Crack Filling and Sealing in Cedar Rapids, IA

Crack filling puts a flexible sealant into pavement cracks so rain and snowmelt cannot reach the stone base, and in Cedar Rapids it is the job that most affects how a driveway comes through March, the month that averages close to 19 freeze-thaw days at the airport station. Water that reaches the base freezes, expands and leaves the soil soft when it thaws. Silty soils, including the loess on the area's paha ridges, are the kind that lose the most support in that thaw. Filled cracks keep the problem at the surface, where driveway sealcoating can finish the job; ignored ones become the potholes covered on the patching page.

Cracks are not all the same problem. Pavement Interactive describes block cracking, interconnected cracks that divide the surface into rough rectangles, as a result of binder aging and daily temperature cycling. Longitudinal and transverse cracks are single lines, often along a paving seam or straight across the drive. Alligator cracking, small interlocking pieces usually found in a wheel path, comes from repeated loads on weak support and is a base problem that filling will not fix. Good crack repair starts by sorting out which kind is present, because only the first three respond to filler.

Two families of material are used. SealMaster describes hot-pour sealant as heated blocks of rubberized asphalt that set in 10 minutes or less, generally used on roads and larger lots, and cold-pour filler as a clay-filled, polymer-modified asphalt emulsion that flows into cracks at air temperature and is common on driveways. Pavement Interactive notes that cracks should be routed and cleaned before sealant goes in, and it reports an average life of about 3 to 8 years for crack seals. Crack width, traffic and total footage decide which one fits.

Timing matters as much as material. Pavement Interactive recommends moderate temperatures, spring or fall, and filling soon after cracks develop, before water has worked into the base. At the airport station April averages about 8 freeze-thaw days and October about 7, which makes late April through May and September into early October the natural crack seasons locally. Filling ahead of a summer sealcoat also lets the filler set before it is coated.

Some cracks point to something else. A line that runs from the edge of the drive toward a ground-out stump, or a hump beside the spot where a tree's root plate lifted in 2020, signals a disturbed base. The city alone had more than 8,000 street-tree stumps to grind after the derecho. Filling those cracks is still worth doing, but if the pavement moves when stepped on, the fix is a patch. Per-foot prices and typical driveway totals are on the cost page.