouragement, complaint or controversy.

© The Last Straw The Last Straw is printed entirely on recycled content ISSN# 1077-997332. paper, using soy-based inks. Inside Editor’s Note

CONTENTS Summer is upon us and that means everyone is busy on everyone answer this question for their upcoming projects. The their projects. While the economy hit most of us hard in recent answer as to what is the best way to orient bales (flat or on-edge) 5 Editor’s Note years it seems things are picking up if the level of activity in is not really clear and concise. As with anything else it seems to natural building is any indication. The types and scales of various depend on a variety of factors. We hope you will find value in the 6 Rediscovering in Costa Rica natural building projects around the world is truly amazing and responses, which were too long to re-print here. We have provided by Ryan Chivers seems to be on a widening trend. We are excited to share this latest a link to the full report and invite you to find the article on our issue, which exemplifies the diversity of natural building. Such website and comment further to continue the conversation. 12 Jules Ferry Residence diversity is deserving of the “natural” title. by Jeff Ruppert This leads me to our regular reminder of the TLS website. We Materials and feature projects seem to dominate this issue. On publish all of the articles found here online as we edit them. Some The Benefits of Using Welded Wire Mesh 15 the materials side we have two excellent pieces on the use of lime of them are restricted to subscribers, which means you have access by Andrew Morrison in the trades. Ryan Chivers returns and shares his experience to all of them, including past content that has been printed since our revival earlier this year. This body of content will only grow. More Straw Building in Japan in Costa Rica, sourcing and experimenting with local lime for a 18 recent workshop at Rancho Mastatal. is the new friend of What you can’t find in the printed version of TLS are the high- by Kyle Holzhueter lime in this issue. As the first part of a two-part series, hempcrete resolution images within each article where you can really see 23 Building with Hempcrete (hemp-lime): (or hemp-lime) is back on our pages with a more in-depth look details that are not always apparent in the magazine. Our website 6 Essential Tips for the Beginner (Part 1) by practitioner Alex Sparrow. Because hemp is an industrial crop is just as important to our survival as the printed compilation by Alex Sparrow in the UK, they are pushing forward, using hemp in all sorts of we refer to as the magazine. We hope you find both useful and interesting configurations, and generously sharing their experience. informative. 29 Light Clay-Straw Mountain Home Look for The Hempcrete Book: Designing and building with by Jeff Ruppert hemp-lime by Alex due out in October, and look for the follow-up As always, if there is something you would like to see changed or article in Issue #65. And there is a gift for those of you interested if you want to see us cover something of interest, let me know and 33 CASBA Rides Again! in buying the book. Read the details at the end of the article and we’ll bring it to you. Calling for All Bicyclists for 2015 and you’ll be able to receive a 30% discount if you pre-order by the end of October. Beyond In international news New Zealand has announced it will host the next International Straw Building Conference (ISBC) in 2016, Here in the U.S. we have some hope of industrial hemp, but much 34 Bale Orientation within and Australia will host their annual conference in Adelaide in work still needs to happen to make this a reality. Hempcrete could September of this year. You can find both events listed on the back be a big part of our future if we could only free the fiber. 36 Book Review: cover of this issue and on our website in our events calendar. We Earthen Floors: A Modern Approach to hope to see you there. Our regular contributors, Kyle Holzhueter and Andrew Morrison, an Ancient Practice share their work and insights in Asian natural building and why we Finally, We would like to welcome CASBA members as use mesh on our bale walls, respectively. Kyle’s ongoing series 39 Classifieds subscribers of TLS. CASBA has subscribed their entire 23 on Asia continues with Japan and the unique use of tatami mats in membership, which supports our work and ensures their members wall construction. As in previous issues, we are treated to insight Events and Human Resources on the are receiving the best in natural building. We offer reduced and experimentation not found anywhere else but in the pages of back cover subscription rates to associations so if you are part of one contact TLS. us and we’ll get your members signed up.

We feature another light clay-straw home here in Colorado. This With that I’ll let you get on to enjoying this issue. We look one is a great example of beautiful architecture and thoughtful forward to bringing you the next issue in October. And remember, decision-making by a couple who were able to take their time send us your articles or pictures of projects so we can follow up during both the design and construction processes. The results are and share them with everyone. I challenge everyone in all regions stunning, which complement the breathtaking view of the Rocky of the world to see who can be most represented in these pages. Mountains. We look forward to hearing from everyone. The views expressed by our authors do not necessarily To wrap up the issue we give you the results of our survey on bale represent our own. We retain the right to edit, change All the best on your next project! orientation. We asked our website visitors to answer a few short or refuse to print submitted content. All submissions -Jeff Ruppert become the property of The Last Straw. And remember, questions about how they prefer to stack bales on their projects. safety is of the highest priority on construction projects. We received nearly 50 thoughtful responses which should help 29 The Last Straw • No. 64 Summer 2014 5 Materials Materials and sold in huge quantities, and so is almost always sourced relatively locally. This report will focus on lime technology as it relates to building construction. The main uses will be formulations for , and mortars for masonry. Two related raw materials will be covered. The first one is hydrated lime, which has been fired in a kiln and slaked with water. The second material is crushed limestone, which is essentially a of different gradations that could be used as the aggregate portion of all lime formulations. It has been my experience that the use of calcium carbonate based aggregates in pure lime formulations yields plasters and mortars that are stronger and more workable than more commonly used silica based pit or quarry . The theoretical reasoning is that calcium carbonate sands allow for faster and more thorough carbonation, creating a mortar or that becomes chemically pure CaCo3, or limestone, when it has fully cured.

Lime also at the Teatro Nacional

Costa Rica Lime In Costa Rica, a large majority of processed lime and crushed limestone is used for agriculture. Almost all industrial agriculture, bananas, coffee, palm oil, pineapple, etc. use lime or crushed limestone as amendments, pH buffers, and anti-fungal treatment. They are both produced in large quantities. We discovered two large lime RediscoveringRediscovering LimeLime inin CostaCosta RicaRica producing areas in the country. One is in the south at Palmar by Ryan Chivers Norte, and the other is 10 km or so south of San Jose, at This research and investigation was done as part of a natural building course I Patarra. co-taught with Liz Johndrow at Rancho Mastatal in Mastatal, Costa Rica. Rancho This research and Mastatal is a Permaculture farm and has been a pioneer for natural building and investigation was done as part sustainable living technology in Central America. What I found out about lime in of a natural building course at that part of the world was eye-opening and enlightening. Rancho Mastatal in Mastatal, Costa Rica. Rancho Mastatal is a permaculture farm and Historically, as in almost every other society in the world, lime was used as has been a pioneer for natural the primary binder for masonry, plaster and render in Costa Rica. It was not until building technology in Central the 1950s and 60s that production became widespread eventually replacing America. lime altogether. Today, the building industry in all of Latin America is dominated by Portland cement with most of the markets being controlled by a handful of billion- Crushed Limestone dollar multinational companies. At Palmar Norte, we found It is unheard of for a modern Latin American mason or plasterer to be using pure lime and stone production lime mixes with no cement. In Costa Rica, they don’t use lime in construction at happening at small quarries all. At builders and masonry supply yards it is virtually impossible to find a bag of adjacent to each other. Crushed hydrated lime. stone and lime production Fortunately, lime is one of the most widely used man made materials and is were separate operations. critical for almost everything that is produced in the modern world. Limestone is The crushed limestone was abundant. It makes up 20% or so of the earth’s crust, and its abundance makes it a screened into 3 different grades material that is relatively cheap to produce. For industry and agriculture it is bought as follows: Lime render from 1897 at the Teatro Nacional Courtesy www.chalkdownlime.co.uk

