Sometimes even the best planning can result in a mistake. For example, I recently heard from someone who purchased a house and found that there is no dryer vent through the straw bale wall to the exterior of the home.

Here’s a quick step by step guide to installing a vent after the fact. Be sure that you do this job with the power turned off to the house. I suggest you turn off all of the power, so there’s no risk of hitting a live wire buried in the bales.

It’s best to cut a larger hole than what you need as trying to cut a perfect size hole in a bale wall can be difficult. By all means, try it if you want as you can always enlarge your first attempt and continue with the method below. Much will depend on what size vent (or other protrusion you’re working with) you are trying to install. It will also depend on the density of your bales.

For the larger box method, start by using a rotary hammer drill with a chisel bit to remove the plaster. I suggest you score the outline of the area heavily with a scoring tool so that the plaster doesn’t continue to break in all directions as you go.

Cut out any mesh in the wall. Be sure to leave enough mesh when you cut it out to later anchor the framing that will go in the hole. You’ll need to bend it out of the way for now.

Use a chainsaw to plunge cut the straw out of the hole. Again, watch for wiring here!!!

Insert a small wood frame into the new hole and anchor it to the wall by attaching the bent back mesh to it.

Insert the dryer vent exterior wall fitting.

Insulate around the piping.

Trim out the new box with a wood detail, tile around the vent pie as necessary to hide the repair, or replaster the area with a skim coat over the entire wall to hide the repair.

Connect the dryer vent to the stub out.

Get going on the laundry that’s been piling up!

When building curved walls, some of the most difficult aspects to deal with aer 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.
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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.
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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
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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.
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There are so many options for anchor bolts these days that it is hard to know what to use. I believe I have found the best option for most straw bale projects. Keep in mind that with both interior and exterior toe ups, there are a LOT of anchor bolts in a bale house. Because of this, expense has to be considered; however, it should not be the main factor.
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Many people have mentioned an interest in building a straw bale greenhouse. I have seen several different approaches to this idea over the years. I have two different column in which these projects have fallen. Some of the greenhouses have been absolute disasters, while others have proven to be beautiful and successful. Just how to move forward and how the design is realized will affect the column into which your project lands.
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It must be something in the air. I have received a bunch of emails about building landscape walls in the last week. This after a long drought of such questions. So, I guess it is time to talk about them again. The majority of the questions I have been getting are around the foundation system and the restrictions of building a landscape wall with bales.
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Windows are one of the most risk prone and failure prone areas of a house, conventional or straw bale. In fact, any penetration in the exterior wall is at risk of water infiltration and thus failure. Most contractors are aware of the risks associated with this area of construction yet they do not fully understand how to minimize that risk.
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Okay so it’s not poop, but it could be from a distance! These are piles of extra concrete. It is so important to calculate materials well and it could be the straw that breaks your back. (I meant that pun by the way.) In this case, the truck load was too short for what the concrete guys had planned so they had to thin the slab thickness which ultimately left a lot of excess concrete. To be sure, I mentioned it to the concrete company owner. It was a mistake, and not a huge deal because the slab in this case was so small; however, on a big job, the little extras can run wild quickly.
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Vapor barriers often create more damage than they prevent in straw bale houses. Why then are they required in straw bale building codes? The answer is not complicated; however, the impact of vapor barriers on homes of all types is.
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When building a straw bale house, the question of what type of mesh, if any, should be used is a big one. I show the use of 14 gauge welded wire mesh in my DVDs, and that is a great option; however, it also has its downsides like any other application. For one, it is expensive. Secondly, it is a bit harsh on the environment to use so much steel. So, what other options are there?
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On November 16th, I wrote a blog entry about retying straw bales, the new way! The new way is to use the Miller’s knot instead of the trucker’s hitch which has been used for years. In the first half of this two part entry, I showed you the basics of how the knot works and why I use it on all my straw bale homes. In this entry, I have included a video that shows you, in depth, how to tie the knot….well, you know what I mean.
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When people consider building with straw bales, they most often find their top concern is how to protect the bales from rain. All too often, snow is not considered a threat to the structure. In most cases, this is true; however, in areas where large snow drifts are the norm, the impact of snow cannot be overlooked without consequence. It is typical that climates with a lot of snow, especially powdery snow, will eventually blow hard enough to create drifts. Those drifts will pile up on whatever interrupts their path, even if it happens to be your front door!
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Today I received the following question and I thought it was worth sharing my response with you all. Here’s the question, my response follows:
“Well the time for using all this information is almost upon us. We are looking at a property at the moment to build on; however, it is quite a steep property. Do you have any ideas or photos of straw bale houses built on steep sites with out doing major earth work? Thanks in advance.
Regards Chris and Jenny”
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Here are some questions I got from a client yesterday. I think they are worth sharing.

Q1. How much force is required to tie the bales tight. (my elbows are killing me)

A: The knot that I use, the Miller’s Knot (although I have been told that the name might be incorrect) is so strong that it is possible to tie the bales tighter than the original baling machine. This requires a strong twine as well as the standard twine often snaps under the added pressure of this knot. Super blue twine works very well. In general, I try to tie the bales as tight as I can. This usually means that when I am done, the old knots are slightly loose and the new twine is very tight to the bales. In terms of foot-pounds, I have no idea. IN terms of elbow pain, I would suggest a little less than what causes pain!

