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Compost as insulation

 
Mike Winfrey
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I know this has been done but I can't find anything on it. I have a concrete slab that our house sits on and this house is constructed out of concrete blocks. I am entertaining the idea of putting down a moisture barrier on the ground around the house and put compost on that barrier. The idea is that the heat generated by the composting process will heat the edge of the slab thereby providing some heat to the house reducing the demand of other systems. Comments?
 
allen lumley
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Mike Winfrey : 1st -you will need a Total final vapor barrier for the top of your compost. Nothing spoils ether the heating potential or the insulating potential than water .

Also Ether wet hay or Manure will stain your concrete, not necessarily a problem with your slab but unsightly around the base of your house .

A minimum mass needed to start producing heat without losing too much heat energy to the cooling potential of the concrete mass Would be close to 4' X 4' or

possibly bigger And this mound heaped up against the side of the house is potentially as long as the entire perimeter of your structure !

as this mound of material will both settle and slump eventually your mound will take on a cross-sectional shape similar to a 1/4 pie slice or section .

If you have the amount of mass to make this work go for it , if you can only cover part of your perimeter i would recommend doing it on the Windy side of the house

doing everything you can to keep your compost pile as dry as possible !

I hope this is timely and helpful, for the Good of the Craft ! Big AL

 
Mike Winfrey
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Outstanding reply. Thank you very much. You confirmed everything I was thinking and gave additional info. I wasn't sure about covering the compost and I wasn't sure how much I needed. I was going to just pile some up an see what happens. Now I have a recipe. I have access to as much material as I need because I am affiliated with a riding stable. I've already run an experiment of sorts by piling up a bunch of thus in an open area without any cover. I left it there during the winter for about 3 weeks or so before I dug into it. I didn't measure the temp but I dug into the pile with my hand and as I dug the temp rose nicely. I dug about 3 feet. Anyway, thank for the guidance.
 
Mike Winfrey
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Also how long do you think this will last. I'm thinking it can stay forever and just be an insulator for the slab. I'm familiar with water shed umbrellas and figure it will work just as well if not better than straw which is is recommended.
 
Ryan Skinner
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Not sure what you mean as an insulator. are you talking about leaving it in place after it has given off all of its heat?
 
Mike Winfrey
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Yes. Leave it there to insulate the slab just as a watershed umbrella will do.
 
Ryan Skinner
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Out of my knowledge zone but I would imagine that the benefit of straw is that it typically is dry and creates a bunch of air space? I think the compost would be the opposite of those things. Do you know of anybody else that has used finished compost as insulation?
 
Bryant RedHawk
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Mike, the insulative properties of finished compost is going to be close to that of soil.
This will work if you are planning on using it as it would be in a soil bermed house, where the walls are covered with soil.

Straw has more air spaces, hence more insulative quotient for a given thickness and depth than soil.
Finished compost has just a little more insulative quotient than soil.
While a compost heap heats, it provides heat and insulation, once it is finished the heat is gone and the insulation has compacted so it's value goes down.
 
Mike Winfrey
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That makes sense about the comparison to soul. I should have thought of that myself. I guess the compost will at least get me through the winter and then I can install the watershed umbrella the right way I the spring.
This us a link explaining the umbrella if anyone is interested.
https://www.thenaturalhome.com/frostwalls.htm

Here is another Google search that gives more links on the umbrella.
https://www.google.com/search?q=john+hait+umbrella&rlz=1CDGOYI_enUS591US593&oq=john+hait+umbrella&aqs=chrome..69i57.15130j0j4&sourceid=chrome-mobile&ie=UTF-8&hl=en-US#imgrc=_
 
Mike Winfrey
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By the way the watershed umbrella can be installed on a buried house as well as above ground.
 
Roberto pokachinni
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One idea that immediately refreshed in my mind when I saw this thread was a design I had thought about which included a large mulch vermicompost, along lower edge of the outer exposed wall of a bermed structure. The bin would be covered with an insulated lid that had a plastic layer, which would shed water away from the house. The worms would actively compost the material, and create heat via composting and their own vital functioning. The long wide bin, or combination of bins, could be emptied in the spring, for use in the garden, and be filled again in the fall with fresh composting ingredients. The contained box or bin would keep the moisture of the compost from being against the wall.
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