Installing driveway culverts may help to prevent erosion and flooding, but several tips should be followed to ensure proper functionality. The correct diameter and length of culvert pipe must be installed to efficiently handle the flow of water. Large, heavy driveway culverts may require the use of a backhoe for trenching and lifting. Asphalt and concrete driveways should be cut with a masonry saw for smoother resurfacing. Driveway culverts must be installed in a compacted gravel base to prevent future settling.
Driveway culverts must be the correct diameter to permit the maximum flow of water during heavy rains. Choosing a pipe with a larger diameter may also prevent debris from accumulating at the entrance. Driveway culverts must be the correct length as well. As a general rule, culvert pipes should extend 1 foot (30.5 cm) beyond the edge of the driveway on either side. This additional length usually prevents soil erosion around the pipe ends.
When dealing with large diameter pipes, it is best to use a backhoe for trenching and lifting tasks. Steel and concrete driveway culverts can be quite cumbersome and must be handled carefully. These pipes must sometimes be buried deep below the driveway surface to properly align with the ditch bottom. A backhoe can quickly dig a straight, deep trench and lift heavy pipes with ease. The backhoe can also widen and slope the sides of the surrounding ditches for better water flow.
Existing asphalt and concrete driveways will need to be resurfaced after culvert installation. Asphalt and concrete surfaces should be cut along the trench path with a masonry saw for smoother resurfacing. Keep the trench aligned with the center of the ditches and place a chalk line on the surface as a cutting guide. Remember to cut the trench a little wider than the culvert pipe’s outside circumference to allow maneuvering room. The trench bottom must follow the natural slope of the ditch for proper drainage.
Driveway culverts have a tendency to settle over time which may cause a depression to form at the surface. Placing a layer of compacted gravel beneath the culvert usually prevents settling. The trench bottom should be at least 4 inches (10.1 cm) lower than the ditch to allow for placement of the gravel base. After installing the pipe, refill the trench with compacted soil. The surface material should be smooth, level, and well compacted to prevent future settling or erosion.
