Crack sealing and sealcoating sound similar. They treat different parts of the pavement.
Crack sealing places a flexible material in or over selected cracks to limit water and debris entry while accommodating movement. Sealcoating applies a thin treatment across the asphalt surface. A contractor may recommend both, but one should not be described as a substitute for the other.
Start with the cracks
Cracks vary by width, movement, pattern, and cause. A single transverse crack is not the same as a web of alligator cracking. The first may be a candidate for crack treatment. The second can indicate fatigue or support failure that needs a different repair.
FHWA guidance notes that crack-treatment performance depends on the sealant, installation, temperature extremes, pavement condition, traffic, and crack movement. That is why a square-foot sealcoat quote cannot answer the crack question by itself.
What crack sealing requires
A crack-sealing scope should explain:
- which cracks will be treated;
- minimum and maximum crack sizes;
- cleaning and drying;
- routing, if specified;
- material type;
- application profile; and
- treatment of failed or alligator-cracked areas.
Loose dirt and vegetation do not belong under sealant. Excess material on the pavement surface can also create problems. Ask for the contractor’s installation standard, not just a total number of linear feet.
What sealcoating requires
Sealcoating is considered after repairs and crack work on pavement that remains basically sound. It treats surface aging and appearance across an area. The proposal should identify preparation, material, coats, application, weather requirements, and cure time.
Applying a surface coat over open cracks does not turn it into a crack repair. The cracks can return quickly because the coating was never designed to handle that movement.
Sequence the work
A common order is:
- inspect and diagnose failures;
- correct drainage or base issues;
- complete full-depth or surface repairs;
- treat appropriate cracks;
- allow required cure time;
- apply the surface treatment; and
- restripe after cure, if needed.
The exact sequence and cure windows depend on the materials. Get them in writing.
Ask for a marked map
On a larger lot, request a plan showing repair areas, crack treatment, sealcoat limits, and striping. It makes quantities easier to compare and the completed job easier to inspect.
The short version: crack sealing manages selected cracks. Sealcoating manages the surface. If the pavement is failing below both, fix that first.