Asphalt seal coating is recognized as one of the most beneficial preventative maintenance treatment for your asphalt parking lot when TIMED PROPERLY. The keys to a successful sealcoating program include preparation of the asphalt surface, crack filling (if applicable) and application of a coal tar based pavement sealer in optimal weather conditions.

Far too many times, either inexperienced seal coating contractors or unscrupulous ones “over sell” seal coating to unsuspecting property owners / managers. Property owners rely on what they assume sometimes are professionals to guide them in making the proper buying decision. Because 90% of seal coating contractors fall into a category of sales people versus “pavement consultants”, when the property manager approaches them for honest straight-forward advice, the fear of losing the sales kicks in and they will sell the prospect on seal coating when they themselves know it will provide little value other than cosmetic enhancement of the asphalt, and most of the time that is short lived.

What Asphalt Sealcoating WILL DO:

• Either coal tar emulsion, asphalt emulsion or petroleum based emulsion will protect an asphalt parking lot from gas & oil spillage, oxidation from the sun, deterioration from de-icing chemicals, waterproof the surface, help melt snow & ice faster and will beautify the pavement.

• When used as part of a preventative maintenance program, seal coating when first applied 12-18 months after asphalt installation and then every 2-3 years thereafter, if applied as per the manufacturers specifications (Proper water dilution, addition of a latex modifier & addition of silica sand for traction and durability) will extend the life of an asphalt parking lot by 20 years on average if completed in conjunction with a Preventative Maintenance Plan to include hot rubberized crack sealing and inspection of the parking lot on an annual basis to cure issues right away.

• Seal Coating will help melt ice and snow faster as the deep rich black color retain heat from the sun.

• Seal Coating will make sweeping and cleaning the asphalt parking lot easier as it creates a smooth surface.

What Asphalt Sealcoating WILL NOT DO:

• When an asphalt parking lot is neglected for 10-15 years, is covered with cracks, alligator cracked areas, erosion of the fines from the asphalt leaving behind a rough surface with exposed stone, seal coating will provide NO structural value and will only be cosmetic. Seal coating a 15 year old neglected parking lot will look great for a photo on LoopNet or Co-Star, however, a discriminating property inspector that performs their due diligence will certainly ask for a concession for repaving.

• Seal Coating will only add a few years of life to the asphalt at best for a deteriorated parking lot that has not been maintained.

• Seal Coating will not level or fix low spots.

• Seal Coating will not resurface asphalt, even though some seal coating products use the word “resurfacer.”

• When seal coating is performed on asphalt where all the fines have eroded and the stone is now rough and protruding, the seal coat application will quickly wear off of the top of the stones in high traffic areas.

• 1 coat of spray applied pavement sealer will not protect the asphalt as well as 2 coats.  Some contractors will tell you “they can apply the same amount of sealer in 1 pass instead of 2” or make claims such as “it is a 1 coat application and is being applied at the manufacturers recommendation of 70 sq ft per gallon” etc.  If you go to any seal coating products manufacturers website and look up their technical bulletins, they all recommend when spraying pavement sealer to apply 2 thin coats versus 1 thick coat.

Source: http://www.fixasphalt.com/blog/what-seal-coating-will-and-will-not-do