Asphalt Sealcoating

Example Sealcoating Spray Wand Commercial 2


    • Protect and seal the asphalt surface extending its lifespan significantly
    • Give your property the best visual first impression
    • Lower costs for cleaning and snow removal
    • Allow for higher traffic marking visibility and a safer environment

A properly sealcoated asphalt pavement can extend the life of that pavement by as much as 300%! The cost of sealcoating is truly a minor expense compared to the cost of pavement replacement.

Life cycle cost analysis studies have established that unprotected pavements will likely cost a property owner as much as five times more compared to a pavement that has been protected with a regular maintenance program. See for more information.

Sealcoating acts as a shield, protecting against weathering effects and oxidation caused by the sun’s UV rays. Sealcoating also acts as a barrier and protects against gasoline, oil drippings, grease and deicing salts.

Application Cleaning Broom and Blower Crew Application Cleaning Power Edging Driveway Application Cleaning Broom Wire Brush by Hand

Cleaning the asphalt surface first

For a successful sealcoating application ALL dirt must be removed from the asphalt pavement. Embedded dirt must be removed by a process of power washing, brushing, sweeping and/or mechanical blowing.

A reputable contractor will start with a powered edger, a weed eater, good high powered blower and will spend the time to trim back the vegetation (in some cases power wash problem areas), broom and then blow off ALL of the dirt, sand, and debris on the asphalt. Not just the stuff you can see on the top of the surface, but down into the profile of the asphalt where the dirt is stubborn and hides between the stones in the asphalt. They may have to get a metal wire broom out to hit the difficult spots with elbow grease and sweat. This is where a good deal of manpower and man-hours are spent in the time billable on a job site. It is common to see a crew cleaning for hours, and sealcoating for minutes.

Duramax is different:

We take cleaning and lot preparation very seriously. Cleaning is HARD work, and its labor can be expensive, but it has to be done! Failing to do this step properly can lead to disastrous results. Any sealcoating you lay down will stick to whatever it is applied to, and if that material is dust and dirt, not the asphalt surface itself, then it will lift right up as soon as it is disturbed. For proper adhesion, it is essential that the asphalt surface be dry, clean, free of contaminants, and have an adequate surface profile.

Example Oil Spots on Parking Space iStock 47193654 Application Primer Oil Spot Primer

Oil spot treatment and priming before sealcoating

Regarding existing oil spots and oil drippings: It is a common practice to prime oil spots with a special asphalt priming product prior to applying sealcoating.

Oil spot primers are quite effective at sealing oil spot contamination and will keep them from coming up through the cured film of a finished sealcoating job.

If left untreated oil contamination will penetrate into and attack (soften & dissolve) the asphalt underneath. If nothing is done, these spots will still be visible through the sealcoated surface and it may be impossible to correct without actually digging out the damaged asphalt and then patching with fresh asphalt. It is a good maintenance practice to remove the oil spots as soon they are discovered using detergent and a good scrubbing.

Application Edging Sealcoat Brush on Curb Application Edging Sealcoat Brush Detail

Edging by hand brush technique

Brush edging is the careful application of sealer to an asphalt surface that is up against a sidewalk, building or vegetation. It is the process of applying sealer in the most controlled and careful means possible.

Brush edging usually will only happen when the area being coated is large enough to require a spray application. If the area is smaller, then the edging will be a part of the entire brush application of the driveway or surface.

Duramax Is Different:

We take great care in seeing that the sealcoating stays on the asphalt and not on anything else. Edging takes time and a careful, experienced hand. Sloppy work here will result in sealer splashing up on your sidewalk, building or plants.

Application Edging Sealcoat Spray Tip Off 3 Art - Duramax NOT Who We Are Example Star-Seal with Sand Blacktop Sealant Click Here For Manufacturers Specifications

Sealcoating is a complex mixture

Sealcoating is a complex mixture of Asphalt Binder, Mineral Fillers, Surfactant Chemicals, Latex Polymers, and Purified Water. Although it’s not toxic, it should be treated with care and by someone who knows how to properly calculate a mix design and application specification.

Manufacturers’ specification is not to be taken lightly, and too many people do just that – lighten the sealer up with too much water then do further damage by applying that material is too thin of a coating!

Duramax is different:

First, we did our research and found the absolute best performing material in our market area. Then we were trained by the manufacturer and follow the manufacturers’ specifications EXACTLY the way they designed it. And then we tested it ourselves to ensure we had the best performing mix design with the best materials we could provide to YOU, our customer.

Many of those guys in the pick-up truck (and even some larger companies) are applying material that is no thicker than the consistency of milk. Our mix design is THICK, like molasses, with sand mixed in to give the sealer strength, better traction and longer life – per manufacturers specification – You WILL see the difference!

Sealcoating Process

By Brush

Application of sealcoating by brush is usually done in smaller areas or in areas where there are structures or things in the close proximity of the application that cannot be sprayed next to. A residential driveway is usually brush applied. An area where the building is right against the parking lot, or maybe where cars are parked that cannot be moved. These are areas where a brush application may be more appropriate.

