Welcome to StrawBale.com
My name is Andrew Morrison and welcome to my straw bale building site dedicated to anyone interested in building their own straw bale house. If you are brand new to straw bale or are a straw bale construction specialist there's something for you at StrawBale.com.
Click here if you are NEW TO STRAW BALE BUILDING and want to know the basics about straw bale construction.
I have a ton of information for you including: photo gallery, step-by-step instructional videos, information about straw bale workshops around the world, free straw bale articles, free straw bale social network, and a full straw bale building blog.
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This is one of the coolest and most beautiful straw bale construction concepts I have seen in a long time. Although not something for the owner builder per se, this technique makes the potential for commercial straw bale construction a reality and can even be used in residential applications if the site location and project scale are right.
The overall beauty of the finish product is amazing enough, but couple that with the fact that the building is carbon negative, not carbon neutral, and you have a super insulated, beautiful, and environmentally responsible building. Even the factory that makes the panels is mobile, thus reducing the shipping impacts of the panels once they are manufactured.
All in all, I think this product could have a large impact on the way commercial buildings are built. I certainly hope it does. I strongly recommend that you check out the website for this company at www.modcell.co.uk. There is a cool slide presentation on the overview page that is worth checking out to see how the process works from start to finish.
When building curved walls, some of the most difficult aspects to deal with are those that don’t naturally curve. For example, large windows in a curved wall will create an area where the window either sits inside the plane of the wall or outside that plane. There is no way to bend the window, other than buying expensive curved windows, so you have to get creative in how you finish the window installation. You might add an over sized sill to handle the difference, or hang the whole thing out side the plane of the wall with a creative faux finish. It’s up to you.
One place that can be difficult is in the mudsills, or tow ups as they are often referred to in straw bale construction. As you can see in the photo above, bendable steel channel sills have been created to make the framing of conventional curved walls easy. These sills work great for stick framed homes and I have used them on several houses with great success. The problem for us bale builders is that the steel channel does not provide adequate nailing surface for the attachment of our mesh, nor does it give us any uplift for the bales to get them above the foundation or floor system. We need something else.
One of the easiest methods to handle this situation is to use laminated plywood cut to the radius needed. Because many, if not most, jurisdictions call for pressure treated lumber to be used in contact with the foundation, you will want to get a few sheets of pressure treated plywood for the bottom lamination or two. Each layer should be glued and screwed to the next. The screws are more of a temporary hold than anything as the glue, once dry, will be sufficient to hold the lamination together. Be sure to use strong glue and one that can handle getting wet without losing strength or bond. Gorilla Glue is a good option; however, it can be a little different to work with, so make sure you follow the product instructions.
In the above photo, you can see how a scarf joint is used at the linear connection points of the laminates. This gives a positive glue joint from end to end of the plywood as well as face to face. Be sure to stagger any end joints by at least two feet.
By creating a simple template for the curve, you can use a router or jigsaw to cut many layers in the exact same shape. Once the whole assembly is put together, you can move it to the location in which is is to be installed. Don’t try and do the entire sill in one big circle, using scarf joints all the way around. It will end up driving you crazy. Instead, create manageable lengths that can be laid in place like any other toe up/mudsill system. Use anchor bolts as you would with other systems to hold the mudsills in place.
Several people have written to me asking how to find the welded wire mesh I use on my bale homes. It is hard to find, no doubt, but it can be found, I promise. Unfortunately, I don’t have a long list of suppliers. All I have is my West coast supplier. If you have successfully found the material in your part of the world, please let us know where and save the rest of the SB folks out there some time and sweat!
Here’s the name of the company who supplies my mesh. They will drop ship directly to your location which helps in the shipping costs; however, get all that you need at once because the shipping is not cheap and one big delivery will cost you less than two smaller ones.
