Not everyone wants square walls in their house. Some people like round walls, others prefer angular walls. In this post, I give you a simple way to create angular walls in your straw bale home. As always, there are several ways to achieve any one goal, and I’m sharing my favorite way to create the angular walls, not the only way.
Archive for the ‘Tips and Trade Secrets’ Category
Many of you will remember the publication The Last Straw and may have spent many hours reading through the informative articles over the years. Some of you may have never heard of it because it has been “on sabbatical” for some time. The good news is that it is coming back. Please take a few minutes to read the information below from the new editor, Jeff Rupert.
Update on Issue #62 and Our Funding Campaign
Here at TLS we are working feverishly to get Issue #62 out. If you are a subscriber, expect to receive it around the beginning of February. Many of the articles are already up on our website and are accessible to current subscribers.
To re-start The Last Straw we knew it would require more resources than we would collect through subscriptions alone. That is why we have always planned to ask for donations. This is your chance to support us and ensure we will continue delivering your favorite natural building journal.
I know, I know…For most of you this is old information, BUT if there are any folks out there that still have a worry in their minds (and it’s OK if you do!) about straw bale houses and rodent invasions, this latest “Straw Bale Minute” is a must watch. Trust me, rodents would much prefer to set up residence in your neighbor’s conventionally built house with lovely pink insulation than live in straw bale walls. You can hear why in this “Minute” below:
One of the most artistic expressions of a straw bale wall are the niches that are carved into it. There are about as many options of what a niche can be as there are ideas, so describing how to create each one would take just shy of forever. For that reason, I have decided to lay out a step-by-step process for the most common niche I see in straw bale homes: the arch top.
- Decide on the location for your niche. As much as it’s a good idea to lay out potential locations on your construction drawings, I always recommend that people walk the house once the bales are all in place as new locations that you had not considered before may reveal themselves.
- Pay attention to scale. Once you know where the niche will go, be sure to properly size it for the space. I suggest you use “the Golden Ratio” to determine your height to width. No matter which way you orient the niche, the ratio would be 1 to 1.618. This ratio appears all over in nature; the most commonly known example is the chambers of the nautilus shell.
- Calculate the space in and around the niche. Keep in mind that the plaster will reduce the width of the niche so be sure to add in enough “extra width” for that. Look at perpendicular walls or window and door openings and estimate where the finish walls will land so that you can properly center (or not) your niche.
- Use a cardboard template to test your niche out on the wall. Hang it with landscape pins or nails in the desired location and then take a step back to see if it is what you had hoped for.
- Once you are happy with the size and location, mark the outside of the template with spray paint to transfer the shape onto the wall.
- Use a chainsaw to cut out the niche to the desired depth. I prefer to stay around 6″ – 8″ deep in a two-string bale wall and 12″ – 14″ for a three string bale wall. I mark the bar of my chainsaw with spray paint so that I know when I have plunged the blade in far enough. Be aware that you WILL cut the strings of the bales at this depth. As soon as you feel one pop, stop the chainsaw and remove the string from the area. If you don’t, it will wrap itself around the chainsaw sprocket and you will spend a lot of time unravelling it.
- Install the wire mesh on the wall (both sides) as if the niche were not there. Just go right over the top of it for now. If you try to cut the niche out before the mesh is attached top and bottom, it will weaken the mesh and you won’t be able to get it as tight as you need.
- Use wire cutters to cut the mesh out of the niche. It’s best to cut the mesh a little bigger than the opening so that your plaster lath installation is not hindered by the mesh.
- Place the section of mesh that you cut away in the back of the niche and sew it to the mesh on the opposite side of the wall with baling twine. This tightens the mesh on the opposite side of the wall and it provides extra plaster reinforcement in the niche.
- Cut a strip of plaster lath so that it fits tightly in the bottom of the niche from side to side. Cut it at least 6″ wider than the niche is deep so that you can fold the excess lath down over the face of the wall. This provides extra strength for the plaster as it turns from inside the niche to the face of the bale wall.
- Fold the lath over and secure to the mesh with tie wire, cable ties, or landscape pins (into the bales).
- Cut another strip of plaster lath (also at least 6″ wider than the niche is deep) long enough to measure from the bottom of the niche on one side to the bottom of the niche on the other side in one continuous piece. This piece will shape the arch and, once folded over on to the face of the wall, reinforce the plaster for the rest of the niche to wall transition.
- Cut the lath in small sections as necessary to conform to the shape you have created. Use stuffing behind the lath to fine tune the shape.
