| Author |
Message |
Margaret G. Chewning FCSI CCS
Senior Member
Username: presbspec
Post Number: 185
Registered: 01-2003
| | Posted on Monday, March 08, 2010 - 04:48 pm: |    |
Hi All,
I've had a question raised on a federally funded project I'm working on regarding FM standards for roofing.
The manufacturer's rep reviewing the section for my client has stated that we should not use FM standards for fire resistance and wind uplift if the building is not going to be insured by Factory Mutual.
In the 3 roofing UFGS sections used in this project, the FM standard is typically used as an "OR" standard with an ASTM standard. IE meet one or both.
My understanding is that the FM standards are just that, standards. The requirement for them is not contingent on who will be insuring the building upon completion.
Is this correct or should I strike the FM standards from my sections?
Thanks
Margaret |
Richard L Matteo, AIA, CSI, CCS
Senior Member
Username: rlmat
Post Number: 368
Registered: 10-2003
| | Posted on Monday, March 08, 2010 - 04:58 pm: | |
The premise that you only spec FM when the Owner is insured by FM is substantially correct.
That being said, I have referenced FM Wind Load Standards any way, especially if there is no other reference.
Recently, here in CA, they now reference ASCE 7-05 and apparently this comes from the Building Code, so you may need to look into the Code you are using |
(Unregistered Guest)
Unregistered guest
| | Posted on Monday, March 08, 2010 - 05:43 pm: | |
FM standards are property loss standards that are not necessarily required, but if property owner desires reduced insurance premiums from FM insurance, then construction to such FM standards generally qualifies for some premium reduction. That's the way it used to be or I understood to be when working for FM-insured company (pre-2000). |
J. Peter Jordan
Senior Member
Username: jpjordan
Post Number: 403
Registered: 05-2004
| | Posted on Monday, March 08, 2010 - 07:37 pm: | |
I have been omitting FM standards from my specs unless I know that the Owner is FM insured (usually comes up in one of the design reviews). It is my understanding that above the FMG-75 level, the number of fasteners required by FMG is significantly greater than the number of fasteners needed if one relies of ASCE 7-05.
Our confusion (including mine until relatively recently) is further compounded by the habit/practice of specifying FMG-90 for commerical roofing installations. For most one or two story commercial buildings away from the coast FMG-60 may be adequate (30 lbf/sq. ft. uplift in the field of the roof). Unless you are right along the coast, FMG-75 may be more than enough. |
Mark Gilligan SE, CSI
Senior Member
Username: mark_gilligan
Post Number: 262
Registered: 10-2007
| | Posted on Monday, March 08, 2010 - 09:44 pm: | |
ASCE 7 is referenced from the IBC and I would expect by any local codes. Thus there is no need to reference FM standards to get the wind loads. Note that IBC Section 1504.3 of the 2009 IBC specifies that wind pressures are defined by Section 1609 which references ASCE 7
Several Factory Mutual standards are referenced in the 2009 IBC, see Chaptger 35 for a complete list of the referenced standards. FM 4474 is listed as an alternate way to comply. Suggest that if you do not want to mandate FM 4474 you look to 2009 IBC Section 1504.3 for alternate acceptable language.
It would not surprise me if FM standards were written such that strict compliance is not possible unless FM was involved with the project. |
Ralph Liebing, RA, CSI, CDT
Senior Member
Username: rliebing
Post Number: 1147
Registered: 02-2003
| | Posted on Tuesday, March 09, 2010 - 07:13 am: | |
Having been through a couple FM jobs of late, I can tell you that their system for roofing is a very convoluted and "messy" process. One I would not recommend unless it is necessary! It is not really conducive to competitive bidding!
When they switched to their parochial system in 2007, it created a massive title wave throughout the indsutry that has not been fully resolved today. The other references noted in this thread are valid and useable, and will serve your clinet well. |
Dale Hurttgam, NCARB, AIA,LEED AP, CSI
Senior Member
Username: dwhurttgam
Post Number: 54
Registered: 10-2005
| | Posted on Tuesday, March 09, 2010 - 02:14 pm: | |
We typically specify FM ratings for wind and fire performance even when a building is not FM insured. We also typically review and establish the required rating through the FM Roof Nav tool which is available for use with no charge if you register online and establish a password. We also fully specify the roof system and typically have local roofing manufacturer representatives review the spec before we issue it. FM is an established roofing industry "standard" that most roofing manufacturer's readily relate to. It does become more difficult to use when FM is actually involved in the review process since they only accept products in the assembly that have been specifically tested together as an assembly - everything has to match up exact.
The following is from the MasterSpec Evaluations:
FM Approvals requirements may be specified for the membrane roofing system's standard of construction if the Project is not FM Global insured. The absence of more demanding construction standards for roofing has been recognized by specifiers who have often turned to referencing FM Approvals requirements. Setting an FM Approvals rating for the roofing system should not be indiscriminately specified because it may increase costs. It may also be more difficult to enforce if the Contract Documents reference an FM Approvals rating alone without fully detailed and specified construction requirements |
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