Effect of "Blistering" on the Ignition and Flammability of Painted Gypsum Wallboard.
Effect of "Blistering" on the Ignition and Flammability
of Painted Gypsum Wallboard.
Mowrer, F. W.
NIST GCR 01-804; 15 p. January 2001.
Fire and Materials 2001. 7th International Conference
and Exhibition. Proceedings. Interscience
Communications Limited. January 22-24, 2001, San
Francisco, CA, 197-208 pp, 2001.
Sponsor:National Institute of Standards and Technology,
Available from: National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
1-800-553-6847 or 703-605-6000;
Fax: 703-605-6900; Rush
Service (Telephone Orders Only) 800-553-6847;
Order number: PB2001-102790
wallboard; gypsum board; cone calorimeters; fire models;
flame spread; paints
More than 300 gypsum wallboard samples coated with 0 to
8 layers of paint have been subjected to flammability
testing in the Cone Calorimeter. Testing has been
conducted with samples coated with either latex-based or
oil-based interior paints and subjected to imposed heat
fluxes ranging from 25 to 75 kW/m2. During some of the
tests, "blistering" of the painted surface has been
observed. This blistering phenomenon is most pronounced
in samples coated with multiple layers of oil-based
paint. As the number of coats of paint increases,
blistering is observed at lower imposed heat fluxes.
When blistering does occur, the time to ignition
decreases significantly, typically by a factor of 3 to
4, when compared with samples that do not blister, while
the burning duration remains approximately the same. The
potential for upward flame spread on painted gypsum
wallboard is addressed in terms of a modified version of
the Quintiere flame spread model. The concept of a
critical heat flux for upward flame spread is developed
as a means to account for the race between ignition and