Roof Covering Classes

The astm e 108 ul 790 roof coverings test does not produce a flame spread rating.

Roof covering classes.

The preeminence of ul is most likely due to their ansi ul 790 protocol. The class a brand weighs 2 000 grams class b 500 grams and class c 9 1 4 grams. Class a provides the best fire resistance and therefore the best protection for your home. The operative word here is systems.

The list of approved laboratories is shown below. Fire resistance is covered in section r902 and insulation is addressed in section r906 but the majority of the requirements are presented in section r903 and r904 which address weather protection and materials respectively. Contrary to what many think there are no class a roofing membranes. Roof coverings that have passed the ul standard 2218 test are classified as either class 1 2 3 or 4.

We recommend having a class a fire rated roof covering but you should understand its limitations particularly those related to edge of roof issues since standard roof tests do not evaluate potential vulnerabilities at these locations. An example of an unrated covering is an untreated wood shake roof. Common stand alone class a roof coverings include clay tiles slate asphalt glass fiber composition shingles and concrete tiles. The fire rating of roof coverings is determined for all materials used in code compliant housing and is classified as class a b c or unrated.

It is a pass fail test under which a product either passes the criteria as a class a b or c roof covering system or it doesn t. A gas flame is cycled on and off. Examples of a class a roof covering include concrete or clay roof tiles fiberglass asphalt composition shingles and metal roofs. Assembly rated class a roof coverings are those that meet class a standards when combined with other elements.

It comes in various grades and colors. Class a is the highest rating offering the highest resistance to fire and unrated is the worst. As you contact various contractors or suppliers you should ask about roofing materials that meet ul standard 2218. It is very high quality and very low maintenance with a life expectancy of hundreds of years.

Commercial roofing 101 is a free 2 hour demonstrative class focusing on the principles of roofing and the relationship to property management. A class 4 roof covering receives the highest premium credit. Slate roofing is the perfect topping to an elegant home providing amazing textures and style. The irc addresses roof covering requirements in several areas.

Failure is defined as the point where the roof deck ignites. Under ul 790 roof systems are evaluated for external fire. We will discuss the different roofing systems advantages materials and demographic concerns of roofs and common problems associated with roof failures and how to identify them. Slate is considered to be the classiest type of roof cover.

The intermittent flame test. To meet class a the test specimen must resist 15 cycles class b eight cycles and class c three cycles.