- Author
-
HInkley, P. L.
|
Wraight, H.
- Title
- Contribution of Flames Under Ceilings to Fire Spread in Compartments. Part 2. Combustible Ceiling Linings.
- Coporate
- Fire Research Station, Borehamwood, England
- Report
-
FR Note 743
January 1969
44 p.
- Distribution
- AVAILABLE FROM: BRE, Fire Information Services, BRE Library, Garston, Watford, Herts WD2 7JR, UNITED KINGDOM. Telephone: 44-1923-664069, Fax: 44-1923-664910, Email: [email protected] Website: http://www.bre.co.uk
- Keywords
-
compartments
|
combustibles
|
fire spread
|
ceilings
|
linings
|
heat transfer
|
burning rate
- Abstract
- In order to devise rational tests and performance requirements for combustible linings in various positions in buildings it is necessary to have some quantitative design criteria either from direct experience or from research. There are still many difficulties in presenting a clear description of the processes of fire growth and the contribution of the many factors involved. In parallel with an international study covering the factors in fire growth, certain fundamental features are being studied in detail, and this report is one of a series investigating the characteristics of flames beneath various kinds of ceiling. At some stage in the growth of a fire in an enclosed space the flames from materials on the floor are deflected by the ceiling and extend horizontally. It was shown in part 1 that, even when the ceiling is incombustible, the horizontal flames dramatically increase the radiation to unburnt fuel away from the fire and this alone leads to fire spread irrespective of other influences. This report shows that a combustible lining will cause an increase in the length of the horizontal flames and a more rapid increase in the intensity of downward radiaiton thatn an incombustible one. The types of lining investigated were all cellulose-based building boards ans with most of these (including untreated fiber insulating board) the lengths of horizontal flames depended on the size of the fire on the floor; when this was restricted fire would spread indefinitely beneath only one of the boards tested, a stove-enamelled hardboard. Apart from this material, differences between linings lay in the rate of increase of downward radiation much more than in the intensity finally attained. The measurements of downward radiation were used to estimate the spread of fire over a narrow strip of combustible material on the floor, the assumption was made that the flames from a narrow strip would be small so that they would not affect the ceiling fire and it was found that the initial rate of spread varied with performance of the material on the Fire Propagation Test. The final rate of spread with the exception of stove-enamelled hardboard did not depend on the type of lining.