6 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 7 Materials Materials It is then shoveled into 23 kilo bags for sale. It is approximately The lime putty was soaking for several years in 200-liter barrels, $3.00 USD per bag. and it had about 8-12 inches of water on top of it. The water Having been produced in such a traditional way this lime was covered with floating carbonated lime indicating that it was had relatively low levels of plasticity and water retention. It chemically reactive and therefore able to carbonate. It had a thin also contained several pieces of unburned stone fragments. In layer of creamy material at the top, but quickly became thick and order to use this lime, we had to make some adjustments and chunky, seeming to be chunkier deeper in the barrel. take some steps to make it workable. This stiffening over time may indicate that this lime may have At Rancho Mastatal they have been doing work with natural very slightly hydraulic properties. building since their beginning in the late 1990’s. In 2008, they The water was poured off and the putty was broken into pieces. Primera Segunda Trecera bought a load of quicklime from the kilns at Pattara. They We noticed that physically beating the putty seemed to change the slaked it in water and left it to soak from that time on. Since viscosity quickly. • Primera was the finest sand. It has a top size of that time, they had used it to create some lime plasters and lime The next step was to powerfully knock the putty up with a mixing approximately 70 mesh, with gradations down to 325 mesh washes that were of variable quality. drill. Surprisingly, the putty quickly changed into a milkshake like fine powder. This material is their main product and is used consistency. as a soil amendment in agriculture. In building, this fine Slaked, hydrated lime ready for bagging sand could be used in very fine finish plaster work. • Segunda is the next size up. It has a top size of approximately 16 mesh, down to a small amount of sub 200 mesh particles. This would be the main aggregate for use in finish coats, tadelakt and thin base coats and small mortar joints. • Trecera is the coarsest sand they produce. It contains particles from approximately 10 to 30 mesh. This material works well for thick base coats and mortar joints. Because of its lack of fines content, workability would be greatly improved by adding a small percentage of Segunda and The top of the kiln from the outside Primera to this aggregate for base coats. Open bags of hydrated lime Open bags of hydrated lime Bags of lime ready for shipment

*Note the angular particle shape of the sands, this property is a basic principle for creating strong mortars and plasters. Crushed stone particles are generally quite angular.

All three of these materials are for sale at less than $3.00 US per 100 kilos.

Lime The lime kiln and process at Palmar was as close as you can get to lime Looking Into the kiln from the top production in ancient times. Limestone Raw, chunky lime putty at the bottom of The water was poured off and the putty Knocking the putty up with a powerful is quarried from the slaking barrel broken into pieces. drill a hillside and Next, we filtered the putty through a window screen to remove the unburned stone particles. loaded into a very basic pot type kiln approximately 18 feet deep and 12 feet across. The kiln is built into the earth and lined with stone. Limestone is loaded from above. The crushing operation There is a fire box below where scrap wood is burned as fuel. When the firing is complete, the quicklime is removed from the bottom of Looking into the firing the kiln and slaked to a dry hydrate by sprinkling it with water. chamber Filtering the putty through a screen...... to remove unburned particles Unburned limestone

8 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 9 Materials Materials Using Lime in the Workshop Ryan Chivers has been a natural plasterer since 1998. He has played a fundamental role in the development of natural plaster At Rancho Mastatal there were several projects that needed lime. A tadelakt systems used on the Front Range of Colorado. In 2006 Ryan traveled to Marrakech, Morocco on a quest to learn the ancient art bathroom and shower, some fresh lime wash over previously lime washed walls, and of Tadelakt. He has developed his own style of tadelakt that follows the Moroccan tradition using domestic tools and materials. some exterior lime finish plaster over wattle and daub walls. We had a workshop with Ryan has completed many successful tadelakt projects and has taught courses on the technique in the U.S, Canada, and Mexico. 16 mostly inexperienced students to complete the work. Overall, the plasters turned Ryan’s company, Artesano Plaster is located in Boulder Colorado and can be found at www.artesanoplaster.com. out beautifully. The workability of the mixes was good and the plasters seemed to cure strong and hard. For this project, we only had access to the “Primera” sand, having not yet discovered the other two gradations. The ability to source local lime and crushed limestone resources to create functional and beautiful plasters is something that I have done in several locations throughout the United States and Canada. This latest work with more crudely produced materials in a less developed country like Costa Rica was very exciting. With the ubiquity of lime and limestone production throughout the world, I believe that Finished lime putty ready for use similar results to these could be reproduced almost anywhere. The ability to create locally sourced lime mortars and plasters could be a powerful way to reduce dependence on expensive and poorly performing cement-based materials. Adding functional beauty to a world dominated by and latex paint. Lime and crushed limestone are already being produced for other industries. They are typically readily available, cheap, and potentially produced by small scale local operations in the developing world. The development of effective and functional lime plasters and mortars could also play a key factor in the further adoption of viable and appropriate earth building technologies. Tadelakt plaster ready for application (1 part lime putty, 1 part Primera sand)

The Finished Work

Lime finish coat over wattle and daub. Relief finished with clay paint Tadelakt Tadelakt surround for a composting toilet Shower surround

10 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 11 Projects Projects Some of the benefits of this type of construction Jules Ferry Residence are: • Seismic Behavior – Wood is light, by Jeff Ruppert meaning seismic forces are less than for a more massive structure. Shear walls are embodied in the The Jules Ferry Residence is an eight-story panel construction. urban housing development in Saint-Die-des- • Fire Resistance – During a fire, the Vosges, France incorporating pre-fabricated straw solid wood panels and large beams carbonize on bale panels and many other highly sustainable their surface protecting the inner core, retaining features. The project is a comprehensive structural integrity. The straw, in the absence of approach to sustainable urban lifestyles through much oxygen within the boxes will char slowly conscious planning, design and construction. and offer thermal resistance to adjacent spaces. The buildings themselves are carbon positive • Construction is fast, clean and healthy - and energy net-zero, supplying high-density Prefabrication allows for a cleaner, faster process. living space at a huge reduction in operating The use of bio-based materials greatly reduces costs, compared to other housing choices in the health risks for workers and residents. surrounding area. Jules Ferry is built on a 2,500 m2 (0.62 acres) Estimated costs to live in one of the T4 site of a former school playground. It is tightly apartments is as follows: integrated with the existing urban fabric of Saint- Die-des-Vosges. There are 19 units in Building • Heating 3€ / month Jules Ferry Residence Illustration (Courtesy of Le Toit Vosgien) A, and seven units in Building B offering both T3 • Hot water 2€ / month (76 m2 or 760 sf) and T4 (90 m2 or 900 sf) sized • Ventilation 2€ / month units. Each building is designed around a central “sheath” that houses all of the mechanical fluid systems (heating, hot water and • Maintenance 4€ / month air exchange). A bioclimatic design approach brings full solar gain to This is approximately 11€ per month or 132€ each unit, which provides 30% of total heating requirements. per year! (Excluding personal electrical ranging Access to each unit is provided from a protected corridor, from 200 to 500€ per year, depending on the leaving both the North and South facades largely open to the variety of uses of tenants). outdoors. The South facades have balconies that are sized to allow direct solar radiation in during the winter while shading Jules Ferry Residence was inaugurated on January in the summer. 10, 2014. Efficiency was built in to every part of the buildings, including the construction process. The building envelope is homogenous and comprised of both wood and pre- fabricated straw bale panels. The walls are twice as tight as a standard level Passivhaus. This type of panel construction ensures 40cm of insulation around the entire building that is comprised of 100% natural fibers of wood and straw, which provides natural hygro-dynamic control. The panels are exposed to the interior, architecturally expressing themselves as part of the finish. With a combination of the modular panels and walls, construction sequencing was dramatically accelerated. A video illustrating how this was accomplished can be found in the links at the end of this article. The straw panels were designed to be simple and economical. Each panel is made of a wood box filled with five bales of straw. Each box being a sealed assembly, there was no need for the application of render. The amount of straw used on the project was grown on approximately 10 Typical Floor Plan (Courtesy of Le Toit Vosgien) hectares of land and will be renewed in one year. The panels were fabricated off-site and delivered as needed. Through the use of bio-sourced materials the project has sequestered 1000 tons of CO2[1]. In comparison, the same building constructed of concrete and polystyrene would use 600 tons of CO2 embodied in the materials and process. Jules Ferry Site Plan (Courtesy of Le Toit Vosgien) Bale Panel Construction (Courtesy of Le Toit Vosgien)

