- Author
- Fleischer, H. L.
- Title
- Performance of Wood in Fire.
- Coporate
- Forest Products Lab., Madison, WI
- Report
- Report No. 2202, November 1970, 10 p.
- Keywords
- wood | ignition | flame spread | penetration | timber | construction | building design | impregnation | fire retardant coatings | sprinklers
- Abstract
- About 60 miles west of Portland, Oregon, in what was once a fine timbered area, lies the small city of Tillamook. During World War II, several large dirigible hangars were built there, which have since been used for factory purposes. One ot these hangars is 1,000 feet long, 170 feet high at the crown, and 296 feet wide. It consists of a wood arched roof shell. The arch ribs are of the truss type, 18-1/2 feet deep, spaced on 20-foot centers. Wood purlin trusses, rafters, and roof sheathing of 2-inch wood planking complete the construction. All wood parts in this building were pressure treated with fire-retardant chemicals. In the summer of 1955, a fire started in an exhaust duct, at a considerable height on the roof. the fire swept both up and downward over the roofing material on the outside of the building, stimulated by a strong wind. Firemen called to the scene were able to reach only about one-third the height of the building with their hose streams. After the fire had burned for about an hour, firemen working on the roof were able to reach the flames with their hose lines, and the blaze was controlled. for 6 additional hours, the fire continued to smoulder in hidden spots until finally extinguished.