Residential FAQ's
Below are some of the most commonly asked questions we receive about Residential Sealcoating Projects:
This is a very common problem. These many little cracks are usually caused by previous coatings of inferior sealer material which probably did not have the correct amount (if any) of rubberized latex which helps give the sealer the flexibility needed to expand and contract with our changing seasons. This problem may also be caused by poor paving or severe sun oxidation. You will still be able to see these cracks through our new sealer. This problem cannot be fixed by using sealcoating material.
Since some stained areas may be heavier or worse than others we cannot guarantee that you will not be able to see these areas upon the completion of sealcoating your pavement, or that the sealcoating material will adhere to the affected areas for an extended period of time. Please note that water from sprinklers and hoses may stain a driveway for a short period of time or until a good rain. This is not always the case, but sometimes we have found that houses with hard water or added water softeners may have this temporary mineral deposit problem. Please rest assured it is only temporary. Oil saturated asphalt has to be cut out and replaced.
Once your pavement cracks and/or chicken wire cracks are filled and sealcoated you will see a shadow under the sealcoat where we have applied the crack filler and/or chicken wire crack slurry patch. This shadow cannot be prevented, but is surely better than having the cracks worsen to an unfixable state leading to complete driveway failure. Synthetic asphalt and Hot asphalt repairs can show different texture and/or seams.
This is probably the most commonly asked question that we receive at our office. The reason there are some tire marks on the sealer is because we use sand in our material for added traction and durability. Without the use of sand in our material the sealer would only last for about half of it's normal life span. Since the sand is uniformly mixed into the sealer some of the surface sand will roll out when vehicle traffic is reintroduced to the pavement leaving some tire marks. This is a common concern, but rest assured these marks will dissipate within a few weeks. Be gentle with your turning for four weeks to limit any tire marks. No "K" turns! Please also be gentle when turning on any newly completed hot crack repairs on your pavement. The superior winter flexibility makes them easily marked during the summer months. Note, tire marks cannot be repaired, so please be gentle to your newly sealed pavement.
Please rest assured that when the new sealer is applied any leaves that fall on the new wet surface may stick for a day or two, but will blow off or disintegrate shortly thereafter not harming the new sealer in any way.
Sealcoating extends the useful life of the capital asset - your residential driveway - by protecting the pavement from the natural aging process caused by sunlight, water and debris. Sealcoat also protects pavement from degrading caused by leaking oil and other caustic products. An added benefit is that sealcoating adds to the "curb appeal" of a paved surface, giving it a clean, uniform look.
There are two essential options for sealcoating: refined coal tar- based sealers and asphalt-based sealers. Other options are cost-prohibitive for most applications. Coal tar can last 2-3 years while asphalt lasts approximetly one year. We only offer coal tar for the reason of value for the customers.
Asphalt parking lots and driveways are capital investments, increasing the value and functionality of a property. Like any infrastructure investment, sealcoating an asphalt driveway or parking lot must be maintained to keep both value and functionality over time.
Refined coal tar-based sealers are based on a selectively refined fraction of crude coke oven tar, which is a byproduct of the steel making process. Similarly, asphalt-based sealers are based on a selectively refined fraction of crude oil.
The majority of pavement sealers are an emulsion, a mixture typically consisting of water, clay, sand, polymers and usually less than 20% of either asphalt or refined coal tar.
Pavement sealers have been applied for over six decades. Sealing is a tried and true way to protect and beautify a pavement, prolonging its useful life and minimizing the need to replace the asphalt, which consumes a lot of energy (fuel to manufacture, deliver and install) and natural resources.
Most sealer manufacturers make both refined coal tar-based products and asphalt-based products. Even though most sealer manufacturers make both, most recommend refined coal-tar based for most applications because the superior performance of tar-based sealcoat allows the manufacturers to stand behind the performance of their products, enhancing the reputations of their businesses. Research and development projects continue to improve the performance of asphalt-based sealer, but there remains a way to go.
Refined coal tar-based sealers (1) protect the underlying asphalt pavement from leaking oil and gas spills, (2) last longer than asphalt-based sealer, (3) are more resistant to natural aging processes caused by exposure to the elements (sun, rain, freeze-thaw, etc.), (4) adhere (that is, “sticks”) to the underlying pavement better, and (5) are manufactured to a performance-based specification (ASTM® D490).
