Asphalt Advisor

Flawed Studies Attack Refined Coal Tar Sealers

2012-02-24T13:18:00.001-06:00

With the recent attacks on Refined Coal Tar (RCT), more sealcoaters and homeowners are looking into Asphalt Emulsion Sealers (AE). There are some big differences between the two and while Sealer Manufacturers are making strides in offering a more stable AE Sealer, the fact remains that Asphalt Emulsion sealers can't compete with Refined Coal Tar Sealers on durability, appearance and consistency.

Refined Coal Tar Sealers. Refined Coal Tar based sealers are more durable and last longer than Asphalt Emulsion Sealers. They retain color better and are resistant to gasoline, oil, UV fading and road salts. RCT sealers are more forgiving, curing more readily in lower temperatures and humidity. RCT Sealers meet or exceed specification ASTM D 5727, making them similar to other RCT Sealers.

Asphalt Emulsion Sealers. Asphalt Emulsion sealers have less odor and potential for pitch burn to the Applicator, but there are no specifications for AE Sealers, making them less predictable and harder for the contractor to control.

If you're considering a switch based on recent articles, keep in mind that the USGS studies in Austin have been proven flawed and none of the cities that have banned coal tar have done their own studies. There has never been a documented case of cancer resulting from the use of Refined Coal Tar Sealers. RCT Sealers are unjustly confused in the USGS studies with Crude Coal Tar - it's not the same material.

Some AE Sealers are better than others, so make sure you check out the manufacturing process and if you're concerned enough to switch, you need to stay within the limitations of the manufacturer mix design and weather conditions. It's a good idea to be upfront with customers in regards to the limitations of Asphalt Emulsion, if your customer is expecting the same results as with Refined Coal Tar Sealers, they'll be disappointed.

More information on Sealer Ban: Science...and Fiction

Spray or Squeegee?

2012-01-30T14:59:00.000-06:00

The answer to which application process is better, spray or squeegee is - it depends. There are reputable companies that use both processes or one or the other, but the condition of the asphalt should play a part in the decision. Up near the house and next to sidewalks, an edging brush should be used to avoid over-spray. The larger open areas are where the applicator has to make a decision on which process to use.

Over-sealed surfaces can benefit from a spray application - the applicator can leave a thicker coat than with a squeegee. When using a squeegee on a smooth surface with very few voids to accept the sealer, the squeegee leaves very little sealer. The right spray technique can leave a better coat of sealer.

Porous surfaces will always cover well when sealer is hand applied, but can suffer if too light a coat is applied by spray. With spraying there are more variables that come into play, spray tip size and spray wand speed determine how thick the sealer goes on.

Professional sealcoaters can achieve great results with both processes. Hire a reputable contractor and trust them to use the process that works best for your driveway.

Find a Contractor in Illinois
Purchase Squeegees & Spray Wands

Will Snow Plowing Damage My Asphalt?

2012-01-03T15:53:00.002-06:00

Anything that scrapes your driveway or parking lot can damage it. Most of the snow plow damage I've seen on asphalt is minor and doesn't need structural repair. Many scrapes and scratches look worse than they really are. The sealer can be scraped off leaving unsealed aggregate, a sealcoat application in the spring should take care of the issue. Deeper scratches can be filled with crack-filler prior to the sealer application. If the gouges are deeper than 1" and the asphalt is loose, additional repairs may be necessary. The Infrared process can be used to heat the area and work asphalt back into the surface.

Some snow removal companies use a rubber or polyurethane cutting edge on their plow blades to lessen the impact on your driveway, while others set the plow blade 1/2" above the surface to avoid damage. Both of these options can leave excess snow on the asphalt. Flat surfaces usually don't see any damage, it's uneven surfaces with high areas or sudden grade changes that are most susceptible to winter plow damage.

Keep in mind that if you are looking for a very clean surface, there is a chance your asphalt may be damaged. Unless the damage is severe, ask your sealcoating contractor to address the areas in the spring and chalk it up to Mother Nature.

