Crawl Space Moisture Problems in Montgomery, AL

combination of humid summer air, frequent rain, and clay soil that holds water creates a perfect

environment for mold, rot, and pest infestations. Left unchecked, moisture destroys floor joists,

subfloors, and insulation.

Sources of Crawl Space Moisture

Moisture enters crawl spaces through several paths. Ground moisture evaporates from bare

soil, raising humidity to near 100 percent. Water from rain or irrigation flows into crawl space

vents or access doors. Plumbing leaks, especially from older homes, add water. Even

condensation occurs when humid outdoor air enters a cooler crawl space, forming water

droplets on pipes and joists. Montgomery Foundation Repair Co identifies the specific sources

in your crawl space before designing a solution.

Measuring Relative Humidity

A dry crawl space should have relative humidity below 65 percent, and ideally below 55

percent. You can measure humidity with a low‑cost hygrometer available at hardware stores. If

your crawl space consistently reads above 65 percent, you are at risk for mold and rot. Above

75 percent, active mold growth is almost certain. Montgomery Foundation Repair Co uses

professional‑grade data loggers to track humidity over days and weeks, giving a complete

picture of your crawl space environment.

Consequences of Excess Moisture

Prolonged high humidity leads to wood rot, which destroys floor joists and subfloors. Rotting

wood loses up to 90 percent of its strength, causing floors to sag and bounce. Mold spores

circulate into your living space, triggering allergies and asthma. Musty odors are unpleasant

and can lower your home’s resale value. Termites and carpenter ants thrive in damp crawl

spaces, causing additional structural damage. Insulation sags, falls down, or becomes

waterlogged, losing its R‑value. Montgomery Foundation Repair Co has seen crawl spaces

where floor joists had turned to powder from decades of moisture exposure.

Solutions for Crawl Space Moisture

The most effective solution is crawl space encapsulation. We remove debris, install a heavy

vapor barrier over the entire floor and up the walls, seal all vents, and add a dehumidifier. For

less severe moisture problems, a simple vapor barrier on the floor (without wall coverage or

dehumidifier) may suffice. However, in Montgomery’s climate, a sealed encapsulation with

active dehumidification is usually needed to maintain humidity below 55 percent year‑round.

Montgomery Foundation Repair Co offers both basic and full encapsulation, tailored to your

home’s specific conditions.

Frequently Asked Questions