How to Repair an Asphalt Walkway

Over time, tree roots, weather, and general wear can damage your asphalt walkway, creating unsightly bumps or cracks in the path. Fortunately, repairing an asphalt walkway is a manageable DIY project for many homeowners.

In this video and guide, This Old House landscape contractor Roger Cook demonstrates how to efficiently repair a ruptured asphalt walkway caused by a tree root.

Understanding the Problem

Before beginning any repair work, it’s identify the cause of the damage. In many cases, tree roots are the culprits behind asphalt walkway issues. To determine the extent of the damage:

1. Use a 4-foot level to measure how much the walkway has been lifted
2. Inspect the surrounding area for visible tree roots
3. Check for cracks or other signs of stress in the asphalt

In the video, Cook identifies a 3-inch-diameter root as the source of the problem. He explains that for a tree of that size, removing this root won’t significantly impact its health. This assessment needs to happen before proceeding with any repair work. Other causes of damage may include weathered asphalt, which causes deterioration, or asphalt chipped by a heavy object falling on it.

Preparing for Repair

Once you’ve identified the problem, it’s time to gather the right tools and materials for the job.

To repair an asphalt walkway, you’ll need:

Gather these materials before starting, as well:

• Asphalt cold patch
• Asphalt sealer
• Pack (a mixture of stone and stone dust)
• Two 2×6 lumber planks, for forms
• ½-inch-diameter x 24-inch-long rebars

Removing the Damaged Section

The first step in repairing your asphalt walkway is to remove the damaged section and the underlying cause of the problem.

1. Use a pointed shovel to dig down on either side of the walkway, exposing the tree root.
2. Cut through the root on each side of the walkway using a pruning saw.
3. Use an electric chipping hammer with a wide chisel blade to cut through the asphalt on either side of the severed root.
4. Pry out the asphalt between the two cuts.
5. Dig up the severed tree root and remove it from the area.

Preparing the Base

A solid base is key to a long-lasting asphalt repair. Take your time with this step to create a stable foundation.

1. Tamp down the bottom of the trench with a 10-pound sledgehammer
2. Spread about 2 inches of pack into the trench
3. Compact the pack with a hand tamper
4. Repeat the process, adding 2-inch layers of pack and compacting until the compacted pack is about 2 inches below the asphalt surface

Creating Clean Edges

For a professional-looking repair, it’s important to create clean, straight edges where the new asphalt will meet the existing walkway. To do so, you’ll have to cut the asphalt again, this time with even more precision.

Cut Straight Edges

1. Use a level as a straightedge to draw perfectly straight lines across the walkway on either side of the repair area.
2. Cut along these lines using a wet circular saw fitted with a diamond-impregnated blade. Be extremely diligent and pay close attention to this step to get a clean line.
3. Remove the trimmed pieces of asphalt.

Install Forms

1. Put a 2×6 form along each edge of the walkway.
2. Secure each form on the edge with two ½-inch-diameter x 24-inch-long rebars.
3. Use a 3-pound sledgehammer to pound the rebars into the soil directly behind each form.
4. Backfill with soil against both forms to provide support during the patching process.
5. Use the hand tamper to thoroughly compact the area between the forms.

Applying the Asphalt Patch

With the preparation complete, it’s time to apply the asphalt patch. This step requires careful attention to detail to get a smooth, level surface.

1. Begin by dumping 1 inch of asphalt cold patch over the area and spreading it evenly with a rake.
2. Compact the asphalt with a hand tamper.
3. Add another inch of cold patch and compact again.
4. Continue this process until the area is filled with the asphalt cold patch.
5. Add a final layer of asphalt cold patch, spreading it about ½ inch higher than the adjacent walkway surfaces.
6. Compact the cold patch until it’s perfectly flush and even with the walkway on either side of the repair.

Finishing Touches

To make sure your repair blends seamlessly with the existing walkway and lasts a long time, there are a few final steps to complete.

1. Wait two weeks for the patch to fully settle.
2. Remove the forms and backfill with soil.
3. Apply an asphalt sealer to the entire walkway, including the patched area.

Maintenance Tips

To keep your repaired asphalt walkway in top condition, clean the surface periodically to prevent staining. Reapply sealer every few years to protect against weather damage, and regularly inspect the asphalt for new cracks or damage.