Crack Filling and Sealing in Sioux Falls, SD

Crack filling puts hot rubberized sealant into every crack wider than a hairline, and in Sioux Falls it is the step that keeps snowmelt out of a frost-prone base, because each open crack is a funnel for it. Sealcoat is a thin film and cannot close a real crack. Water that gets through runs down to the silty soil under the asphalt, where the county's loess and the slow till beneath it hold water in place to freeze. The city's own pothole guidance describes the result: water seeps into cracks, freezes, and expands and weakens the ground underneath. SealMaster times the work for cool days because cracks open wider as pavement cools, so filler placed then fills the full gap.

Local cracks come from two directions. Cold shrinks asphalt: Foss Field averages 26 nights a year at or below zero and about 92 at or below 20 degrees, and the transverse cracks that result run across the drive, perpendicular to the direction it was paved. Water does the rest. The eastern two-thirds of Minnehaha County is loess over glacial till, and NRCS describes that profile as moderately permeable silt over slowly permeable till, so water that slips through a crack tends to linger in the base where ice lenses can grow. Unfilled cracks here widen, and their edges break down through the spring thaw.

Timing is different from sealing. SealMaster's advice for cold-winter climates is to apply hot rubberized sealant when the air is between 45 and 65 degrees, because cracks open wider as the pavement cools and filling them then leaves material across the full width. In Sioux Falls that describes April and May, when normal highs run from about 59 to 70 degrees, and late September into October, when they fall from 73 to 60. Summer heat closes cracks and makes them look smaller than they are. Hot-pour material can go down as low as 40 degrees, which leaves room to keep working into the fall before snow.

The work is mostly cleaning. Dirt, weeds and loose chips come out with a wire brush or a router, and the crack is blown dry with compressed air or a hot-air lance, since filler will not bond to damp or dirty walls. The heated sealant is poured in and finished with a thin band on each side of the crack. SealMaster warns against thick bands and ridges, which a plow blade or snowblower can catch and tear out, a real concern where Foss Field records an inch or more of snow on about 12 days a winter and lighter snow on many more.

Filling has limits. When cracks have joined into small plates, the pattern Pavement Interactive calls fatigue or alligator cracking, the asphalt has failed under repeated loads and SealMaster's advice is removal and replacement with hot mix, which is asphalt patching work. On sound pavement, crack repair and sealing work as a pair: fill in spring or fall, then seal the whole surface in summer. SealMaster's estimate is that a program of crack filling and sealcoating can more than double the life of asphalt pavement.