Ever build or remodel houses with
crawlspaces? Or put an addition on a
crawlspace? Ever wonder about how to
insulate them? Or how to keep them
dry enough so the wood doesn't rot? I
have. Here are my most recent
thoughts.
The Old Way
Traditionally, moisture control in
crawlspaces has consisted of screened
vents to the outside—sometimes with
an added ground cover of plastic film.
The idea is to get outside air to carry
away the moisture. The ground cover
is there to slow the rate at which moisture
enters the crawlspace air from the
earth.
The CABO and BOCA codes both
require crawlspaces to have 1 square
foot of free vent area for every 150
square feet of floor