EPS: Is it totally nontoxic? No offgassing?
My wife and I became super-sensitive to all kinds of chemicals after she had to strip and wax floors at her job and I used those smelly markers loaded with xylene and tolulene that have since been outlawed because they gave so many designers and artists severe nerve damage or killed them. Tried icynene spray foam into the basement joists in 1995 which almost drove us out of our home. I had to go down and scrape it all off and remove it. We now have a cabin with a good large garage I am thinking of getting in floor radiant geothermal heating for and wondering about the expanded polystyrene panels that would have the pex tubing snapped into and whether I could also use EPS for added insulation there in the attic and possibly redo the cabin with some of it, but leary about toxicity. I cut up XPS expanded polystyrene and lined the kneewall closet with it many years ago on our home and ever since can’t close up the place and spend time in the rooms next to those without headaches and dry mouth and sinus blockage. I’d love to use cork board and have bought what I can barely afford but it is so expensive and would run me into the ground to buy enough for the whole project.
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EPS blowing agents are recovered in the factory as part of the manufacturing process. As with nearly anything, there will be some trace amounts remaining, but of the three normal rigid foam types, EPS is going to be the least of an issue here. You'll probably still have some "new plastic" smell with it though, but it will be minimal. Polystyrene, which is what EPS is made from, is a pretty stable material. I'd suggest you go to a box store that carries EPS foam and do a sniff test on it.
There is another option for you too. Normally I recommend the use of reclaimed foam because it's cheaper, and it's a form of recycling. In your case, reclaimed foam has another advantage: it's been "aged" already, and the offgassing already occurred -- somewhere else :-) Reclaimed foam of any type is going to release far less of anything since it's already further along in it's life cycle, so that's something you might want to consider.
Bill
Man, that's some solid advice on a niche topic... Great work Bill. Kudos.
Hmm, thanks. Hadn't ever heard of reclaimed foam, will do a search for it. Can't really tell from a sniff test. The XPS seemed find when I did that, and even when cutting and installing it. But when the house is closed up and I'm in those rooms for some hours, then it is palpable.
You can skip any foam products and go for a mix of mineral wool and cellulose.
https://www.buildingscience.com/documents/building-science-insights/bsi-118-concrete-solutions
Rigid mineral wool can be used under concrete slabs, you can insulate walls and roof with mineral wool batts or cellulose.