I recently wrote to someone who is trying to find an inexpensive way to build with bales. The intention is to wrap existing houses with bales in the cheapest way possible. There are no codes that need to be met on the reservation in question and a few dollars saved on each house could mean that one more home gets retrofitted each year. As it stands now, at least one person dies from the cold every year on this reservation. It’s time to stop that from happening.

Most of the work I do is on higher end homes and relates to teaching people the techniques I find applicable to most people. That said, I have outlined some ideas of how I think they could cut costs while still keeping the safety and integrity of the buildings. Please add your thoughts to mine in hopes that we can together find ways to help save lives and improve the quality of living for the people of this reservation, and hopefully beyond.
(more…)

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!

I recently received the following question from a visitor to my blog named Pat. I get this question and variations of it quite often. Here is the question:

I have a house built in 1911, the wood frame is 2×10 and 2×4 pine construction the wood is now so strong that a nail must have a pilot hole drilled first. Is it possible to add additions to this house using straw bale construction and tie the two together somehow? I live in Minnesota so I love the high R value of bale construction. I had also thought about completely encompassing the whole house and slowly removing the exterior of the existing house. The purpose would be to allow us to live here while we are building the additions. If you have done this how did or would you do it?

Here’s my answer
The idea of wrapping the house in bales is a common one and sounds like it would be a good idea in Pat’s climate. I have attached a video below that discusses three of the major areas of concern when working with wrapping an existing house with bales.
(more…)

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.

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.