[VAC] Re: insulation - heaters - cold climates

["Dr. Gerald N. Johnson, electrical engineer" <geraldj@xxxxxxxx>]

Fiberglass bats on the outside walls can drain and dry. The floor
probably won't. If a foam that used to be closed cell looses a lot of
its very thin cell membranes then it becomes sponge and holds water.
Poly wrapped fiberglass bats should be a good investment where the poly
wrapping that keeps them from irritating the installer ought to also
keep them dry.

I used some Great Stuff to foam around the bottom of the steel siding
added to this old house. So far there's not been one mouse and there's
only been a few crickets that have gotten, unlike the past where I could
catch at least a mouse a week, and turn the basement floor black from
stomping on crickets. The jeans that gained some touches of the foam
rotted from old age and washing before wearing the foam off. It might
even stick to ungluable polyethylene though I've not tried it. Wear
gloves and old clothes and expect it to stick to everything. Dogs, cats,
and small children don't understand "don't touch" so they need to be
confined until its no longer sticky. You only get if off skin by
sacrificing the skin it touched.

The old foamed in place foams that were banned used or produced
formaldehyde which is an allergen to a significant fraction of the
population. Many interior plywoods and especially particle boards also
use(d) a formaldehyde based adhesive so that new construction and new
furniture can still be annoying to some of us. I'm not sure I'm
bothered, but when choosing plywood for a confined space its probably
still a good idea to select exterior grade glue which does not produce
formaldehyde. It can take years for the formaldehyde to work its way out
of thick particle board and dissipate when well ventilated. In a metal
enclosed Airstream that may take longer. Early Airstreams are valued for
anti allergen housing because what particle board and interior plywood
that was used can be completely removed without having to destroy the
unit.

I've not tried a latex foam, they seem hard to find and are expensive...

Gerald J.