How to Fix Cracks in an Asphalt Driveway: Seal, Patch or Replace
SealMaster's guidance: clean cracks of dirt and vegetation, blow them out, then fill them with a hot-pour or cold-applied crack filler. It adds that severely cracked areas may need to be removed and replaced with fresh hot-mix asphalt. The Colorado Asphalt Pavement Association likewise says weak spots, holes and large cracks should be cut out and patched.
Cleaning and filling a crack
SealMaster's crack-repair guide says proper cleaning means removing vegetation, dirt and debris so the filler can flow in and stick to the crack walls, then blowing the crack out with a leaf blower or compressed air. Both hot-applied and cold-applied fillers are used; SealMaster notes that cold-applied materials are common on home driveways, and that hot-pour materials go on in cooler weather, as low as 40°F.
Hot-pour rubberized sealant
According to SealMaster, hot rubberized crack sealant is a blend of asphalt and polymers heated to about 400°F in an oil-jacketed melter and poured into the crack, where it cools into a moisture-proof, flexible barrier. In areas with cold winters, SealMaster says it is ideally applied when the air is between 45°F and 65°F, because cracks open wider in cool weather. It recommends a thin band of sealant on each side of the crack and warns that thick ridges invite snowplow damage.
When to patch or replace instead
SealMaster says severely cracked areas may need to be removed and replaced with fresh hot-mix asphalt. The Colorado Asphalt Pavement Association gives the same advice before any overlay: weak spots, holes and large cracks should be cut out and patched with hot-mix asphalt first. For potholes, SealMaster says to fill them as soon as they begin to form, placing patch material about half an inch above the surface and compacting it level.
Why winter makes cracks worse
The U.S. Geological Survey notes that ice is about 9 percent less dense than liquid water, which means water takes up more room once it freezes. Water that sits in an open crack through a freeze has nowhere to go but outward. The National Asphalt Pavement Association calls standing water the leading cause of driveway failure.
What maintenance buys you
SealMaster's position is that a systematic program of periodic crack filling and sealcoating will more than double the life of asphalt pavement.
Keep reading
Sources
- SealMaster, How to repair cracks in asphalt pavement
- SealMaster, What is hot rubberized crack sealant?
- SealMaster, How to fix a pothole
- Colorado Asphalt Pavement Association (via the Asphalt Institute), “Best Practices” for the Use of Asphalt Driveways, Technical Brief
- U.S. Geological Survey, Water Science School, Water Density
- National Asphalt Pavement Association, Hiring an Asphalt Contractor for Driveways
Frequently Asked Questions
SealMaster says to clean the crack of vegetation, dirt and debris, blow it out, and fill it with a hot-pour or cold-applied crack filler. It notes cold-applied fillers are common on home driveways.
SealMaster says severely cracked areas may need to be removed and replaced with fresh hot-mix asphalt, and the Colorado Asphalt Pavement Association says weak spots, holes and large cracks should be cut out and patched.
SealMaster says cold-applied crack fillers need 24 hours to cure before traffic, while hot-pour materials need 15 to 20 minutes to cool.