[Greenbuilding] NumberNoidal stuff (was Re: using roxul-confessionsof an old foamer)

[Alan Abrams]

<Or for non-allergenic Murrican non-sparkies ( metrically-challenged sorts):

For concrete density 150 lbs/cu ft,
Unfactored slab dead load:   - 3" slab thickness = ~38 psf  (6" = ~76 psf)
Unfactored Code-minimum specified live load: 40 psf

So stresses from *unfactored* residential slab live + dead load not likely  
to exceed 5.5 kPa  (or 0.8 psi in Murrican).

Recall that compression resistance of Roxul's "Drainboard" product = 17  
kPa ( or 2.5 psi)

But enginoids would never design anything using unfactored, specified  
loads as the design criteria. (ie For (Canadian) Limit States Design,  
specified live loads are in most cases, multiplied by a factor of 1.5 ...  
and dead loads by a factor of 1.25)  And no one who aspires to make good  
buildings would use Code minimums as a target to aim for. Eh ?>




so, even designing for a four inch slab (3" is risky; murrican tape measures
are not all that accurate) and clogging night with the Banty Roosters
(brother Art on the bass), roxul makes out ok. 

-AA