Just found out building is to be FM insured - been showing Type V-A

Archive of Older Topics Archive - Product Discussions #6
1

The design team just found out that a project, which is about 75% done with CD’s, is supposed to be FM-insured. The FM review indicates that “all materials used in this construction should be, in order of preference, noncombustible, FM Approved or Class 1.” We’ve designed for Type V-A construction.

I can’t figure out if fire-retardant-treatment gets wood studs to Class 1 in the eyes of FM. I can’t find anything that is clear about that, although I’ve found some wood stud wall assemblies that appear to be FM approved.

Does anyone know if we can use fire-retardant-treated wood if they’re calling for “all materials” to be “noncombustible, FM Approved, or Class 1”?

2

I think I’ve answered my question - FM Global Property Loss Prevention Data Sheet on “Fire-Retardant Treated Wood” indicates that we can “Consider fire-retardant treated wood (lumber or plywood) to be the equivalent of Class 1 building materials if they have passed a 30-minute fire test (ASTM E84, UL 723, NFPA 276, or FM Global roof calorimeter test).”

If anyone has other insights, please share!

3

In my experience FM has lots of requirements regarding roofing and exterior wall insulation. I’ve seen several AEs get burnt not checking those out.

4

Thanks so much, Ellis. I feel as if the roof stuff is pretty clear, but I will check closely into the insulation. Thanks for the tip!

5

FMG’s review comments are for construction to obtain best insurance rates. This means that the review is not a mandate to change, but recommendations. Before charging blindingly into this particular storm, consult your client. Many Owners will not be willing to incur the additional building costs for reductions in insurance rates. In this particular case, I can well imagine that the savings in annual insurance premiums will never completely pay for the premium of using fire retardant treated lumber for all wood framing.

6

Peter, thanks so much.

7

Liz, FMG’s Loss Prevention Data Sheet 1-1 “Firesafe Building Construction and Materials” provides recommended practices for wood frame construction, so it’s use is not prohibited.

Here’s what it states under 2.0 “Loss Prevention Recommendations”:

“Use noncombustible and fire-resistant structural framework, such as reinforced concrete or protected steel frames, in high-rise buildings (see Data Sheet 1-3, High-Rise Buildings) and, whenever practical, in other multistory buildings, based on value or importance.”

Doesn’t sound very definitive to me.

Loss Prevention Data Sheet 1-61 “Fire-Retardant-Treated Wood” states that FRTW should be used when a wood frame building is not sprinklered; thus, it sounds like if a sprinkler system is installed, then FRTW is not required.

8

Liz,
I have specified for several FMG insured projects. I coordinated closely with my local FMG engineer and the roofing materials manufacturer. Wood was never a discussion for these projects but ROOFNAV Numbers were coordinated ad nausea with FMG.
Roof edge and parapet flashing also.

9

Thank you, Ron and Wayne.

10

One place you may get tripped up is using materials requiring some sort of fire-rating (say ASTM E-84), which have been UL-tested/certified but not FM-tested/certifed. It makes no sense, but they can demand it. Better to try to use materials with FM certifications, or to meet with the FM engineer assigned to the project during design to see where they will be flexible and where not.