Fire Performance

How well a building performs in protecting life and property during a fire, rather than the composition of its materials, is the important criterion by which to judge the ultimate safety of a structure. Although hardwood flooring will suffer damage in a fire to an extent depending on the temperatures to which it is exposed and the duration of heating, certain Australian species exhibit an unusual resistance to flame spread.

Numerous flame-spread tests are used but the most common one cited by building codes is the ASTM E-84, the 25 foot tunnel test. This test method involves the use of a 20 inch by 25 foot specimen exposed horizontally to a furnace operating under forced draft conditions. The two results of this test are the flame spread index and the smoke developed index.

In the past, select grade red oak flooring was used as a standard and was given a flame spread index of 100. Today, red oak still has an index around 100 but is no longer used in the calculation of the flame spread index. The smoke developed index is still based on red oak flooring having a value of 100. The indexes are also based on inorganic reinforced cement board having a value of zero.

For regulatory purposes, interior finish materials are classified according to their flame spread. The classes are 0-25 for Class A or I, 26-75 for Class B or II, and 76-200 for Class C or III. For regulatory purposes, the requirement for smoke developed index is usually 450 or less.

	FSI	SDI
Alpine Ash (Eucalyptus delegatensis) 17mm	51	43
Australian Beech (Eucalyptus pilularis) 17mm	69	54
Australian Cypress (Callitris Glaucophylla) 17mm	51	184
Brushbox (Tristana conferta)	65*	450*
Jarrah (Eucalyptus marginata) 17 mm	26	20
Karri (Eucalyptus diversicolor)	45
Sydney Blue (Eucalyptus saligna)	55*	100*
Red Oak (Quercus spp.)	100	4100

Flame spread values for additional species of Boral Australian flooring will be available in the future as Boral pursues testing with the appropriate certified US laboratories. Please contact the Boral US office for additional information.

Reference:
Fire Safety of Wood Products, USDA, Forest Service, Forest Products Laboratory, Madison, WI

*Hardwood Plywood & Veneer Association Laboratory & Testing Service
Reston, VA