PennDOT to Begin Tar-And-Chipping Operations in Washington County

Crews from the state Department of Transportation will soon be out and about to seal coat about 200 miles of roadways in Washington County.

PennDOT crews in Fayette, Greene, Washington and Westmoreland counties will soon begin this annual roadway-maintenance treatment—known more commonly as “tar and chip"—helps maintain and seal the road surface from moisture.

Seal coating is a crucial tool that PennDOT uses to stretch taxpayers’ dollars. “Repaving a roadway is always preferred over seal coating, since repaving can last up to 10 years with only routine maintenance,” said PennDOT District 12 Executive Joseph Szczur. “But given our financial realities, seal coating can add about four to five years of useful life to a roadway since it seals hairline cracks that can undermine the integrity of the road.”  

Seal coating is inexpensive compared to repaving, but motorists must contend with lose, chipped stones until the material settles into a solid surface. Generally, PennDOT can seal coat a roadway for about $10,000 per mile, while resurfacing costs approximately $150,000 per mile.  

This activity is performed only during hot weather and involves sweeping the roadway then applying hot, liquid asphalt. Fine stones are spread on top of the asphalt then the area is rolled and swept again to remove loose stones. Generally, it takes about two or three days for the stones to fully bond in the hardened asphalt.

Motorists should expect to reduce their speed on these roads until the stone and the asphalt fully bond.