[Greenbuilding] Basement EPS with plywood (acceptable)

Alan Abrams alan at abramsdesignbuild.com
Sat Jul 13 19:45:04 CDT 2013


John--

I never cease to marvel at how thoughtful and well expressed--and how well
founded on carefully considered experience--your observations are.

AA

On Sat, Jul 13, 2013 at 6:01 PM, John Salmen <terrain at shaw.ca> wrote:

> Not sure to be honest. ****
>
> ** **
>
> Formaldehyde is not the worst carcinogenic chemical in most homes so its
> about trying not to not add more to the mix when avoidable. Inhalable
> fibres and dusts are a legitimate concern. But mostly it was the sense that
> it was not well suited to the application in comparison to eps and it is
> truly noxious to work with. I’ve not seen it used in sips other than
> commercial panels nor is it used in geo fill. Its basically a compressible
> fibre made stiff with a glue that may or may not have good water resistance
> depending on what was used.****
>
> ** **
>
> As for plasteech. In building most every material has an inherent
> toxicity. Both for builders and end users. It remains for us to use
> material wisely but remain critical and keep gathering information – not
> just beat drums. Rockwool is implicated in workplace cancers and workplace
> exposures to rockwool dust/fibres exceeds glass wool exposures for some
> reason (dustier?).  Rockwool can have a resin content of 5% of its weight.
>  The styrene content of polystyrene is .1% by weight and polystyrene is 2%
> by volume of eps. There is also radon. I mention these things only to say
> that there are no simple directives.****
>
> ** **
>
> The real culprit in building is pvc as it is the cheapest and most toxic
> plastic out there on the ranking. A good example is waste and drain
> systems. Perforated pvc pipe for drainage probably has more plastic content
> than an eps wrap of a house. It is hard to get builders to substitute with
> polyethylene because it is not considered standard or good practice – in
> reality you can eliminate piping altogether and simply use washed rock and
> that is approvable (though most inspectors would argue). ABS plastic for
> dwv is more benign than pvc yet in the US pvc has become the standard. Is
> anyone still using copper in water supply systems?****
>
> ** **
>
> End of rant****
>
> ** **
>
> John****
>
> ** **
>
> ** **
>
> *From:* Greenbuilding [mailto:
> greenbuilding-bounces at lists.bioenergylists.org] *On Behalf Of *Alan Abrams
> *Sent:* July-13-13 1:05 PM
>
> *To:* Green Building
> *Subject:* Re: [Greenbuilding] Basement EPS with plywood (acceptable)****
>
> ** **
>
> John--If I understand your comments, the big objection to Roxul is in the
> potential for outgassing; secondarily, a question about its structural
> capacity.  I agree that any unusual load should be carried through the
> floor system to proper bearing--or--in the case of a bearing wall with
> modest loading, perhaps that could be supported by a strip of high density
> EPS (aka Geofoam) in order to minimize thermal bridging.  With regard to
> the outgassing issue, my sense (not having tried this yet)  would be to
> trust taping the seams of the subfloor, and taping the edges to the
> perimeter walls.  Lastly, a double staggered lap of subfloor ought to
> bridge local deficiencies in the insulation itself--unless this stuff is
> grossly incompetent.****
>
> ** **
>
> On the other hand, I probably wouldn't exceed using a single three inch
> thick panel--given its "off label" application.  Not until someone braver
> has tried it with success.****
>
> ** **
>
> For years, wiser members of this listserve have been beating the drum to
> wean ourselves from plast-ecch foam.  Alex Wilson and now even PHIUS is
> making the same case.  The rationale has been slow to penetrate this thick
> skull, but it is beginning to seep through into the void.   ****
>
> ** **
>
> -AA ****
>
> On Sat, Jul 13, 2013 at 12:50 PM, John Salmen <terrain at shaw.ca> wrote:****
>
> Tried that. The fiber industry uses formaldehyde as the binder to achieve
> densities. Higher densities more resin. Roxul states the urea is cured with
> little potential for offgassing. Technically I am not sure what they are
> talking about as curing reduces strength and ultimately density. The use of
> formaldehyde is generally a compromise between emissions and strength. The
> residential ‘comfort board’ I think reflects that compromise with a density
> of only 745 psf. EPS type 1 (the lowest density) is about double that. I
> would be concerned about using it as long term structure (under partition
> walls, etc.). ****
>
>  ****
>
> My experience with the product was that it was,  dusty, noxious and worst
> of all inconsistent in density (roxul) – imagine a beehive hairdo. You can
> crush the board with your foot or punch your fist through - so it was
> difficult to work with as a board stock.****
>
>  ****
>
> I could see using the higher density commercial roofing boards but then
> would be concerned about offgassing.****
>
>  ****
>
> *From:* Greenbuilding [mailto:
> greenbuilding-bounces at lists.bioenergylists.org] *On Behalf Of *Alan Abrams
> *Sent:* July-13-13 6:26 AM
> *To:* Green Building
> *Subject:* Re: [Greenbuilding] Basement EPS with plywood (acceptable)****
>
>  ****
>
> because XPS has a significantly higher global warming potential than EPS,
> I'd prefer the latter--even at somewhat lower R-value per unit of
> thickness.  Others on this list (John Salmen) have written extensively
> about using adhesives instead of mechanical fasteners to connect the
> components.  ****
>
>  ****
>
> it raises another idea--to use rigid mineral fiber instead of foam.  Roxul
> comfort board is rated at R-4 per inch, and is said to compress only 10%
> under 743 LBs per SF.  dunno how that extrapolates to ordinary live loads,
> but it still suggests a double, staggered layer of plywood, mechanically
> fastened.  many other advantages, including dimensional stability, fire,
> rot, and pest resistance, high permeability, and low embodied energy.
>
> Alan Abrams****
>
>  ****
>
> On Fri, Jul 12, 2013 at 10:55 PM, Sam Ewbank <g.l.ewbank at gmail.com> wrote:
> ****
>
> From the green building archives.  A similar application to what you are
> looking to do but with the suggestion of using 1.5" EPS****
>
>  ****
>
>
> http://lists.bioenergylists.org/pipermail/greenbuilding_lists.bioenergylists.org/2012-April/003703.html
> ****
>
>  ****
>
>  ****
>
> On Fri, Jul 12, 2013 at 9:52 PM, John O'Brien <john at boardom.ca> wrote:****
>
> Friend is doing some work, looking to put down 1" EPS, with floating
> plywood, tapcon'd down, followed by some floating laminate.
>
> Would this be considered an acceptable base, or would it be beneficial
> to bump up to XPS or run a double layer of 1/2" ply staggered for more
> point load compression protection?
>
> Cheers,
>
> J****
>
>  ****
>
>  ****
>
>  ****
>
> Sam Ewbank****
>
>  ****
>
>
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> ****
>
>
>
> ****
>
> ** **
>
> --
> Alan Abrams*
> **certified professional building designer, AIBD
> certified passive house consultant, PHIUS*****
>
> *certified passive house builder, PHIUS
> *Abrams Design Build LLC
> *sustainable design for intentional living*
> cell     202-437-8583
> alan at abramsdesignbuild.com
> www.abramsdesignbuild.com****
>
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-- 
Alan Abrams*
**certified professional building designer, AIBD
certified passive house consultant, PHIUS*
*certified passive house builder, PHIUS**
*Abrams Design Build LLC
*sustainable design for intentional living*
cell     202-437-8583
alan at abramsdesignbuild.com
www.abramsdesignbuild.com
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