Construction crews had been installing insulation foam board and a rubber membrane on the metal roof of a building reportedly rented by Diversitech when they reportedly noticed smoke coming from the roof around 12:30 p.m.

All the occupants and employees were evacuated from the building, and there were no injures. It was unclear how the fire got started, said Rockdale Fire Division Deputy Chief Mike Lee.

The windy conditions of the day made putting out the fire difficult.

"The wind was blowing between the roof decking and underside of the membrane," said Lee. "It was pushing it underneath. You can't see it until you tear it apart. The more you tear it apart, the more it pushes the heat along."

About a quarter of the building's roof, or an area approximately 100 feet by 200 feet, was damaged, said Lee. No fire and very little smoke got inside the building, said Lee.

A nearby business, Llio-Chem, offered and brought over 200 gallons of foam for firefighters to use if needed. "I thought that was a very nice gesture, because they didn't have to do that," said Lee.

Four engines and about 25 fire division personnel turned out for the effort. Mutual aid from DeKalb County was requested and on standby at Station 7 in case of other fires.