How to Put in Drainage for an Asphalt Driveway
If an asphalt driveway has poor drainage, standing water will cause cracks, pits and other damages that affect the function and appearance of the driveway. Putting drainage in a driveway is a labor-intensive project that involves cutting a path through the surface to install underground drainpipes. The project takes about a weekend to complete but permanently solves drainage issues and reduces maintenance.
Mark where the largest puddles form on the asphalt driveway, using chalk. This spot indicates the lowest lying area of the driveway. Snap a chalk line from this marking to the side of the driveway.
Insert garden stakes every 3 feet along one side of the driveway. The first stake should be even with the chalk marking, and the following stakes should run in a straight path parallel to the driveway, ending at the street.
Place the tip of a cold chisel in the center of the chalk mark and tap it with a hammer. Move the chisel down the chalk line, hitting the end of the chisel to score a cut line in the asphalt.
- Mark where the largest puddles form on the asphalt driveway, using chalk.
- Snap a chalk line from this marking to the side of the driveway.
Make a cut through the asphalt following the score line, using a handheld cutoff saw with a diamond-tipped blade. Make a parallel cut 8 inches apart. Use a pry bar to remove the asphalt within the cut strip.
Dig out a canal 24 inches deep along the 8-inch-wide cut line, using a shovel. Continue this canal along the side of the driveway. Once complete, it will have an L shape. From the beginning point in the asphalt, dig a 1/8-inch decline every foot to slope the bottom so water flows toward the street.
- Make a cut through the asphalt following the score line, using a handheld cutoff saw with a diamond-tipped blade.
Fill the entire canal with 10 inches of gravel and shape the gravel into a dip using the tip of the shovel.
Lay 4-inch perforated PVC drain pipe in the canal with the holes down. Stretch drain pipe fabric over the pipes as you lay them in place. Connect the lengths with an elbow connector at the corner.
Fit a drainage grid over both ends of the drain pipe to block debris from entering.
Fill the remaining expanse in the asphalt side of the canal with gravel. Tamp the gravel down at the top so it is even with the asphalt surface.
- Fill the entire canal with 10 inches of gravel and shape the gravel into a dip using the tip of the shovel.
Add a 6-inch layer of gravel in the portion of the canal along the side of the driveway. Fill the remaining part with an even mix of sand and dirt and cover the top with flood-tolerant grass seed, such as Bermuda grass.
- Chalk snap line
- Garden stakes
- Cold chisel
- Handheld cutoff saw
- Diamond-tipped blade
- Pry bar
- 4-inch PVC drainpipe
- Drainpipe fabric
- Elbow connector
- Drainage grid
- Flood-tolerant grass seed