What OverKote Sealer Is, and Why Sealer Type Matters

What a sealcoat is for

A sealcoat is a thin protective layer applied over sound asphalt. It is not structural and it is not a repair. Its job is to stand between the pavement and the things that destroy pavement, which are ultraviolet light, oxygen, water, and petroleum products.

Think of it as a wear surface. The sealer takes the abrasion and the sun so the asphalt underneath does not. When it wears down, you renew it. That is far cheaper than renewing asphalt.

Robert E. Sutton Co. uses OverKote sealer on the work we do. We have been maintaining pavement in the Truckee and North Tahoe area since 1965, and product choice up here is about what survives the freeze cycles and the plow blades, not about what looks best in a brochure.

Coal tar versus asphalt emulsion

There are two main families of pavement sealer, and they behave differently. Refined coal tar sealers are known for resistance to petroleum. Fuel, oil, and hydraulic fluid do not dissolve them the way those products dissolve asphalt. That is a real advantage in parking areas and anywhere vehicles leak.

Asphalt emulsion sealers are made from asphalt itself, so they are chemically similar to the pavement. They are more flexible in cold weather and they have a lower odor and lower emissions profile during application. They are also more vulnerable to petroleum, since oil dissolves them the same way it dissolves the pavement.

Environmental regulation matters here too. Coal tar sealers have been restricted or banned in a number of jurisdictions over concerns about polycyclic aromatic hydrocarbons in runoff. That is a factor for anyone working near water, and in the Tahoe basin water quality rules are taken seriously.

What actually determines results

Product family gets debated more than it deserves. In the field, three other things determine whether a sealcoat performs. Preparation, application rate, and conditions.

Preparation means the surface is genuinely clean and dry. Blown, swept, edged, and with oil spots degreased and primed. Sealer does not bond to dirt, moss, pine needle residue, or oil. Most early failures we get called about trace back to prep.

Application rate means the right thickness. Too thin does not protect. Too thick does not cure through, stays soft underneath, and flakes off in sheets. Conditions means warm enough, dry enough, and early enough in the day that the material cures before evening. At 6,000 feet that window is narrower than people expect, which is a large part of why our season runs June through September.

What sealer will not do

We say this on every job. Sealer does not fix cracks, does not fill low spots, does not level a birdbath, and does not add strength. It protects sound pavement. That is the whole job description.

If your pavement has open cracks, those get sealed with hot rubberized material before any coating goes on. If it has base failure, alligator cracking, or potholes, a coating over the top is money down the drain and you need a paving contractor. We do not pave, patch, or overlay, so we have no reason to tell you otherwise.

Deciding whether your pavement is a good candidate is a walk-through, not a phone estimate. Call (530) 587-4161 and we will look at it.

Quick answers

See the rest of the pavement library, or if you are trying to identify something specific, start with pavement problems.