I was browsing through craigslist and there were various listings of reclaimed xps, eps and iso. What could be some possible applications of such products in my case? My new construction will have ICF basement and Gigacrete walls for the main floor so no need there. I can think of 2" xps for sub slab insulation in the basement? Would it matter if the xps is wet? I was also going to go with a heated garage but will decide whether to go with it or not after getting heating bids. Regardless, the garage will be insulated so xps can be used under the garage slab as well. There will also be a bonus room above the garage that will be insulated and obviously the whole roof need to be insulated(blown cellulose).

Reclaimed foam board can be used pretty much wherever virgin-stock foam board would be used.  I used 3" reclaimed polyiso to insulate my poured concrete basement. A friend I helped on a deep energy retrofit of a 3-story 3- family ended up saving well over 10 grand in material costs with the major foam-over (4" on the walls, 6" above the roof deck.)  He ended up using virgin stock XPS under the slab though for shipment scheduling reasons.

At reclaimed-foam pricing why restrict yourself to 2" sub-slab? R10 has a financial rationale even for unheated slabs in US climate zone 6 even at virgin-stock pricing, making R20 a reasonable target given that it's 1/4-1/3 the price of new goods.  See Table 2, p10- go at least double if heating with the slab, at least 50% if unheated.  Even R20 using reclaimed foam won't cost as much as R10 with new stuff.

Both EPS and XPS tolerate water well and are fine to use under slabs. Polyiso does not, but is fine for insulating concrete foundations on the interior, but not the exterior.

Posted By Dana1 on 12 May 2014 04:47 PM

Both EPS and XPS tolerate water well and are fine to use under slabs. Polyiso does not, but is fine for insulating concrete foundations on the interior, but not the exterior.

Is there such a thing as reclaimed polyurethane and how does it tolerate water?

Posted By Lbear on 12 May 2014 06:53 PM

Posted By Dana1 on 12 May 2014 04:47 PM

Both EPS and XPS tolerate water well and are fine to use under slabs. Polyiso does not, but is fine for insulating concrete foundations on the interior, but not the exterior.

Is there such a thing as reclaimed polyurethane and how does it tolerate water?

SFAIK polyurethane hasn't been widely marketed as rigid sheet goods the way polystyrene and polyisocyanurate have. While there are closed cell polyurethane SIPs out there, I've never seen polyurethane panels with thin (or no) facers.

At any given density closed cell polyurethane is more resistant to liquid moisture than it's chemical kissin'-cousin polyisocyanurate, but I don't know at what density you can bury it without issues.  At 3lbs density it's suitable as roofing, provided it's protected from UV degradation by paint or stone ballast, etc., and I presume that's probably dense enough for sub-slab applications.  People have used 2lb polyurethane under slabs but there are persistent rumors of problems with that. (I've yet to find any detail on what the problems were/are.)  I recently mistook a 25 year old sample of a 1.5lb density polyurethane stressed skin panel as polyisocyanurate- they have a lot of look/feel commonality, but they do not behave identically in every aspect (derating with temperature being one major difference.)

Dana,

I appreciate the input. Did you mean to add a link for the table you were referring to?

I was wondering if there here be a use of these materials in a ceiling or bonus room insulation application. How about between bonus room floor joists and the garage ceiling drywall?

Also as long as we are talking about polyurethane, what do you think about this? http://minneapolis.craigslist.org/csw/mat/4472209591.html

The missing link the document with the whole-assembly R-values table.

Regarding the sheet goods in the Minneapolis craiglist link, it's hard to say what that stuff really is, but at a distance from the texture & color it looks like EPS (polystyrene).  A close-up picture might have more clues.  They don't even tell you the dimensions, only the total square feet.  Aged polyurethane is usually a bit more yellow than that, but maybe.  I'm not sure who (if any body) is currently selling rigid polyurethane in the US, or whether it is/was available without facers.   Product name or manufacturer's name would be useful for digging up specs on it.

Huntsman apparently sells it with different facers, but I didn't find a spec sheet online.

It looks like eps and shows a lot of miter cuts on the ends which means you would have a jig saw puzzle putting the pieces together. If that's the good side of the pile I can't imagine what the back looks like.

Dana or anybody else,

I can get a decent price on some Geofoam. I am considering it for two possible application. I would appreciate some opinions/critiques on it.

1. Sub slab application

2. "Cut and cobble" attic insulation: I will have a 12" truss heel. I was planning on insulating the attic with 15-16" of cellulose. I might not have enough geofoam to get that thickness. How about using 10-12" of geofoam + 4" of loose fill cellulose? What would be the best way to use the geofoam in such situation?

Thanks