Sealcoating vs Crack Sealing: What's the Difference?

Sealcoating and crack sealing are two different services that protect different parts of the pavement. Sealcoating is a thin surface coating that blocks UV, water, and petroleum from damaging the asphalt surface. Crack sealing fills individual cracks with hot rubberized sealant to stop water from reaching the base. They are not interchangeable, and doing one without the other leaves your pavement vulnerable. Crack sealing should always be done before sealcoating.

What sealcoating does

Sealcoating applies a coal tar or asphalt emulsion sealer over the entire surface of the pavement. It creates a protective film that:

• Blocks UV rays that oxidize and brittle the asphalt binder
• Creates a waterproof barrier that slows surface water absorption
• Resists oil and gas spills that soften asphalt
• Fills micro-cracks and surface checking
• Restores a dark black appearance

Sealcoating protects the surface, but it does not fill structural cracks. Sealer applied over an open crack bridges it temporarily but does not seal it. Water passes through the sealer into the crack and reaches the base. See our sealcoating guide.

What crack sealing does

Crack sealing fills individual cracks with hot rubberized sealant that bonds to the crack walls and stays flexible through temperature changes. It creates a waterproof barrier inside the crack that stops water from reaching the base layer. It is the most cost-effective preventive maintenance you can do because it prevents the base damage that leads to potholes and pavement failure.

Crack sealing does not protect the surface from UV or petroleum. It only addresses the cracks. See our crack sealing guide.

Side-by-side comparison

Which comes first

The proper sequence for a full maintenance pass is:

• 1. Clean the surface. Blow or pressure wash the entire lot.
• 2. Treat oil spots. Apply primer to petroleum-stained areas.
• 3. Seal cracks. Clean, heat, and fill all cracks with hot rubberized sealant.
• 4. Allow sealant to cool. Wait for the crack sealant to set before applying sealcoat.
• 5. Apply sealcoat. Two coats of commercial-grade sealer over the entire surface.
• 6. Re-stripe. After the sealcoat cures, apply fresh striping. See our striping guide.

When you need each one

You need sealcoating when:

• The surface is turning gray from oxidation
• It has been 2 to 3 years since the last sealcoat
• The surface is absorbing water instead of shedding it
• You want to restore the black appearance and protect the surface

You need crack sealing when:

• There are visible cracks wider than a quarter inch
• It is time for sealcoating (crack sealing is always done first)
• New cracks have appeared since the last maintenance cycle
• Existing crack sealant is pulling away or failing

For crack sealing costs, see our cost guide. For the difference between crack filling and crack sealing, see our comparison guide.

Why you need both

Doing one without the other leaves your pavement vulnerable:

• Sealcoating without crack sealing: The surface looks protected, but water is still entering through open cracks and saturating the base. The base continues to degrade, and within a season the cracks will widen and the sealer over them will crack open.
• Crack sealing without sealcoating: The cracks are sealed, but the surface is exposed to UV oxidation and petroleum damage. The asphalt turns gray and brittle, new micro-cracks form, and the surface raveling accelerates.