Asphalt-based sealers have many of the same beneficial properties as refined coal tar-based sealers. The tar-based product, however, is superior in strength, resistance to leaks/spills of petroleum products, UV bleaching and road salts.
One of the byproducts of manufacturing steel in coking ovens is coal tar. Out of the coking oven, this material is “crude coal tar” which, like “crude oil,” serves as a raw material that is distilled into many different fractions in coal tar refineries. The different fractions are then used to make many different products.
Some activists say that refined tar-based sealers are a health threat, but across the two, three and four generation memories of the many family-owned companies in the business of making or applying sealcoat, there are no reports of adverse chronic health effects – including cancer - that can be attributed to exposure to sealcoat.
Expanding the search for evidence of cancer to other products made from refined tar, every day millions of people world-wide use coal tar soaps, shampoos and creams approved for use as over-the-counter medicines to treat skin disorders such as eczema, psoriasis and dandruff. Coal tar and coal tar derivatives are listed by the US Food and Drug Administration (FDA) as “generally recognized as safe and effective” active ingredients for use to treat these skin ailments with coal tar concentrations up to 5% in over-the-counter products. Because of its use in medicines, many studies have been performed over nearly a century to see if the patients who intentionally expose themselves to high level doses of coal tar for long periods of time have increased risk of cancer. All the studies have reached the same conclusion – there is no evidence of cancer.
Studies of humans exposed to coal tar (other than via medicinal coal tar products) can be summarized as follows:
• There is no evidence that low level or intermittent exposure to coal tar or coal tar pitch has caused cancer in humans. This category describes exposures to refined coal tar-based sealer.
• There is little evidence that high level, repeated exposures has caused cancer in humans. This evidence is largely reports from the past, such as chimney sweeps in London in the 18th century (but not chimney sweeps in other countries at about the same time) and late 19th – early 20th century factories, at a time when industrial hygiene practices were virtually non-existent. The working conditions described in these reports include exposures to many chemicals in addition to coke and coal tar.
• There are some studies conducted in modern factories with high temperature (1000s of degrees Fahrenheit) industrial processes such as aluminum smelting or coke oven gases that show some adverse effects.
Because of the observations discussed in the previous paragraph, occupational exposures to coal tar and coal tar pitch in high temperature industrial settings have been listed as carcinogens by the International Agency for Research on Cancer (IARC). The listing is specifically for those very high temperature occupational settings, and is NOT for intermittent, incidental low to moderate temperature exposures such as might be associated with pavement sealer.
Similar to health agencies elsewhere in the world, the US FDA lists coal tar as "generally recognized as safe and effective" for sale as an over-the-counter (no prescription needed) skin medication. The FDA has found no evidence that coal tar causes cancer.
As discussed later on, there is a conflict between regulations based on actual human exposures to coal tar and those based on exposures of laboratory animals to laboratory-made compounds, for example in some states such as Minnesota.
In the US, the Resource Conservation and Recovery Act (RCRA) regulates waste materials “from cradle to grave.” RCRA exempts coke oven byproduct materials that are recycled to the “tar recovery process as a feedstock to produce coal tar, or mixed with coal tar prior to the tar's sale or refining” from hazardous waste regulation because refined coal tar does not exhibit any of the toxicity characteristics used by RCRA to identify hazardous wastes.
In addition to the coal tar generated as a coke oven byproduct,coal tars were produced during the now-defunct process of manufacturing gas from coal for use as a source of energy in municipalities across the North American continent. Hundreds of former manufactured gas plants (MGP) around the country are listed as “hazardous waste sites,” not because of the coal tar but because of substances mixed in with the coal tar that do have toxicity characteristics. The US EPA and federal courts have issued opinions that, unless a material displays toxicity characteristics because other substances are present, “MGP remediation wastes [that is, coal tar] are unlikely to be RCRA hazardous waste under the federal program, and would not be required to meet RCRA requirements, including Land Disposal Restriction requirements.”
Refined coal tar that is the base material used to make pavement sealer has been tested and does not meet the RCRA hazardous waste criteria. Different brands of pavement sealcoat emulsion tested at different times in different labs have all passed the EPA’s toxicity characteristic test, indicating that RTS does not meet the criteria to be a hazardous waste and disposal in non-hazardous waste landfills is appropriate.