Is it Too Cold to Pave?

2011-09-23T14:47:00.005-05:00

Over the years, I've inspected many asphalt surfaces that were paved when the weather wasn't ideal. Paving in colder temperatures introduces challenges to the Paving Contractor that are not present in warmer weather. The main challenge is getting the asphalt to the job and laying and compacting it before it cools down. It takes an organized crew with the proper equipment to deliver a quality job at the end of the season. In the Midwest, asphalt plants are usually open until early December. Prepared companies can usually attain good results all the way up to the end of the season. However, companies that are not set up to work fast will run into problems. Having the proper amount of people on the crew and the right equipment insures that the asphalt will be laid and compacted in a timely manner.

If you are only repairing sections of asphalt, Infrared Repairs are a nice option. If executed properly, Infrared Repairs can be done in cold weather as long as hot asphalt is available. Infrared crews typically haul the asphalt to the job in a hotbox, which keeps it at the right temperature. In colder weather it takes a little longer to heat the repair area; but if the crew waits the proper time to heat through the whole lift, great results will follow. Adding hot asphalt into hot asphalt takes the temperature variable out of the equation.

If you hire a reputable company, they will tell you when it's too late to do asphalt work. If you trust the company and they will guarantee the work, go ahead and have it done all the way up to the end of the season.

For more informaton on Infrared Repairs, check out Asphalt Restoration, Inc.

You Can Drive On It, But It’s Not Cured

2011-08-22T11:23:00.010-05:00

Now that you've spent the money to replace or repair your asphalt driveway or parking lot, it’s time to protect your investment. In hot temperatures, it’s a good idea to stay off your new asphalt for 2 days. After the 2 days are up the pavement is not cured, but is ready to be opened up to traffic. It can take up to 12 months for the liquid asphalt to fully cure, so during this time it’s important to avoid the following situations.

When driving on your new asphalt, be conscious that your car should remain in motion as you turn the steering wheel. Turning your wheel while the car is stopped will cause your tires to skid across and grab your new asphalt, causing the surface to scar. You should also avoid parking in the same spot every day, as it could cause depressions where the tires sit. Anything parked on the pavement with kick stands or trailer jacks can sink into the driveway. Make sure the surface is protected with a board to displace the weight. Gasoline, oil, transmission and power steering fluids can all penetrate into asphalt, softening it and causing structural damage. Once the asphalt has been sealcoated a few times, the chances of penetration will be diminished.

Your driveway or parking lot is naturally flexible; even when fully cured, it will never be as hard or smooth as concrete. Keep these situations in mind and you should get your pavement through the early stages without any trouble.

If any of the above situations have damaged your pavement, Infrared Repairs are ideal for repairing them without cold joints www.asphaltrestore.com

Does it Matter How Your Sealer is Made?

2010-12-29T14:11:00.006-06:00

Many property owners and sealcoating contractors think that all sealer is made using the same process. There's a huge difference between the two types of manufacturing- Colloid Mill and Batch. Most sealer looks the same going down, but the longevity and color consistency really tells the story.

When sealer is made with a colloid mill, raw material is squeezed using pressure and sheared through the mill. The mill controls the pressure, temperature and flow; delivering a more homogeneous and stable material.

The batch system is similar to a cake mixer; blades spin around and mix parts of the mixture, while other parts rise above the blades. The simplicity of the system can leave you with an unstable, improperly mixed material.

Hiring a good contractor to do the job is important, but a successful project starts with the right material. The difference between the consistencies of the two products is like night and day. Ask your contractor how the sealer they use is manufactured- if they say the batch system, keep your fingers crossed that you get a good batch.
For more technical information on the two processes, go to http://www.gemseal.net/contractors/manufacturing-process.cfm

Crackfilling Before Winter

2010-09-13T08:56:00.009-05:00

We recommend sealcoating every other year, but that doesn’t mean that you shouldn’t fill cracks and potholes every year before winter. While the sealer from the year before should still be protecting your drive, any cracks that were filled will probably be re-opened. Water will get into open cracks and expand with freezing, this will make the cracks bigger and accelerate the deterioration.

