FM Global, est. in 1835, is the largest commercial and industrial insurance company in the world with more than 2.000 loss prevention engineers.
To help prevent and mitigate loss, the company recommends FM Approved products as the best products to prevent different types of risks.
FM Approvals, est. in 1886, certifies products and services focused on loss prevention.
It counts currently with more than 60.000 products from 61 countries certified under its own 215 Product Testing Standards.
“There has not been a hurricane in North America in the last 25 years which would have damaged a building constructed in accordance with FM Global design guidelines.”
Peter Sparks, Clemson University
Standard Class Number 4431 states Approval requirements for skylights preventing hazards such as fire, hail and wind.
Spread of Flame Test
All FM Approved skylight are subjected to a fire test to evaluate their ability to limit flame spread and the propensity to melt and drip and its ability to maintain its structural integrity.
Two independent tests are conducted, in accordance with the Spread of Flame Test from an Exterior Ignition Source, with a continuos exposure of 10 minutes to the whole product as itself.
Rating available are Class B and Class A (the most restrictive), what means:
· End test sample shall not propagate flame more than 6ft (1,8m) from the flame exposed end.
. Any particles that melt, drip or otherwise fall off during the test shall not be flaming or glowing upon contact with the floor.
Sunoptics classification: Class A at 1/4 in 12.
Hail Resistance Test
The FM Approved skylight are tested under a simulated hail impact in accordance with the Simulated Hail Resistance Test Using Freezer Ice Balls.
Two products are tested, one of them after a exposition of UV radiation for a period of not less than 1.000 hours.
Two ratings are available:
· Moderate Hail: 1,5in (38mm) diameter ice ball with a kinetic energy of 10,4J.
· Severe Hail: 1,75in (44mm) diameter ball with a kinetic energy of 20,3J.
In addition the Severe Hail could be done with a 2,0in (51mm) ball and 36,4J.
Sunoptics classification: Severe Hail with 2.0in diameter ice balls.
Wind Uplift Resistance
All FM Approved skylight are subjected to simulated wind uplift resistance test in order to determine the product’s ability to resis anticipated loads imposed by wind forces on a roof system.
The test defines that air is introduced from below the sample in steps of 15psf (0,7kPa). After each increment, the pressure is maintained for 60 seconds and visually examinated to ensure that it continues to meet the Conditions of Acceptance.
The minimum ratio shall be 60psf (2,9kPa).
Sunoptics Classification: 180psf (8,6kPa).