Mechanical Alteration

Avoid moisture accumulation near the foundation. Divert water away with properly functioning downspouts, gutters and splash blocks. Ground near the foundation needs to be sloped or graded in order for surface water to drain away from the building. Termites and ants are attracted to moisture.

Reduce humidity in crawl spaces with proper ventilation. Crawl spaces should have ventilation openings in the foundation at the rate of two square feet per 25 linear feet of foundation wall. One vent needs to be within five feet of each exterior corner of the building.This helps keep the ground dry and unfavorable for termites.

Prevent shrubs, vines and other vegetation from growing over and covering the vents. It is important to have maximum cross-ventilation. Install polyethylene sheeting over 75 to 85 percent of the soil surface in crawl spaces to reduce excess moisture.

There should be no contact between the building woodwork and the soil or fill. Exterior woodwork should be located a minimum of 6 inches above ground and beams in crawl spaces at least 18 inches above ground to provide ample space to make future inspections.