Should I Insulate Floor Over Crawl Space

Fiberglass insulation batts or rolls are the most economical and easiest diy choice for insulating between the floor joist in a crawl space.

Should i insulate floor over crawl space. Without insulation heat and cool air are easily lost through the floor. People ask me all the time if insulation is necessary in the crawl space. Fiberglass insulation on the floor joists in a crawl space will help keep the floor above warm. If you are thinking of insulating the floor over a dirt crawl space we recommend you think about the long term of what you will be doing with the crawl space if you plan to encapsulate the crawl space your insulation procedure may be different than if you are.

Holes for electrical wiring and plumbing should be sealed with spray foam insulation. In those days common building practice was to insulate the floor above the crawl space and to leave the crawl space s wall vents open so any moisture buildup would vent to the outside a. When insulation is installed it is most commonly found between the floor joists to prevent the crawl space air from entering through the floors above. An insulation contractor can calculate the ventilation your crawl space needs and will cut in new vents as required.

To enclose the space in a thermal envelope. However in a moist ventilated crawl space this insulation will eventually rot and become soaked with moisture this will cause it to fall off the ceiling and on to the floor. This type of crawl space also allows insulation with an r value of 19 installed in the floor joist if the crawl space and has a permanently installed dehumidifier. Should i insulate the floor over my dirt crawl space.

The goal however is the same. This type of insulation allows for conditioned air to be introduced into the crawl space. Rather than trying to cut off the crawl space from the conditioned upper floors you should bring the crawl space nearer to upper floors temperatures by leaving off the underfloor insulation and by sealing the crawl space against outside moisture and temperatures. Insulation of foundation wall and floors above many crawl spaces are built without any insulation in them.

The idea is to condition the crawl space much in the same way that you might condition other parts of your home. Department of energy recommends r 11 3 insulation under floors in warm climates and an r 25 6 to 8 in cold climates. A crawl space under a house helps protect against certain pests but a crawl space with abundant moisture can invite problems including mold wood rot and vermin. There are two types of crawl spaces ventilated and unventilated and each requires its own form of insulation.

However the insulation needs to be treated with a fire retardant.