aemeijers wrote:
On 4/16/2011 11:13 PM, wrote:
Hello all,
Looking for opinions on crawl space insulation. This is for an old
rent house on block and pad foundation. I am considering either R13 or
1 1/2" rigid foam (vapor barrier on one side and radiant barrier on
the other).
Fiber seems to have better cumulative R-value. However, I don't know
if bugs and crawlies nesting in it will be an issue. I can get the 1
1/2 for about 10 dollars a piece. Fiber will let me do this
incrementally as time allows.
Trying to get a feel on what is the better option.
thanks
richard
Get it spray-foamed. You can probably take an energy credit (if I
understand the IRS page correctly), and you can depreciate it on your
taxes (schedule E) as a substantial improvement.
Second the spray foam. Your gain will be more noticeable in comfort
than $$ saved--- but if you're renting, keeping those tenants for a
second winter is a plus.
Fiberglass will last a couple years before critters make it useless.
Rigid foam *could* be done with a whole lot of crawling in the dirt
and sealing edges with great stuff. [ideally the rigid stuff would be
placed between the joists with 1/2 dead air space between it and the
floor-- edges 'caulked' with expanding foam-- a foil sheet in there
would probably be a good idea, too.]
The spray foam will be most expensive-- but you can be doing something
more productive for the days you would have spent crawling in the
dirt.
Jim