It’s a good idea to walk your drive before winter and look for cracks that have opened up. Cracks that are ¼” or larger should be cleaned and filled with a pourable crackfiller. This is an easy job for a homeowner and will save you money in the long run. Many hardware stores carry pourable crackfiller in 1 gallon jugs, just follow the manufacturers instructions for application.

Water infiltration is the most common cause of asphalt deterioration, so make sure you fill cracks every year – even if you’re not sealcoating.

Buy Crackfiller Online http://tinyurl.com/3xj9a32

Calling the Right Driveway Contractor

2010-08-10T16:37:00.014-05:00

Calling the right type of Contractor to work on your driveway can save you a lot of time. When your driveway needs work, it helps to know who does what type of work. Some Contractors do it all while others specialize in certain areas. The 3 main types of driveway contractors are Paving, Repair and Sealcoating.

Pavers will generally handle repaving the whole surface by either Resurfacing or Removing and Replacing your driveway. They are usually capable of excavating and installing a gravel base as well. If you find yourself saying the driveway is [insert problem] all over, you probably need a new driveway and should call a Paver.

Repair Contractors can either specialize in sawcut and remove or Infrared Repairs. If you have a few bad areas that can not be crackfilled, they may be candidates for repair. It’s usually not cost effective to repair single cracks; but alligatored cracks, settling and potholes are problems often repaired. As a rule of thumb, if less than 20% of the drive has issues it may be worthwhile to find a Repair Contractor.

Sealcoaters fill cracks, fill potholes with cold patch and apply either coal tar or asphalt emulsion sealer. If the only real issues on your drive are single cracks, calling a sealcoater every other year will keep your driveway protected.

To recap: If most of the drive is in poor shape - call a Paver, if you have a few problem areas - call a Repair Contractor and if the drive only needs minor crackfilling and a coat of sealer - call a Sealcoater.

It’s best to explain your problem when calling for an estimate and let the contractor decide if you are calling the right place. Most good contractors will refer you to a company that may be better suited for your project.

Email photos of your problem to danbrowne@asphaltadvisor.com and we will try to direct you to the right type of contractor.

White Stains on Freshly Sealed Asphalt

2010-06-17T08:54:00.008-05:00

It's not uncommon to see white or even rust colored stains on a freshly sealed asphalt driveway or parking lot. The natural inclination would be to blame it on the sealer, but the stains actually come from natural compounds found in water, gravel and soil.
Mineral Salts can dry on the surface as a result of water run-off. They can also be pumped up through soil and gravel to the asphalt surface. White residue will often show up where there are cracks.

Calcium Carbonate is also common in soil and gravel and can leave a white residue.

Rusty red orange and brown are other common colors of residue left from rusty cars and plant byproducts.

Stains are more noticeable on freshly sealed asphalt, due to the contrast. Be patient, the stains can't be avoided and will wash away in time.

Investigative Geology Report http://www.nacsupply.com/documents/AsphaltReport.pdf

Is Thicker Sealer Better?

2010-05-18T12:34:00.010-05:00

When it comes to the application of sealer, thicker is not better. Thick coats don’t cure evenly, are prone to tracking and can lead to surface cracks. A thicker coat takes longer to cure, which can lead to degradation and will reduce the life of your sealcoating project.

A sure sign of a driveway that has been over-sealed is a driveway without texture. An asphalt driveway should not look smooth like concrete, the asphalt texture should be visible. Applying a thick layer of sealer will not provide more protection. Sealer manufacturers set specific mix designs for their product; when you stray from these specifications, the product will not perform as intended.

Avoid the typical more is better thinking —with sealer, thicker is not better.

Brochure on the Benefits of Sealer http://www.tinyurl.com/35qwntz

How Thick Should My Asphalt Be?

