How It's Made: Sealcoating

Sealcoating is a thin protective coat applied over an existing asphalt surface to slow weathering from sun, water, and traffic. It is made from a sealer, which is a liquid, and that sealer is either coal tar based or asphalt emulsion based. The right type is chosen for each job, and the written estimate recommends one. To learn more about this service, see driveway sealcoating.

What does sealcoating do?

Asphalt is a petroleum-based material, and over time sun and oxidation dry it out and make it brittle. A sealcoat forms a protective film on the surface that slows that process and helps keep water from soaking in. It improves the appearance of the pavement, but it is not a repair. Cracks and potholes need to be addressed separately, because sealer applied over an unrepaired crack does not close it.

How is the sealer chosen for each job?

Bruck Construction chooses between coal tar and asphalt emulsion for each job and recommends one in the written estimate. Factors generally considered include the condition of the existing surface, the traffic and fuel exposure it receives, any local rules that apply, and the timing and weather needed for the sealer to cure. The estimate explains the recommendation so you can ask questions before work begins.

What is coal tar sealer?

Coal tar sealer is made from coal tar, a dark byproduct of coal processing. It has a long history in pavement work and is valued for its durability and its resistance to fuels and many chemicals. Coal tar sealers are restricted or prohibited in some areas, so it is worth checking local requirements before choosing one.

What is asphalt emulsion sealer?

Asphalt emulsion sealer is a water-based product in which fine asphalt particles are suspended with additives. As the water evaporates, the asphalt particles bind into a film on the surface. Asphalt emulsion is a common choice where local rules limit coal tar, and it is often selected for surfaces where its properties suit the job better. Like coal tar sealer, it needs suitable weather to cure.

How is the surface prepared?

Preparation is what allows the sealer to bond. In general, the surface is swept or blown clear of loose debris, and oil spots are treated because oil can keep sealer from adhering. Cracks are normally filled before sealing, since sealer does not close them. The pavement should also be dry, and the forecast should show no rain for the cure period. Sealing is done in warm weather, because sealer needs temperatures above freezing and dry conditions to cure properly.

How is the sealer applied and cured?

Sealer is applied in thin, even coats using a spray or squeegee, and the number of coats depends on the surface and the product. Each coat must dry before the next one is applied. Vehicles and foot traffic are kept off the surface until the sealer has cured, and the timing depends on temperature and humidity. Rushing this step can leave marks, tracking, or a surface that does not hold up.

Frequently asked questions

Which sealer is better, coal tar or asphalt emulsion?

Neither one is better in every case. The right choice depends on the job, the surface, and local rules, so the written estimate explains which one is recommended and why.

How often should pavement be sealcoated?

That depends on how much sun, water, and traffic the surface receives and what condition it is in. Ask the contractor for a recommendation based on your pavement.

Can sealcoating be done in winter?

No. Sealer needs temperatures above freezing and dry weather to cure, so it is applied in warmer months.

Bruck Construction's sealcoating estimate states which sealer is recommended. Request a free estimate, or request a sealcoat quote and call (614) 298-0828 with questions.