FAQ’s About Hawk-Seal-E (HSE)

After the surface turns gray, is it still waterproof and protected?

Yes. The waterproofing remains long after the initial beading action is gone.
The only way to effectively remove HSE from the surface binder is to mill up the surface.

At what time in the life of asphalt will you receive the maximum benefit?

The earlier in the oxidation cycle, the better. Usually 6-12 months after laydown.
We recommend that a new overlay go through one summer to allow it to reach optimum compaction.

Can older surfaces benefit from a HSE treatment?

If a surface is old and in still in good condition, it will benefit significantly from a HSE treatment.  HSE has been successfully applied to surfaces over 15 years old.
Additional applications may be needed to waterproof older, more porous surfaces.

Can you use HSE on concrete?

Yes.  It will waterproof concrete, but will turn the surface dark;  however, if HSE gets into concrete curbs and gutters the color will fade in a matter of months.
The concrete will be water and acid-rain resistant but this is not a recommended use.

We do have Hawk-Seal Clear Concrete Sealer (CCS). 
CCS will waterproof the concrete and significantly increase the surface’s resistance to damage from acid rain.
The application process is like that of HSE.

Do streets need to be closed during application?

No.  The client has the final decision.  
Traffic has been known to follow directly behind the application equipment.
We strongly advise that signs or personnel warn motorists to drive
no more than 5 MPH if the surface is wet.  This is to prevent HSE from
splashing onto vehicles.

Usually within 15-45 minutes traffic can resume normal speed.


Do you have an engineer, public works official or city mayor who can recommend Hawk-Seal-E?

You may also contact us for further information.

Does an asphalt surface need to “breathe”?

Does HSE track?

Once it dries, usually 15-30 minutes after application, it does not track.
Even when the surface is wet, tracking is minimal.

During or after application, is the surface slick?

During application the surface should be treated as you would any rain-slick surface. Usually, traffic can resume normal speed within 15-45 minutes after application.
After application the surface is no more slick than it was before the treatment.

How does HSE work?

There is a very strong attraction between the HSE naphthenic emulsion and any asphalt surface that has lost its naphthenic acid fraction due to damage from water and oxidation.   The asphalt surface rapidly absorbs the HSE naphthenic emulsion, thus drawing in the co-polymers and filling surface voids.   Once surface voids are filled and the asphalt binder treated, the surface is waterproof and oxidation is significantly reduced.   By sealing the surface voids, you retard shrinkage, slow the migration of water to the base, extend the performance life and reduce maintenance.

How is HSE applied?

Application is simple.
Distributor trucks, detached spray bars and backpack sprayers work well.
Select the method that best fits your requirements. 


How long will it last?

This will vary with age and condition of the asphalt at the time of sealing.
In reality, the only way to remove HSE is to mill up the surface.


How much Hawk-Seal-E is used per square yard of surface?

The standard application is 0.12 gallons of mix per square yard per application.
A minimum of three applications is made for a total of 0.36 gallons of mix per square yard.
If the asphalt surface is extremely porous, additional applications will need to be applied.

How much time does it take to make the three applications?

Under dry, sunny conditions usually all three applications can be made the same day.
Conservatively, allow 1-½ hours between applications for complete penetration and drying.
Drying and penetration times really depend upon surface condition and compaction levels.



If only one or two applications are made in one day, is this a problem?

You can make the individual applications a day, week or month apart.
If it rains once the first application is down, that treated surface will dry much faster than an untreated surface.

Is Hawk-Seal-E like a chip seal, slurry seal, micro-surface or asphalt emulsion?

Other systems inhibit the natural release of moisture vapor (steam).
HSE was specifically formulated to allow steam to escape while maintaining a waterproof barrier.

HSE is designed to penetrate and does not sit on top of the asphalt surface.


Is it necessary to use sand?

No sand or aggregate is required before, during or after treatment.

What happens if it rains during treatment?

If the application has already penetrated, no problem. If the treatment was still wet (i.e. not penetrated), it will be washed off and will need to be re-applied. We normally allow a surface to dry for at least one day before resuming work.  If HSE is washed from the surface, it poses no hazard to ground water.

What is Hawk-Seal-E (HSE)?

HSE is a modified naphthenic emulsion that is cross-linked with specific co-polymers and contained in a stable, proprietary concentrate.
This unique combination gives Hawk-Seal-E its ability to penetrate, waterproof and protect an asphalt surface. This product is highly resistant to oxidation.

When is the best time of the year to apply Hawk-Seal-E?

When overnight temperatures are above 50 degree F and will rise during the day.

Will HSE help to prevent damage from freeze/thaw cycles?

Freeze/thaw is discussed in several of our videos.