F
Floyd L. Davidson
chrisv said:Contributing factors, to be sure. In practice, it's very difficult to
keep interior moisture from penetrating the walls. Areas around
electrical outlets and windows, both interruptions in the vapor
barrier, are largely to blame.
Actually it is fairly easy to keep interior moisture out of the
walls, but it means using the right construction practices to
begin with! Trying to fix it later can be, errr, interesting.
If you have the problems described, it is very likely that
careful application of foam insulation sprayed behind the
various electrical fixtures, can cure it. Getting that right
the first time is important though, because one you block off
the easy access to that area with foam, it gets harder to try a
second application!
I lived near Fairbanks for a couple decades, in a house that had
an unheated crawl space in the area between the ceiling and the
roof. It turned out that a "hatch" going up through a closet to
that area, and two of the several ceiling mounted light
fixtures, were leaking massive amounts of moisture filled air up
into the crawl space. By the second or third warm period we had
water dripping out of the light fixtures. (I didn't even see
the "hatch", until I crawled around up there to fix the lights
and discovered the hatch from to top.)
I lifted the insulation up from between the joists, sprayed the
entire area on top of each electrical fixture, and put the
insulation back down. Never had another problem.
The hatch took a little more doing. I lifted all the insulation
on both sides and directly over it, and put in a layer of
plastic sheeting that extended 2 feet farther than the cracks,
in every direction and then put the insulation back down. That
cured that one.
A tightly sealed house can get quite humid in the Winter, what with
people breathing, taking showers, cooking with gas, doing laundry,
etc. Condensation on your windows is evidence of excessive moisture.
Condensation on your windows merely indicates you've got single
pane glass windows in a climate where double or even triple
panes should be used! (Or that the window isn't shut tightly
enough.)
I'm not uncomfortable, although some may be more sensitive...
Fix the problems though, not the symptoms.