Brush applications are not as easily measured and in most cases are heavier (thicker) applications of sealcoating. It is normal to only do one coat application by brush where a spray application might normally have two coatings. The brush application will still be thicker than the spray application in many cases.

By Spray

A spray application is made by pumping high-pressure sealcoating through a hose, and out a spray nozzle at the end of a long wand. This process is one of the most effective ways to apply a consistent, even coating of sealer onto an asphalt surface. Traditionally two passes are made as the applicator walks the surface in overlapping applications. After the entire lot is properly covered, the process is repeated for a second coating after the first has had time to dry on the surface to allow walking on the freshly applied coating. The second coating is applied at the same thickness as the first.

By Mechanical Sprayer

Mechanical spray units (generally a tank you can drive on, or a trailer that has a spray bar on the backside of it) are used when there is a very large area to apply sealer onto. Large parking facilities, roadways, bike trails are all areas where a mechanical spray rig would be used. These machines function the same way the hand sprayers work but cover an 8-10′ wide swath of asphalt in one pass.

One Coat or Two Coats?

Plan On Applying Two Coats of Sealer; This is necessary to maintain the sealers’ protective quality as well as its’ longevity. Understand that sealers applied in two thin coats dries and cures much better than one thick coat. Sealers are water-based coatings, which cure through the process of water release (evaporation). A thin coat will release water faster than a thick coat. If applied in one thick coat, the sealer will have a tendency to hold water longer and will likely cause tracking before it properly cures.

Drying and curing sealcoating

The sealcoating manufacturer recommends 24-48hrs before you open your driveway or parking lot to traffic. You will be able to walk on your driveway much sooner than this, but we recommend not driving on it for at least 36hrs if at all possible.


In ideal weather conditions, the drying will only take a few hours. However, just because it’s dry on top and dry to walk on does not mean it’s CURED. Drying is the formation of a film on the surface of the sealcoating that was just applied. It may be dry to the touch, but the coating may still be somewhat fragile until all the moisture is CURED out of the coating from top to bottom.


Curing is the evaporation of all liquid from the sealer. The dryer and hotter the weather the faster it will cure. You can drive on a driveway that is not fully cured but understands that you are risking leaving marks from turning tires (power steering marks) and tracking from heavy vehicles. 100% cure may take longer, but after 36 hours it will be cured to about 95% and you will not easily hurt your sealcoat. That last 5% of the cure takes the longest!

Weather Limitations

Rain Events

Weather and the potential for rain create the most horror stories in the sealcoating industry. A rain event within a few minutes, or even a few hours can lead to disastrous results. Some of the more obvious are; environmental concerns of uncured sealer washing off your pavement and into sewers, black sealer splashing up onto buildings and cars, and ultimately premature failure of the coating itself.

It is important that there not be any rain in the forecast both before application and also during the first 8 or so hours after the sealer has been applied. After a few hours (ambient temperature and humidity allowing) the sealer will form a fairly resilient film on its surface that will not be damaged by a normal rain event, but until this occurs, your sealer is vulnerable to water and will need time and good weather to properly form that protective film over its surface.


Humidity or Relative Humidity (R.H.) of the atmosphere plays a significant role in the cure mechanism of a sealcoating.

Humidity directly influences the rate of water evaporation from the sealcoating film. Relative Humidity (R.H.) is the ratio of the actual moisture content of the air, at a specified temperature, to its total capacity. For best results, an R.H. below 70% is beneficial to the cure mechanism inherent in the sealer. Higher R.H. means the atmosphere is unable to absorb additional moisture readily, thus drastically slowing down the release of water from the sealcoating film.

Sealcoatings, understandably, will cure faster at lower humidity than at higher humidity. Under highly humid conditions, sealcoatings should be allowed longer drying time before finally opening to traffic.


Sealer should not be applied unless the pavement temperature is at least 50°F and the air temperature is 50°F and rising. The fusion of the binder particles (in the sealcoating) to form a uniform and continuous film depends on their ability to soften under the ambient and pavement temperatures. The process of fusion is greatly enhanced at higher temperatures; say 75°F to 85°F. Conversely, it is significantly reduced at temperatures below 50°F.

When sealcoating is applied below 50°F, tar or asphalt particles do not soften and form a continuous film. The color of the sealcoating cured under such conditions usually turns out grey and blotchy in appearance and never returns to its normal slate black appearance even at higher pavement temperatures.

Needless to say, sealcoating cured under cold weather conditions lack the integrity and sealcoating properties that are normally expected.

After The Lot or Driveway is Opened Up to Traffic

“I am seeing tire marks where the cars are turning on my parking lot, why is this?”

Nothing is wrong!

This is a normal part of the process. The material used to seal your driveway is thermoplastic and the marks left by your tires will run themselves out and disappear. It’s just like freshly paved asphalt, those tire marks will disappear. Once your driveway has achieved a complete 100% cure, it will no longer mark.

Is there anything I can do to avoid marking the driveway before it is 100% cured? Yes. Try to avoid turning your tires very hard or turning the wheels while the vehicle is not moving. Again, if you do leave marks, they should eventually go away.

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