Crack filling is the cheapest hour of pavement maintenance you'll ever buy
Asphalt fails from water. Water gets in through cracks. In Idaho, that water freezes — and freezing water expands. Each freeze cycle widens the crack a little more, until eventually the surrounding asphalt fails and you have a pothole.
The fix is dirt cheap if you do it early. A few hundred bucks of crack-fill work today saves you a $3,000 patch-and-sealcoat job in three years and a $7,000 mill-and-overlay in seven.
What we use — hot-pour rubberized sealant
The bag of cold crack filler at the hardware store is fine for a one-time DIY fix. For lasting results, we use hot-pour rubberized crack sealant, the same material road crews use on highways.
It's heated to ~380°F in a melter, poured into the crack, and squeegeed flush. As it cools, it forms a flexible rubberized seal that moves with the asphalt through freeze-thaw cycles instead of cracking off. Done right, it lasts 5–8 years.
Our crack-filling process
1. Crack identification & cleaning
We walk the surface and identify every crack wider than ⅛" and narrower than ¾". (Anything wider than ¾" needs a saw-cut patch — see asphalt repair.) Cracks are blown out with high-pressure air to remove dirt, vegetation, and old debris.
2. Routing (when needed)
For larger commercial jobs, we sometimes rout the crack with a router blade — cuts a clean reservoir for the sealant and gives it a much longer service life. On smaller residential jobs, we typically skip routing because the cost-benefit doesn't favor it.
3. Sealant application
Hot-pour sealant is applied directly into the crack, slightly overfilling. As it cools, it self-levels and adheres to both crack walls. Cracks that are too wide for hot-pour get a hybrid treatment — backer rod plus sealant.
4. Cure and back to traffic
Hot-pour sealant cures in 30–60 minutes. The lot or driveway is drivable as soon as we're done.
If you have alligator cracking (interconnected cracks in a small area), crack filling won't help — that's base failure and needs patching or replacement. If 50%+ of the surface is cracked, sealcoating won't save you either; you need new asphalt.
When to schedule crack filling
Spring and fall are ideal — we want pavement temperature between 40°F and 80°F so the sealant adheres properly. Cracks should be dry; we don't crack-fill within 24 hours of rain.
Crack filling pairs perfectly with sealcoating: fill cracks, let sealant cure, then sealcoat the entire surface. The sealcoat hides the crack-fill lines and gives you a uniform black surface. Most of our customers do both at the same time — same mobilization, dramatically extended pavement life.
FAQ
How much does crack filling cost?
It's priced by linear foot of crack, typically $1–$3/ft for residential and $0.50–$1.50/ft for larger commercial work (more linear feet = better unit pricing). Most residential driveways come in under $500.
Will the crack-fill be visible?
Yes — fresh hot-pour sealant is black and slightly raised. It's most visible on faded gray asphalt. If aesthetics matter, follow up with sealcoating to hide the lines.
How often should I crack-fill?
Walk your driveway or lot once a year. Anything new gets filled. A well-maintained surface might only need crack-fill every 2–3 years; a lot in active decline could need it annually.