12 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 13 Projects Education Project Participants

Owner References: LE TOIT VOSGIEN 1. Dossier_presentation_Residence Jules Ferry.pdf 6 rue breuil 2. Vincent Pierre of Terranergie 88100 Saint-Dié-des-Vosges Tél : 03 29 55 15 10 Further Information: Mél : [email protected] 1. http://www.youtube.com/watch?v=tsOyx_3uAhU 2. http://www.youtube.com/watch?v=yUrNZDJyr2Y Contractor ASP ARCHITECTURE 18 rue A de St Exupéry 88100 Saint-Dié-des-Vosges Tél : 03 29 56 86 78 Mél : [email protected]

Thermal Planning and Eco-Building TERRANERGIE TheThe BenefitsBenefits ofof UsingUsing WeldedWelded WireWire MeshMesh 1 rue du Kemberg byby AndrewAndrew MorrisonMorrison 88580 Saulcy-sur-Meurthe

Wood Structure I know there are those in the world of straw bale construction who don’t like the idea of using welded wire mesh on their INGENIERIE BOIS projects. I understand that for some, the inclusion of the mesh is considered counter to the concept of natural building as the 1 rue du Marais production of steel is relatively resource heavy. I, on the other hand, believe that the use of mesh is vital to creating a strong, 67800 Bischheim durable, and well built structure that will not only ultimately reduce the use of resources over time, but also speed and simplify the construction process. Consider that a home built with mesh is stronger and more durable than one built without mesh and that the added durability will mean less repairs, less chance of water intrusion and less reuse of resources such as plaster to make the otherwise needed repairs. I have built and/or consulted on hundreds of straw bale homes and I have used many different methods over the years. I can honestly say that the use of mesh has improved the overall results so much that I can’t imagine going back to building without it. To give some reference as to how I got to this place, I should mention that I have built projects without mesh of any kind, with jute netting, with chicken wire, with plastic mesh, with 16g and 14g welded wire mesh (1” x 2”, 2” x 4”, and 2” x 2”), and with several different types of either rebar, wood, or bamboo pinning (both internal and external). The best results from all of these approaches has been the use of 2” x 2” welded wire mesh (either 14g or 16g), bar none.

The benefits of building with welded wire mesh from a construction standpoint are summarized in the following paragraphs.

Shear strength The use of welded wire mesh can effect the shear value of the structure in two main ways. The mesh can be used as the primary shear resistance for the structure or the secondary/redundant shear resistance. In the case of the primary shear, the mesh is the only requirement for protecting the building from racking under shear loads. Although the requirements of this system are rigorous, they can simplify the construction process and save an owner/builder money during construction. What is more common is to use the mesh as a secondary/redundant shear system. This is accomplished by using the mesh in conjunction with a primary shear system such as X-bracing, braced frames, or other similar systems. Plaster reinforcement Plaster is similar to concrete in the sense that it has very high compressive strength but relatively low tensile strength. Although lime and earthen plasters are more flexible than cement based plasters (which should not be used on straw bale structures at all in my opinion), they still benefit from reinforcement. The 2” x 2” welded wire mesh provides plenty of space for the plaster to move through it and key tightly into the straw. This process means that the mesh will end up fully embedded in the plaster, strengthening it, without isolating the plaster from the straw. The plaster to straw connection is vital for long term durability, so this Jules Ferry Cladding Construction (Courtesy of Le Toit Vosgien) size mesh is a perfect match. Added Shear Strength

14 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 15 Education Education

Plaster Reinforcement

Cabinet Backing Hanging Cabinets The old method of hanging cabinets on wood backing affixed to the bales with dowels is simply not as good of an approach as the use of mesh. I attach all of my cabinets by notching wood nailers into the bales such that they end up flush with the surface of the wall. I cover them with roofing felt and then temporarily tie them to the bales with baling twine. Once the mesh is installed on both sides of the wall, it is stapled to the nailers roughly every six inches and then sewn from one side of the wall to the other. The nailers are thus locked firmly in between the mesh layers and unable to dislocate as a result, no matter how much weight is applied to them. Installing electrical I was never a fan of No Pinning Required the old school “vampire spikes” used in the Eliminates pinning electrical installation The mesh adds excellent out of plane resistance to the walls. materials you use and the installation practices you employ will process. I found that the This means that when a force is applied perpendicular to the translate directly to the quality of the structure you are building. boxes were never attached wall, the bales will not fall over or move “out of plane” when I suggest that you do what it takes to build the structure right the well enough to the wall to mesh is properly installed. The strength that is thus added to the first time, and build it to last for generations to come. Mesh is a Electrical Box Installation avoid shifting during the wall improves the overall quality and durability of the entire strong step in that direction. plastering process. I also wall system. It also improves the plaster penetration and bond found that leveling the boxes was difficult as they had a tendency to pull out of because the walls are able to manage more force applied to them Andrew has a passion for straw bale construction that is the wall, even when plaster lath was used to help anchor them to the bales. I now when the plaster is installed. The harder you can push the plaster matched only by his desire to teach his knowledge to others. use plywood plates with “old work” electrical boxes installed in them to create into the walls, the better. With nearly 20 years of building and contracting experience, very strong and permanent points of installation. The plywood plates/electrical he has now moved his practice entirely to consulting and boxes are anchored to the wall with the mesh, and cannot move up, down, side to In my opinion, if you want to build a durable and high teaching. He shares his knowledge with thousands of people side, or in and out of the wall. Plaster rings are then used to extend the boxes to quality structure, mesh must be an integral part of your design via his DVD series, blog, and hands on workshops. www. the face of the finish plaster, meaning the depth of the box will always be exactly and construction process. Making sure that the mesh is installed StrawBale.com. what it needs to be. properly, with adequate tension and fastening is paramount as Simplifying stuffing and shaping well, so don’t skimp on the installation. Be sure to overlap the Adding stuffing to the walls won’t do much good unless you have a way mesh by at least 6” when neighboring pieces abut each other. to hold it in place. After all, loose stuffing will easily fall out of the wall if not Fasten the mesh to all exposed wood at least every 6” with 7/16” anchored firmly behind either mesh, burlap, or some other fastening system. The crown, 1 3/4” long, 16 gauge staples. If you plan to use the mesh 2x2 mesh does an excellent job of anchoring the stuffing while still allowing the as your primary shear system, then the fastening details are more plaster to penetrate and bond directly with the straw, something that burlap or stringent; however, for most applications, the above details will other “solid” materials cannot do. Shaping suffice. As with all aspects of construction, the quality of the

16 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 17 Japan Japan

Clay-rice hull sample with split bamboo lath to improve seismic stability

Further details regarding these results will be presented in a future article on earth building in Japan. With the author’s assistance, in 2013, the first full fledge light straw clay home was built in Japan. The building was designed by Tadashi Ryoukawa and built by master carpenter Asao Tamai. MoMorere StrawStraw BuildingBuilding inin JapanJapan byby KyleKyle HolzhueterHolzhueter

