Class a roof assembly

Class A B or C is a measure of the external spread of flame on a roof. A roof is classified as a Class A as the result of one test the external spread of flame test ASTME 108 or UL 790 Standard.

What is Class A.

Class a roof assembly. Class A roof assemblies are those that are effective against severe fire test exposure. Class A roof assemblies and roof coverings shall be listed and identified as Class A by an approved testing agency. Class A roof assemblies shall be permitted for use in buildings or structures of all types of construction.

Accordingly Class A roof assemblies are suitable for use where Class A Class B or Class C roofs are required and Class B roof assemblies are suitable for use where Class B or Class C roofs are required. Unrated roof assemblies are not suitable for use in any applications requiring a Class A B or C rating except when specified in a code. Class A roof assemblies are those that are effective against severe fire test exposure.

Class A roof assemblies and roof coverings shall be listed and identified as Class A by an approved testing agency. Class A roof assemblies shall be permitted for. What is the difference between a Class 1 and Class A roof assemblies.

A roof is classified as a Class A as the result of one test the external spread of flame test ASTME 108 or UL 790 Standard. A Class 1 roof has undergone a series of tests that evaluate the entire roof assembly including the external spread of flame test utilized for the Class A rating. What is the difference between Class 1 and Class A roof assemblies.

A roof is classified as Class A as the result of one or three tests the external spread of flame intermittent flame and burning brand ASTM E108 or UL 790 Standard. Two consecutive passes of the 2-hour intermittent flame test are required to achieve a Class A rating. Four ways to achieve UL Class A with Atlas Roofing products.

Atlas has several ACFoam roof insulation products that can be used to help achieve a Class A fire resistance rating for a roofing assembly installed over combustible wood roof decks. These four designs offer a variety of options to. UL CLASS A APPROVALS.

ACFoam -HD CoverBoard-FR was developed with the same inorganic coated glass facers as ACFoam -III. ACFoam-HD CoverBoard-FR facers are bonded to a high-density polyiso foam core that offers increased dimensional stability and helps meet a UL Class A Rating in combustible roof deck assemblies. When completed the distance that the flame spread along the 8 ft length of the sample is measured.

If the flame spread is 6 ft or less the test result is Class A. If it greater than 6 ft but less than 8 ft it is a Class B. So the answer to the question of the difference between Class A and Class B is 2 ft.

In accordance with these standards all classified roof covering assemblies fall into one of the three following categories. Includes roof coverings which are effective against severe fire exposures CLASS B. That roof covering on roof assemblies that incorporate EPS insulation must be classified as part of a Class A B or C roof assembly.

Fireresistance classifications A B and C relate to exterior fire exposure and are intended to represent different levels of fire resistance performance. Common Class A roof coverings include asphalt fiberglass composition. Shingles concrete and flatbarrel-shaped tiles.

Some materials have a by assembly. Class A fire rating which means additional materials must be used between the roof. Covering and sheathing to attain that rating.

While roof assemblies containing polystyrene insulation can meet Class A there are no roof assemblies with polystyrene insulation applied direct to a steel deck that qualify as a Class 1. Understand the differences between a Class 1 and a Class A roof assembly containing foam plastic. A Class A rating is only for external fire performance.

Assembly-rated Class A roof coverings are those that meet Class A standards when combined with other elements. 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. Class A roof assembly containing foam plastic.

A Class A rating is only for external fire performance and is governed by compliance to either the UL 790 standard. Not all Class A roof systems meet Class 1. For example while roof assemblies containing polystyrene insulation can meet Class A there are no roof assemblies with polystyrene insulation applied direct to a steel deck that qualify as a Class 1.

What is Class A. Class A B or C is a measure of the external spread of flame on a roof. Barrier is not required for foam plastic insulation that is part of a Class A B or C roof-covering assembly provided the assembly with foam plastic insulation complies with NFPA 276 or UL 1256.

To qualify for use under Section 2603415 of the 2012 2009 and 2006 IBC a thermal. Yes all metal roofing has a default class A rating. However unless you can design a way to just put metal roofing on the building without a support system ie.

Floating the entire assembly has to have a rating. Most often UL or Gypsum Assoc. DECRA offers not only Class A fire rated roof assemblies to comply with WUI code but also can address Cool Color offerings for its stone-coated roof panels that meet California Title 24 energy code requirements or for anyone else seeking to significantly reduce solar.

G-P Gypsum DensDeck United States Gypsum Co SECUROCK Glass-Mat Roof Board Type SGMRX National Gypsum DEXcell Glass Mat Roof Board or DEXcell FV glass Mat Roof Board. Any UL Classified Type G1 G2 or G3 baseply sheet Type 15 20 or 30 felt or UL Classified prepared roofing accessory or GCP Applied. IBC Section 1505 requires that roof assemblies meet the UL 790 Class A B or C fire performance based on the type of construction of the building on which they are utilized.

UL 790 evaluates the ability of the roof assembly to resist a simulated fire source originating from outside the building on which the roof coverings are installed. Provided that the assembly with the foam plastic insulation is a Class A B or C roofing assembly where tested in accordance with ASTM E108 or UL 790. Building Code 2018 of Illinois 26 Plastic 2603 Foam Plastic Insulation 26036 Roofing.

Helpful documents and resources for USGs roof assemblies can be found on this page. Refer to our roof-ceiling assembly documents which includes UL fire-rated roof assemblies for easy guidance through the assembly of a roof or ceiling on your next project. Roofing systems are often specified according to the Class of roof required.

The class source or classifying authority however is frequently unidentified or omitted. Agencies governing the classification roof assemblies and components include the following. Underwriters Laboratories of Canada ULC.