Construction workers have always favored crawl spaces because they’re faster and less expensive to build than a full-blown basement foundation. This type of traditional crawl space utilizes openings or air vents in the crawl space walls so that the air outside can circulate underneath your living space.

If there is any insulation installed, you may find it in the form of fiberglass batts, placed between crawl space joists, while the crawl space’s floor will be made of soil, or concrete. The fiberglass insulation easily absorbs moisture, and may sag or fall out of place, settling onto the crawl space floor. In winter, there’s a new set of problems: the floors become too cold because of the wet and missing insulation, meaning higher heating bills.

During the summer, warm and moist air can enter the crawl space, condensing on the cooler crawl space surface. When the crawl space continuously receives this warm air, it can cause moisture to form, which invites mold to grow and causes wood to rot. The presence of wet wood can also attract insects such as termites and carpenter ants, who want nothing more than to chew up the wood and terrorize your home.

One factor that isn’t determined by season is the indoor air pollution that can cause respiratory problems, because of the mold spores that enter the living space through the cracks and gaps in the walls and floors of the crawl space.