Did you know that proper grading and drainage are crucial to the well-being of your home? The soil in the Houston area is often referred to as “gumbo clay” meaning that it is expansive clay. Each molecule of this clay can expand up to 300 times its size and exert enormous pressure on foundations. Foundations are designed to accommodate a lot of pressure and some movement. But when the pressure is unevenly applied over years, it can cause long term issues. The best approach is preventative maintenance. There are two common mistakes that can be corrected and improve your home’s life.
Grading Too High
Every year people buy mulch and throw it in the gardens next to the house. It creates a welcoming and pretty view. Unfortunately, having the soil up high against the house also creates a welcoming environment for ants and termites. To protect your home, it is recommended that the soil is kept 4 inches below for masonry and 6 for any other siding. If the soil line is kept at the same level around the house, it won’t keep water and moisture against the foundation unevenly. Keeping the grading below the siding exposes the top of the foundation so it can be seen and monitored for cracks while preventing them in the first place!
The opposite problem is negative grading which means the soil or grass angles toward the house instead of away from it. The water will flow the way the soil is sloped. Depressions in the soil where water sits for days in some places and not others is called ponding. The typical reasons for these holes are dogs digging to keep cool, sprinkler systems spraying too close and hard against the house, and not having gutters. When the house doesn’t have gutters or the gutters are full of debris, the rain pours off of the house and creates a small trench or drip line. Over time that line grows and will hold the water against the foundation. Because Houston has so much rain, draining all that water is important. Homes need to be re-graded from time to time. The appropriate slope for the ground is a 6 inch drop away from the house for 10 feet. Where there isn’t 10 feet between houses, at least a 3 inch drop is needed to direct water away from the home.
Some people intend well when they put rocks next to the house, but if the yard wasn’t properly graded away from the foundation before the rocks were added, it can cause the water to be diverted underneath the foundation. This can cause a serious condition where the perimeter dries out first and the soil underneath stays wet for a long time. This can cause the foundation to heave (push up in the middle) and crack. To prevent a disaster, a professional landscaping contractor can design a solution for diverting the water away from your house.
Many Houston area homes have swales, subsurface drains, or French drains. These are all good options to make sure your yard drains water properly and your house lasts a lifetime!