Using Lath as Many areas of Japan have hot, humid summers with relatively small diurnal temperature swings. Traditional Japanese and permanent southeast Asian architecture deals with summer heat through cross ventilation. Open floor plans and large window and door formwork Interior and... openings encourage air movement. Moreover, evaporation from thatch roofs and adjecent gardens with water elements also help ...Exterior Finish to cool interior spaces. In contrast, the American southwest, the home of the modern straw bale revival, experiences relatively large diurnal temperature swings in summer and relies on isolating the indoor environment from the hot outdoors during the day, The thickness of the light-straw-clay insulation is 120mm, A base coat of earth plaster was applied to the exterior and and then letting in cool air during the night. Utilizing diurnal temperature swings is possible in some areas of Japan. Where this is which is the depth of the posts. In order to improve seismic interior of all light straw clay walls. In order to protect the not possible, straw bale buildings require air conditioning in summer. In these cases, one could argue that the level of insulation stability, horizontal wood lath was applied to the exterior and fisrt story walls from rain erosion and moisture damage, wood provided by straw bales is unnecessary. interior of the light straw clay walls. In some cases, the lath siding (rain screen) was used. The second story walls are Given the complications involving straw bale building in Japan, namely, (one) the lack of availability and high cost of bales in doubled as permanent formwork, but we found that the lath finished with Shikkui . Japan, (two) the relative incompatability of straw bales and conventional Japanese timber framing and (three) the need for super tended to bow outwards when the wall cavity was packed with insulation in only cold regions, one could argue that straw bale building might not be the best form of straw building in Japan. The light straw clay. following methods, light straw clay and old straw tatami mat infill hold significant promise.

Light Straw Clay Since 2010, Nihon University’s Architectural and Regional Ecological Design Studio has been researching the potential for light earth construction in Japan. Numerous samples using various light weight aggragates, including straw, rice hulls and wood chips, have been made and the thermal conductance measured.

Thermal Thermal Conductance Conductance measurements on measurements clay-wood chip on clay-straw Formwork Completed walls before Sealing walls with an earthen ...and applying rain screen on samples samples application of wood lath plaster... first story walls

18 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 19 Japan Japan Two methods were used. In one method, the tatami functioned as the base for a Shikkui lime plaster, similar to a drywall or plywood panel. Shikkui was chosen because of its strong adhesive qualities. In this case, tatami mats were attached to the posts and horizontal 36mmx36mm framework with washers and screws. The joints were first treated by applying a thin coat of Shikkui, pressing in a strip of burlap tape, and then following with a second coat of Shikkui. After several months, there has been one small crack, and the author would recommend gypsum when preparing joints for greater strength.

Second Story Shikkui Finish With passive solar design, the masonry rocket stove only ...and mixed with earth for plaster in Kyoto Prefecture needs firing for roughly 30 minutes a day to keep interior temperatures comfortable in winter. Otherwise, home owners sometimes use old tatami as mulch under fruit trees or simply allow them to decompose in some back corner of the garden. In either case, the brocade Simple Bamboo, Tatami...... and Earth Structure edging and strings can be problematic. The use of old tatami mats as infill insulation continues to spread in Japan. It is difficult to say who first thought of the idea, and there are no organizations in Japan promoting the reuse of old tatami mats as insulation. The following are just a few examples of the use of tatami mats as insulation. In 2008, Permaculturist Phil Cashman Brick imported from South Korea renovated a home in Hayama, Although some aspects require further development, light Kanagawa straw clay holds tremendous promise in Japan. Prefecture with old tatami mats Old Tatami Mat Infill Insulation and finished the Tatami mats are traditionally used as a flooring material walls with earthen ...and after plastering in living rooms and bed rooms in traditional Japanese homes. plaster. Tatami mats decomposing in a garden Tatami walls before... They vary in dimensions, but are generally 1820mm x 910mm In the second method, tatami were cut to fit between posts and horizontal wood lath was attached to the posts, covering the x 60mm. They consist of a straw core with thin soft rush finish. In 2012, Akira tatami. A base coat of earthen plaster was applied. It costs a home owner or tatami manufacturer roughly Yamaguchi built a 1000JPY (approximately $10USD) to dispose of a tatami mat. small structure of Old tatami are often salvaged, shredded, mixed with earth and bamboo, tatami and fermented by dorokonya, the businesses which produce earthen earth in Kimino- plaster for walls and tile roofs. cho, Wakayama Prefecture. In 2014, the author led the finish plastering of a home renovation using tatami as insulation in Ayakawa-cho, Kagawa Prefecture. The designer and head carpenter was Yoshiro Benjamin Straw tatami mats...... shredded... Tatami Renovation Iida. Preparing joints

20 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 21 Japan Materials

...and application of earthen plaster

Mixing local earth and straw fibers... Base coat earthen plaster over wood lath

BuildingBuilding withwith HempcreteHempcrete (hemp-lime):(hemp-lime): EssentialEssential TipsTips forfor thethe BeginnerBeginner (Part(Part 1)1) byby AlexAlex SparrowSparrow Composting toilet

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.

Introduction Following on from Tom Woolley’s article in the last issue of TLS, I thought some practical tips on building with hemp-lime would be a natural progression (if you’ll Shikkui Finish forgive the pun). My business partner William Stanwix and I run a company called Hemp-LimeConstruct which has been building commercially with hempcrete in the UK Niche for 6 years now, both in new-build (from small extensions, of domestic houses to large community buildings) and The use of old tatami mats as infill insulation also holds tremendous promise in Japan. in the restoration and retro-fit of traditional and historic One could argue that using discarded tatami or inexpensive straw mixed with clay instead of costly straw bales is closer in buildings. We have learned a great deal along the way, and spirit to our historic Nebraskan straw bale ancestors. In any case, the author expects in Japan the number of new homes using light now provide consultancy and training services to others straw clay or old tatami infill will surpass the number of new straw bale homes within the next five years. wishing to use hempcrete; self-builders, construction industry contractors and architects alike. The desire to Kyle works as a builder, consultant, researcher and educator specializing in natural building materials such as straw bale, disseminate information to others has culminated in our light straw clay and natural plasters. He has a PhD in Bioresource Sciences from Nihon University where he researched the forthcoming book The Hempcrete Book: Designing and hygrothermal environment of straw bale walls in Japan and building practices to control moisture. http://holzhueter.blogspot. building with hemp-lime which is to be published later com, http://japaneseplastering.blogspot.com this year. A new build hempcrete house under construction

