What is "Factory Mutual"?
What relation does Factory Mutual have in a building project?
Is Factory Mutual a provider of specifications and/or industry standards?
Is Factory Mutual related to other trades?
As noted by Rowe, they are in the risk insurance business. They provide a standard (fairly comprehensive manual) outlining methods of construction for various components of a building. They also specify loadings and types of construction that may exceed those requirements of local codes. A few years ago they became known as FM Global and they can be reached at
Many of FM's design criteria are more strict than the governing building codes. This seems to be especially true for roofing components. We have binders and binders full of FM data. It's a pain in the neck, really. You think you have it licked using ASCE, ACI, AISC, NFPA, and the governing model building code, then you need to comb through FM as well to see if it will govern.
What you need to do is talk to your client to find out if their facility must follow FM guidelines. We have some large clients who refuse to do certain things FM "requires" and simply negotiate their insurance rates accordingly.
IRI is another agency fimilar to FM but with a less extensive repertoire of requirements.
With many projects, I usually check with the client to see if they require FM conformance..., and generally include it in a covering letter listing design loads, etc. for client approval.