Has anyone ever heard of straw bales being used as insulation in a brick house?
I’m going to build a timber frame using OSB. Then put a red brick skin around this. On the inside of the timber frame I’ll line all the outer walls with bales.
Bales will be fitted end on end flat to the wall so all the strings will show and run from floor to ceiling. This will make it much easier to cut out vertical runs in bales every 400mm to fit in 3×2 that will be fixed at ceiling and floor. This will hold up bales and give something to fix the inner wall of OSB to. Before OSB is fitted all the strings on the bales will be cut. This will let the bales open and they then fill all the larger air gaps in the rounded edges at each end of the bales by going back to the shape the baler made them.
Then put OSB lining over bales making my inner wall. I’ll then batten out the inside so I’ll have a gap between OSB and plaster board to put all the power and water.
We should have some nice wide windows to sit in when it’s all done!
Bales are now all in the barn.
Making some samples of the wall this month so others will better see my ideas. Will try to get some pictures up.
Does anyone know if this as been used before?
If you want to know more just ask.
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Replies
Martin,
Be sure that you understand how to flash brick veneer. Failures in brick veneer installations are usually due to the failure to maintain an air space between the bricks and the WRB, and failure to understand the principles and practices of through-wall flashing and weep holes.
For such a complicated wall system -- not particularly easy to build or cheap -- I'm surprised that you are including OSB, which isn't as durable as plywood.
It sounds to me as if you are covering up your timber frame -- so why not just use studs?
I'll be using a brick and mortar outer not a veneer. This will be fixed to the OSB using self tapping ties. So there's a 2 inch air gap between brick and OSB.
The timber frame will be built off site then craned into place. Cutting the build time over a stud build by 2/3. By doing it like this we can be fitting the bales on the inside while the brickies are laying the outer skin around the building.
With no bridges in the insulation other than the first floor and ceiling this will keep the U value for the straw bales at their highest.
For the C/O2 tec heads we can off set the firing of the bricks against the C/O2 the bales will hold for the life of the building. Also on what energy that is not used to insulate the building because a raw plant is used with no refining needed. If one works out what you'd need to get a U value of 0.18 w/m 2/2 of an oil based foam insulation or rock wool.
On the cost front brick or clay based render and then inner plastering or dry wall. We work it out that this method should just have the edge. Also the time on the build is cut with both work on the inside and the outside going on at the same time.
I will look more at using ply over OSB.
You have given me things to think about Martin and I hope for more input from you and others.
Martin,
I'm not sure what country you are building in, but in the U.S., the type of cladding you are describing is known as brick veneer. In other words, it's not a load-bearing multi-wythe brick wall -- just a single-wythe layer of bricks that functions as siding.
Again, talk about a complicated and expensive wall! Good luck.
Your materials are very moisture sensitive. It's almost like you are daring your assembly to not fail.
Way opposite my build safe assemblies convictions.
Anything can be done, but... Good luck. Watch thy moisture entry and exit paths.