Q2. How to handle situations where you are only 3 to 4″ short and too small for a bale. How to stuff, how to lock the bales from moving and the use of tar paper under the bales and strapping.
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Where welded wire mesh is used as the structural shear of a building, it is very important that temporary braces be used to secure the building before the mesh is applied. This is a common practice with conventional construction as well. 2×4 braces are used to support the walls and maintain a plumb line until the plywood is added. In a bale house, the system is a bit harder to deal with.
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Gene wrote to me this week asking about the viability of retrofitting an existing structure with straw bales. I get that question a lot and figured it was time to blog about it. Any structure can be wrapped with bales, it is simply a question of how much extra work will be required to make that structure function properly once wrapped. Consider that you will be adding about 2′ to the exterior of the house and that all bale walls need to have adequate roof overhangs to protect them from rain. So, unless your house originally had 4′ overhangs, you will have to extend the roof to accommodate the bales. This means opening up the roof system and “sistering” new rafters to the old ones with enough attachment to support the cantilevered rafter tails. A good rule of thumb is that should be a two to one. If the overhang is 2′ then the attachment needs to be at least 4′ long. Of course then the sheathing will need to be attached and the roofing material feathered back into the existing roof.

Another area of concern are the window and door openings. These will end up recessed into the wall by the thickness of the bales, leaving a large sill that could collect water. Your options here are to move the windows and doors to the outside of the wall using standard bucks, or to slope the sills and cover them with some protective material that will quickly drain any water away from the house. Some options are concrete, granite, or finished wood sills. Doors don’t have this option because they don’t have room for sills.

Finally, will the bales collect moisture against the existing building? If the building is wrapped in a non breathable material like metal siding, the chances are high that the bales will end up soaking in the moisture that collects against the metal surface. A drainage system is a good idea in this case. Something like the product on this website (www.mortarnet.com) is a good idea in this application. Regardless of whether the back of the bales is separated from the existing structure by a drainage channel, the bales need to be fire proofed which means a layer of plaster needs to be added to the bales. This is easy on the face of the new wall, but the back of the bales will not be accessible once the bales are installed. For that reason, each bale needs to have plaster or a clay slip applied to the back before it is installed. This is a slow process, but an important one. The bales could otherwise present a fire risk if not covered. This is most important when using the drainage system but should also be done without a drainage system for added protection.

It sounds like a lot of work, but the results are beautiful and efficient. You may have to work hard to accomplish the wrap, but you will be paid back for years and years with lower utility bills, a more beautiful home, and a higher resale value should you ever decide to leave. I hope this gives you some ideas of what is needed for a bale retrofit.

It is important that all wood surfaces be covered with roofing felt to separate them from the plaster. If you do not do this, the plaster will adhere to the wood and will be prone to extensive cracking as the wood dries and moves over time. a typical house has a lot of wood members that will need to be isolated so the process can be time consuming. It can also go quickly with a little planning and forethought. Here’s what I suggest. Figure out the major widths of the wood components that need to be covered with the felt. Add 4″ to that width for some overlap (I’ll tell you why in a minute). Now the roofing felt to the chop saw (use an old blade because the felt will gum it up terribly!)and cut the roll into smaller rolls matching the width you determined. Cut slowly to stop the felt from melting to itself rendering it useless. Now you have precut rolls of the size you need to move quickly through the structure. These rolls are not only cut to size, but also easier to carry around the job site and up ladders if necessary.

Now, why did you add 4″ to the measurement of the wood members? When notching your bales, I always tell you to over cut the notch rather than under cut it. If you try and hit the notch size exactly, you will miss most of the time and the trimming of the notch in the bale is hard to accomplish well. This means the bales will be harder to get into place and the time you’ll spend trimming, fine tuning and installing your bales will be huge. If you over cut the notches, you will speed the process immensely; however, you may end up with a bunch of 1″ gaps on the outside of the structure against the posts and beams where the over cut took place. You could stuff these, but it is hard (because they are only a few inches deep) and very time consuming (now you’re back to where you started with lost time!). The extra roofing felt (4″ over cut) acts as backing for the plaster as long as there is no more than an inch or so of space behind the felt. The other 1-3 inches of felt laps onto the bale, bridging the gap. There is no significant affect on the R-Value of the wall and the process is sped up greatly. Again, the faster you can move through the baling process, the sooner you can get the bales protected with plaster.

When adding a straw bale addition to an existing straw bale house, you have to be sure to create a connection between the two walls (old and new). One way to do this is with dowels or rebar embedded into the old wall and laid in place in between courses of new wall. This allows you to leave the existing plaster in place and still accomplish a connection. Another way is remove the plaster from the existing wall and then use plaster lath on the top of each new course that is bent at 90 degrees and pined to the old wall surface. Use landscape pins on the old and new walls to attach the plaster lath. You will want to offset the new walls in either application so they are not in line with each other. In other words, add a right angle turn from the old wall and offset the new wall by at least one foot. This will help when you plaster because it gives you a stopping point (the corner). Without it, you will see a large plaster scar or will be required to plaster the entire wall (both old and new) to a corner.