- Fold the lath over and secure to the mesh with tie wire, cable ties, or landscape pins (into the bales).
- You may need to use some landscape pins on the interior surface of the niche to hold the lath in place. If you cut the lath big enough, you will be able to jamb it tightly into the wall and avoid the pins. Do whatever it takes to make the lath tight and sturdy. You don’t want it bouncing around when you plaster.
- Eat a lot of yogurt. Okay, that’s not entirely necessary, but the yogurt lids make the perfect plastering tool for the soft edges and tight corners of the niche. Cut the rigid part of the top off and use the pliable plastic as a curved trowel. You will proceed with the plastering the same way you would on the rest of the wall and at the same time. Just be careful when working in the niche as it is a small and delicate space that can be difficult to plaster well.
- Decorate as you will…Now you get to turn the show piece (the niche) into a vessel for other items you wish to showcase.
Even if you don’t choose an arch top niche for your straw bale home, you can transfer the steps of this tutorial to just about any style you choose. You may have to tweak a step here or there, but the overall process is the same. Happy Baling, and create something beautiful!
We receive several emails each week from people all around the US looking for recommendations for certified balers and professional contractors that have experience with straw bale construction. The truth is that most of the time we don’t have leads on whom to recommend. It seems like a shame since we know that there are talented balers all over the country (and world!).
We really want to change this and to set up a resource list on www.StrawBale.com linking up those looking for balers with those that can bale. It is also our wish to help support any of you who want to earn a living baling houses by offering the resources and training to help make that dream come true.
So, starting with the 2014 straw bale workshop season, we invite anyone interested in becoming a Certified Baler to join us and start moving forward on that goal.
Here’s how it will work:
IF YOU ARE A GENERAL CONTRACTOR AND WANT TO BECOME A CERTIFIED BALER and have not attended a workshop with us yet, please let us know that you want to be certified when you sign up for a workshop. We need to know before the workshop starts so that during the week we can personally work closely with you and make sure that you are understanding the process well and so we can be there as a resource for you if you have further questions. Upon completion of the workshop, assuming your performance shows that you understand the baling process at a proficient level, you will officially be a Certified Baler.** Upon your request, we will provide you a free spot in our General Contractor Certified Baler Resource Page for you to post your bio and contact information.
IF YOU ARE NOT A GC*, BUT WANT TO BECOME A CERTIFIED BALER and have not attended a workshop with us yet, at workshop sign up, please let us know that you want to be certified. We need to know before the workshop starts so that during the week we can personally work closely with you and make sure that you are understanding the process well and so we can be there as a resource for you if you have further questions. Upon completion of the workshop, assuming your performance shows that you understand the baling process at a proficient level, you will officially be a Certified Baler.** Upon your request, we will provide you a free spot in our Unlicensed Certified Baler Resource Page for you to post your bio and contact information.
IF YOU HAVE ALREADY ATTENDED A WORKSHOP WITH US and want to be listed as a Certified Baler for free in our Resource Page, please email us at firstname.lastname@example.org as this option may still be available to you.**
IF YOU ARE A HOME/LAND OWNER looking for a Certified Baler to work on your project, please check back in with us once the 2014 workshop season has begun. We will be adding names to our Resource pages as we receive them. We will do everything in our power to only certify balers that have demonstrated a thorough understanding of the baling process; however, it will be up to you personally to interview baling candidates and to obtain references as you feel necessary.
We will be opening up registration for our 2014 workshop season in just a few weeks (November 29th). Stay tuned to our newsletter for more information on the time and specifics of the season launch release.
*Contractor boards in your area may dictate that only licensed contractors are able to legally work on someone else’s project. It is up to the individual to investigate what restrictions apply to their area.
** Please note that we can not guarantee certification. Certification will be based on workshop participation and showing that a deep understanding of the covered material has been achieved.
One of the most stunning aspects of a straw bale home is the shape that window and door openings take. The gentle curves flood light across the room and lend a sense of calm and peace to the occupants. Almost every person who walks through a straw bale home for the first time makes some comment about just how beautiful the curves are.
These very same curves that bring so much joy and serenity can also drive home owners crazy. That sounds unlikely; however, when the curves are not properly built, they can cause all kinds of problems as the home is finished. Obviously, knowing how to avoid such problems is important, so I’ve given you a quick description of how to stay on the right side of the curves.