Flynn & Enslow Inc
1530 17th St
San Francisco, CA 94107
Here’s a great article about the effectiveness of straw bale walls in earthquakes. This study shows how strong they really are by subjecting the 14’x14′ straw bale house to 200 percent more shaking than was seen in the Northridge, CA earthquake of 1994 which holds the largest measured ground acceleration in the world. You can view the article here: http://www.sciencedaily.com/releases/2009/04/090403104229.htm or read it below.
Straw Bale House Survives Violent Shaking At Earthquake Lab
ScienceDaily (Apr. 5, 2009) It huffed and puffed, but the 82-ton-force, earthquake-simulation shake table could not knock down the straw house designed and built by University of Nevada, Reno alumna and civil engineer Darcey Donovan.
The full-scale, 14-by-14-foot straw house, complete with gravel foundation and clay plaster walls, the way she builds them in Pakistan, was subjected to 200 percent more acceleration/shaking than was recorded at the 1994 Northridge, Calif. earthquake, the largest measured ground acceleration in the world. After a series of seven increasingly forceful tests, in the final powerful test the house shook and swayed violently, cracked at the seams and sent out a small cloud of dust and straw … and remained standing.
Donovan oversaw the successful series of seismic tests run March 27 at the University’s world-renowned Large-Scale Structures Laboratory. She was testing her innovative design for straw bale houses she has been building since 2006 throughout the northwest frontier provinces of Pakistan, in the foothills of the Himalayas between Pakistani tribal areas and Kashmir. Her design uses bales as structural and load-bearing components rather than just insulation as in other straw-bale designs.
“We’re very pleased with the results,” said Donovan, founder/CEO of the non-profit Pakistan Straw Bale and Appropriate Building (PAKSBAB) organization. “The house performed exceptionally well and survived 0.82g (0.82 times the acceleration of gravity) and twice the acceleration of the Northridge quake. The Geological Survey of Pakistan estimates the 2005 Kashmir earthquake to have had peak ground accelerations in the range of 0.3 to 0.6g.
Most people were killed and injured in that October 2005 earthquake as they slept when their poorly built houses collapsed on top of them. The magnitude 7.6 earthquake killed 100,000 people and left 3.3 million homeless or living in tents.
“Our goal is to get the largest number of poor people into earthquake-safe homes. We want to make it as affordable as possible so they build a safe home. We want to save lives.”
“Straw bale houses are used around the world, but those have posts and beams for support and rely on energy-intensive materials, skilled labor and complex machinery, making it unaffordable for the poor,” Donovan said. “In our design, the straw bales are the support, and not just for insulation. Our design is half the cost of conventional earthquake-safe construction in Pakistan. The materials we use clay soil, straw and gravel are readily available; and we utilize unskilled labor in the construction.
“We build a small, steel compression box, pack it with straw, which is readily available from the Punjab District, literally stomp on it to compress it, add a little more, stomp on it a little more, and then finally use standard farm-type hand jacks to do the final compressing of the bales,” Donovan said.
The site-fabricated bales are not as wide as those used in a typical straw bale building, and the fishing-net reinforcement and gravel-bag foundation are nonconventional.
“We fill old vegetable sacks with gravel, like sandbags, for the foundation. The bags are fully encased, or boxed, in a mortar made from clay soil and cement. It’s as low-tech as possible using indigenous, affordable materials,” she said. The earthquake-safe buildings are 80 percent more energy efficient than modern conventional buildings at 50 percent of the cost. Her group also trains local residents how to build the homes.
“Our system is different than anything ever tested,” she said. “We’re doing seismic research on the house to have data to show its structural integrity.” While there are no building codes in the region, Donovan and the organization she founded, PAKSBAB, are pursuing an endorsement from Pakistan’s newly formed Earthquake Reconstruction and Rehabilitation Authority.
Scientists will analyze the seismic-testing results, and Donovan will write a detailed report and seismic design and construction recommendations to be published in the Earthquake Engineering Research Institute’s World Housing Encyclopedia.
