Sealcoat Does More Than “Just Make It Black”

I can’t tell you how many times this comment has been communicated to me when speaking about sealcoating a parking lot. As I mentioned in my previous article, preventative maintenance is the key to a long-lasting parking lot. Within our goal of #pavingitforward is a commitment to provide education to the property managers that we serve. With that being said, I must address the benefits sealcoating provides as part of a pavement maintenance plan.

It may seem as though you are saving money by delaying necessary repairs and sealcoating. However, much like the majority of the medical community will agree that spending the money on daily vitamins and regular doctors’ visits will reduce your likelihood to spend money on major health procedures in the future, consistent maintenance of your parking lot will create the same result. Or as I heard it recently, price is different than cost. The price you pay now will prevent much greater costs in the future.

What is happening to my asphalt parking lot?

Asphalt used in paving a parking lot, also known as “Hot Mix Asphalt” is made using a process of mixing aggregate(stone, sand) with liquid asphalt, which is refined from petroleum. Once it is machine installed, rolled to compaction, and begins to cool it is open to the elements. Exposure to UV rays(sun), water, oil and gas, salt and the cold weather begin to work against the new parking lot you have just paved!

No matter when the asphalt was laid:

  • Exposure to sun and also the application of salt cause what is called unraveling. These two components dry out the oil which is within the asphalt causing small pieces of the surface layer of the asphalt to work their way free.
  • Oil and gas leakage from cars can also affect the integrity of the pavement by deteriorating the surface.
  • Water, which seeks the lowest level it can travel to before evaporating, works its way into crevices, cracks and separations within your parking lot–it not only erodes, but freezes when temperatures drop, expanding as ice within your cracks and underneath your parking lot.

One of the only things I remember from high school science is the Second Law of Thermodynamics; everything deteriorates. There is no avoiding natural law, however, you can fight back!

So what is the best one-two punch you can give these elements?

Hot Crack Filling

Paying close attention to continued cracking within your parking lot and then filling those cracks is the most beneficial maintenance you can do. Hot crack filling battles against water by sealing the cracks which allow the most water to flow through them(those that measure 3/16” or wider), preventing the water from wreaking more havoc. Not sealing the larger cracks which form leads to what we call “Alligatored” cracking. Alligatored cracking is when the pavement starts to look distressed and leads to areas which begin to break open. Delaying the distress of your lot is vital to saving money on parking lot solutions in the future.


Whether your lot has been recently paved or has not been paved for a while, sealcoating is extremely advantageous for the protection of your parking lot. Many think that sealcoating is simply aesthetic. While it does improve the curb appeal of your property greatly, sealcoating preserves your parking lot, limiting costs down the road.

Sealcoating combats the elements at work against your asphalt by shielding it from:

  • UV rays at work against it; sealcoating “seals” in the oils which make up the asphalt, hindering the unravelling process. Your parking lot is now protected from the sun continuing to “dry out” the asphalt.
  • Oil and gas eating away at your asphalt is impeded by the sealcoat.
  • Water does not flow as easily through the smaller cracks and crevices which were not wide enough for hot crack filling. Sealcoating fills in those small areas before they become the bigger, issue-causing cracks we spoke about above. Less water means less freeze and thaw which means longer-lasting parking lots.

Sealcoating is an integral part of your pavement maintenance plan. The asphalt industry as a whole is in agreement of the value of applying sealcoat every 24-36 months.

What is your next step?

If your parking lot was recently paved, I cannot stress the importance of sealcoating a parking lot the year following it was paved for the reasons I have stated above. If your lot was not recently paved, partnering with a trustworthy paving contractor is key. An honest assessment of your lot can either confirm sealcoating is the best option at this time or to hold off for the time being. There is such a thing as sealcoating too much, which will cause your pavement to be extremely prone to slipping in wet or icy conditions. There are also situations where crack filling and sealcoating do not make sense due to the condition of the lot. There is no use in paying for a service unnecessarily simply because your rhythm is to sealcoat every couple of years.

The best time to have this conversation is now! Even though there are days where you can’t see your lot because of the snow and ice, find a day when the weather allows for the lot to be clear and get things in motion. Contractors are going to give you better pricing within the winter months and you will be first on their list of projects come Spring. You want to be able to enjoy your newly sealcoated lot for as long as possible within the Spring, Summer and Fall months.

Find an asphalt contractor who makes a regular practice of visiting your parking lots annually. This is the best way for you to determine TOGETHER the best plan of attack. Avoiding the issue is not the answer. Put a pavement maintenance plan in place so you don’t end up with major costs before you are ready for them.

-Nate Olson | Pavement Consultant | [email protected]Connect with Nate on Linked In