A consulting client recently asked me what the best practice is for removing rotten straw from an existing straw bale house. I realize that this is a topic that concerns a lot of people when they first learn about straw bale construction and I want to make clear that this is extremely unusual and not something that most people will ever have to deal with. The most important thing when designing and building a straw bale house is to ensure that you do so with the understanding that water must be kept away from the walls. The client I am working with (in the rainy Pacific Northwest) has a home in which the architect did not include any roof overhangs on two walls. That is a recipe for trouble in any house, not just a straw bale home. So although I believe it is important to share with you the proper steps for replacing straw, the overwhelming data shows that you will never need to.
Below are the steps to replacing rotten straw in an existing house. Although each specific location may have subtle differences, the basic steps are still the same. The level of difficulty you will experience in replacing straw in an existing structure will increase with the amount of straw you need to replace and its location. For this reason, it’s best to only replace the straw that absolutely needs to be replaced, and no more.
Whether you need to replace a small amount of straw or an entire section of bales, the process is pretty much the same. The biggest difference is that when fixing a small patch, the surrounding bales don’t need to be supported at all once the material is removed. If, however, you need to replace entire bales, you will need to provide support for the rest of the wall so that things don’t sag into the gap you create when the bales are removed. It is also more difficult to remove entire sections of wall because the plaster in both sides of the wall needs to be removed or, at the very least, loosened from the bales.
- Remove the plaster in the identified area of damage with a hammer drill and a chisel bit. Over excavate the area of concern so that you expose the wire mesh about six to eight inches away from the damaged area in all directions. This will allow you to replace the rotten straw and properly tie-in the new mesh.
- Cut the mesh away from the damaged area. Be sure to leave at least six inches of undisturbed mesh around the damaged bales. This will meet the requirement for mesh overlap later, which is vital to eliminating potential plaster cracks in the patch.
- Scoop out the damaged straw. You may want to use a small gardening rake (hand-held with 4 sharp tongs) to more aggressively remove the material.
- Use a moisture meter to determine where the damaged straw ends and the clean straw begins. Make sure that you are at least one inch into the clean straw when you stop digging. You don’t want to go through all this trouble and leave rotten straw, in any amount, in the wall. Check for high moisture readings in every direction: up, down, left, right, and back into the wall. Anything above 18% should be removed. Ideally, the moisture readings should be no higher than 10-12%.
- Slide a piece of burlap underneath the mesh that you left exposed and in tact. Leave the top side of the burlap loose and long enough to be tucked under the mesh later. Use landscape pins to secure the other edges of the burlap.
- Stuff fresh and clean straw behind the burlap so that the patch is tight. It may bulge away from the wall a little, which is fine; however, make sure that when you pres against the patch, it flattens out properly so you don’t end up with a bump in your finish wall.
- While placing pressure against the patch, pull the top portion of burlap tight behind the mesh and secure it with landscape pins into the bales.
- Cut a piece of mesh large enough to cover the entire exposed area and place it against the wall. Tie it to the existing mesh with tie wire or cable ties. Be sure to pull it as tight as possible to help flatten out the patch.
- Apply plaster to fill the patch. You will need to do a scratch, brown and finish coat. The finish coat will cover the entire wall to clear stopping points. If you just do the patch, you will have a permanent “burn mark” that will not look good. If you are using 100% earthen plaster, you can simply replaster the patched area and feather the new plaster into the old by properly wetting the existing plaster. This only works with 100%, unsealed, earthen plaster.
The reality is that you will likely never need to use the information in this blog post; however, if you do find yourself with water damaged straw, the sooner you dry out the wall and replace the non-salvageable straw, the better. Remember that bales are like giant sponges and the longer they are exposed to water, the more they will absorb and the farther the water damage will extend.
One thing that goes without saying (but I’ll say it anyway) is that you MUST identify and repair the source of the water damage before you start replacing straw. There is no point in doing all of this work without knowing what caused the problem in the first place as it will simply return and damage the new straw you have installed.
Like many of us, Ryan (a 7 day straw bale workshop graduate) held a deep desire to build his home using his own two hands. After all, growing up in a family in which his father had built three (the last of which Ryan was heavily involved in), the concept was familiar and natural. While attending a green building conference circa 2002, Ryan was introduced to the concept of straw bale construction. Being an environmental consultant, the merits of this technology made sense so he proceeded to create a multi year plan to build his own house using straw bales.
