Driveway Sealcoating in Saint Paul, MN

Driveway sealcoating is a thin coat of asphalt-based or acrylic sealer that keeps water and sunlight out of the top of the pavement, and it matters in Saint Paul because the airport station records about 78 days a year when pavement freezes and thaws within the same day. Each of those days gives water sitting in the surface voids a chance to expand and pry the stone apart, and a sealed surface sheds most of it. Driveway sealing will not fix a failed base or close a wide crack, which is why crack filling comes first, and it has no business on the concrete apron at the street, which the city keeps in concrete by rule. Done on a sensible cycle, it is the least expensive thing an owner can do for blacktop.

The coating is the short part of the job. Most of the time goes into preparation: blowing out sand and leaves, cutting back sod that has crept over the edges, scrubbing and priming oil drips so the sealer can bond, and cleaning out cracks. On alley pads the seam along the garage slab needs its own attention. Asphalt and concrete move differently as the temperature swings, and that seam is often the widest opening on the lot, so it gets hot-pour filler rather than a coat of sealer brushed over it.

Product choice is simpler here than in most states. Minnesota Statutes section 116.202 bars both applying and selling coal-tar sealants for asphalt, so the realistic options are asphalt emulsion, polymer-modified emulsion and acrylic. The Minnesota Stormwater Manual describes asphalt-based sealcoat as the most common replacement and says that, properly applied, it performs as well as coal tar or better at a similar cost. Ask for the product by name, the number of coats and whether edging and crack filling are in the price.

Timing does as much work as the product. GemSeal asks for pavement and air at 50 degrees or above and rising, with no rain for 24 hours, and notes that sealer can take about twice as long to dry at 50 degrees as at 80. At MSP, June averages about 3 nights at 50 or below, July and August about one between them, May 17 or 18 and October about 27. A coat applied ahead of a cold night can stay soft long enough to track. The price ranges show what the work runs by size.

Seal coating on a Saint Paul lot usually stops at two boundaries. One is the apron in the right-of-way, which Public Works requires to be concrete unless its director approves asphalt. The other is the alley surface, a public way the city keeps up at a minimal level; owners answer for their own aprons and the connection into the alley, not the alley pavement. Coating a strip of the public alley does nothing for the pad and is not the owner's job to pay for.