2010-04-26T14:22:00.006-05:00

For the standard asphalt driveway over gravel, 2" is the most common specification. For an overlay (over asphalt), 1-1/2" is the typical specification. These thicknesses are after compaction, this is what you end up with. Some contractors put the thickness before compaction on their proposals, while other contractors list the finished thickness. it's very important to make sure you understand what the contractor is proposing so that you can compare contractors equally.

Lifts over 2-1/2" will not compact properly; if they say they're giving you 3", they will need to lay two 1-1/2" lifts for proper compaction. Any lift under 1-1/2" over asphalt will not be sufficient and will eventually segregate from the surface it was laid over.

Choosing a contractor is a leap of faith, you never know if you are going to get what you pay for. Knowing what you are looking for is the first step to finding a contractor that can deliver the job you deserve.

Resurfacing or Removal and Replacement?

2010-03-31T07:50:00.008-05:00

When the time comes to repave your driveway, the big decision is whether to resurface (overlay) or remove and replace the asphalt.

A typical resurface would include installing butt joints (cutting out asphalt where it butts up to other surfaces such as garage floors, aprons, sidewalks & curbs), the application of primer over the existing asphalt (this bonds the new asphalt to the old) and the installation of 1½” compacted surface asphalt. Resurfacing is less expensive than removal, but is prone to reflective cracking and drainage problems if your existing grade is marginal.

Removal and replacement would include removal of the existing asphalt, adding gravel to the base to obtain the correct grade, compaction of gravel and the installation of 2” compacted surface asphalt. While removals are more expensive, they should provide ideal drainage and reflective cracking is not an issue.

Resurfacing can be a viable option if removal doesn't fit into your budget; just keep in mind that when those first reflective cracks appear, it’s important that they be filled. If you are looking for a long term solution – it is usually more cost effective to opt for the more expensive removal and replacement.

Hiring an Amateur May Cost You

2010-03-17T08:40:00.010-05:00

A sealcoating business is relatively easy to start, all you need are a few supplies and you're in business. With that in mind, it's important to realize that there are many sealcoaters that have legitimate businesses, with a great deal more overhead than the guy sealcoating on the weekends out of buckets. You should always look for a local company that has insurance; if there is a problem, they will be easier to find and more likely to have the problem fixed.

There are companies out there that will sealcoat your driveway for less than it would cost you to do it yourself. If they don't value their services enough to charge accordingly, their services probably don't have any value. How can a company charge so little and still profit? They could be diluting the material (sealer is water based) to cut down cost or they may not be profiting at all and won't be in business for long. Anyone who has had a bad sealcoating job can attest to the value of choosing a qualified contractor. Look for a professional to do the work, stay away from amateurs just working for beer money. With sealcoating work, you really do get what you pay for.

For Qualified Contractors in Lake, McHenry, Cook & Kane Counties http://www.nacsupply.com/pages/find-sealcoater.html

Avoid This Driveway Scam

2010-03-12T15:03:00.005-06:00

You should be leery of any solicitor that comes to your door offering contracting services on the spot, the following driveway scam has been making the rounds for years. This scam has been used by both sealcoaters and pavers alike. The scammer comes to your door, claims that they have leftover material from a job they did down the road and says he is willing to offer you a discounted price. He then asks for payment in advance, does little or no work and then disappears with your money.

Contractors are very careful about the amount of material they pickup for a job and to have enough to properly complete another job is far fetched. Tip-offs are rented equipment, trucks without company names, out of state plates and a sense of urgency to do the job right away. Never pay up front for sealcoating or paving services; if you can't inspect the work before you pay, look elsewhere.

If you're approached with this scam, call the local police to report the offenders before they have a chance to scam your neighbors

For qualified sealcoating contractors in Illinois visit http://www.nacsupply.com/pages/find-sealcoater.html

When Is The Best Time to Sealcoat?