A plan of action, timeline, and goal are incredibly useful tools when bringing big dreams to fruition. They serve as guideposts when we feel overwhelmed and give us perspective on what the next step is. With these tools, it doesn’t matter how far into the future your goal might be or how many actions will need to be taken to reach it. As long as you continue to follow each step, in time, reaching your goal is inevitable.
For Ryan and his wife, their steps included selling their condo in the city, renting a cottage in the area they wanted to settle in, and then waiting patiently for the right piece of property to show up. For three years they waited. And when their dream property showed up on the market, they didn’t hesitate.
Ryan was already experienced with Auto-Cad (professional architectural design software) so he undertook the 2,000 sqft home design process himself. He also did all of his engineering calculations. Before turning his plans into the building department, he had them professionally reviewed and stamped by an architect and structural engineer to make certain that the residence was well designed. Though he navigated his way through the whole design process successfully, he wishes that he had enlisted professional help earlier on to simplify the whole process.
The actual building process was an adventure. For Ryan, there were “a million ups and downs”. Some days felt easy and perfectly on schedule. Other days he felt defeated and would ask himself, “What have I done??” Peace of mind was re-established each time doubt came in by reminding himself to just take things one step at a time. During the build, he made it a point to break down each task into manageable bites so that in general, none of the jobs took more than a day to complete. He also quickly realized that it was much more productive to spend time in action rather than spending too much time thinking out every single step ahead of time.
Obtaining a loan and insurance for his straw bale home posed no obstacles for Ryan and his wife. He shares the secret to his success was in his approach. He arrived at all of his meetings with as much information as he could, answering questions before they even had a chance to ask them. He went to all of his meetings with a comprehensive business plan and presented himself professionally. Ryan’s efforts paid off without a hitch.
When I asked Ryan if he has advice to anyone building their own straw bale home, he shared (wisely) that as tempting as it may feel in the moment to cut corners not only in craftsmanship but also in materials, that it’s extremely important to stay committed to the values of safety and creating a house that will last for generations. One of the big pieces of the success and beauty of his build is that he stayed true to his commitment to build the best house that he could.
When Ryan first informed his father that he was going to build his house with straw bales, his dad thought it was the craziest thing he had ever heard of. He could not for the life of him understand why his son would build with straw. I am pleased to report though that his father now “gets it”. It’s so important that those of us who are passionate about building a straw bale house do so even at the risk of having others deem us insane (even if just temporarily). When others see the process and the end result, they can’t help but see the light. We are the ambassadors for this technology and the more of us there are, the more available safe, beautiful, energy efficient and green straw bale housing is to those around the world.
We want to congratulate Ryan on doing a beautiful job on his home. It is wonderful to see past workshop graduates go out there and build their own dream straw bale homes. We hope to see you at a workshop sometime in 2013!
I believe that this quote from Albert Schweitzer speaks volumes to the confusion that many people have in regards to achieving success. I LOVE what I do and I hope that shows in my work. I trust that it does.
“Success is not the key to happiness. Happiness is the key to success. If you love what you are doing, you will be successful.”
Do you LOVE what you do? If not, why are you still doing it?
I’d love to hear your thoughts on this. I imagine there are some different beliefs that float around the “need” to do a certain job or a certain deed. In my experience, when I hear my inner voice say I “should” do something, it usually means I’m holding on to a fear that if I don’t do it, something bad will happen. That’s just me though. What’s your experience?
Plastering is perhaps the hardest part of the entire process when building a straw bale house. Think about it, your framing, although difficult, is hidden within the walls nine times out of ten. As long as it is structurally sound, you will be fine. Furthermore, it is inspected (in many cases) so you end up with a “free” set of helpful eyes to make sure you are doing the work properly. The same is true for the other major systems of the house: plumbing, electrical, mechanical, and so on. As long as the systems are built properly and they meet or exceed codes, you are all set. What those systems actually look like is mostly irrelevant.
The same cannot be said about plaster. That’s a system that not only has to be structurally sound and function in a way that protects the bales, and ultimately your entire house, but it also has to look good. After all, when have you ever heard someone say “Wow, you really did a great job with the rough plumbing in this house. It sure is beautiful.”? Probably never. How about someone commenting on plaster? Now that’s one that you have likely heard or even uttered yourself. “Man, that plaster looks amazing!”
Below is a section from my upcoming book. The focus of the section is on planning for and installing partition walls in straw bale homes. I have also included a detailed description of how to properly layout framed walls. This is a pretty simple process, but you might be amazed at how many people make mistakes along the way. The mistakes they typically make can all be fixed, but it’s better to learn how to do it right the first time and avoid the mistakes. I hope you enjoy this chapter on framing partition walls. You may find it a bit technical, since it is just a section from within the book, but it will all make more sense in the overall context of the book.
