Asphalt Crack Sealing in Pittsburgh, PA

Asphalt crack sealing is the least expensive maintenance a Pittsburgh driveway or lot can get, and in a freeze-thaw climate it does the most good per dollar. Every open crack is a path for rain and snowmelt into the stone base. Once water is in the base, each freeze expands it and each thaw leaves the base softer, and the crack widens, branches and eventually turns into a pothole. Sealing the crack closes that path before the damage spreads.

Which cracks get sealed

• Linear cracks running along or across the driveway, usually from shrinkage, age or joints between paving passes
• Edge cracks near the street apron or along the sides where the pavement has less support
• Reflective cracks in an overlay, showing joints or cracks in the pavement underneath
• Joint cracks where the asphalt meets a concrete slab, walk or curb

Hairline surface cracking is usually handled with sealcoat. A web of connected alligator cracks means the base has already failed, and sealing it will not hold; that area needs a patch. We separate the two at the estimate so you are not paying to seal cracks that need repair.

How we seal

Cracks are cleaned out with compressed air or a hot-air lance to remove dirt, vegetation and loose material, because sealant will not bond to a dirty or damp crack. Wider cracks may be routed to a clean reservoir. We then fill them with hot-applied rubberized crack sealant, which stays flexible in cold weather so it can move as the pavement expands and contracts. Very wide cracks may need a filler first. The sealed driveway can usually be driven on after a short cure.

Timing around Pittsburgh's winters

The best window is late summer through fall, when cracks have opened up slightly as the weather cools and the pavement is dry. Sealing before the first hard freeze keeps that winter's water out. Spring sealing also works, once the pavement is dry, to close the cracks the winter opened. Sealant needs a dry crack, so we do not seal in rain or on frozen pavement.

Crack sealing and sealcoating

The two are separate jobs that work best together. Crack sealing fills the openings; sealcoating covers the whole surface with a protective layer against water, salt and sun. When a driveway gets both, cracks are sealed first and the sealcoat goes over them. On parking lots, a crack-seal round every year or two between sealcoats keeps small cracks from growing.

What it will not fix

Crack sealing does not fix sunken areas, heaved sections, potholes or alligator-cracked patches. Those are base problems, and they need cut-out repair. It also will not make an old, brittle driveway new. If cracks cover the whole surface, we will tell you whether resurfacing or replacement is the better use of your money.