Donovan has been a practicing engineer since 1986. She has a bachelor of science degree in mechanical engineering from Stanford University, a master of science in civil engineering from the University of Nevada, Reno, and is a licensed Professional Civil Engineer.
The research was conducted at the Network for Earthquake Engineering Simulation Consortium, Inc. (NEES) shake-table site at the University of Nevada, Reno as a NEES Management, Operations and Maintenance award shared-use project.
“I am extremely grateful to EERI, NEES and UNR for their generous support, and to all the hardworking volunteers who dedicated countless hours to this project, Donovan said.
The non-profit PAKSBAB relies on donations and grants to continue its work. For more project information, visit http://www.paksbab.org.
Adapted from materials provided by University of Nevada, Reno, via EurekAlert!, a service of AAAS.
I received the following email a few days ago. It is a really sad story about how insurance companies can take us all for a ride, straw bale or no straw bale. The owners of the nearly complete straw bale home need an attorney’s help to battle their insurance company who is refusing to pay out for damages after a non straw bale related fire destroyed their home. There are important lessons to be learned in this sad story. Please read on and if you are an attorney who wants to help, please let us know by commenting on this post. I will put you in touch with the owners. Thanks in advance
Hi Andrew – At the end of February, our 80% complete straw bale/steel frame home burned to the ground. There was a propane tank leak, and it didn’t take long for the air to catch fire. Of course most people would like to blame the straw; however, there is little evidence of this being the problem. After the fire, there was tons and tons of piles of straw that did not burn. In fact, right next to where a very thick steel I-Beam twisted under the heat of the fire, lay clean bales with just one scorched side. I was quite surprised how well the straw held up to the heat, while the OSB SIP panel roof and the wood floor trusses completely disappeared.
I am writing to tell you that our insurance company is being very ruthless. Having found no blame on our part, nor the straw … and calling it a combustible accident … the only thing they can cling to is giving us a percentage of our policy … NOT the dollar amount of our loss. As this will force us to go bankrupt and not be able to rebuild unless we can get our full policy, I thought it couldn’t hurt to reach out to the straw bale community in hopes there is an attorney among us that would be willing to fight on our behalf for little compensation.
What is most profound to me after all this tragedy is remembering all the “fire” jokes about straw for years when I would tell people about my dream. So the first thing that happened when people found out about the fire was was that they felt their fears were vindicated. But when they see the photos, and see sooo much straw left and not but a couple scraps of wood …. it’s definitely something to make you stop and think.
In a way… the fire confirms to me that straw is a very safe product if the site is kept clean, and there aren’t any combustibles like propane tanks and wood!
I have a photo that shows how far away from the house the fire burned. It actually caught our conversion van on fire but the straw wall between the house and the van got only slightly scorched. It’s the only wall the firefighters didn’t use the back-hoe to tear apart bales because by that time they figured out that breaking the bales apart was spreading the fire, not stopping it. Had they known to keep the bales together, the fire would have gone out sooner. You can see all the photos of the damage at http://s211.photobucket.com/albums/bb71/CadillacMeaghan/2009-02-28%20Fire/.
We had just gotten half the slab heated with the in-floor, and were using a propane salamander to help get the rest of the house warm so we could plaster the following week. The fire never would have happened if we had been able to get to plastering.
I hope this won’t happen to other people. It started way back in July when we wanted to order our SIP roof panels, but the bank wouldn’t pay for them until they were on site, and the SIP supplier wouldn’t ship them unless they were paid for. So we were at a stand still until the lumber yard agreed to buy them for us on NET30. I shed a lot of tears back then, knowing what that was doing to my timeline. The Roof did not show up till the first week of November, and the panels were installed during the first snow storm. That is why there was no plaster on the bales. That would have stopped the fire after it had consumed all the propane in the air. Unfortunately, you can’t plaster when it’s freezing. Of course, the bank wasn’t so concerned then, but they are now! A small delay in the timeline proved to be the thread that burn downed the house.