It’s not unusual to end up with extra bales after building a straw bale house. In fact, I recommend it. Those extra bales are great to have around as steps or scaffolding supports when plastering. Furthermore, I would always rather have a few too many bales than not enough when building. The question is, what to do with the extra bales when the project is done?
If you live on a big piece of land, you can spread the bales out as mulch in your garden, bedding for chickens or other livestock, or simply to decay back into the soil. If you don’t have a spread of land big enough to accomplish that, you can try and find someone who does and offer them the bales either for a price or for free. This is also a great idea (either of those two ideas) for the loose straw created during construction. Believe me, there will be lots!
Another great way to use the bales if you dont have that room to spread them out is as a gardening tool. Straw Bale Gardening is a good way to grow plants in limited space, or if you have poor soil. It also helps if you have a hard time bending over as the bales lift the plants 18″ or so off of the ground. If you just finished building your own house, the idea of not having to bend over to harvest your lettuce may sound pretty good! Anyway, there are some good advantages to using straw bale gardening techniques, not the least of which is that you will use your excess bales in a healthy, positive way. Here’s a good website to get you started on this process. Enjoy!
You wouldn’t be the first person to try and carry a piece of plywood up a ladder by yourself. You might be the first to do it without hurting yourself! When working alone we are faced with many difficulties that would otherwise be simple for people working in groups or pairs. One of these is getting plywood up to a roof structure. Here are a couple options to consider, based on the size of the job at hand.
A simple way to get a bunch of sheets to the roof is to build a simple rack out of framing lumber (2x4s are fine) on the ground onto which you stack your plywood sheets. Make it tall enough so that you can pull the sheets from the roof and install them in place. Be sure to install the first sheet on the roof directly in front of the rack to increase the safety of the setup. Don’t forget to make sure that piece is in line with the general layout of the roof and the plywood that will cover it!
Sometimes the idea of building a rack is over the top because it will take more time and materials than the job you have to do on the roof. For example, perhaps the majority of the roof is already sheathed and you simply need to get the last two pieces up that were not in your original material calculations. The crew that you had to help install the rest of the sheets is gone, so now it’s up to you. In this case, carrying a sheet or two up a ladder can be the easiest way to do it. Now don’t plan on carry the sheet over your shoulder, as that’s a recipe for disaster. Instead, use a C-Clamp attached firmly to the leading edge of the sheet as a handle. It’s quick, easy, and inexpensive and it will make carrying the sheet so much easier.
Dun, dun dun…… Can you feel the excitement? I just got back from working on a project in Portugal and the plaster machine was one of the coolest I’ve seen. This monster mixed up to 1 1/2 bags of lime plaster at a time (35 kg bags). The capacity was not what made the machine exciting as some of the mortar mixers I use here in the States will mix twice that capacity at once. What was cool was everything that the machine was able to accomplish. Here’s a run down.
The machine should be placed directly behind the pile of sand. The reason is clear: why carry sand when you can use an automatic, winched sled?! That’s right, this baby comes with a remote controlled sand sled that places the sand directly into the holding barrel. That brings us to the next cool part of the machine, the holding barrel. This section of the machine allows you to pre place all of your materials, even water if you choose although I think it’s better not to put the water in at this time, into a holding tank of sorts. That way when you are ready to mix your next batch you simply empty the mixing barrel of the machine and add the next batch, already pre measured and ready to go.
What’s also cool is that this holding barrel is hydraulically lifted, so there’s no strain to your back. You simply hit a switch and the hold thing lifts up and dumps the material into the mixing barrel. Add your water and you’re off. While the plaster is mixing, you can get the next batch pre measured and into the holding barrel. This is especially useful when using a material like Natural Hydraulic Lime because that material has to actively mix for 20 minutes. While it’s mixing, you prepare the next load. It’s a great use of time. Otherwise, a 20 minute mix takes 30 minutes start to finish. This way, it’s 20 minutes on the nose.
Another aspect of working with plaster is moving it from the machine to where you need it. Most machines require a wheel barrow, a string back, a well inflated tire, and some relatively good balance. This is usually not a problem (save the well inflated wheel barrow tire), but it is work. This machine would simply pump the mix from the mixing drum directly to where you need it. In fact, it can pump the material up to 10 stories up! Most of us won’t need that, but it does help to send the mud up a steep driveway or hill where a wheel barrow might end up costing you hundreds in chiropractic repairs.
