[Greenbuilding] [BULK] Re: using roxul-confessions of an old foamer

[Lawrence Lile]

To put this in perspective, what would be a typical range for PSF under
a slab on a typical house?  

 Us Erlectrical injuneers don't do much of this kinda stuff, because we
are allergic to any units that aren't metric.  I know that is heretical
in 'Murrica, so you can call me a terrorist or a revolutionary or
something.  
 
Lawrence Lile, P.E.,

-----Original Message-----
From: greenbuilding-bounces at listserv.repp.org
[mailto:greenbuilding-bounces at listserv.repp.org] On Behalf Of Rob Tom
Sent: Tuesday, June 12, 2007 1:10 PM
To: GB REPP
Subject: [BULK] Re: [Greenbuilding] using roxul-confessions of an old
foamer
Importance: Low

some Murrican old foamer (MOF) figgered:

> convert KPA's to PSF's, which if my cypherin' is good is 355 psf at
> 10% deformation.

>> Compressive resistance 17 KPA at 10%


FWIW, Roxul also makes a higher compression resistance board insulation:
"RXL 80"  compression resistance = 27.1 kPa  ( or 3.9 psi in Murrican) @

10% deformation

For the sake of comparison,
   compression resistance (CR) of Expanded Polystyrene (EPS) = ~ 10 psi

@10% deformation
    and CR of XPS (Extruded Polystyrene) (ie Dow-Corning's "SM") = 30
psi

If using Roxul under a slab, I would suggest perhaps using small
"islands"  
of the higher strength but not-so-Green) XPS to carry the majority of
the  
live and dead loads and fill in the majority of the area with the more  
sustainably-correct Roxul. You know, sort of ying-yang  
always-a-little-bit-of-one-in-the-other thang ?

-- 
=== * ===
Rob Tom
Kanata, Ontario, Canada
< A r c h i L o g i c  at   C h a f f Y a h o o  dot  C a  >
(winnow the chaff from my edress in your reply)


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