Drought can damage foundation, cause structural damage to home

Q. Watching the news, I notice that some areas of the country are receiving unprecedented amounts of rain. But where I live there is an ongoing drought and it has been suggested that I water the foundation to prevent damage. Is this true and, if so, can you explain why?

A. Should you water your foundation? Yes, if water is available and the drought has not limited the municipal water supply. A drought dewaters the soil, allowing the soil to shrink to a point where severe settlement of the home can lead to serious structural damage.

Improper grading of the yard, installation of a sump pump or directing gutter drains away from the foundation of an older existing home also can dewater foundations.

Drastic changes to the amount of water in the soil will alter the soil’s characteristics.

In areas with heavy rains and flooding, the soil becomes unstable and unable to bear the weight of the structure. Sinkholes form under homes or foundations settle unevenly, causing structural damage.

In areas suffering from droughts, smectite clay soils, which are found in all the continental states, will shrink, leaving voids under the supporting foundation. The voids can lead to foundation settlement, which could then cause major structural damage to the foundation and structure.

According to the American Society of Civil Engineers, about half of the houses built in the United States each year are located on unstable soils and about half of these will suffer some soil-related damage.

There’s not much you can do during a drought where water use is restricted unless you can reduce personal use. However, if this is an annual occurrence, you might consider a well to maintain the soil with a foundation watering system.

If your home has been damaged by flooding or drought, a series of steel piers or helical piers can be installed to support the foundation independent of the soil. Both solutions are expensive, and you should contact a structural engineer before deciding on any type of foundation repairs.

Ÿ Dwight Barnett is a certified master inspector with the American Society of Home Inspectors. Write to him with home improvement questions at d.Barnett@insightbb.com.

Scripps Howard News Service