Manassas Journal Messenger | Insulation ignites on school roof

For the second time in less than three months, a Prince William County high school under construction caught fire when a worker accidentally ignited highly flammable material on the roof.

Georgia-Pacific foam insulation ignited, and flames rapidly spread on the roof of what will become the county’s ninth high school. The as yet unnamed school is in the county’s Dominion Valley area north of Haymarket.

A similar fire in late May at a high school on Neabsco Mills Road in Woodbridge when a torch used by a worker to cut a hole in the roof ignited the Styrofoam insulation. Part of the roof there was destroyed.

Firefighters at the scene said the Styrofoam is petroleum-based.

The circumstances and effects of the two fires are identical, a firefighter at the scene Wednesday said. Two different general contractors are working on the schools.

No one was hurt in either blaze.

A plumber from the Tyler Mechanical Company was making a hole from underneath the school’s roof Wednesday with a cutting torch and lit the Styrofoam insulation at 7:30 a.m., said Battalion Chief C. Hadden Culp, Prince William Department of Fire and Rescue spokesman.

Workers are required to follow a specific process when cutting from underneath a roof, including measuring the distance of the hole and having a spotter, according to officials.

“Clearly, not all the steps of that process were followed,” Culp said.

Wednesday’s fire destroyed an entire stack of Styrofoam, which was shoveled off the roof by firefighters and construction workers after the blaze was put out.

The west side of the building had heavy smoke stains, and the roof decking was charred and covered with small bits of crisped foam. In a muddy area below the school, workers and firefighters with blackened turnout gear tossed the burned pieces into a large pile with girders, beams and scrap floor decking. Firefighters sprayed the pile from above to extinguish the smoking remains.

It took 60 firefighters from Prince William, Loudoun, Fauquier and Fairfax counties and Manassas one hour to control the blaze. The cellular structure of the Styrofoam helps repel water, the makers of the insulation said in product literature.

“Based on what I’ve observed, it’s very flammable and generates a lot of heat and a lot of flames,” Culp said. “By that very nature, it means it needs a lot of water to put out.”

Water and specialized fire-suppression foam were used to stop the fire, which was encroaching on a higher roof section also covered in flammable material. Another pile of insulation was stacked next to the one that burned, but never caught fire.

“When you take a material like this that is very flammable or combustible, when you stack it up like this, it poses one of the challenges for the fire department in dealing with a building under construction,” Culp said.

The project is being supervised by the Dustin Construction Company of Gaithersburg, Md., which has not yet turned over control of the building to the school board.

The school is set to open in September 2004 and will not affect the coming academic year, Culp said. Damage costs were not available Wednesday. Total estimates will depend on whether the smoke-stained bricks will have to be replaced.

Staff writer Daniel Drew can be reached at (703) 878-8065.