On Apr 17, 2:33*pm, aemeijers wrote:
On 4/17/2011 2:16 PM, ransley wrote:





On Apr 17, 12:04 pm, "Bob *wrote:
ransley wrote:
On Apr 16, 10:13 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

Foam board is easier to work with , not affected by moisture, no itch..

Getting foamboard to fit tightly will be way more work, IMHO.

Fiberglass looses R value as it gets colder near zero,

Really? Where did this come "data" come from?

filber glass

irritates but there are types they say dont but they cost more. Foam
should be easier to get an airtight seal between sheets.

Somehow, I doubt that. Cutting foam to fit, especially around cross bracing will
never be easy.

Google it,

Okay, dumb question- what if you applied foam board below the joists,
running it crossways. Hang it with those screwgun screws with the big
washers, and tape the joints? Would the dead space between foam and
subfloor cause problems, assuming the foam board was rated as a vapor
barrier? That way it would go up pretty quick, and if you marked where
any ducts or utility lines run, it would be pretty easy to get at them,
later. Is there something obvious I am missing? I've seen detached
garage ceilings done this way, to keep the vented attic from
superheating the garage bay while it is closed up all day.

--
aem sends....

--
aem sends...

It would work and lower humidity in the house in summer by keeping it
in the crawl space. Just butting the joints will seal most of the air.
I wonder if just stuffing batts up in the rafters might not be best
for a cost reason, fiberglass has to be cheaper. and it wont get any
drafts or rel low temps that would disadvantage it. It has to be a
cost decision I would guess. Unless the crawlspace is a swamp !