22 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 23 Materials Materials In this two-part article I’d like to share some key tips Pre-cast hempcrete blocks, laid in a lime mortar, are and important “dos and don’ts” when using the material in also used and for large scale applications these blocks, construction. In this, the first part, after discussing terminology or pre-cast hempcrete composite panels, are a sensible and the basics of using hempcrete in construction, we will go option, as both methods eliminate the problem of on to look at the first steps in constructing a hempcrete wall variable drying times on site which can have an impact taking us as far as the construction of the structural timber on the schedule of the build. frame. In the next issue of The Last Straw the concluding part When building with cast in situ hempcrete drying will cover key techniques for mixing and placing hempcrete times should be kept in the forefront of your mind together with essential tips for the drying stage. from the outset, since this is major cause of delays before finishes can be applied, and thus the major Nomenclature cause of disagreements with clients and/or main- To start with, let’s look at the terminology; there are contractors. The drying time can be dramatically numerous ways of using hemp in construction and the different reduced through the choice of materials, through A small hempcrete design studio, with green roof and reclaimed brick plinth methods can sound very similar: skilful mixing and placing of the material, and through “Hempcrete” or “Hemp-lime”: A hemp-lime composite, sensible “drying management” on site, so it is important non-load bearing construction material providing both to be aware of this from the start; both to ensure good construction practice and to manage the expectations of everyone involved insulation and thermal mass. The hemp shiv (chopped hemp Hand-placed hempcrete cast around a central softwood frame from the very start of the project. stalk) forms the majority of the composite, and creates an open When casting hempcrete on site, two main options exist: hand-placing, or spray-applying. In hand placing, the material is matrix structure with a lime (or lime-based) binder coating each particle of shiv and binding them together. mechanically mixed, then transported by hand to the shuttering in large tubs (it is not very heavy), where it is placed by hand. In “Lime-hemp plasters”: spraying, the mixing, delivery and application is all mechanised. We have tried both, and we prefer hand-placing for a number of A lime plaster (either reasons. based on fat lime putty- or Hand-placing is the more accessible and low-tech approach. Hempcrete sprayers are not readily available to hire, and they cost hydraulic lime-sand mix) money to buy, store, transport, clean and repair. In our experience sprayers produce a more binder-rich hempcrete, adding to the with the addition of a small density of the material and its embodied carbon (although the finished material is still a net carbon sink – locking up more CO2 proportion of hemp fibres for the lifetime of the building than was used in its construction). The process of spraying requires the use of a vapour permeable (usually the strong bast plaster carrier board as permanent shuttering on one side of the wall (to spray against) which introduces another highly processed, fibres – the long fibres which high embodied energy material to the wall build up, and adds another cost. wrap around the outside of While spraying reduces the number of people on site (3 people, as opposed to 5 or 6, for an average sized house; around 70- the stem - but the woody 80m3 of hempcrete), it doesn’t reduce the build time on a project of this size. Spraying is a noisy, messy business, requiring heavy hemp shiv can also be used). duty protective masks to be worn, and somehow detracts from the sociable experience which can be had when hand-placing The addition of the hemp hempcrete in a larger team. The action of spraying also means that significant amount of the material ends up on the floor (as provides a little insulation to much as 10-20% wastage) although this can be mitigated by collecting it up and using it to cast a hempcrete floor slab if one is the finished plaster, improves required. Lastly the surface of a sprayed hempcrete wall is uneven and unconsolidated, (in comparison to the flat even surface of a its hygroscopicity, and also hand cast wall once the shuttering is removed. This means that more plaster is taken up by the wall in the basecoat, adding to the Industrial hemp has been grown in the UK Bales of hemp shiv waiting to be used on site adds strength in tension cost of finishes. Nevertheless, when casting larger buildings – above 120m3 of hempcrete say – or when applying hempcrete to an since 1993 (in the same way that hair existing masonry wall, the efficiencies achieved mean that spray-application really comes into its own. does in traditional lime plastering), allowing the application of thicker layers of plaster, and preventing shrinkage cracking. Hygroscopicity refers to a material’s ability to absorb moisture from the air during periods of high humidity, thus maintaining Hand-placed hempcrete construction healthy indoor air within the building. When hand-placing hempcrete the key dos and “Hemp fibre insulation”: A manufactured insulation quilt, or batt, produced from don’ts relate to the mixing and placing of the material, the strong bast fibres of the hemp plant. In comparison to synthetic insulations, hemp and we will explore these in the 2nd part of this article, fibre, like other natural fibre insulations (e.g. sheep wool or wood fibre), is vapour however there are also mistakes to be avoided during permeable and hygroscopic and keeps its shape (and thus its insulation value!) even the initial stages of the work. after repeated exposure to moisture. These insulations are always combined with a There are many possible options when designing a binder (usually polyester) during the manufacturing process and, since they contain no hempcrete building, too numerous to discuss here, but lime to provide these functions, require chemical treatment for fire and pest resistance. it is worth noting that hempcrete buildings are usually Various other innovative uses of hemp are gradually appearing on the market, such much more successful when detailed by someone as hemp fibre underlay felts, hemp fibre board materials and clay-hemp load bearing who understands the material fully (preferably bricks. A type of hempcrete which uses clay as the binder is also viable, although this someone who has first-hand experience building with is not sufficiently weather resistant for use in external walls. it). There are also advantages when the designer is knowledgeable about the use of natural materials The ‘basics’ generally, and understands the way that natural This article will focus only on cast in situ hemp-lime, commonly known as buildings work holistically, with each building element hempcrete, a vapour permeable (or ‘breathable’) hygroscopic non-load bearing working together to ensure airtightness, thermal material with exceptional thermal performance. In new buildings, hempcrete is performance and effective moisture management. usually cast on site, in shuttering (formwork) around a structural timber frame, but it The smooth, but 'open' surface of a hand- Since hempcrete can be used in walls, floor slabs, roof Laying pre-cast hempcrete blocks can also be cast against existing masonry walls as a retro-fit insulation for solid walls. placed hempcrete wall insulation and ceilings, it is possible to cast the whole

24 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 25 Materials Materials building envelope in one piece, thus taking full advantage take floor joists in buildings of multiple floors. It is usual to of the exceptional thermal performance and airtightness construct a roof frame which includes a good overhang at that the material offers. The greatest challenges for building the eaves to give maximum protection to the wall, although designers are the insulation of the plinth at the bottom of examples exist in the UK where hempcrete buildings have the hempcrete wall, and effective detailing at the eaves if a been built with little or no overhang, using proprietary different material is to be used for the roof insulation. formulated lime renders which are hydrophobic while A hempcrete wall is usually constructed to a thickness remaining vapour permeable. The framework for windows and of 300-350mm (12-14 inches) which, depending on the doors is either constructed as part of the frame or offset from it. exact binder used, achieves a U-value of around 0.2 W/ m2K at 300mm (12 inches) to 0.17 W/m2K at 350mm (14 Fixings and Services inches). However it is worth remembering that a) the actual Due to the extreme alkali environment inside the hemp- U-value achieved depends on the skill of the person placing lime wall, all fixings within the wall should be of stainless the hempcrete on site, and b) the thermal performance of steel (screws or nails), or hot dip galvanized (nails). Cheaper Spray-applied hempcrete around a central softwood frame hempcrete exceeds what is expected for such U-values galvanized fixings (such as electricity back boxes) are due to the interaction of insulation and thermal mass in the acceptable for non-structural fixings only, as they will corrode Services are run in the frame prior to casting the hempcrete same material. to some extent where they are in contact with the hemp- Plinth lime. Where other structural fixings are required, that are not The standard basic construction detail for walls is a available in stainless or hot dip galvanized versions, these can be painted to protect them before the hempcrete is cast. masonry plinth at the base of the wall, to keep the hempcrete Electrical installations running through at least 250mm (10 inches) off the ground. This ensures hempcrete need to be run in conduit (either PVC that the plant aggregate in the hempcrete is not exposed to or stainless steel) since it is surrounded by an standing ground water or excessive splash back from rain. insulating material. The usual way is to clip this On top of the plinth sits the sole plate of the timber frame into the frame before the hempcrete is cast, with which is usually placed centrally in the wall. A rubberised back boxes positioned on noggins at the face of damp proof course (DPC) is usually specified by building the wall, so shuttering boards can be run straight control authorities to sit on the plinth underneath the sole across the front of them. However it is easy to plate (although if your plinth is built with vapour permeable chase services into hempcrete once it has hardened blocks and mortar, or a free draining construction, then this using a disc cutter. DPC is not strictly necessary). Thought needs to be given Water and gas services can, if absolutely to insulating the plinth otherwise you will have a huge necessary, be run within (or more usually across) thermal bridge running around your building at the base of the hempcrete wall, taking care to protect any the wall. This is usually achieved by the use of load bearing copper piping from the lime by running it inside thermal blocks, such as recycled glass foam blocks, or by a A two storey hempcrete extension under construction, showing a PVC conduit sheath, and remembering that any loose fill natural hempcrete walls and roof insulation joints in pipes should be positioned outside the insulation cast material in case access is required at a later material such as light expanded clay aggregate (LECA) in a cavity construction. Note date. Again, such services can be positioned before that the latter would involve moving the frame to one side of the plinth rather than Harvesting hemp casting, or drilled through afterwards (as long as placing it centrally. you know the exact position of the timber frame inside the wall!). Timber frame Once the hempcrete has hardened, light to medium duty The timber frame acts as a support for the hempcrete (until it dries fully) and fixings can be made directly into the hempcrete wall, but takes all the structural loads of the building, so it should be specified by a suitably for areas where heavy duty fixings will be required (e.g. for experienced or qualified person, and signed off by the relevant building control high level kitchen cabinets), consider designing in a timber authority. In a hempcrete building (with a frame placed centrally in the wall) the attached to the frame, so that you know a strong fixing timbers can be untreated softwood, since the vapour permeability prevents excess can be found at a given height around the room. Instead of moisture being held against the timbers, and the surrounding lime prevents rotting, fixing shelves to the wall afterwards, consider designing in and keeps the timbers safe from insect attack (nothing eats lime!). The presence of recessed alcoves for shelving which can be formed with the the hempcrete - which, while not load bearing, is very strong in tension - also allows shuttering and cast in the wall during construction. a reduction in timbers compared to a standard structural timber frame. In particular The concluding part of this article will feature in hempcrete provides a huge amount of racking strength to the frame and reduces the the next issue of The Last Straw (TLS65); in which we need for diagonal bracing (though you still need to fix temporary diagonal braces will cover the fixing of shuttering around the timber to frame before the hempcrete is placed). It also eliminates the need for horizontal frame, mixing and placing hempcrete, and good drying noggins, as the hempcrete around the vertical studs provides complete stiffness. It is management after casting is complete. actually important to leave out all horizontal timbers unless absolutely unavoidable, The issues and methods outlined above are discussed since it is difficult to place hempcrete around them evenly. in more detail in William Stanwix and Alex Sparrow’s Hempcrete apartments at Tomorrow's Garden City, Letchworth, UK (built by North The vertical studs of the timber frame extend up from the sole plate to support forthcoming book: The Hempcrete Book: Designing Hempcrete apartments at Tomorrow’s Garden City, Letchworth, UK Hertfordshire Homes and Rowan Homes) the wall plate around the top of the wall and intermediate plates, as necessary, to and building with hemp-lime. The book is in three parts: a (built by North Hertfordshire Homes and Rowan Homes)

