Poor drainage caused by a lack of soil grading, missing drains or improper gutters can cause serious lasting damage to a home. With this August being the wettest on record for Sherman, it is important for homeowners to take care to maintain proper drainage for their homes.
Jim McNeme, owner of GEO Dynamics and a foundation engineer, said North Texas experiences damage from drainage issues due, in part, to the type of soil found in the area.
“Typically when houses have poor drainage conditions around the foundation, primarily with slabs, in North Texas, it affects the clay soil,” McNeme said. “If the poor drainage causes a problem, it causes the house to go up because the moisture will increase the moisture content of the expansive clay. When it expands, it pushes the house up and that is called upheaval.”
A house that experiences upheaval may have damage to the foundation, plumbing, drywall and more. McNeme recommends taking care of roof water as a first step in remedying poor drainage.
“A boat load of water comes off a roof during the rain,” McNeme said “And it sits next to the house. Instead, rain gutters can take the water fifteen to twenty feet away from the house. The hardest part about putting the down spout in is digging the ditch. But the rest isn’t hard at all.”
Mark Brown, owner of Heritage Home Inspections, agreed saying that gutters and proper soil grading can make a big difference.
“The role that the gutters play is that they collect water from your roof and they take the water and place it in a more desirable location,” Brown said. “Without proper drainage and grading of the soil, water can gather under a house. All of that water and moisture leads to dry rot and mold.”
Soil grading in this context occurs when the ground for a home is engineered to have a specified slope in order to move water away from the home during heavy rainfall.
Brown explained that there are also two types of drains that can help improve drainage: french drain and surface drain.
“A french drain is designed for the purpose of collecting water that is subsurface — as the water seeps below the soil, it collects excess water into a gravel bed and is carried away to a more desirable location,” Brown said. “The most common drain needed is a surface drain. A surface drain helps deal with run-off water whereas moist soil can be dealt with using a french drain.”
McNeme said Sherman is an area that experiences difficulty with expansive soil.
“I’ve done inspections for several homes in Sherman,” McNeme said. “There was one house and there wasn’t any doubt that the foundation had heaved up because of the expansive clay. Another problem with upheaval of a slab foundation is that once they heave, they very seldom go back down. They may go down a little, but not back to original elevation.”
McNeme explained that although proper drainage may help minimize foundation movement, it may not be able to completely eliminate the problem due to soil composition.
“It is a generally accepted fact in North Texas that homeowners should attempt to keep the moisture content of the soil around their foundation at a constant rate year around,” McNeme said. “You do not want to allow the soil to get too wet or too dry. This usually means that it is important to have drainage conditions around a foundation that, during wet times, will allow the surface water to run rapidly away from the foundation and then in time of drought not allow the soil to become too dry by watering the soil.”