Asphalt Crack Filling in Charlotte, NC

Which cracks get filled, and which do not

Straight cracks running across or along the lot, cracks at the joint between two paving runs, cracks along the edge of the asphalt. Those are all straightforward candidates. They reward sealing because they are a route for water rather than a symptom of a base that has already gone.

Very fine hairline cracking will not take material at all. There is nowhere for sealant to go and forcing it just leaves a smear across the surface. Those areas are better handled by sealcoating, which is what a surface coating is for.

At the other end, an area broken into interconnected pieces that look like reptile skin is telling you the base underneath has already softened. Filling that is wasted work. It wants cutting out and patching, or replacing in a bad case, and a contractor who offers to fill it instead is taking the easy job and leaving you the real one. Cracks opened up beyond the working width of hot-pour material generally want patching too, or a two-stage treatment with backer rod.

Preparation, which is most of the job

A crack is full of dirt, sand, old sealant and usually something growing in it. Sealant poured onto that bonds to the debris instead of the asphalt, and the whole bead pulls out later in one piece.

Routing cuts a clean reservoir along the crack with a carbide wheel, giving the sealant a defined shape and two fresh vertical faces to grip. That is what a router is for. Not widening the crack for its own sake, but creating a joint the sealant can key into, at a depth-to-width ratio that lets the bead stretch as the crack moves.

Then it gets cleaned out. Compressed air moves the cuttings. Where there is moisture or stubborn material a heat lance dries the crack and warms the faces so hot sealant does not chill on contact. A damp crack is a hard stop, trapped moisture flashes to steam under hot material and blows the bead out from underneath, sometimes days later.

Materials and application

Hot-applied rubberized sealant is the standard for commercial work. Heated in an oil-jacketed melter to the range on the manufacturer label, held there with continuous agitation, applied through a wand into the prepared crack. Rubber in the formulation is what lets the finished bead stretch and recover as the crack opens in winter and closes in summer. A rigid filler cannot do that, it splits away from one face.

Cold-pour materials exist and have their place on small areas and light-duty surfaces, but they cure by losing solvent or water, so they shrink. A cold-pour bead often ends up a sunken channel that still lets water in.

Finish is either flush with the surface or banded slightly over the top. An overband gives more contact area at the crack edges, though on a hot lot with turning traffic a heavy overband can soften and track. Where it gets used the band stays thin and gets dusted with a detack material so the lot can reopen quickly.

Timing, weather and the working season

Cracks are widest when the pavement is cold and narrowest in the heat of summer. Seal during a hot spell and you are filling a joint that is currently closed, so when it opens back up in January the bead is stretched thin across a gap it was never sized for. Spring and fall generally give the best compromise here, surface dry but the cracks reasonably open.

Dry is not negotiable. Surface and crack both. After heavy rain that can mean waiting a day even when the lot looks dry to the eye, and Charlotte humidity draws that out compared with a drier climate. Same reason a storm that arrives mid-afternoon can end a crack day as fast as it ends a striping day.

Order of work, and how it fits a site

Crack filling comes first in any sequence. Fill, then seal, then stripe. Sealing over a working crack hides it for one season and telegraphs it back through, and striping over it means repainting sooner than you should have to. If a lot is getting all three, the striping is the last thing to happen, and that is also the moment to correct accessible spaces that have drifted. A car space wants 96 inches of width with a 60 inch access aisle beside it, a van space 132 inches, and those are cheapest to put right while the layout is already coming off.

Crack work suits a live site because it moves in a line rather than covering an area. A crew takes one run at a time with cones and keeps nearly all the lot open, and treated cracks accept traffic quickly once cooled. Large sites usually get walked and marked out first so the property manager can see the linear footage and agree scope before a melter is fired.