How long should an asphalt parking lot be closed after it has been sealcoated?

How long should an asphalt parking lot be closed after it has been sealcoated? Opening a parking lot too soon can affect the short and long term performance of the sealer. Sealcoating even under ideal conditions requires time for it to dry and cure properly.

Sealcoating dry’s by dehydration. Perfect weather conditions for sealcoating are 70 degrees, sunny, and a breeze with low humidity. The process of the sealer curing is in three steps.

The first phase the sealer is dry to touch. In ideal weather conditions this may take less than an hour. At this point it is dry but cannot be driven on and may re-emulsify if water comes in contact with it by rain or sprinklers.

The second phase occurs 24 hours after the final coat has been applied in ideal weather conditions. At this point the sealer has set up to resist water and can be driven on. Products such as QSA, FSA and other fast setting additives can be added to the sealer before it is applied to cut phase two’s curing time by 50% or more. These products allow parking lots to be opened up to traffic much faster. In phase two the sealer can be driven on but may show signs of scuffing or power steering marks caused by vehicles taking sharp turns or just turning its wheels, while staying in place. The warmer it is the more scuffing that occurs.

In phase three the curing process is complete. This could take as long as three to four weeks depending on the weather conditions. The lower the humidity, the faster it cures. At this phase the sealer binder has hardened and has become resistant to markings by vehicles and water.

Everyone wants there parking lot opened right away. Opening the lot up to early may cause harm to the sealer and cause premature wearing. The end result is you may have opened up the lot to traffic sooner and making everyone immediately happy; but in the big picture you will be inconvenienced by having to seal your pavement more frequently. The answer maybe to do the area in sections. New England Sealcoating can help you to devise a sealcoating plan that will be the least disruptive to your business, tenants, customers or residents.

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Why do I have rust spots on my tennis court?

Rust or brown spots on the surface of an asphalt Tennis or Basketball court are becoming unfortunately very common. These cosmetically undesirable spots and streaks on the playing surface usually do not affect play in the beginning; but do detract from the appearance of the court.

These brown spots are also found on asphalt driveways, parking lots and roadways but they are not as visible as they are on a court. The colorcoating makes the spots stand out. These spots are actually metallic metals called Pyrites (iron). Which contaminate the stone used to make asphalt.

Asphalt allows moisture vapors to go through it. The moisture from rain or leaves accumulating on a court goes through the asphalt making the Pyrite wet. The Pyrite then begins to rust. This rust stain eventually comes to the surface of the court causing the ugly brown spots.

In the early stages these spots are just cosmetically undesirable and do not affect the play on the court. Eventually the rusting aggregate begins to swell and causes small bumps in the court. These bumps will start to effect the bounce of the ball. These bumps typically will pop open creating small holes all over the court.

If the brown spots develop on your court these are a few options to try and make them go away. None of these can be guaranteed to solve the problem.

  1. You can drill out each spot and then patch the holes with a product similar to Court Patch Binder. Many times by the time someone notices the brown spots on their court there is a huge number of them to address and it may be too late. It becomes an expensive process. The other problem is, this year you may have drilled them all out and the next spring find an entirely new group of spots have developed. You then have to go through the same process again.
  2. Changing to a textile surface on the court will end the brown spots.
  3. The other option is to replace the court using a different source of asphalt. This still does not guarantee you will not get the iron spots in the new asphalt.

A few manufacturers of the color coatings have developed a coating with a stain blocker in it to blocks out the stains. New England Sealcoating has been trying them for a few years and has had some success. There is one or two courts it has not worked on. We do not feel we have put it on enough courts to say it works. Most of the courts we have used it on, the appearance has been vastly improved.

In the end it is not the contractor that is at fault but the asphalt plant. The contractor purchasing the asphalt has little or no say about the stone in the mix that is being produced.There are som eways to try and avoid getting these ugly stains from developing on your court. If building a court make sure not to use recycled asphalt. Also find out which asphalt plant the pavement is coming from and find some courts that have been paved in the last few years with this mix. Even then it still not possible to predict if the asphalt will contain the Pyrites. The asphalt plants source of the aggregate may vary from time to time. It is impossible for the producer of the asphalt on the contractor to guarantee that the asphalt will not contain Pyrites.

In trying to slow down the appearance of these ugly brown spots you should be proactive. Do not allow leaves, pine needles, or branches to accumulate on the court. Stop mold or mildew from growing on the court. Wash it off when you see it starting to develop. Remove anything that will keep moisture on your court and keep your court clean.

These are what some rust spots look like:

rust spot              rust-spots