When Should You Seal Asphalt Cracks?
Updated July 11, 2026
Seal asphalt cracks as soon as they're wide enough to let water in — generally cracks around a quarter inch or wider — and before they branch into alligator cracking or potholes. Spring and fall are common timing because moderate temperatures help the sealant perform, and it's smart to seal before winter so water can't get in and freeze. Sealing early is far cheaper than the repairs it prevents, so the best rule is to seal on a regular cycle rather than waiting for visible damage.
The trigger to seal a crack is water intrusion: once a crack is wide enough to let water into the pavement, sealing it early prevents the base damage that turns cracks into potholes.
This guide covers which cracks to seal, when in the year, and why acting early pays off. When it's time, find crack sealing contractors in your area.
Crack sealing is usually paired with a sealcoat cycle — see the parking lot maintenance cost guide for how it fits a plan.
Which cracks to seal
Not every mark in the asphalt needs sealing, and some are past it:
- Seal working cracks roughly a quarter inch or wider that can admit water
- Seal transverse and longitudinal cracks before they branch
- Monitor very fine hairline cracks — they may not need sealing yet
- Don't seal alligatored or crumbling areas — those need patching or repair
- Prioritize cracks in low spots where water collects
The best time of year
Crack sealing performs best in moderate temperatures, which is why spring and fall are common. In peak summer heat cracks are at their narrowest (closed), and in deep cold sealant is harder to apply well. Sealing in fall, before winter, is especially valuable: it keeps water out ahead of freeze-thaw cycles that do the most damage. Exact timing depends on your climate and the contractor's materials.
Why sealing early pays off
Water is what destroys asphalt. A crack lets water reach the base, where it erodes support and, when it freezes, expands and widens the crack — a cycle that turns a cheap crack into an expensive pothole or alligatored area. Sealing a crack for a dollar or two per foot defers repairs that cost many times more per square foot. That economics is why waiting until damage is obvious is the costliest approach.
Make it a recurring cycle
New cracks form every year, so crack sealing works best as a recurring item — commonly annual — rather than a one-time job. Pairing it with your sealcoat cycle (sealing first, then coating) covers most of a basic maintenance program. Inspect at least once a year and seal the new cracks before they widen.
Frequently asked questions
When should asphalt cracks be sealed?
As soon as they're wide enough to let water in — generally around a quarter inch or wider — and before they branch into alligator cracking. Sealing before winter is especially valuable.
What time of year is best for crack sealing?
Spring and fall are common because moderate temperatures help the sealant perform. Sealing in fall keeps water out ahead of winter freeze-thaw cycles.
Why not just wait until the cracks get worse?
Because water intrusion turns a cheap crack into an expensive pothole. Sealing early for a dollar or two per foot defers repairs that cost many times more per square foot.
How often should cracks be sealed?
Because new cracks form every year, sealing works best on a recurring cycle — commonly annual — as part of a maintenance program rather than a one-time job.
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