Amazingly, the fire department not once blamed the straw and in fact said it made their job harder to put the fire out because the bales didn’t want to burn fast enough.
Thanks for any advice you could give us.
What is the perfect bale to use in a straw bale house? I am asked this question a lot. Most times, the question refers to what type of straw is the best. Some people say rice, others say wheat. I always tell people to buy what is most local as long as it is dense, dry, and clean. The other side of this question is in relation to the size of the bales to be used. Many people want to know if a 2 string bale is better than a 3 string bale for home construction.
Once again, I believe the best bales are those most local to your construction site. In general, most farmers are moving towards bigger bales and so that will have an impact on what you can find in your area. Three string bales stack more easily in the field and are more stable when moved by a squeeze (farm machine that moves large blocks of bales). For that reason, more 3 string bales are available today than 2 string, in most markets. So, first concept: buy local.
Here’s the advantage for two string bales: they are easier to work with. They are lighter, smaller, and generally easier to work with than 3 string bales. I prefer two string because I can handle the bales by myself whereas three string bales take two people to move and stack, especially after a long day of baling. The R-value on a 2 string bale is less than a 3 string bale; however, it is already so high, that the difference is not that noticeable. Unless you live in a VERY harsh climate (either hot or cold) the difference between 2 and 3 string bales will be hard to notice.
The advantage of 3 string bales is that they are more solid when stacked. As mentioned above in the field stacking ability of 3 string bales, they are very sturdy because of their larger base surface area. This translates into strong walls as well. I prefer 3 String bales when building load bearing for just this reason. In addition, because they are wider, you can cut deeper niche into them which is also a nice feature.
The reality is that both 2 string and 3 string bales have their advantages. See what is available to you locally and then decide which advantages best lines up with your plans to build. You may find that it really doesn’t matter to you which size you use. In which case, stick with the local kind.
This is really cool. William McDonough is shown in the small video below describing the design for a true eco city in China. Although he has a pretty flat and dry delivery, the 3:20 second video is worth watching. There is so much that can be done in development if we are only willing to think outside the box. The before and after photo of the proposed city site is amazing and absolutely gives me hope for what is possible.
Check out the video here and see what I mean. Consider some of the topics as possibilities for your own home, obviously on a smaller scale. There is much to consider here.
Plastering is hard enough, so don’t beat yourself up trying to figure out how much plaster you will need. The first option I HIGHLY recommend is to contact the management at the place from which you intend to order your material and ask them to calculate the order. You can give them your building’s dimensions and other details they request and they will give you a very accurate bag count and sand quantity. In fact, they will most likely be more accurate than you will with the formulas below.
There are two major players in the Natural Hydraulic Lime Plaster arena. The East Coast is covered by De Gruchy’s Lime Works located in Pennsylvania. They will happily help you estimate the material order and are also able to send out samples of materials and colors to help you choose the final coat material and color. They ship directly to you and if you use my vendor code (95501NHL) they will give you a discount on any purchase you make. Check out their website at http://www.palimeworks.com/lwus/. You can also purchase a cool plaster application gun that allows you to spray on your plaster, speeding the application process!
The West Coast is Handled by one main distributor: TransMineral USA, Inc. located in California. They supply many retail stores with the plaster and can also drop ship larger orders directly to you. The folks there are always happy to help clients get the order right, the first time. You can check out their website at www.limes.us. Let them know that I sent you and they may be willing to help you out a bit on the product pricing. I can’t make any promises right now, but it is possible.
So if you insist on doing your own calculations, give the following numbers a shot. Best of luck and don’t forget to plan for the necessary excess of mistakes and dropped mud. The following is based on an estimated wall surface of 900 Square Feet. I have also used the NHL 3.5 as the material as that is the norm for my climate. DO NOT assume that this is the right material, and therefore ratio, for you. Ask the folks above to help make that determination. Also, I have given you a couple different options for the sand/lime mixing ratio. The more lime, the stickier the plaster. The more sand, the less expensive the plaster.
