Sealcoating Parking Lots
Sealcoating can DOUBLE the life of your pavement by protecting it from its enemies: sun & oxidation, water, gasoline, oil & jet fuel. New England Sealcoating applies sealcoating products tailored for each particular situation to form a tough protective coating over your parking lot. Sealcoating preserves the investment you have in your asphalt, while at the same time making your property safer, cleaner and more attractive.
Properly designed parking lots rarely wear out from traffic. Surface deterioration is usually caused by the weathering effects of the sun and rain as well as the softening effects of deicers, gasoline and oil drippings.
Before & After
Oxidation, the graying in color of asphalt pavement, is a sign of fatigue, aging and general surface deterioration. When unprotected pavement becomes oxidized, the aggregate will begin to ravel from the surface making the pavement rough. Once the surface becomes brittle, cracks develop, and the pavement deteriorates. Furthermore, water which accumulates in open pavement structures is a major cause of pavement damage.
Instituting a preventive maintenance program before these damaging elements get a hold on your pavement is important. Application of a rubber fortified coal tar emulsion is the most cost effective maintenance procedure available. When you sealcoat asphalt, you double its life by shielding it from a variety of destructive forces. In addition to its practicality, sealcoating also enhances the appearance of your pavement by giving it an attractive, easy-to-clean, slate black color finish.
Silica Sand is usually added to coal tar sealer to provide a heavier wearing surface. The addition of sand also means that the sealer will last longer and will be more skid resistant than sealer which does not contain sand. Typical sand load is 4 to 6 lbs. of silica sand per gallon of the Coal Tar Emulsion. (Based on concentrate.)
How Asphalt Breaks Down
Air, sunlight and moisture are the major causes of surface deterioration. Unprotected surfaces oxidate and allow the aggregate to be washed away.
Unprotected pavements lose flexibility; aggregate ravels from the surface and the pavement becomes rough. The surface becomes brittle and develops cracks.
Water penetrates the cracks and damage progresses. hydraulic pressure (expansion and contraction) enlarges the cracks. Damage occurs faster under heavy traffic and/or during freeze-thaw cycles.
Cracks allow water to penetrate to the sub-surface and rupture the pavement; causing small cracks to enlarge until the pavement actually separates, creating a pothole.
15 Year Cost Comparison
Maintenance costs for unsealed asphalt over a 15 year period
are 50% more than for asphalt that is sealed every 3 years.
Why Apply a Penetrating Primer
Older asphalt surfaces become oxidized from the sun and weather. Oxidation causes the asphalt surface to become brittle, exposing the aggregate. Coal tar emulsion sealcoating material needs a good, sound surface that it can bond to. If the sealer is applied over exposed aggregate or old, porous and oxidized asphalt surfaces, the sealer will not bond properly. Furthermore, the effects of traffic and weather will cause the improperly bonded sealer to wear prematurely. You would never have your car painted without putting a primer coat on first. Our penetrating primer, in essence, works the same way. Applying Polyprime® leaves a surface that the sealer can bond to.
There are three types of primers:
- Diluted Coal Tar Sealer
- Diluted Asphalt Emulsion
- Penetrating Primer
Diluted Coal Tar or Diluted Asphalt Emulsion do very little more than coat the top surface. Neither of these types of primers has long-term bonding, nor do they penetrate the pores or voids. The dispersed particles of tar or asphalt are too large to get into the surface and must sit on top. These two types of primer will wear quickly due to traffic and weather, and will do very little to improve long-term bonding of the sealer.
Penetrating Primer is a special solution of tar in solvent. It is a multi-polymer/refined coal tar primer specially formulated to improve adhesion of pavement sealer to oxidized asphalt and the exposed stone. Its molecular structure allows it to quickly and effectively get down in the pores of the surface and create a good, sound surface to which the sealer can bond. The primer coats the exposed stone and penetrates the surface. When the solvent evaporates, the surface is coated with tar to which a sealer can be applied and bond to properly. The end result is a much stronger, and less porous pavement.