FM (FM Global)

FM, long known as FM Global, is a mutual insurance company that specialises in commercial and industrial property insurance and loss prevention engineering. Its oldest predecessor, the Manufacturers Mutual Fire Insurance Company, was formed in 1835 after a textile mill owner, Zachariah Allen, sought lower premiums for a mill he had protected against fire. The company is headquartered in Johnston, Rhode Island, United States, and its website is fm.com.

FM is included in an encyclopedia of roofing because of its large role in research, testing and standards for commercial roofs.

Research campus

FM operates a research campus of about 1,600 acres (648 hectares) in West Glocester, Rhode Island. Testing there covers fire and explosion hazards and how building components perform in conditions such as hurricane winds.

FM Approvals

FM Approvals is the company's testing and certification unit. It tests loss-prevention products and services and certifies those that meet recognised standards; it reports having tested more than 50,000 products. For roofing, FM Approvals certifies roof assemblies, membranes, insulation, fasteners and roof edge systems for properties such as:

• wind uplift resistance, expressed in classes based on the pressure an assembly withstood in testing;
• fire performance, both from above the roof (ASTM E108) and from below through the roof deck;
• hail damage resistance;
• water leakage, foot traffic, corrosion and heat-damage resistance.

For membrane roofs these tests are set out in FM Approvals Class Number 4470, which covers single-ply, polymer-modified bitumen, built-up and liquid-applied roof assemblies.

Approved roof assemblies are listed in an online directory used by designers, contractors and insurers.

Property Loss Prevention Data Sheets

FM publishes engineering guidance in Property Loss Prevention Data Sheets. Several deal with roofs, covering topics such as wind design of roof systems, roof deck securement, roof loads and drainage, and hail. Insurance policies written by FM may require buildings to follow these data sheets, which can be stricter than local building codes.

Wider influence

FM worked with SPRI on edge securement standards, and its approval tests are referenced by many manufacturers worldwide. Owners insured by other companies may still specify FM-approved assemblies as a quality benchmark.