8510 concord mills blvd. a building under construction having a layer of tar on the roof caught fire. the cause was a torch and the tar and propane line burned. engines 6,7 both 75 foot quints got all workers off the roof. 2 lines on the roof and 1 inside to control the fire. engines 5 at hydrant for supply ladder 3 on rescue and search. rit by rescue 5,3. danage was minor but did burn 30,000 square foot of roof tar. smoke seen for 4 miles.engines6,5,7 ladder 3 rescue5,3 bc1