Everything I have read about insulating the floors above a crawl space
make a point of saying that the insulation should be placed directly
against the floor with no air gaps. Why do they insist on the "no air
space"? Not knowing anything about insulation, it seems that an air
space between the floor and bat insulation would be good.

We are building a house and the floor joists are going to be I beams
that are 12" tall. Since the R19-22 bats are only about 6" thick,
how is the insulator going to get the bats against the floor and make
them stay there? The one insulator I have talked with says that he
staples a nylon mesh against the bottom of the joist to hold the
insulation in. It seem that would let the bats drop away from the
floor and create an air space.

Any help and advice will be appreciated.

Also, our crawl space walls are concrete block. Should we insulate
the walls? If so, what would you suggest?

there's a video and some explanatory stuff he


http://www.jm.com/insulation/buildin...ation/3499.htm

wrote in message
...
Everything I have read about insulating the floors above a crawl space
make a point of saying that the insulation should be placed directly
against the floor with no air gaps. Why do they insist on the "no air
space"? Not knowing anything about insulation, it seems that an air
space between the floor and bat insulation would be good.

We are building a house and the floor joists are going to be I beams
that are 12" tall. Since the R19-22 bats are only about 6" thick,
how is the insulator going to get the bats against the floor and make
them stay there? The one insulator I have talked with says that he
staples a nylon mesh against the bottom of the joist to hold the
insulation in. It seem that would let the bats drop away from the
floor and create an air space.

Any help and advice will be appreciated.

Also, our crawl space walls are concrete block. Should we insulate
the walls? If so, what would you suggest?

You could use R-38 which is 12" tall. Depending upon your climate, it might
make your floor more comfortable.

For the concrete block, check out
http://www.owenscorning.com/around/i...rmNDriProp.pdf

-al sung
Rapid Realm Technology, Inc.
Hopkinton, MA

Most of the heat that you are loosing through the floor is going
through the walls in the crawl space. I would put down a vapor
barier on the floor of the crawl space and only insulate the
walls. I would use unfaced fiberglass bats draped against the
walls and 2-3' on the floor. You will use a lot less insulation
if you insulate the walls.

wrote:
Everything I have read about insulating the floors above a crawl space
make a point of saying that the insulation should be placed directly
against the floor with no air gaps. Why do they insist on the "no air
space"? Not knowing anything about insulation, it seems that an air
space between the floor and bat insulation would be good.

We are building a house and the floor joists are going to be I beams
that are 12" tall. Since the R19-22 bats are only about 6" thick,
how is the insulator going to get the bats against the floor and make
them stay there? The one insulator I have talked with says that he
staples a nylon mesh against the bottom of the joist to hold the
insulation in. It seem that would let the bats drop away from the
floor and create an air space.

Any help and advice will be appreciated.

Also, our crawl space walls are concrete block. Should we insulate
the walls? If so, what would you suggest?