How Warm Does It Have to Be for Asphalt Sealcoating?
Winters in Chesterfield County can vary considerably from one year to the next. However, during a typical winter, your asphalt pavement will be subjected to multiple freeze/thaw cycles, freezing rain and sleet, and snowfalls that can result in accumulations of up to four inches. Around the middle of February, asphalt companies begin receiving numerous calls from property owners and managers who are dismayed by the condition of their asphalt parking lots or other pavements. Before the onset of cold weather, their pavements had a smooth, unblemished surface that had a lustrous, rich, dark color. With the official end of winter still a month away, they are chagrined to find that their pavements look dull and are showing signs that the sealant has deteriorated. The question that they want answered is whether it is warm enough to have fresh sealant applied. The answer is that it is probably not going to be possible to perform a high-quality sealant application before the middle of March. However, there could be isolated days before that date when it might be possible. To understand why contractors prefer to avoid sealcoat jobs during the winter, it might be helpful to understand how temperatures affect sealants.
How Warm Does It Have to Be for Asphalt Sealcoating?
How Do Temperatures Affect Asphalt Sealants?
By volume, sealant mixes contain more water than any other ingredient. This water must be evaporated for the sealant to cure properly and form a continuous film that creates a hard shell over your pavement. As you are probably aware, the higher the temperature, the greater the rate of evaporation. This is why a pan of water placed on a stove burner at high heat will evaporate faster than an identical pan of water sitting on your kitchen counter, which will evaporate faster than an identical pan of water placed in your refrigerator.
Sealant manufacturers specify that their products should not be applied unless both the ground and air temperatures are at least 50 degrees Fahrenheit and rising. Furthermore, for at least the first 24 hours after application, the temperature cannot fall below 50 degrees. If the sealant is subjected to lower temperatures, the particles will have difficulty knitting together to create a continuous film. In addition, even if the top layer seems dry, the curing process is not complete until the underlying layers have dried. These uncured layers will fluctuate with temperature changes at a different rate that the top layer, resulting in flaking and cracking of the sealant. At best, the life of the sealant will be dramatically reduced; at worst, the entire job will need to be redone if you want to ensure that your pavement is properly protected.
Are There Other Factors Besides Temperature That Affect Asphalt Sealants?
There are times when the temperatures are marginally acceptable, but other factors may still make it unwise to apply a sealant. High humidity levels and extremely still air both slow the rate of evaporation. If temperatures are marginal, the relative humidity would need to be below 50%; there should also be a slight breeze. Because sealants need to be exposed to several hours of sunlight to cure properly, the shorter days of winter can pose a problem, especially if the area lies in heavy shade.
The scope of the job can also influence a contractor’s decision about applying a sealant. For example, if parking lot striping is to be performed after the sealant is applied, the weather will probably need to be cooperative for two or three consecutive days. The type and scope of other asphalt paving services, including crack filling and pavement patching, can also be a factor. Extensive parking lot repair services to correct alligator cracking, sinkholes, or foundation issues may need to be completed before the contractor can even consider applying a sealant.
Because conditions can change rapidly, your best bet is to contact US Asphalt Maintenance for a free asphalt service consultation and quote. We keep a careful eye on the weather, so we can advise you on whether conditions will likely make it feasible to perform the work you need on the day you prefer. We are the company trusted for asphalt sealcoating Midlothian and Richmond properties for more than three decades. We offer an extensive range of services for maintaining asphalt pavements, including sealcoating, crack filling, striping and pavement marking, and preventive maintenance programs. We are known for our integrity, our high-quality work, our professionalism, and our customer service. For a free quote, call 804-625-7325 or submit the online form.