Fire Retardant Roof Covering Class C

The maximum flame spread is 6 feet for a class a rated roof 8 feet for class b and 13 feet for class c.

Fire retardant roof covering class c.

The rating is determined by a set of fire tests in a simulated fire. Wood shake plywood or particle board roof are the most common roofing types listed as class c. This fire retardant treated wood shake roof covering is an assembly rated class a roof. Fire retardant surface coatings and other building materials.

Class b fire retardant treatment is effective against moderate fire exposures. How fire resistant is your current roof. Class c roofing materials. Obviously since wildfires and the fire season has become increasingly worse it is important to note the roofing materials that are the lowest rated.

In this case the fire retardant treated shake is a stand alone class b covering. Class a b c roof coverings class a b or c roofing systems are sometimes confused with class a b c i ii iii flame spread categories above. Class c fire resistant roofing material. Tested roof systems are fire classified class a b or c where the most fire resistant roof assemblies are class a and class c is least resistant.

An unrated roof is the most vulnerable the most common example of an unrated roof covering is one made using non fire retardant treated wood shakes or shingles. The underlying gypsum glass fiber panel densdeck material provides additional protection and is required for the class a rating. If wood shakes and shingles are impregnated with fire retardant chemicals they meet the requirements for a class b fire rating and can meet a class a rating if additional materials are included in the roof assemblies. 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.

Fire resistant roofing materials have specific classifications. Class a is the most fire resistant and should be the. Under such exposures roof coverings of this class are not readily flammable afford a moderate degree of fire protection to the roof deck do not slip from position and pose no flying brand hazard. The tendency is to assume that class a roof systems have a class a flame spread and so on but there is no correlation.

It means how your roof performs in a fire on the exterior of your property where coverings are installed on a non combustible or combustible deck. For example shake roofing with a fire retardant treatment rates class b on its own but achieves a class a rating when combined with specified underlying materials such as type 72 roll roofing material. The fire rating of a roof covering is either class a class b class c or unrated. The astm e 108 ul 790.