SCRATCH & BROWN
Scratch Coat: 1 part NHL 3.5 to 1.5 parts sand (mixing ratio) at 3/4″ = 1440 lbs.
Brown Coat: 1 part NHL 3.5 to 2 parts sand (mixing ratio) at 1/2″ = 728 lbs
Total Scratch & Brown = 2,168 lbs / 55 lb bags = 40 bags
Scratch Coat: 1 part NHL 3.5 to 2 parts sand (mixing ratio) at 3/4″ = 1092 lbs.
Brown Coat: 1 part NHL 3.5 to 2.5 parts sand (mixing ratio) at 1/2″ = 560 lbs.
Total Scratch & Brown = 1,652 lbs / 55 lb bags = 31 bags
Alternative 1: 1 part NHL 2 to 2 parts sand (mixing ratio) at 1/8″ = 164 lbs or 3 bags
Alternative 2: Ecomortar F premix at 1/8″ = 14 bags (This is much easier to use than mixing with sand. I strongly recommend the pre mix bags.)
Many of you have been waiting to see when I will be teaching hands on workshops this coming summer and fall. Well, the wait is over. I have finally posted the majority of my workshop dates on my website. I still plan on adding 2 or 3 more dates and am still in contact with several potential hosts to make those workshops a reality. In the meantime, I have confirmed dates in 4 different states from coast to coast. I also will be offering a special 3 day workshop focusing entirely on plaster with Natural Hydraulic Lime plaster. Participants will get hands on experience with all three coats, something impossible to do with most workshops due to the waiting period in between coats. Because I have several structures in several different stages of construction, we will do the scratch, brown and finish coats all in three days! I am really excited about this opportunity to teach a skill that is all but impossible to learn from a book. Hands on is by far the best way to learn, especially when we are talking about plaster.
To sign up for any of my workshops, please visit my website and click on the registration page. Here’s the web address: www.StrawBale.com/store. If your excitement is so high that you can’t wait for a new page to load, then just check out the dates below! I have included the dates without confirmed hosts as well in case you would like to step up and host a workshop during those dates. Being that the potential hosts are still unconfirmed, the dates are still available.
2009 Seven Day Intensive Straw Bale Construction Workshops
May 11-17 Williams, Oregon
June 15-21 Midpines, California
August 10-16 Scipio Center, New York
September 7-13 Grants, New Mexico
2009 Three Day Complete Natural Hydraulic Lime Plastering Workshop
May 29-31 Jacksonville, Oregon
2009 Available Dates for Interested Workshop Hosts
September 28-October 4
First of all, I want to extend a word or two of support and sympathy for our brothers and sisters down under as the fires of a heat wave have torn through their beautiful land. Having personal experience with wildfire, I know the challenges and hardships they can create. Several years ago, a roughly six thousand acre fire was stopped on my doorstep, literally. The crews were able to steer the flames and squash them down into a manageable slot and snuff them out just a few hundred feet from the front of my house. We were evacuated at the time, and I remember the impact of the flames and smoke on my family and my animals. I remember having elk in my field, something that does not happen around here, because the smoke had flushed them out of the higher elevations. I can imagine what our brothers and sisters in Australia are experiencing and I send my emotional support out.
Be sure to remember as these fires move through that straw bale homes are very safe in fire prone areas. They have a high level of fire resistance. They have been proven to resist fire much longer than conventional homes. When the impact, speed, and fierceness of wildfire comes knocking, it is comforting to know that a bale home can keep you and the ones you love safe. Of course, this is not to say that you could ride out a fire like the one shown above in a bale home, but that home will offer you more security against fire than a conventional home and that may just be the difference between saving or losing the ones you love.
Once again, I hope for rain and I send you thoughts of happiness and safety from up North.