Creative Ideas for Insulating Earthbag Home Builds in Illinois

Heya folks!   This is my first post so bear with me.

I've been scouring and studying books, videos, forums for a decent inexpensive way to insulate earth bag homes that doesn't use scoria (expensive) or rice hulls (unattainable in quantity).  I've read so much and nothing is standing out.   We're in the middle of purchasing a 48 acre parcel in Southern Illinois and can't wait to get outta dodge so to speak. We're wanting to get our ducks in a row with the home plans to ensure that all the materials are lined up and we know what we're getting ourselves into.  Insulation is truly the last thing we need to buckle down before we start digging.

i've read from people living in Canada and places where it regularly gets sub-zero that they've not done any insulating other than the earth bags themselves and are easily able to stay nice and cozy.  Ive also read that the thermal mass without insulation will make it hard to heat and/or cool the structure.

So whats the deal? 1. Do I need insulation or will the earth bags be themselves be enough? 2. What are some alternative options?

I did read somewhere that someone had used spray foam insulation on the outside of the bag structure and them lime-plastered over the foam. Seems like a good idea.   Does anyone have any experience with that?


Thank you in advance!
Dave Presley

Hi Dave,

Welcome to permies, three months in.

I don't come online much and just read your post.

Have you found any other information about Insulating Earthbag builds in Illinois?

Have you checked out websites of Kelly Hart and Owen Geiger. THey have over 3000 pages of free information.:

earthbagbuilding.com
naturalbuildingblog.com
dreamgreenhomes.com

and one or two more sites, which are ilsted on the others.

I remember Owen talking about how not insulating earthbag in a very cold climate
can be like living in a cave, he said that in at least one post on one of those sites.

THe folks, Canadian Dirt Bag blog, metioned this too.

also, might go to BUILD IT SOLAR. A GREAT DIY site for various ideas for insulation. movable and stationary.

http://www.builditsolar.com/index.htm
~~~~~~~~~~

I live in Appalachia, a little different from Illinois, yet cold and wet winters. Snow, below zero can happen and more...

THere is a SIPS panel company within thirty miles. and they give away extra rigid foam they don't use.
some pieces are huge--4'x10' etc.

this isR4 per inch value. pieces are 4, 5.5 and 7.5 inches thick.

I rented a U=haul truck and filled it. it cost $140 dollars for truck rental/petrol for more than a thousand dollars worth of insulation!
What a great deal.

I super insulated the interior of my exterior walls, floor and ceiling where i live, (220 sq ft part of a mobile home)

having added akin to R20 and R28 to those surfaces.
AND now the space is very nice.-- shorter to stand in so not heating tall ceiling.



I also used Armafoil radiant barrier and 2x2's to create dead air spaces between walls , ceiling and the insulation.

Doing that, added extra depth to the walls. This created space to put movable insulation into the
new "window and door wells' to keep even more heat in the home.



~~~~~~

I know this isn't your exact question, yet it may trigger some other answers for you from other folks.

Dave Presley wrote:Heya folks!   This is my first post so bear with me.

I've been scouring and studying books, videos, forums for a decent inexpensive way to insulate earth bag homes that doesn't use scoria (expensive) or rice hulls (unattainable in quantity).  I've read so much and nothing is standing out.   We're in the middle of purchasing a 48 acre parcel in Southern Illinois and can't wait to get outta dodge so to speak. We're wanting to get our ducks in a row with the home plans to ensure that all the materials are lined up and we know what we're getting ourselves into.  Insulation is truly the last thing we need to buckle down before we start digging.

i've read from people living in Canada and places where it regularly gets sub-zero that they've not done any insulating other than the earth bags themselves and are easily able to stay nice and cozy.  Ive also read that the thermal mass without insulation will make it hard to heat and/or cool the structure.

So whats the deal? 1. Do I need insulation or will the earth bags be themselves be enough? 2. What are some alternative options?

I did read somewhere that someone had used spray foam insulation on the outside of the bag structure and them lime-plastered over the foam. Seems like a good idea.   Does anyone have any experience with that?


Thank you in advance!
Dave Presley

Dave,

Check out calearth.org  they've been doing earth bag building for decades, and have answers to most questions.  If I was to do an earth bag home, I'd sink it at least 4 or 5 feet, if not more into the ground.... the earth is a wonderful insulator/heat sink.  

Strawbales, reeds, or straw/woodchip clay slip attached and then plastered to the outside may be helpful for your situation, but I think you might be better off changing the design of your house. From what I understand, thermal mass and insulation are like 2 different directions on a scale. I believe in exterior walls if you try to incorporate both systems and are planning to get heat from passive solar thermal mass, they tend to cancel each other out. You would be either insulating yourself against your thermal mass if insulation is on inside of exterior thermal mass walls, or insulating your walls from collecting passive solar if insulated on the outside of thermal mass walls. If your are only planning to charge your thermal mass via windows and an interior source(aka rocket mass heater or masonry heater) then insulating outside an earthbag structure should be fine.

If any of this info is incorrect PLEASE correct me! I am by no means an expert.