FM Global Wind uplift
FM Global Wind uplift
(OP)
I do not have much experience with the FM Global building requirements and I have a project where it popped up at the last minute and I am now trying to ply catchup. I am trying to replicate the values in FM Global Data Sheet 1-28 table 3 (attached). I don't know if I am doing this wrong or not, but looking at my calculations which used ASCE7-05 and the numbers given in the table which are suppose to use ASCE7-05 and they don't match.
For example, given exposure C, V=100mph, H=30ft I calculate a wind pressure of 25.1 psf while FM calculates a wind pressure of 29psf. I know FM is suppose to yield higher uplifts, but they seem to specifically reference ASCE 7 and I am wondering why my numbers do not match.
Amy insight would be appreciated.
For example, given exposure C, V=100mph, H=30ft I calculate a wind pressure of 25.1 psf while FM calculates a wind pressure of 29psf. I know FM is suppose to yield higher uplifts, but they seem to specifically reference ASCE 7 and I am wondering why my numbers do not match.
Amy insight would be appreciated.






RE: FM Global Wind uplift
RE: FM Global Wind uplift
RE: FM Global Wind uplift
Sorry for the rant, but I just wanted to make you aware of the issues I have had recently in dealing with the FM design requirements.
JWB
RE: FM Global Wind uplift
RE: FM Global Wind uplift
RE: FM Global Wind uplift
I don't really care if they are more conservative or not, I would just like to understand where their wind loads come from.... especially since they are referencing ASCE7 which I would like to think I know how to use.
nowing how to reproduce the chart goes a long way to understanding how to use it. I know a few engineers who can only design things that come out of charts. Drives me nuts when they are interpolating or extrapolating charts and could reproduce the chart if their life depended on it (and.... go figure, it sort of does).
RE: FM Global Wind uplift
RE: FM Global Wind uplift
1. Building components and cladding and their immediate supports (wall siding, roof assemblies, etc.)
2. Opening protection (doors, windows, etc.)"
The following sentence is at the bottom of 1-28's page 6:
a) Use an importance factor of 1.15 for components, cladding and secondary structural framing.