Crawl Spaces are notorious for being damp and moldy as
well as a popular hideout for all kinds of insects and critters.
A damp crawlspace environment can be both unhealthy to the homeowner
as well
as destructive to the home. Dirt crawl spaces have the high humidity
levels necessary for mold growth. It is not uncommon to see 50% to
90% humidity levels in dirt crawl spaces that have never been flooded.
Mold
thrives and reproduces in these high humidity levels by producing
airborne spores by the millions. Mold can grow on any organic material
such as
wood, insulation, dirt and carpet.
We know that warm air rises. As heat rises, the natural
air movement in a home is upward. Air escapes out of the upper levels,
and is drawn upward from the lower levels. Mold spores, odors and
humidity coming from the crawlspace create an uncomfortable environment
for people.
The natural airflow sucks the moist air and everything in it up from
the crawl space and into the living areas of the home.
Health
and Allergies
Many people are allergic to these things and experience
a host of symptoms
while not realizing that their dirt crawl space may be affecting
their health.
Reducing the humidity level in you crawl space can also reduce
the spreading of mold spores under your house. Mold needs only
three things to thrive; an
organic material, the right temperature range and moisture.
Controlling the amount of moisture is the one thing
a homeowner can do to battle the potentially damaging affects of mold.
Depriving
mold of moisture will stop it from growing but will not actually
kill the mold. Existing mold will still remain. Reports have
shown
that mold will remain dormant as long as humidity levels are reduced
below 40%.
For many years the preferred method of dealing with
wet crawl spaces has been to install a sump pump and try to insure
there
was proper ventilation. For the past 10 years or so there has been
an ongoing debate on whether crawl space ventilation was a good thing
or
a bad thing.
According to many leading publications
and experts in the industry, crawl space ventilation can cause
an increase in moisture under
the house. “This is something that we in the Midwest want to
avoid,” Says
Ken Swain, General Manager of Americrawl. “If
you live in Nevada or Arizona where the humidity is low, this is not
some thing that keeps builders awake at night.” The question
of venting a crawl space seems to have two opposing advocates.
Here in
Indiana, about the only thing vents will do for a crawl space
is invite hot humid air when they are open. This moisture laden
air
entering
a cool crawl space will only add more problems.
Wrap
It Up
One
of the best ways to protect a crawl space is to encapsulate it. This
involves covering the crawl space ground and foundation walls
with a heavy plastic material; preferably a product like Clean Space.
This is
a 20 mil thick material that can be sealed at all the seams
and at the top of the foundation wall. Next you’ll want to seal
all the foundation vents. (I imagine John Hudson may have something
to
say about this!)
For best results, it is a good idea to also install a dehumidifier
or a heat register from one of the heat ducts in the crawl
space.
Crawl spaces are all too often forgotten about after
the home is finished and simply taken for granted. If we, as builders,
can head off potential problems in these orphaned spaces, everyone
benefits.
