Roof Covering Classes

The irc addresses roof covering requirements in several areas.

Roof covering classes. As you contact various contractors or suppliers you should ask about roofing materials that meet ul standard 2218. The preeminence of ul is most likely due to their ansi ul 790 protocol. Class a is the highest rating offering the highest resistance to fire and unrated is the worst. An example of an unrated covering is an untreated wood shake roof.

A gas flame is cycled on and off. 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. The astm e 108 ul 790 roof coverings test does not produce a flame spread rating. Class a provides the best fire resistance and therefore the best protection for your home.

Slate is considered to be the classiest type of roof cover. Assembly rated class a roof coverings are those that meet class a standards when combined with other elements. Examples of a class a roof covering include concrete or clay roof tiles fiberglass asphalt composition shingles and metal roofs. The class a brand weighs 2 000 grams class b 500 grams and class c 9 1 4 grams.

Participants earn 2 0 cma continuing education credits. A class 4 roof covering receives the highest premium credit. It is an entirely different test from astm e 84 ul 723 and it includes weathering per the astm d 2898 standard rain test. It is very high quality and very low maintenance with a life expectancy of hundreds of years.

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. 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. Common stand alone class a roof coverings include clay tiles slate asphalt glass fiber composition shingles and concrete tiles. To meet class a the test specimen must resist 15 cycles class b eight cycles and class c three cycles.

Slate roofing is the perfect topping to an elegant home providing amazing textures and style. It comes in various grades and colors. 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. The operative word here is systems.

The list of approved laboratories is shown below. Contrary to what many think there are no class a roofing membranes. The intermittent flame test. Commercial roofing 101 is a free 2 hour demonstrative class focusing on the principles of roofing and the relationship to property management.

Under ul 790 roof systems are evaluated for external fire. Roof coverings that have passed the ul standard 2218 test are classified as either class 1 2 3 or 4.