5 Fire Behavior And Building Construction Flashcards
Exposed interior surfaces of buildings including but not limited to fix your movable walls and partitions columns and ceilings commonly refers to finish on walls and ceilings but not floor coverings
Interior finishes
Building code usually exclude surface treatment such as paint and wallpaper no thicker than
1/28 “
Degree to which fire can spread over the surface of a material is technically referred to as the
Surface burning characteristics of the material
Speed of flame spread over interior finishes influenced by factors such as
Composition of material
Ventilation
The shape and space in which the material is installed
Whether the finish material is applied to ceiling or wall
Within product, quarter inch or less, will propagate flame faster one attached to studs with airspace behind it then when attached directly to more solid material such as gypsum. Building codes therefore require
Those materials with faster burning rights to be installed over noncombustible surface
Three classes of interior finishes
A, B, C
Class a material interior finish
0 through 25 flame spread rating are required in vertical exits of most occupancies
Interior finish class B material
26-75 flame spread rating required and hallways that provide exit access
Class C interior finish material
76-200 flame spread rate
Class a B or C interior finish materials may be required in other rooms and spaces depending on occupancy rooms of healthcare in assemblies for example will require
Either class a or B interior finish
HHR heat release rate
Total amount of heat produced or released to the atmosphere from the convective lift fire phase of a fire per unit mass of fuel consumed per unit time
A greater heat release rate results in faster developing fire. The faster the available fuel burns the
Greater the heat released rate will be
Flame spread rating
Numerical rating assigned to a material based on the speed and extent to which a flame travels over its surface
Steiner. Tunnel test
Unofficial name for the test used to determine the flames spread ratings of various materials
Assembly
All components or manufactured parts necessary for and fitted together to form a complete machine structure or system
Most commonly used method for evaluating surface burning characteristics
Steiner tunnel test
Interior finishes are tested to derive several measures of a materials flammability:
Flame spread rating and smoke developed rating
Steiner tunnel test is also identified as
ASTM standard E84, UL 753, NFPA 225, standard method of test of surface burning characteristics of building material
Flame spread rate of gypsum wallboard
10-15
Flame spread rate of treated Douglas fir plywood
15-60
Flame spread rating of mineral acoustical tile
15-25
Walnut faced plywood flame spread rating
171-260
Flame spread rating veneered woods
Approximately 515
To derive the numerical flame spread rating what is used as a baseline
Asbestos cement board and red Oak flooring