A Project Manager hired a roofing contractor to replace the roofing on a pavilion-hipped 1906 building during the winter season. Although the hipped roof was a shingle job, buildings were added to the south and east sides, requiring the addition of a built-up valley for proper water drainage. This required a rolled roofing system to be installed in the valleys. The project’s execution plan specified a self-adhering membrane system for the valley with no hot work being required.
When the contractor was ready to remove and reinstall the self-adhering two-sided base and granular surfaced top cap membrane in the valleys the outdoor temperature was only 38 degrees. Therefore, the contractor decided they would need to warm the material with a propane torch.
As required, the contractor requested a Fire Hazard Permit. Neither the roofing contractor, nor the authorized representative issuing the Fire Hazard Permit, informed the Project Manager of the change to use a propane torch from the project’s original plan.
The inspection of the work area by the authorized representative did not adequately identify the hazards/risks involved with the hot work on the wooden structure. The representative failed to:
§ Visit the inside of the building during his inspection;
§ Complete the Fire Prevention and Protection Instructions section of the permit; and
§ Require any additional safety measure (i.e., extend the length of time required for the fire watch based on the potential hazards/risks of the hot work).
The authorized representative approved the Fire Hazard Permit and the roofing contractor assigned two Fire Watchers; one on the roof, and the other inside the building as the roof was visible from the floor. The authorized representative or roofing contractor did not address the following Fire Watch concerns:
§ The level of dedication to fire watching by the inside fire watcher;
§ The diminished amount of light inside the building at the roof height; and
§ The use of indoor/outdoor semi tinted safety glasses by the inside Fire Watch.
The roofing contractors completed their torch work and conducted the OSHA minimum 30-minute fire watch before leaving the roof. However, it is questionable whether the inside fire watch was conducted for the entire 30 minutes or if the individual was dedicated to their fire watch responsibilities.
Shortly after the torch work had completed, the Authorized Representative made his final inspection of the work area, however the following procedure deviations took place during the inspection:
§ The roof was not entered to fully inspect the work area, as it was viewed through a window; and
§ The inside of the building was not entered to inspect the roof from below.
It is suspected that the torch work in the corner of the valley caused debris, dust, or other materials inside the dead area, below the corner of the valley, to ignite and smolder. Inside the building the ventilation pulled any smoke from the smoldering fire toward the vent on the roof. While it is apparent that this smoke was not seen by the roofing contractors before they left, the visibility issues and potential lack of dedication to fire watching makes it difficult to definitely say that some early signs of smoke may not have been present at the time the fire watch ended. The first report of the roof being on fire was one hour after the roofing contractors had left the roof.