26 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 27 Materials Projects 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.

Interior of a self-build hempcrete house

The publication dates are 9th October (UK) and 1st LightLight Clay-StrawClay-Straw MountainMountain HomeHome November (USA). More information can be found at by Jeff Ruppert http://www.greenbooks.co.uk/the-hempcrete-book

TLS readers can buy ‘The Hempcrete Book’ at 30% off either hardback or paperback edition. Just Hal Brill and Allison Elliot created a beautiful go to www.ipgbook.com/hempcrete and use the code living space in the mountains of Western Colorado HEMPFALL14 by the end of October. through a hands-on approach and taking their time with major decisions. Hempcrete apartments at Tomorrow's Garden City, Letchworth, UK Hemp-LimeConstruct can be contacted through their 6,000 ft (1,830 m) above sea level and at the top (built by North Hertfordshire Homes and Rowan Homes) website at www.ukhempcrete.com, or via twitter: @ of a newer subdivision on the outskirts of Paonia, UKHempcrete and @hempcretebook. Colorado the Brill/Elliot home is on a two and a half acre parcel with breath-taking views of the West Elk A video showing hempcrete being mixed in a drum mixer is Mountains and 11,400 ft Mount Lamborn. It is a available at: http://www.youtube.com/watch?v=w1FupaK-rvM very custom habitat for two people who value living lightly on the earth. Their approach has allowed See also: them to combine newer technology with a warm, Allin, S. (2005) Building with hemp. Seed Press: welcoming feel. Their home costs nothing to operate Rusheens Co. Kerry and exemplifies modest, customized living through natural building. Bevan, R. and Woolley, T. (2008) Hemp Lime Construction: A guide to building with hemp lime The Construction Process composites. IHS BRE Press: Bracknell House construction commenced in 2010 and was completed in 2012. The first phase of the project Daly, P., Ronchetti, P. and Woolley, T. (2013) Hemp Lime consisted of building the garage/office space as a staging area for the house construction the following year. Instead of doing A large department store constructed with pre-cast hempcrete panels Elsmere Port, UK (built by Marks and Spencers) Bio-composite as a Building Material in Irish Construction. everything at once Hal and Allison took their time, as they did during the design process, making thoughtful decisions at every Environmental Protection Agency Ireland: online only. http:// step. erc.epa.ie/safer/iso19115/displayISO19115.jsp?isoID=202 Both the garage and house are dug into a hillside, meaning there are tall retaining walls on the Northern side of the structure. Instead of using regular concrete foundation walls they chose Faswall blocks, which are a combination of wood chips and cement, Woolley, T. (2006) Natural Building: A guide to materials incorporating rock wool insulation into each block. The block cores are filled with concrete and reinforcing to create a substantial and techniques. The Crowood Press: Marlborough wall capable of withstanding normal soil and water pressures below grade.

28 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 29 Projects Projects zero Rocky Mountain winter temperatures while the interior of the house dropped no lower than 60 degrees without any other heat source than the sun. The entire house has earthen floors using local materials and bring the grounding energy of the home together. The floor acts as a huge thermal bank, moderating temperature swings in both the winter and summer. After two years of regular use they look and feel great. One aspect of the house design that contributes to its exceptional efficiency is the modest size (1,500 sf). The house has only one bedroom and a “flex” room that doubles as an entertainment room or spare bedroom. It has a master Walls with formwork and finished clay-straw bathroom and a three-quarter bathroom for guests. The kitchen and eating area is the focal point for social activity and includes a large open pantry that doubles as an informal entry hallway for the building occupants.

Electrical and Mechanical Systems A solar electric system was installed on the garage to supply electricity during the construction project. Even though the electric system is grid-tied, Hal and Allison wanted to be energy net-zero from the beginning. There is a substantial solar hot water system that supplies all of their needs for in-floor heating, domestic hot water and even a hot tub. To monitor this system Hal uses a dedicated laptop that is connected to dozens of sensors throughout the house. He is able to monitor the temperature of any part of the hot water system and make decisions about where to move available hot water, which can become critical during those long but rare periods of cloudiness in Western Colorado. On the exterior, all greywater and rainwater is used as irrigation for the garden and landscaping. Runoff swales direct rainwater into tree wells and planted areas. Allison is a master at desert landscaping, using indigenous vegetation and hard-scaping to create a beautiful and welcoming outdoor space.