2010-03-02T15:00:00.007-06:00

You can usually get a quality sealcoat job from mid April to November in the Midwest. However, in the beginning and end of the season your applicator will need to keep an eye on a few variables. It's very important that the temperature is above 50 degrees and rising and that there isn't a chance of heavy rain within 24 hours. A light rain may not damage the coating if the sealer has had a few hours to skin over. Coal tar emulsion sealer is a safer bet early and late in the season, since asphalt emulsion has been known to be a little touchy in colder temps. On a hot dry day (above 90 degrees) the asphalt should be misted prior to sealing, to prevent the sealer from drying too fast and wearing prematurely. It's important that the misting doesn't cause puddles, too much water will dilute the material.

If you had to pick a perfect temperature, it would be around 70 degrees; but with the right preparation and care, a proper coating can be applied throughout the sealcoating season.

Reasons Behind Heaving Asphalt

2010-02-25T11:29:00.012-06:00

Frost heave is a common problem in colder climates. Many people are watching their asphalt heave as the winter temperatures fluctuate. The cause is the freezing and thawing that comes with above and below freezing temperatures that start the formation of ice lenses. Ice lenses form in the soil under the asphalt and push the surface up as they grow. They are fed from every direction and will continue to grow as long as there is an available water supply. Silt or clay soils are more susceptible to frost heave than better draining soil mixtures. Many people never notice the winter frost heave on their older driveways that have sunken at the garage; but once they repave and have a surface that is even with their garage floor, the heaving is much more noticeable.

Frost heave will take care of itself in many situations, once the temperatures raise. The best course of action is to wait until spring and see if the asphalt settles back to the correct grade. If the asphalt is still high, the severity will dictate whether it should be lowered by infrared repair or sawcut repair.

Are Infrared Repairs Seamless?

2010-02-18T11:53:00.010-06:00

Every repair process has seams, what matters is whether the seam is a cold joint or a hot joint (thermally bonded). Even new driveways have seams - everywhere a joint is matched, there's a seam. When infrared companies advertise their repairs as seamless, they are really saying that there isn't a cold joint where the repair meets the surrounding asphalt.

Every sawcut repair has a cold joint - this joint is a point of weakness that will always open up. The perimeter of the repair is sawcut, asphalt is removed and hot asphalt is installed against the cold edge of the surrounding asphalt. The two surfaces never bond and eventually separate.

Infrared repairs are thermally bonded - the asphalt is heated just beyond the repair area, allowing the repair area to become part of the surrounding asphalt. Without cold joints, there is no point of weakness.

Seamless (invisible) repairs are just not possible. The repair area is new asphalt, so the closer the texture of the surrounding asphalt is to new asphalt, the better the repair will blend. Sealcoating will help in blending the color, but extreme texture differences will appear as different shades of black. If you're looking for invisible repairs, it's time for a new driveway.

For More Information on Infrared Repairs go to www.asphaltrestore.com

Cold-Pour Crackfiller Expectations

2010-02-15T15:55:00.003-06:00

Most cold-pour crackfillers that are applied to cracks before sealcoating are used as a temporary solution to the problem. If you are really particular about having every crack filled perfectly, you might want to consider filling the cracks yourself before sealcoating. A typical sealcoating company will fill the cracks and then sealcoat the drive right away. As the crackfiller dries it usually shrinks down from water content evaporation, settles down from gravity and sets below the grade of the surrounding asphalt. If you do it yourself, you can apply a second round of crackfiller to make up the difference. If a sealcoating company were to do this, it would be very costly. Most people don't get crazy enough about the cracks to care, but if you think you might, you should consider doing the filling yourself.

Cracks that are 1/4" or larger are filled with a cold-pour crackfiller to slow the cracking process. Cracks under 1/4" are filled by way of the sealcoating process that follows, since they're too small to fill manually. Deep cracks may need to be filled first with a backer rod or silica sand to form a bed for the sealer to sit on. Each year cracks will get bigger, but without crackfiller the process will be accelerated. In the winter, water gets into unfilled cracks, freezes and expands the crack. In the spring you will notice that some of the filled cracks have reopened and will need to be refilled the next time you sealcoat.