So now we have mixed our plaster, placed it within inches of where it will be used, and the only thing we have had to lift is a bag and half of lime at 35kg each. Not bad. So how about applying it, any savings there? Of course. The machine uses the same compressed air that drives the mix up the hill to run a plaster spraying gun. This speeds application and does a great job of both leveling the wall on the first shot and penetrating the straw.
The down side to this machine? It costs about $8,000. If you can find one to rent or borrow, go for it. Otherwise, just think about how cool it is and marvel at what we have been able to build as humans!
Mixing plaster is as much of an art as it is a science. It’s important to keep a consistent mix from one batch to the next and this isn’t always easy to accomplish. One of the most common mistakes people make when creating plaster mixes is to lose track of how much sand has been put into the mixer. Have you ever mixed plaster with a bunch of folks helping you? If so, you know exactly what I mean.
Picture this: you’re using a 5 gallon bucket to place sand into the mixer. You need 4 buckets of sand for every bag of lime you add to the mixer. Your helpful friends are filling up the bucket as fast as you empty it and you guys are totally cruising through the mixing process. Suddenly you ask your friend “is that 3 or 4 buckets?” In return you get what a friend of mine calls a “goat face,” a look of complete disconnect. Now you retrace your steps to try and figure out how much sand is in the mix. You look at the plaster tumbling on the paddles in hopes of recognizing the texture of the mix. IN truth, neither of you have any clue how much sand is in the mixer. There’s a better way.
Instead of using one bucket, use 4. Three buckets should be the same color and the last bucket a different color. This way know if you’ve made it to the end of a load. For example, when I mix plaster, I can usually fit 3 bags of lime in the mixer at a time which means I need 12 buckets of sand. Counting those out one by one would be hard to track, so I use the 4 buckets. I put in three white buckets of sand and then an orange one (you could always use another white bucket and just pray paint it or wrap it with tape). As soon as I see that orange bucket go by, I know I’m at the end of a run. Now my helper can fill all 4 buckets again while I add the bag of lime and we’re ready for the next grouping. It’s easy!
Have you seen a bunch of these in your house? Do you have what you thought might be termintes only to discover that termite treatments don’t do much to battle the infestation? If so, you likely have an infestation of psocids. These tiny little insects are also known as booklice and barklice and are known to feed on old books and other natural materials. It’s rare to have them infest a straw bale house, but it can happen. In most, if not all cases of home infestation, the insects come in on the bales and are already in the straw when you build your house. They take a relatively high level of moisture to live and so keeping your bales dry will almost always end any infestations. Here’s some more information about these insects, how to stop an outbreak, and how to minimize your risk of infestation to start with.
Psocid infestations typically more prevalent in areas with high moisture content and which are often contaminated with microscopic mold. The psocid’s life cycle includes eggs, four nymphal stages, and adult females. Eggs usually take about 21 days to hatch and adults tend to live for between 20 and 100 days. This puts an entire lifecycle somewhere between 40 and 120 days. The sooner you discover an infestation and start to take action the better as females can each lay up to 2 eggs a day during their adult life. That’s a reason for the sudden outbreaks most often noted.
The best way to handle an existing infestation is to dry out the space in question. The psocids take a high level of moisture to survive and so a dry and hot space will quickly solve the problem. Because of the number of eggs that each female can lay, you’ll need to keep the location hot and dry for at least 4 months to be sure of total removal of the problem. It has been said that bringing a room to 120 degrees F for a short period of time can also kill the insects completely. The challenge is getting that 120 degrees F to reach the internal sections of the bale walls as the insulation value is what is so loved about these homes. As we’ve seen in fire testing, it is not easy to transfer high or low temperatures through a bale wall and so the likelihood of achieving a sustained 120 degrees F in the center of a bale wall is low.
To lower your risk of ever getting an infestation I suggest you treat your bales during installation with borax. Just a gentle sprinkle of borax on each course of bales during installation can be very helpful for eliminating any pest problems. I want to be clear here, I have only twice seen this situation actually happen in a bale structure and I do not use borax on any of the homes I build. I make the suggestion only for those homes that are at high risk. For example, homes that will likely experience high moisture levels in the walls due to a lack of dehumidifying system and high relative humidity in the environment. Otherwise, I don’t think the borax is necessary.
