How To Sealcoat in Cool Weather

Tips for sealcoating as the temperature cools in fall.

Crews work to sealcoat a road at the University of California/Davis.
U/C Davis Arboretum and Public Garden, courtesy of Oregon State University, Wikicommons

As the sealcoating season nears its end, customers often urge contractors to try to squeeze in one more job, and contractors themselves want to complete as much work as possible rather than bump projects to the spring.

And while sealcoating as the weather cools can be successful, there are precautions to consider.

1.      Factor into your bid and production process that there are fewer daylight hours and temperatures are cooler. Ambient temperature needs to be 50° F and rising at the time of application for sealer to be applied successfully, so start sealcoating later in the morning and stop earlier in the afternoon to give the sealer hours of sunlight to dry.

2.       Because of shorter sealcoating windows, your crews will produce less square footage in a day, which could mean applying coats on separate days on two-coat jobs. A second workday means an additional mobilization, so factor that into your bid and scheduling.

3.       Keep an eye on the overnight temperatures. If the overnight temperature drops below about 40° F it’s unlikely the pavement will warm enough to sealcoat the next day.  

4.       Always follow manufacturer’s recommendations but consider using about 5% less water in the mix design aid drying. Consider additives designed to speed drying and curing, and follow manufacturer’s recommendations closely.

Following these suggestions – and your sealer manufacturer’s’ recommendations – you should be able to sealcoat deeper into the season. But if you’re concerned about the success of the job, try to convince your customer to move the job to the spring. And if your client insists on your sealcoating their parking lot, have them sign a waiver. Anytime you’re doing work that conflicts with sealer manufacturer’s specifications you need to protect yourself.