The FDA evaluated safety of coal tar based on exposure of humans to medicinal products that contain coal tar. Controversies about the safety of refined coal tar-based sealer began because one of the components of coal tar-derived materials is a class of chemical compounds called polycyclic aromatic hydrocarbons (PAHs). Cancer classifications of PAHs by environmental agencies typically evaluate how laboratory animals such as rats and mice react when exposed to high doses of individual PAH compounds made in a laboratory. Test results in laboratory animals exposed to laboratory-made compounds are then used by regulatory agencies to make assumptions about how humans might react if exposed to PAH-containing materials.
Thus there is a conflict between regulations based on actual human exposures to real-world substances and regulations or guidance based on exposures of laboratory animals to substances that no one (except maybe laboratory technicians) is actually exposed to.
In the US, the Environmental Protection Agency recognizes that there are thousands of products and foods that contain some mixture of PAHs. Testing each one would be prohibitively expensive. So EPA's solution has been to develop methods of estimating risks that could be associated with products containing PAHs by extrapolating from laboratory animals to humans based on calculations of PAHs contained in a food or product. How the PAH compounds that are part of the make-up of coal tar and, to greater and lesser extents, of coal tar derivatives, could be calculated to cause effects so different from those seen in people exposed to products containing refined coal tar is a matter for academic study.
PAHs occur naturally; they are all around us and always have been. PAHs are made whenever something organic is heated up or burned. Smoke from forest fires and wood burning fire places contains PAHs. Plants decaying in a swamp or a compost pile are making PAHs. Emissions from planes, trains and automobiles, cooking food, lubricating oils, volcanic eruptions – PAHs are in all those substances as well as in materials derived from coal tar. This means that PAHs are everywhere in our environment. PAHs have been around since the dawn of man. If there was a fire that offered our ancestors warmth or light, or cooked their food, PAHs were present.
Like latex paints, sealer is applied as a water-based emulsion. All emulsions contain water. Evaporation of the water starts the process of “sticking” the sealcoat particles to each other and to the coated pavement. Sealer that is dry to the touch means that the surface can be open to foot traffic, but not vehicle traffic. Sealcoat can be driven on once the process of curing is well underway, meaning that the sealer particles are sticking to each other and the pavement. Curing takes more time than drying because it takes longer to drive out moisture that remains after the initial drying.
The odor of refined tar-based sealer is easily identifiable, for good reason: refined tar-based sealer has a very distinct odor, and the human nose is able to detect it at extremely low concentrations. But just because it may smell bad doesn’t mean it is bad!
The smell is primarily the presence of one substance among the many that are part of refined tar-based sealer – naphthalene. The odor threshold for naphthalene is below three parts per billion (ppb), a very low concentration. To put this concentration into perspective, the odor threshold for nail polish remover is 7,000.
According to the American Conference of Governmental Industrial Hygienists, the level of naphthalene that is considered safe for workers is ten thousand parts per billion. So the difference between being able to smell it and worrying about it is huge – four orders of magnitude, to be exact. Even refined tar-based sealer workers don’t experience those levels of exposure.
Industry standards recommend that you wait 6 months to a year or go through one winter before you sealcoat a new driveway.
Industry standards recommend every two years; allowing the sealer to wear away before you reseal the driveway. For more information about sealcoating asphalt driveways in New Jersey, contact us today!
Cracks 3/8 inch or up to approximately 1" ( excluding pavement edges) will be cleaned of all dirt and debris and filled with Crafco's Superflex HT HOT applied crack sealant. Crack sealant may settle below surface level and be visible after sealcoating. This is within industry specification. Edge Cracks/Broken off asphalt are not included in crack repair. Expansion Joint seams at the garage or street are not included in crack repair as well unless listed on your estimate.
For cracks greater than 1" or more we can use Cratco's Mastic One which is a HOT applied , pourable, aggregate filled, polymer modified asphalt pavement repair mastic. If you get a qoute from us it will be a separate line item. Ask us for more details or click here
We recommend that you power wash your driveway thoroughly several days before we arrive to sealcoat your driveway. The reason for this is because the sealer will have a chemical reaction with the fertilizer and mulch thus causing discoloration of the sealer.
The best times for sealcoating an asphalt driveway or parkign lot is Spring, Summer and Fall, as long as the ground and air temperature is 50+ degrees.