1. Long straw. Be sure to ask your source is the bales are long straw or chopped/thrashed straw. A bale harvested by a combine will be thrashed straw and the short pieces make for a very weak bale. These are a poor choice for building. A long straw bale will typically be 14″ tall (2-string) and 16″ tall (3 string).
2. Look for a cut edge and a folded edge. If the cut edge is not clearly visible on one SIDE of the bale, it is probably a thrashed bale and the “cut edge” is likely facing up or down. Again, don’t buy these bales.
3. Color. You want a bright, golden color. Brown or black bales have seen moisture damage. Dull bales may have been stored for a season or longer. They can be acceptable if the other details check out; however, fresh bales are best if you can find them.
4. Moisture Content. Bales should be around 8-13% moisture content when checked with a bale probe. Under no circumstances should the bales reach higher than 20%. At that level, mold growth is supported.
5.Density. The easiest test is to pick up a bale by one string. If the bale deforms in any way, then don’t buy the bales. If the bale stays completely in shape, then the density is acceptable.
6. Shape. tight, rectangular bales are what you want. check the corners of the bales to make sure they are not rounded. Rounded corners will mean a lot of stuffing after the wall is stacked. Tight, angular corners mean the bales will fit together well and your stuffing will be limited.
7. Smell. This is another test of moisture. When you walk into the barn, take a deep inhalation through your nose. How does the room smell? Musty is not a good sign. Fresh straw is what you want to smell.
8. Weight. Dry bales will be relatively light weight. A 2-string bale should not wiehg more than say 45lbs. If it’s heavy (you’ll know what heavy means when you feel it) the bale is probably wet.
Most importantly, use your common sense. If something seems off, it probably is. The importance of quality bales can’t be stressed enough. If you get bad bales, you will fight them from the moment they arrive on site to the moment you finish the house. They make for more retying, more stuffing, more material loss, more post stacking compression, less effectiveness of wall clean up (string trimmer work), weaker vertical stands and corners, more tamping to get your walls plumb, weaker plaster substrate and more. Trust me, get quality bales.
Happy (quality) baling!
Chainsaws are an active part of straw bale construction. There are some other options for cutting bales, of course, but a quality electric or gas powered chainsaw is still my favorite. It’s really important that safety be considered when working with any tool and a chainsaw is no different. There are times when a small section of bale needs to be cut off and the temptation to have someone hold the bale while you cut is great. Without that person holding the bale, it’s unstable and tends to shift as the cut is peformed. This makes for a messy cut and a dangerous situation for the saw operator.
You can see in the picture what I recommend. By using a piece of wood long enough to get the bale holder away from the saw and the “kick area” of the saw, he is able to provide adequate support for the bale and allow the chainsaw operator to work without added risk. The “kick area,” by the way, is the apace which the saw would cover if it bound up and kicked back. Kick back happens so fast that there is no way a person could move out of the path, especially if they are not the ones in control of the saw as they would have no indication that the saw was about to kick until it was too late.
Again, the simple use of a piece of wood makes this situation safe. Notice also that both men are wearing safety glasses. No, it’s not sawing hard wood, but yes, stuff can still hurt your eyes.
Here are some basic safety guidelines to keep in mind when working with chainsaws. This is only a partial list, so take whatever precautions you need to stay safe.
1. Work on a stable table. I like to use another bale or even better, two bales run perpendicular to the bale I’m cutting.
2. Keep your body out of the kick area.
3. Wear safety glasses and hearing protection.
4. Work in a well ventilated and light area. You need to see what you;re doing and breathing gas fumes all day won’t make your day any better!
5. Clearly mark your cut in advance and follow the line.
6. Watch for bale twine!
7. Be sure your helper is safe (see above).
8. Clean the sprocket and guard area often to keep it clear of straw. Jammed straw can throw a chain or catch fire.
9. Keep the saw well maintained. Oil and properly adjust the chain.
10. Always unplug electric saws and turn off gas saws before performing any maintenance or adjustments.
The sad and ugly aftermath! In a recent workshop we discovered that the sand that was ordered for the plaster was not acceptable. I blame myself for this mistake as I did not catch the problem in time and allowed the plaster to be mixed. As is always the case, a mistake can be either just that: a bummer, or it can be a learning piece. What I learned in this scenario is the importance of finding the right sand for your plaster mix.
I spoke with the sand yard directly and told them what I needed. The dispatcher seemed to understand completely and the next day, 10 yards of angular, variable size sand was delivered to our very remote building site. There was no sending it back if we didn’t like it, it was what it was and it turned out to be the wrong stuff. The issue was that it had no fines in it.
