[Greenbuilding] using roxul-confessions of an old foamer

[Rob Tom]

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
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