Hot Dry Summers and Foundation Watering
Expansive soils act like a sponge, absorbing water and swelling or losing water and contracting. Just like a sponge, one spot expands with a drop of water leaving the rest of the sponge dry. Clay soil works the same way, expanding with winter and spring moisture while contracting or shrinking during hot, dry summers. As moisture in the soil under the home shrinks and swells with the seasons, so does the house and foundation, moving move up and down.
Small amounts of foundation movement is not a problem. Damage to the house and foundation may appear and disappear when the foundation moves and then returns to its original position.
Looking to stop seasonal house and foundation damage? Start with a watering program with the goal of keeping the moisture content of soil under the foundation constant. This can help stop foundation movement.
Install a buried foundation watering system or soaker host system
- We’ve found many homeowners like to get a three-way spigot splitter so that they can run soaker hoses in both directions around the house, leaving an extra connection for garden hoses.
- Another option is a spigot timer so that you can set how long and often you would like to water the foundation.
- If you use the timer with a splitter, make sure to close any openings not connected to the soaker hoses so no excess water is flowing.
The best way to use a soaker hose is to bury a soaker hose three inches deep, 6 inches from the edge of your foundation. Placing the hose a short distance from the foundation allows the water to soak into the soil evenly.
The hose should not be placed against the foundation. When the soil has dried and cracked, water can travel along the cracks for several feet in all directions. If the soil around your foundation is dried and cracked, then water placed next to the foundation will run through the cracks and accumulate at the bottom of the grade beam (the thick portion of the foundation that is under the exterior walls). In some cases, an accumulation of water in the soil at the base of a foundation can cause the soil to lose some of its load-bearing capacity. If the soil loses enough load-bearing capacity, the house will sink into the ground. Obviously, it is necessary to water more during hot, dry weather and less during cold, damp weather.
How Much Water Does it Take?
The amount of water required to keep a foundation stable during the summer can be surprisingly large. A single large tree can remove as much as 150 gallons of water, or almost 20 cubic feet of water, from the soil each day. Shrubs and other plants can also remove large quantities of water. During persistent hot dry weather, it may be necessary to water a foundation daily.
Watering should supply enough water to keep the moisture content in the soil under the foundation constant.
If the amount of water applied is only enough to keep the surface damp, the watering program will not work. Obviously, the homeowner is the only one who can weight the benefits of controlling foundation movement versus the increased size of the water bill.