The right sand for the Natural Hydraulic Lime (NHL) plaster needs a gradation of sand from the fines to the more coarse. No silts and clays mind you, but the finer end of the gradation is important.
You can see in the picture how the plaster simply did not hold together well. The lack of finer sand made the plaster loose and almost gravelly. I did a stretch test on the plaster by pulling a hawk’s worth of plaster across the table with a trowel. In quality plaster, the mud will spread and stay together, creating a smooth surface. In this case, however, the plaster ripped and tore as I pulled it on the mud board. There was nothing to hold it together.
We tried for an hour or so to get the mud to stick to the wall and eventually the sad truth became all too apparent: the plaster was not good. The worst part of the story is that we had premixed 18 bags of plaster the night before and all of it was wasted! The host now has a very fancy NHL carport floor! I ordered 18 replacement bags for the host and have informed him of the correct sand he’ll need, moving forward.
When you order your sand, be sure it meets the requirements on the NHL bag. Where I live the perfect sand is called “concrete sand.” It is angular, has many different grits (including the finer sands), and is perfect for the proper adhesion of the plaster. The same has been true across the country as I teach. The term “concrete sand” is almost always understood. In this part of New Mexico, that was not true. My plan moving forward is to send future workshop hosts a sample of the sand they should be looking for so they can make sure, well in advance, that they have the right stuff.
Per Martin’s request, here’s an image of the appropriate style of sand to use (size wise). I’ve also heard from an expert that using a lime based sand can cause problems too as the free lime in the sand will take up the moisture and leave the NHL without the ability to attach itself to the sand.
Why would I want to do that? You may be asking yourself that very question and rightfully so. The answer may be simple or complicated depending on the situation. It may be that you have a series of wall sections that need thinner bales than the rest of the house due to framing and engineering requirements. One place where this is common is at the top of the wall system. It’s not unlikely to have a large beam at the top of the wall supporting the roof. That beam, hopefully a 4x something, will not allow you to reach the outside face of the wall with the plane of the bale and you’ll have an entire section of bales that’s 4″ too wide at the top of the wall. In some scenarios, you can simply turn a bale on edge and it will fit perfectly. In others, you can’t. I’m not a huge fan of using lots of loose stuffing in the house to fill larger voids like this. I think that starts to weaken the wall in the end. In fact, the tight fit of the bales to the top plate is one of the ingredients for a tight and solid wall. By cutting down regular bales by the required 4″ (in the scenario described above) you can install regular bales, stay with the running bond pattern, and install them tight to the top plate. Only minimal stuffing will be required.
Here’s another scenario that a friend of mine just experienced. Because of his location, he had to have his bales trucked in from another state. That’s not ideal, as I prefer to purchase bales locally, but he wasn’t able to do that due to current local straw stocks. Having installed his toe ups, and framed the house, he was ready for his bale delivery and it showed up right on schedule. Only one problem…the farmer sent him three string bales, not the two stringers he had ordered. The three string bales were 6″ too wide for the house he had built. He thought about stacking them on edge and I was able to talk him out of that. When he asked me for suggestions of what to do, I contacted a friend of mine with a portable sawmill. Here’s a scenario where he had to trim 6″ off of 400 bales and do it quickly. Every day that he didn’t have bales to install, the job was falling behind schedule.
So with two laborers and one sawmill expert, the entire stack of 400 bales was cut down by 6″ in a little less than 6 hours. If you’ve taken a workshop with me, watched my DVDs or just paid close attention to bales in the field, you’ll already know that a standard straw bale has two edges: a folded edge and a cut edge. That’s due to the way a baling machine works, folding the straw into the chute with a plunger, tying the bale and then slicing off one edge to make the bale the right size. I always recommend that the bales be stacked all the same direction in the walls, cut side in or cut side out. There are some factors that do into deciding which way to face the bales, but that’s not the point of this story. In this scenario, the “new” cut edge was extremely clean and sharp. It made for the perfect interior wall surface as finalizing the wall clean up will be easy with the pre-cut bales all facing the same way. You can see in the picture here how nice the bales turned out and why they create a clean surface for the interior wall.
Although I really don’t recommend planning on the use of a portable sawmill unless entirely necessary, it’s good to know that they work so well and so quickly should you find yourself in a similar situation. The best remedy for this problem is proper planning and proper communication. Mistakes get made, it’s part of life, and so having a back up plan to great planning and communication is a good thing.