Contracting Process Hal and Allison hired a local general contractor, Faswall Blocks (Courtesy of Shelter Works) Frederick Zimmer, to oversee the construction of the building Making Light Clay-straw shell. This portion of the project cost $250,000, or The walls are made of light clay-straw, a mixture of clay was accomplished over the course of a few weeks during the approximately $170/sf. slip and straw packed into forms between columns. The walls hot summer. American Clay plaster materials were used on the Once the shell was complete are 12” (30 cm) thick compared to 18” (45 cm) for a typical interior and local earthen materials were used on the exterior. they took over as their own straw bale wall. The narrower clay-straw wall translated to a The house takes advantage of the ideal solar aspects of the contractors, overseeing the narrower foundation wall, saving in materials and cost. site through the use of south glazing and ample overhangs to remaining subcontractors Wall render consists of clay plaster on both the interior and keep the summer sun at bay. Hal and Allison minimally heat themselves. This saved money exterior. Due to the light clay-straw system, a long drying their home in the winter months using a wood stove and the in- as the General Contractor was period was necessary before the application of plaster. This floor hydronic system. They have experienced weeks of sub- South walls almost ready for plaster not between them and their

30 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 31 Projects Community subcontractors. It was also a little more stressful than if they relied CASBA Rides Again! on the General Contractor, but they stand by their decision to work directly with their subs (whom Calling All Bicyclists for 2015 and Beyond they knew) and take credit for the mistakes as well as the solid choices Team CASBA was once again represented in the 2014 Climate they made along the way. Ride California. Over the past two years CASBA riders have raised As one of many alternative over $10,000 toward straw bale outreach and research and the building projects in the area this one stands code effort. This year’s team increased awareness of straw’s ability to out as a modestly-sized, thoughtful sequester carbon by performing Bob Theis’ ‘We Will Bale You’ during and ultimately comfortable home the Beneficiary Night presentations, eclipsing the other 24 powerpoint exuding quality in every aspect. The talks with a refreshing and unforgettable one. hands-on approach by the owners and the ability to take their time The Climate Ride (climageride.org) is held not only in California bringing their vision to life has but also with NY-DC and Midwest Rides, plus a plan-your-own resulted in not just a house on a nice option. Team CASBA invites riders of any experience level piece of land, but a destination for from around the world to join their team. Contact David Arkin friends and family as a gem in this at [email protected] and/or visit our Climate Ride Team rural part of Colorado. Page: http://bike.climateride.org/index.cfm?fuseaction=donorDrive. team&teamID=5286 This is an excellent opportunity to meet wonderful and interesting people from all walks of life that share a passion for saving the planet in unique and creative ways.

Pictured are 2014 team riders Peter Brock, Ellie Arkin, Michael Jacob and CASBA Director David Arkin; our 2013 Riders included David along with Pete Gang, Karl Sporer, Ian MacLeod.

32 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 33 Survey Survey Bale Orientation within Walls Many years into the bale building revolution, and hundreds of thousands of bales later, we thought it made sense to ask you how you prefer to stack bales in the walls of your buildings. Original bale construction techniques used bales laid flat in the walls, meaning the bales wide dimension creates the wall width. In the case of a typical 2-string bale this means your walls are nominally 18” (45 cm) wide with the strings running vertically at the ends of the bale. In contrast, many folks are now placing the bales on-edge with the strings running horizontally. The smaller dimension across the bale creates the wall width and is either 14” (35 cm) or 16” (40 cm) depending on the type of baler used. The orientation of the bale obviously affects the orientation of the straw within the wall. Many heated debates have taken place in both private and public forums as to the best way to stack bales. Since bales laid flat have been the default since the beginning of bale construction one could say it is up to the bales on-edge folks to prove their system’s worth. Just a few of the advantages of stacking bales on-edge that people refer to are: • Reduced wall footprint, 2-string bale laid flat • Fewer bales per structure Residential structures took a wide majority at 61.6%. The breakdown of the types of structures may be somewhat representative • Equal thermal performance of bale structure in existence today worldwide.

Drawbacks to stacking bales on-edge are: • More challenging substrate for plaster • Exposure of the strings on the wall surface • Less stable when stacked To help fuel the fire of this debate we decided to post a survey on our website asking anyone with experience to participate. The results are not terribly surprising, but they do help us understand what kind of factors go into each choice. We are hoping the information here will help people make the right choice for their projects. 2-string bale on-edge

The Results There were a total of 46 responses, which are too many to print, but we have made the raw data available on our website. The pertinent details of the results are that 43.5% of the respondents use bales laid flat and 23.6% use them on-edge. 19.6% of the respondents answered under the “Other” category usually saying that it depends on the project. We did include an “On-End” option, which received one very positive response

From the comments it appears that many of the projects with bales laid flat use a type of framing system that requires the bales to be notched. For the users of bales on-edge it appears they prefer framing systems that do not require notching, thereby eliminating this issue altogether. This is an interesting result. It means that the framing system influences bale orientation, or is it the other way around? Either way, folks who place their bales on-edge are using a framing system that eliminates the big task of notching bales around posts. This must be a huge time-saver, or at least a sinus-saver due to the reduced amount of straw dust. There are a few comments that are not supported by fact, but are difficult to discern for the casual reader. One example is that bales on edge are more susceptible to failure in a fire unless they are enclosed in mesh. Another example is bales “disgorging,” or exploding, if the strings are cut. Both of the statements imply that if strings are cut or compromised in bales laid on-edge the wall integrity will be compromised. These statements have not been researched and proven on a widespread basis. Or put another way, we do not hear stories of widespread failure or of compromised walls due to the characteristics of bales laid on-edge. If there are examples of this being a problem we hope some of those folks will elaborate and share their experiences with us. But until then we’ll question this claim. There is one respondent that uses bales on-end with great success when it comes to the owner-builder. A couple other respondents have used bales on-end and mentioned how flexible they are with respect to orientation. This seems to reflect how much experimentation takes places with builders of bale walls. What is most important to take away from the survey is that there was no one option that took a clear majority. There are good On a side note is how a farmer stacks bales both on a truck and in their barns or fields. The bottom row of bales is usually reasons for both methods and each respondent has given a thoughtful response. stacked on-edge while the bales above are stacked flat. This is for two reasons from what we understand. First, bales on edge Other notable statistics are the even distribution of the type of respondent. The survey was not dominated by one type of don’t compress and deform under the weight of a full stack above as much as bales laid flat. This provides a stable base over time. professional or lay-person. But the “Owner/Builder” answered more than any other type of respondent at 26.7%. It should be noted Second, the straw within the bale is oriented vertically when stacked on-edge and will wick less water up, thereby rotting one edge that each respondent could answer this question in multiple categories. Continue on bottom of page 36...

34 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 35 Book Reviews

Earthen Floors: Topics for Your Article A Modern Approach to an Ancient Practice Submissions Reviewed by Jeff Ruppert While we are not creating a focus in each issue until we once again have a backlog of Earthen floors are ubiquitous in most of the world. They These issue are clearly addressed. You are shown how to common articles, we are focusing on a few are the most accessible type of flooring to a vast portion of the repair cracks and chips. You are even shown how to properly features in upcoming issues. human population. In the modern world earthen floors are still remove the floor at the end of its useful life, and even how to something of an oddity to most people, until they step foot on reuse the material again for another floor. Being able to reuse Here are some of the topics: one. And then they are hooked for the material or dispose of it in your Water Conservation and Management life. As a simple mixture of sand, yard is a truly unique characteristic • – Catchwater, greywater, water clay, water and fibers, more and of earthen floors and exemplifies storage, composting toilets and waste more people are installing them natural building. management. in their new modern homes with Small details from showing you stunning results. how to protect new door jambs • Putting a Project Together – How to Today’s practitioners of earthen from wheelbarrow damage to work with code officials, architects, floors are able to create extremely dealing with sprouted seeds often engineers, contractors, lenders, beautiful, deeply rich wearing found in the clay and sand mixture insurance companies, etc. surfaces in our most refined spaces. are included. They even cover The techniques used to accomplish earthen counter-tops and supply • Commercial, Industrial and such enjoyable surfaces have been ideas to overcome some obvious Institutional Buildings – Exemplary honed through trial and error by issues. structures and projects that go way a handful of people who readily Earthen Floors: A Modern beyond what today’s “green-building” share their knowledge. Any Approach to an Ancient Practice industry expects. modern home being built today can be purchased from New Society with natural fibers or earthen walls Publishers for $29.95 USD and • Details, Details, Details! – We’ll should also include earthen floors. CDN (print version) or $19.45 USD always be collecting these and The durability and applicability and CDN (e-book). This book is a highlighting them as we go. Please are on par with any other flooring must-have for all natural builders send yours in! system and we are surprised no one and those interested in doing a floor has really covered this topic in a themselves. comprehensive way, until now. If you want your article to be included in any Sukita Crimmel and James Thomson have put together a of these themes, please let us know when work of art matched only by the sheer beauty of their floors. you send them in. They start from the beginning and explain their roots, how Paperback – 288 pages, 7.25 Inches × 9 Inches (w × h) they gained hands-on experience and learned from past Weight: 579 Grams masters. The text is refreshingly easy to read and the layout of ISBN: 9780865717633 the book is logical. This is a how-to manual and you won’t be Pub. Date: 2014-04-01 News Flash!!! disappointed in the amount of details and examples given. As with any type of flooring, earthen floors have limitations, Right before TLS went to press with this issue The leading to minor maintenance and occasional major refinishing. German Institute for Building Technology has given approval for the application of plaster directly on to straw bales without the use of lath. There is also a new service that will test your bales to determine if they are suitable for construction. We will keep you updated on further ... Continued from page 35 progress in Germany and hopefully do a more in-depth report in a future issue. of each bale. The bale with a rotten edge is still usable in of the comments. Due to a limitation with our survey software another stack laid flat within rows above the bottom. As noted we are unable to extract the data in a way that connects the You can find out more about this at the following links: above, this is anecdotal evidence from a few farmers, but it comments with the multiple choice answers. We will resolve seems logical. this in the next couple weeks and post a revised results file. http://www.fnr.de/de/presse/pressemitteilungen/aktuelle- We think it is safe to say the jury is still out on the orientation Thank you everyone who participated and we hope this helps mitteilungen/aktuelle-nachricht/article/pm-2014-32/ of bales. But the information in the results does give us some those of you still trying to make a decision. footing to make educated decisions. As previously noted, you Bale on! http://fasba.de/images//z-23.11-1595%203.6.2014kl.pdf can find the raw data from this survey here, which includes all

