Benefits of Sealcoating: Why Should I Sealcoat My Parking Lot?
Let’s face it, nothing lasts forever – and that includes asphalt pavement. But that doesn’t mean you can’t extend the life of your asphalt parking lot (and improve its life-cycle cost) with timely repair and maintenance – and that includes sealcoating.
To understand the impact pavement sealer can have on the life of your parking lot, it’s first important to understand the nature of asphalt pavement itself. Asphalt – the black stuff that coats the aggregate in the pavement – is a byproduct of the oil refining process. Because it’s oil-based it was excellent waterproofing characteristics, it’s flexible, and it’s sticky so it does a great job of holding together all the aggregate.
In addition to providing a smooth and safe riding and parking surface for drivers, hot mix asphalt pavement protects what’s beneath it – the aggregate base and clay or dirt subbase – from getting wet. Because when water finds its way beneath the asphalt pavement layer, it weakens the structure of the pavement – and that’s when real problems begin including potholes, extensive alligator-type cracking and additional damage that require costly repairs.
Unfortunately, asphalt is not perfect. As it ages it begins to deteriorate – from sun, air, weather, traffic – and begins to break down. The first sign of this is the nice black color fades to grey, then small “hairline” cracks begin to appear.
Timely and proper sealcoating applications can prevent or delay this. And compared with other pavement maintenance options such as cracksealing, remove-and-replace repairs, and asphalt overlays, sealcoating is the easiest, most inexpensive and least-disruptive step you can take to protect your pavement.
So, what, specifically, does sealcoating do?
1. Prevents water intrusion beneath the surface.
Because almost all sealer contains fine aggregate (usually silica sand or Black Beauty boiler slag) sealcoating fills the hairline cracks that are an early sign of asphalt aging. By filling these cracks you’re reducing the likelihood that water will be able to find its way beneath the asphalt pavement surface – and the longer you can keep water out, the longer your pavement will last.
2. Slows deterioration from oxidation.
While you can’t prevent oxidation – the deterioration of the asphalt binder resulting from exposure to the air and the sun’s ultra-violet rays – timely sealcoating slows it. Oxidation causes the pavement to become brittle, makes it easier for cracks to occur and to grow more quickly, and enables other deterioration as well. Applying sealer to the pavement surface adds a layer of protection on top of that asphalt binder so it’s the sealer that takes the exposure to air and sun and not the binder itself. Regular application of sealer – generally every two or three years depending on region and traffic flow – will extend the life of your pavement.
3. Protects the asphalt binder from oils and gasoline.
Because asphalt is petroleum-based, any petroleum-based liquid that leaks on it will essentially “join” with the binder and soften the asphalt. That opens the door to even quicker and possibly more-extensive damage to the pavement. (If you’ve ever seen the black spots near the parking blocks in parking spaces – oil spots – you’ve seen the damage leaks can cause). Sealcoating will protect your pavement from leaks of this type. Note: If your parking lot contains any of those black oil spots they must be repaired prior to being sealcoated. Failure to adequately repair oil spots means the sealer will have no impact on those areas of the pavement and any damage will continue to spread.
4. Enhances skid-resistance.
As asphalt pavement ages the “fines” – tiny sand-size particles – are the first things to wear away. Applying sealer that contains sand or boiler slag not only helps lock those fines in place but also replenishes the fines on the surface, providing some additional traction.
5. Enhances flexibility.
Asphalt pavement is termed a “flexible” surface as opposed to concrete pavement, which is “rigid.” When cars and trucks drive over asphalt pavement it essentially flexes (microscopically) under their weight. As pavement ages and becomes brittle the pavement flexes less and traffic can create cracks. By applying sealer regularly you help the pavement retain its flexibility and slow its path to brittleness.
6. Enables easier pavement cleaning.
While this isn’t a benefit to the physical pavement, it can be helpful. If you don’t think it’s true take a push broom and sweep your concrete sidewalk – then take the broom and sweep a section of sealcoated pavement. Where the concrete tugs on the broom the sealed pavement allows the broom to slide easily over the surface.
7. Extends pavement life.
The combined impact of all these things that sealcoating does to a pavement is that it extends pavement life. A well-constructed asphalt pavement can last well beyond 15 years when properly maintained. And sealcoating is an essential part of that maintenance process.
8. Saves you money!
our parking lot is possibly the single most-costly investment on the property, so anything you can do to extend its life (thereby reducing its life-cycle cost) helps give you more bang for your investment. Research has shown that over a 15-year period a properly maintained 10,000-sq.-ft. parking lot can save a property manager $120,000 when compared to the same parking lot that is not maintained. How’s that for the benefit of sealcoating and proper pavement maintenance?
But there’s even one more benefit to sealcoating – and that’s aesthetics, or “curb appeal.” You want your property to look its best – whether it’s for business tenants, customers or people who live in your apartment building, condominium or homeowners’ association. Sealcoating provides a fresh, black, clean appearance – and when topped off by fresh pavement marking your parking lot looks great. In most cases there is so much parking lot surrounding or in front of the building that it’s the first thing people see. So by sealcoating and striping on a regular basis you are letting your property make a great first impression. Sealcoating and striping is one of the easiest and most cost-effective steps you can take to improve the look of your property.
Note: While sealcoating can benefit your pavement in many ways, it’s important to understand that it is not a structural improvement. Sealcoating your pavement is like painting your house: it protects and improves appearance but provides no structural benefit.