A Guide To Crawl Space
By Jerry Blackburn
Crawl space insulation keeps your house warmer in the winter
time. Insulating under the kitchen floor helps prevent cold feet in the morning.
An added benefit is a lower bill for heating your home. The method and materials
used depends on the construction of the space and if it is ventilated.
Installing insulation isn't difficult. In most cases, for a homeowner with a
little knowledge, this is a good DIY job. The typical space can be insulated
over a weekend.
Types of Crawl Space Insulation
Several materials can be used for insulating your crawl space
. Typical materials are fiberglass, wood fibers, foams and paper fibers.
Insulating materials come in blanket form, in rigid sheets or loose. The type
you choose will depend on whether you are insulating the exterior walls or under
the floor of your home.
Regardless of the material used, the basic concept is the same. The
insulating materials work like the blankets on your bed on a cold night. The
blankets trap air near the source of heat and prevent the warm air from
escaping. Heat normally radiates out and away from its source. Insulating
materials prevent this from happening.
Products are rated based on their efficiency. More effective insulating
materials will be more expensive. The rating is known as the R value, which
stands for flow resistance. The higher the rating, the more energy efficient the
product. You will generally find this information on the package. If it's not
there, ask the salesperson.
Where to Install Crawl Space Insulation
There are generally two choices for insulating a crawl space. You can either
insulate the exterior walls of the space or the ceiling of the crawl space under
the floor of your home. A main consideration in deciding is whether or not the
space is ventilated. You should only insulate the walls of an unventilated crawl
In most cases, it's better to insulate the exterior walls. The typical
material used is fiberglass bat. This will need to be cut to fit the wall from
the top, all the way down and extending onto the ground a few feet. You may need
to attach wood strips to the wall and staple the insulation to the wood. Another
option is to nail into the wood at the top of the wall and drape the insulation.
When you insulate the exterior walls, you need to put a vapor barrier on the
ground. This will prevent moisture from seeping from the ground into your crawl
space. This moisture can cause mildew to grow in the space. The exterior walls
should only be insulated if the space remains dry all year. There should be no
ventilation to the outside and any ventilation should be blocked.
If your crawl space is vented, you will need to insulate under the floor.
When you do this, be sure to insulate any water pipes and ducts in the space. If
you don't do this, your pipes may freeze and burst in the winter. Several
materials can be used for this job. You can use unfaced bats or fiberglass with
a foil vapor barrier if moisture is an issue. Reflective materials are available
and are excellent for keeping the floor warm in the winter.
Insulating the floor can also reduce the noise level in your home. It acts
as a soundproofing material. This results in less noise when the kids run across
the carpet or the tile floor.
When working with any type of materials, safety is important. Always wear
long sleeves and pants, as fiberglass and other materials are irritating to the
skin. Wear gloves on your hands. A dust mask and eye protection are also needed.