"DerbyDad03" wrote in message
...
On Feb 28, 7:57 pm, marson wrote:
On Feb 28, 8:34 am, "JoeSpareBedroom" wrote:





The dining area of my kitchen is built over a crawl space that's
enclosed by
cinder blocks like the rest of the house. In the basement, there are two
openings to this crawl space, but they're only 6" high x 18" wide. I
assume
they were put there for ventilation purposes, since they're useless for
anything else. The area in question juts out from the main kitchen, and
is
12x12 feet.

In winter, the floor is ice cold, so that dining area is useless. I
believe
the traditional first step for dealing with this is to lay a plastic
vapor
barrier on the soil underneath, followed by fiberglass insulation. The
vinyl
flooring needs replacement, so I could also rip up the wood underneath
in
that area and have total access to do the work. Replace the sub-floor
afterward, install new vinyl or tile, and it's done.

BUT: Someone suggested an interesting alternative: When the vinyl
flooring
is removed, drill access holes in the sub-floor and pump the space full
of
foam. It's already a form of plastic, so it should form its own vapor
barrier. And, it'll insulate. Progress could be checked via the access
slots
in the basement. Makes sense, but there's always a "gotcha".

Your thoughts, please.

The spray foam I have seen applied is sprayed from a gun much like an
airless paint sprayer sprays paint. You aim the gun at a surface from
a fixed distance--about 12" is what I have seen--, be it a rim joist
or wall sheathing or whatever, press the trigger, and it adheres to
the surface and expands. I have never seen a foam application where
you could pump it into a hole with any kind of predictable results.

If you could get in there enough to install some sort of sheet
material (plywood, foamboard or the like) or even netting onto the
underside of the floor joists, you could blow dense pack cellulose
from the top through little holes in the subfloor.

The other alternative would be to figure out a way to insulate the
stem walls, and then pump heat in there.- Hide quoted text -

- Show quoted text -

Since you said that removing the sub-floor is not out of the question,
you could...

- Remove the sub-floor
- Crawl underneath and attach 1 x 2's perpendicular to the joists
- Lay plywood strips on these supports, forming a "floor' in each
cavity
- Spray expanding foam insulation in each joist space - the kind you
see used on TOH.
- Replace sub and finish floor
- Save the wooly socks for sledding

==================


Wouldn't I still need a plastic vapor barrier right on top of the soil? It's
cheap enough....

On the other hand, this crawl space is bone-dry.