36 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 37 Classifieds Upcoming issues will include articles How Can You Help Plaster Pump and Power Trowel Apparatus Straw Bale House for Sale in Southern on: TLS? for Sale Colorado • Pre-Fabricated Bale Panels $750 $239,000 • Hemp Lime, or Hempcrete Publishing a magazine like TLS usually Location: Guelph, Ontario, Canada 1824 Sq. Ft., 5.63 acres, open floor plan, • Large Buildings with Bale Walls requires a little more income than we Visit http://harvesthomes.ca tile floors, infloor heat throughout, custom • Plastering Techniques and Materials receive through subscriptions. Thompson Plaster Pump – pumps mortar & cement- kitchen, attached heated oversized 2-car • Regional Associations lime plaster over long distances. Upgrades include: garage with workshop, great well, master The best way for you to support us is to • Details (Send yours in today!) Honda motor complete with external throttle control bedroom, bath & huge walk-in closet, make a donation or advertise with us. • And more… Our website is growing daily and is a & clutch, custom-fabricated “power trowel” to apply upstairs bedroom 15x30 with full bath, great place to gain exposure with your material directly to wall (no messy spraying), several large living room with stove, 1/2 bath in Please tell us what you want to see and send us your target audience. lengths of 2” hose with quick connects; many spare hall, large /laundry area off garage, articles. parts. Thompson piston type pumps were built to last. covered front porch, breathtaking views of If you are a professional organization We’ve invested $3500+ in upgrades &components. the Sangre de Christo and Wet Mountains, To make sure your work is shared among the best of please visit our website and look at Stored idle for 5 years, so will likely need some work year-round access, pictures at MLS#: natural building, send us your articles. our Media Guide. It’s a great way to to make serviceable. Sold as is. $750 OBO 2509189. 141 Navaro Road, Westcliffe, increase business and keep TLS going. Colorado 81252 Call (417) 224-5369 2 Power Trowels – as described in TLS issue #42. Built by the author.

To read the entire listing and view product photos, TLS Human Resource List List your Stuff in the TLS visit the TLS website. Classifieds The Human Resource List, or HRL, is a resource for professionals who want to share their products or services Classifieds in the print publication are with the TLS audience. still free, but you must also list your goods or services on our website. In the past TLS printed an annual Human Resource Issue. Any listing added prior to our deadline To save printing and overhead costs we are keeping the date for publication will be included HRL web-based for the most part. in the print version of the next issue. Thousands of visitors are viewing TLS However, during our start-up period, while the number of website pages each month, which listings is relatively few, we will include those listing in the makes the online Classifieds the most printed issues, free of charge. valuable tool for reaching your target audience. 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 For your listing to be included in every search and listing of services on our site, rotated with the print version of each issue we other Featured Listings. In addition to being featured on our will need a compact version with a website, Featured Listings will also be printed in each issue maximum of 40 words. The online of TLS as an incentive to get you to use the service. limit for your classified listing is 750 words and six images. A basic listing is $15/year per category with a maximum of 2 images. A Featured Listing is an additional $50/year to be Prices at the top of searches. One month $ 9.99 Two Months $17.99 These costs, when spread out over one year, are very Three Months $26.99 reasonable considering that thousands of people visit our site who are looking for resources to use on their next Deadlines project. April Issue March 1 July Issue June 1 The best thing is, you are supporting your favorite natural October Issue September 1 building journal! January Issue December 1

38 The Last Straw • No. 64 Summer 2014 The Last Straw • No. 64 Summer 2014 39 The Last Straw Journal PO Box 1809 Paonia CO 81428 (970) 704-5828 [email protected]

Upcoming Natural Building Events 07/22 Camp Solar - Kids Summer Camp The Solar Living Institute, Hopalnd CA 07/26 Natural Building Extravaganza Asheville, NC 07/26 Make Your Own Soap The Solar Living Insittute, Hopland CA 08/01 4-Day Cob Garden Structures Course Ireland 08/16 Solar Design Waitsfield, VT 08/16 Earth Plaster, Lime Plaster, Earthen Floor Workshop Kingston NM 09/05 2014 Strawbale Building Conference Adelaide, South Australia 09/13 Straw Bale Building Workshop Salida, CO 09/20 Earth Plaster, Lime Plaster, Earthen Floor Workshop Kingston NM 11/08 Design-Build Workshop Ashanti, Ghana, Kumasi 11/22 7-Day Straw Bale Design & Construction Workshop Geraldine, New Zealand 11/29 EcoXpo Sydney 2014 Surry Hills, New South Wales 03/03/16 2016 International Straw Building Conference Methven, New Zealand

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Human Resources TransMineral USA Dan Dorsey Provider of Saint-Astier Natural Hydraulic Limes, Lime Designed and drawn plans for 85+ straw bale projects, Mortars, Lime Putty and Lime Paints know the SB codes, built first permitted SB single www.limes.us family residence in Pima County, AZ, in 1991. Consult (707) 769-0661 and Design on Straw Bale and other natural building projects, do workshops, wall raisings. SolarWise www.sonoranpermaculture.org/teaching-team-members/dan- For the last decade, Solarwise has specialized in dorsey energy and resource efficient straw bale design and (520) 624-8030 construction. We combine a lifetime of conventional construction knowledge with the specific skills needed MG Architects for effective straw bale construction. We design and Full architectural design services including: conceptual build beautiful and healthy homes with exceptional design, construction and permit documents, and attention to detail, quality and craftsmanship. Our construction phase administration. Can assist owner/ projects incorporate passive solar and site appropriate builder with getting approval for construction from local design, local/natural/green/recycled materials, non-toxic building inspector/department. finishes and renewable energy systems to create an www.mgarchitects.net attractive and nourishing home that is both socially and (315) 423-3707 environmentally responsible. (970) 376-3495 or (719) 539-9160