Driveway Sinking Due to Water

Asphalt or Concrete

• If your driveway begins to sink, the material your driveway is made of helps to determine whether your driveway stays intact or if it begins to crack and break apart. Asphalt flexes some if the driveway sinks slightly, keeping the driveway intact. A concrete driveway does not flex the way asphalt does, meaning that unless the driveway sinks along the seams of the concrete slabs, the driveway’s surface will crack and sit at different levels.

Soil

• The soil underneath the driveway determines how durable the driveway itself is. The manufacturer of the driveway’s material should recommend the amount of gravel, sand and other materials you should install on the driveway area first. When you install the driveway, you must first compact the soil to minimize the soil’s settling as much as possible. Consulting with a soil engineer, as you do when building a house, gives you knowledge of the composition of the soil and how much it should be compacted to prevent future settling from the driveway and soil being exposed to normal levels of precipitation.

Drainage

• Improper drainage around your driveway promotes erosion of the soil, which eventually leads to the driveway sinking. If water gathers around the sides of the driveway, or on top of the driveway, you need to take steps to move the water away from the driveway and to lower ground, using ditches or culverts. When water gathers around a portion of the driveway that sits near the house, examine the positioning of all the house’s gutter downspouts. If the downspouts point toward the driveway, find a different direction to point them.

Other Materials

• Sometimes the soil under the driveway was compacted sufficiently before the driveway was installed, and sufficient water drainage is in place around the driveway, and yet it still sinks. If an organic object such as an old tree stump, grass clippings or other dead plant material is buried in the ground beneath the driveway, eventually the material decomposes and breaks down, creating air pockets in the ground. The dirt above the organic material then settles. The larger the mass of the organic material, the more severe the settling of the dirt.