If you want to tackle the crackfilling yourself, you can find an asphalt emulsion based crackfiller at most hardware stores in 1 gallon jugs.

Find Crackfiller Online at http://tinyurl.com/ybcfz2a

When Do I Need More Than a Sealcoat?

2010-02-10T13:36:00.008-06:00

Asphalt sealer protects structurally sound asphalt and does a lot to improve the aesthetics. When paired with crackfilling for individual cracks, sealcoating can get you by for quite a few years. But when you start to notice deep settlement, interconnected cracks (alligatoring), ravelling or potholes, it’s time for more extensive repairs or repaving.

The only time you really need more than a sealcoat is when there's a safety hazard; but sealcoating alone, over a bad surface will only make the surface black for a while and won't really add any structural value. So when you're only making the surface darker and find yourself thinking that the sealer isn't helping much, it's a good time to look into other options.

How Often Should I Sealcoat My Driveway?

2010-02-01T14:36:00.007-06:00

Sealcoating doesn't just make your asphalt black, it's necessary to keep your driveway from deteriorating. When the liquid asphalt that's holding the aggregate together gets oxidized, your asphalt becomes brittle and is prone to cracking. Sealer helps protect your driveway from the effects of the environment, think of it as a sunscreen for your asphalt.

How often should asphalt be sealcoated? The short answer is every other year, but there are exceptions. When a driveway is new, after it has cured, it should probably be sealed the first two years. The first application, generally doesn't cover as well as the coats that follow. After the first two years, every other year should suffice. Ideally, you would like for the sealer to wear off between applications. When a surface is sealed too much, the sealer will build up and can begin to crack.

If you have an asphalt driveway, it should have the texture of asphalt. If it looks and feels like a black skating rink, you've sealed way too much.

Why is My Asphalt Sinking at the Garage?

2010-01-27T11:26:00.010-06:00

Asphalt settlement at the garage is a very common problem and usually has nothing to do with an insufficient base. The settlement is usually due to an unavoidable side effect of new construction. Many new homeowners have a hard time accepting this, but it's possible for a properly installed driveway to settle in the first year. When your house was built, they started by digging for the foundation; the Builder has to dig a few feet further than the foundation, this is called the over-dig. Once the foundation is done, the over-dig area is backfilled. If the backfilled area were allowed to settle for a year, we wouldn't see this type of settlement. Builders are forced to install the gravel base and pave in short order (to get occupancy permits), while the sub-base slowly starts its natural settlement - bringing the gravel and asphalt with it. As time goes by, the sunken area collects water, accelerating the settlement.

In some cases the settlement can be due to undermining, holes may accompany the sinking. If this is happening, look at the edges for clues to see if a rodent is tunneling under the asphalt or if water from a downspout is washing away the gravel base.

If the rest of your driveway is in good condition, then an infrared repair is a good solution to either of these problems. The infrared repair will bring the asphalt back up to the right grade and provide a thermally bonded repair. However, if you have multiple problems, it may be more cost effective to repave.

Does Your Driveway Need To Be Repaved?

2010-01-22T09:59:00.016-06:00

Determining the right time to repave is very subjective. I’ve seen parking lots that are 20 year old messes where the owner is satisfied with a sealcoat. I’ve also seen driveways that are almost new where the homeowner wants a replacement because they don’t like the texture. The real answer falls somewhere between the two extremes. When evaluating a driveway, I ask myself, is it cost effective to repair? If the answer is no, it’s time to resurface or remove and replace.

Whether or not repairs will be cost effective depends on the extent of the damage. If a small percentage of the asphalt is damaged, it may be possible to do an infrared repair for a fraction of the cost of replacement. Problems like settlement at the garage or curb are common repairs that make sense. If a large portion of the drive is in bad shape with cracks or potholes all over, then your best bet is repaving.

When you realize that crackfilling and sealcoating are no longer making a difference and your problem areas are widespread, it’s time to bite the bullet and repave.