Flame Spread Index For Class A Roof

Fibrated coatings and asphalt emulsions retain the class a to higher slopes as do the fr modified and fr single ply systems.

Flame spread index for class a roof.

Smoke developed index 0 450 fire class a designation refers to material that may ignite but will not sustain a flame. Polyiso remains the only foam plastic insulation product for direct application to steel roof decks to earn fm approval for class 1 roof systems. In all cases smoke development must be less than 450. Class a roofing is the preferred choice for any home but this type of roofing is particularly important if you live in an area that is prone to wildfires.

The nature of the surfacing and the slope of the roof greatly affect spread of flame. Experience maximum flame spread of 6 feet. The maximum flame spread is 6 feet for a class a rated roof 8 feet for class b and 13 feet for class c. When conducting healthcare renovations almost all facilities require temporary containment materials to be used the meet the astm e 84 class a fire rated requirement.

Flame spread 25 or less frtw some fr surface coatings class b or ii. Flame spread and smoke development astm e84 in order to obtain the flame spread classification results must fall into a range between 0 and 25 to be class a 26 75 for class b and 76 200 for class c. Through the e 84 test both the flame spread index fsi and smoke developed index sdi are reported for a given sample. Lexan thermoclear thermoclick and corrugated sheet products have a class a.

This is proven if it can. And class iii or c with a 76 200 fsr. Class i or a with a 0 25 fsr. Flame spread 26 to 75 other fr surface coatings class c or iii.

Class a or i. Fsi is the measurement for the speed at which flames progress across the interior surface of a building while sdi measures the amount of smoke a sample emits as it burns. Flame spread index 76 200. Whole wood materials are usually class ii while reconstituted wood materials such as plywood particle board or hardboard are class iii.

In general inorganic materials such as brick or tile are class i materials. Flame spread 76 to 200 untreated lumber and plywood. Foam plastic used for insulating interior walls ceilings and floors of commercial buildings requires class i foam having a flame spread index of 75 or less in some circumstances 25 or less and smoke developed index of 450 or less. Class a products will not generate excessive visibility obscuring smoke an important factor in designing safe egress for building occupants.

Class ii or b with a 26 75 fsr. On very low slope commercial structures even a glaze coating of pure asphalt may meet class a flame spread. The flame spread categories are as follows per astm e 84 ul 723. To achieve a class a rating the roof must be effective against severe fire exposure.

The slope of the test specimen is preselected and since steeper slopes are more of a challenge due to melting material feeding the fire the rating applies to the maximum slope passed. The most commonly used flame spread classifications are.