[Greenbuilding] underfloor insulation R-values & materials

[John Messerschmidt]

Speaking of floor joists, does it make any sense to insulate between floors
inside the building envelope?  There are 8" of empty space there, that I
would rather not heat, but with the cost of insulation, maybe the
cost/benefits wouldn't be worth it.  There are also noise considerations.
Any ideas or comments?




-----Original Message-----
From: greenbuilding-bounces at listserv.repp.org
[mailto:greenbuilding-bounces at listserv.repp.org] On Behalf Of Lawrence Lile
Sent: Wednesday, November 29, 2006 6:50 PM
To: Alan Abrams; Don Jennings
Cc: greenbuilding at listserv.repp.org
Subject: Re: [Greenbuilding] underfloor insulation R-values & materials

I'd keep the cellulose out of basements.  It loves moisture, and looks
like a good platform to launch the next wave of mutant molds from Mars.
Only use it where it can dry out.  They don't even recommend using vapor
retarders with it!  



 
 
Lawrence Lile, P.E., LEED AP
Senior Electrical Engineer
Project Solutions Engineering
573-443-7100 X 221
573-999-3450 Cell
1390 Boone Industrial Dr Suite 200
Columbia MO 65202

-----Original Message-----
From: Alan Abrams [mailto:alan at abramsdesignbuild.com] 
Sent: Wednesday, November 29, 2006 4:28 PM
To: 'Don Jennings'; Lawrence Lile
Cc: greenbuilding at listserv.repp.org
Subject: RE: [Greenbuilding] underfloor insulation R-values & materials

>
> Wet Spray cellulose is your friend.  Cheap, 100% recycled, always
fills
> up gaps and odd shapes unlike Batts, you can spray it upside down into
> an overhead space (usually through a screen that looks like mosquito
> net)  It will fill up any shape space, and it is better R value than
> most of the alternatives.  The only thing better is biobased (made
from
> soybeans) foam, but the price is steep.

LL- 

I agree with you in principle about the use of cellulose.  Please
consider
this, however:  

We've been insulating existing basements by furring out the perimeter
walls
with 1 5/8" metal studs held 2" off the wall, and foaming (with icynene
or a
clone) between and behind the studs.  If there's a moisture problem we
install a conventional subslab perim drain and line the walls with
enkdrain
(down to the subdrain) before patching the slab and installing furring.

What do you think about substituting cellulose in a case like that?

Cheers-
-AA  



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