Seattle Asphalt Crack Filling FAQ
Why should crack filling be performed?
According to the Asphalt Institute, crack filling has two purposes: “(1) To prevent the intrusion of water into the underlying layers of the pavement structure, thus further weakening the pavement. (2) To prevent incompressible materials from entering the crack, thus causing further deterioration as the pavement expands and contracts with temperature changes.”
Any crack will allow moisture penetration into the sub-base, so they should all be treated, with a few caveats: (1) Cracks narrower than 1/8” should not be filled because there is not sufficient area for the crack filler to penetrate and adhere to the inner sidewalls of the crack. (2) Extensive cracking or “alligatoring” should be patched, not crack filled.
The best time of year to perform crack filling is in the fall and spring because crack thickness is at its median point. Asphalt material expands in hot weather and contracts in cold weather, so in the spring and fall, cracks will not be at their widest or narrowest. If we fill cracks in the summer when cracks are at their narrowest, the amount of material in the crack may not be sufficient to keep the crack sealed when the pavement contracts in the winter. Likewise, if we fill cracks in the winter, we may have too much material such that in the summer, the material will bulge out and be increasingly likely to be torn out by crossing vehicle traffic. In the Puget Sound, this is not as critical because we don’t experience the wide temperature swings between seasons like other places such as the Midwest. Consequently, the variance in crack openings is not as large.
The sooner the better. At the very longest, within one or two season after they appear.
The factors that contribute to the cost of crack filling are: (1) How dirty the cracks are, and consequently, how much time needs to be spent cleaning them. (2) The total lineal footage of the project (more feet, less cost per unit. (3) Crack depth.
Approximately 400 degrees.
DuraFil.
Cracks should be cleaned of all dirt, moss, foreign objects and water before filling with crack filler. We use a variety of methods to achieve this including wire brooms, rotating bristle brooms, pressure washers and blowers.
Depending on subsequent weather severity, a properly filled crack should last for 5 to 10 years.
Both are intended to prevent moisture penetration, but have slightly different properties. Tar seal is used to treat the seam of a newly installed asphalt patch and is not intended to penetrate vertically down into a crack. Rubberized crack filler is intended to penetrate the crack and adhere to the inner sidewall. Tar seal has a higher viscosity and lower boiling point.
