Angie's LIST Guide to
Crawl spaces

Homes that do not have basements or cement slab foundations usually have a crawl space to provide an access point for electrical, plumbing, ventilation and gas hook-ups within the home.  A crawl space makes it possible to reach these areas when repairs, installation or other services are necessary.  

Residential housing that is located in prominent flooding zones often use the crawl space as a means of providing the home with extra space should these events occur.  The water will fill into the crawl space before invading the home.  Special regulations and codes are required by federal organizations for building crawl spaces in these locations of the United States.

While it is not possible to include a crawl space within the living space figured for the home as you could with a basement, it is still possible to utilize a crawl space for storage of smaller items. 

While you can’t convert a crawl space into a useful living area like you can with a basement, the area can still be used to store smaller outdoor items. However, it’s recommended not to use your home’s crawl space as a storage area if you have mold, moisture or pest problems in the area. It’ s also a good idea to avoid storing any chemicals or other potentially harmful items in a crawl space.

Mold, mildew and fungus

If a moisture problem within a crawl space isn’t addressed properly, over time, the moisture can produce conditions that are a prime breeding ground for mold, mildew and other microorganisms.  If the air in the crawl space infiltrates the home, mold spores, mildew and other potentially harmful microorganisms such harmful bacteria can do so as well. 

Exposure to mold or fungal spores can irritate home occupants who suffer from asthma, respiratory ailments or allergies, and also cause infections, skin rashes and other medical conditions. 

Pests

If not properly sealed against intrusion, rodents, insects and other pests can enter the crawl space. In fact, the warmth and moisture associated with a ventilated, unimproved crawl space can make them particularly attractive to these types of animal invader.

Animal pest in particular can cause air quality problems and health hazards from their droppings. Both animals such as raccoons and insects such as termites may also actively cause damage to structural elements and systems such as HVAC ducts or electrical wiring.

Poor insulation

The energy efficiency of home’s heating and cooling equipment is also cause for concern in older homes with poorly constructed or unimproved crawl spaces.   If a vented crawl hasn’t been sealed or insulated, outside air that’s hotter or cooler than the home’s indoor air may come in contact with the underside of floorboards within the area.

Via heat transference through the floorboards, the outside air may increase the indoor air temperature during spring and summer months, reducing the cooling capacity of an air conditioning system, or decrease the indoor air temperature during cooler months, reducing the heating capability of a furnace or other heating system.

Installing insulation along with a vapor barrier, as well as sealing ventilation that allows outside air to enter a crawl space can reduce these energy inefficiencies.