SECUROCK Roof Boards— A Weapon Against Fire

Fire is a major concern for every building owner and designer of commercial properties.  Whether it is from inside the building or externally, a fire can cause life safety issues as well as major damage.  Fortunately, roof boards can help contribute to fire safety and lessen this issue for all concerned.  Below are some of the testing agencies that concern themselves with fire ratings, how the SECUROCK Roof Board portfolio can assist in fire safety, and a recent account of how SECUROCK Roof Boards made the difference.

Let’s first look at the two primary certification agencies: UL & FM.  UL (Underwriters Laboratories) is a global independent safety science company offering expertise across five key strategic businesses: Product Safety, Environment, Life & Health, University and Verification Services.  UL has both exterior and interior classifications.  FM (Factory Mutual) is primarily concerned with loss prevention issues. In terms of fire, FM tests are used to judge the contribution of roof assembly components to the spread of fire within a building. Both of these testing agencies are very critical to understanding how building products can contribute to fire safety.

For external fires, UL uses test standard UL 790 (equivalent to ASTM E-108) and FM uses FM 4450 or 4470.  UL 790 has three components: a spread of flame test to see how easy it is for fire to spread, intermittent flame to simulate wind conditions and a burning brand test to simulate burning objects falling on the roof.  From these tests, three classes (A, B, C) are determined with Class A being the best.  For FM 4450 (insulated steel deck) and FM 4470, the roof system is subject to a series of tests that subject it to internal fire, external fire, wind uplift, foot traffic, impact resistance, and susceptibility to heat and damage.

With internal fires, look to UL 1256 and UL 263 as well as FM 4450 or FM 4470.  UL 1256 and UL 263 evaluate resistance to fire that start within a building.  UL 1256 is for fire testing of roof deck constructions and uses two parts to evaluate “White House” and “Steiner Tunnel”.  For UL 263, a P series is given to systems that are able to contain fire and/or retain structural integrity during a given exposure time frame.  And because fire is a concern for parapet walls as well, both ⅝” SECUROCK Roof Boards meet the Type X classification per ASTM C1396, which is a 1-hr load rating on a wood stud wall assembly attached vertically with joints staggered 16 inches on each side and tested in accordance to ASTM E 119. With FM 4450 and FM 4470, a Calorimeter test will measure the fuel added to an internal fire from the roof assembly.  In order to achieve a Class 1 rating, you must pass this test.  A roofing system that qualifies for a FM Class 1 will qualify for the lowest insurance rates from FMG affiliated insurance companies.

We hope that helps with the basics of how products and systems are rated. Here’s how USG’s SECUROCK Roof Board products rate.  As always, fire classification is a complex subject, so don’t hesitate to contact any of our sales representatives, UL, or FM for further clarification.

Click here to download the PDF: Fire rating chart

Click here to open chart in Excel: Roofing Blog Chart

 

Finally, we’d like to share a recent incident that happened on a job that was using SECUROCK Gypsum-Fiber.  All of the pictures shown are from a recent job in Chicago that was under construction when a fire was ignited inside the building from a welder’s torch. This was not an external fire, but an internal fire. Wood blocking at the base of the curb caught fire from the welder’s torches. The fire traveled up the curb and across the roof.  The insulation burned down to the SECUROCK Gypsum-Fiber and was extinguished by the material at that time.  Had it not been for SECUROCK Gypsum-Fiber, more (or perhaps all) of the roof and building would’ve been lost.  Fortunately only a small area of roof board, insulation and membrane had to be replaced.  Regardless, sometimes it’s not only post construction fires that everyone needs to worry about, fires can happen during the construction period as well.

Please let us know if you have any thoughts or questions.