architecture - engineering - construction
Homasote Co.
Structural - Sound Deadening - Insulating Building Products
Flame Spread Ratings
Structural - Sound Deadening - Insulating Building Products
In order to evaluate fire safety of a structure, building authorities consider may factors including flame spread ratings. The best known flame spread test is the tunnel test, ASTM E-84. The following table shows the flame spread index for each of the flame spread classifications:
TABLE 1: FLAME SPREAD RATINGS |
|
Flame Spread Classification |
Flame Spread Index |
Class I (or A) |
0 to 25 |
Class II (or B) |
26 to 75 |
Class III (or C) |
76 to 200 |




