How Foundation Irrigation Can Help
Foundation irrigation systems can help foundations. But standard irrigation systems typically do not do a great deal to help foundations. This may seem odd, but it is true. Irrigation systems are designed to keep the top 6 to 10 inches of soil wet enough to support grass, annuals, and small shrubs. They are not designed to get water deep enough to help a foundation nor are they designed to concentrate water along the edges of a foundation, where it is needed most.
For most homes, the edge of the foundation, often called the grade beam, is 24 to 48 inches thick. Most of that is buried in the ground. So if your irrigation system keeps the top 6, or even 12 inches, of soil wet, it will still not help your foundation.
To protect your foundation from settlement caused by the supporting soils drying and shrinking, you must concentrate water along the edge of your foundation, and apply enough to keep the soils damp down 4 to 5 feet. The best way to do so is by using soaker hoses, which can be linked to an irrigation system.
Soaker hoses should be placed around your foundation. It helps to bury them a few inches deep. By burying the soaker hoses, you help to direct the water down and you also help keep the sun from breaking your hoses down. Soaker hoses must be used more frequently when it is dry and less often when it is wet. It is a good idea to reset the timers on your soaker hoses monthly to reflect the weather.