by Eric Reimschiissel
Why Seal Coat?
A brief summary of the benefits of seal coating asphalt pavements.
What Are Seal Coats?
- Seal coats generally consist of a mixture of emulsified asphalt, water, mineral fillers, black slate, sand, carbon black (for color) and various other admixtures.
- Seal coats are applied directly to the surface of asphalt pavements that are in good condition. They should be applied by rubber squeegee for thickness and void filling, not a cheap spray on.
- Seal coats serve to seal the top of the asphalt, preventing water from penetrating the surface of the pavement and protecting the top layer of asphalt from oxidation and wear caused by exposure to the sun and air. Seal coats also beautify the pavement by providing an enhancing black colored surface ideal for painting lines and sweeping.
- Seal coats are designed for locations where there are low traffic speeds and tight turning radiuses such as homeowner streets, parking lots, mobile home parks and schools.
- Seal coats are different from Type 1, 2 and 3 slurry seals, which are made with 1/8, 1/4, or 3/8 inch aggregate rather than sand and are designed for use on typical streets, higher traffic locations and older rough pavement surfaces needing a thin overlay of slurry.
What Causes Asphalt Pavement to Fail?
- Assuming that the initial asphalt pavement was designed and constructed properly, the primary causes of failure is the hot sun and the absorption of water into the asphalt.
- This process begins with the oxidation of the pavement surface which causes the asphalt to dry and become brittle; this leads to erosion of the top layer of fine particles and the appearance of larger stones and small cracks on the surface.
- If left untreated, the surface continues to ravel and the cracks grow over time and eventually allow water to penetrate to the base of the pavement.
The hot summer sun causes the asphalt surface to dry and become hard and brittle.
- When water enters the asphalt and continues into the base of the pavement, the base material moves and settles leading to further cracking and an “alligator appearance.”
- When the pavement reaches this state, the only option is removal and replacement of the old asphalt. Our goal is to protect and preserve the asphalt pavement with seal coat and slurry seal to prevent costly repairs and replacement. With the costs of asphalt continuing to rise, the cost of replacement of a parking lot or street is unacceptable.
How Does Seal Coating Help?
- Seal coating seals the asphalt pavement, preventing the hot sun from oxidizing and eroding the top layer of asphalt.
- On older pavements, seal coating and slurry replaces fine particles lost from the asphalt surface due to oxidation.
- Seal coating fills the small cracks that can turn into large cracks and prevents water from seeping down to the base material.
- Seal coating helps protect the asphalt from the sun as well as the harmful effects of water and other elements.
- Seal coating provides an attractive black surface that is ideal for painting lines and other markers enhancing the value of your property.
- Seal coating leaves a smooth clean surface ideal for sweeping, lowering cleaning costs.
- Seal coating costs pennies a square foot compared to the dollars needed to repair or replace damaged asphalt.
When Should Seal Coating Be Done?
- We recommend waiting about 1 year before seal coating new pavement. After a surface has been sealed, it should be re-sealed as necessity dictates. The pavement condition prior to seal coating, traffic and the elements will affect the life of the seal coat. A new seal coat depending on these conditions will typically last from 3 to 7 years.
Are All Sealers The Same?
- Absolutely Not. You should use a seal coat material manufactured for the hot Las Vegas climate and our cold winter months. We manufacture AMERICOAT seal coat, which is a proven seal coat for the Las Vegas area. We have streets that were sealed with AMERICOAT years ago that are still performing well. Seal coats should be made with specialized asphalts, sand, black slate, latex and polymers, seal coat for our climate and for longevity of the seal coat application.