Understanding Factory Mutual (FM) Approvals: a Breakdown for Commercial Contractors

In commercial roofing, it is not uncommon for a project scope to require certification from FM Approvals, an arm of Factory Mutual (FM) Global, in order to qualify to perform the work. Experienced roofing contractors have seen this multiple times and understand the purpose, importance, and process required to comply with FM Approvals’ stringent standards. 

Contractors could view this as an unnecessary hurdle, but it is important for business owners looking to protect their assets. FM Approvals is the only organization in the world that tests the effects of hazards such as fire, water leakage, hail, wind uplift, and foot traffic on complete roof assemblies. Building owners require FM Approvals so they can acquire insurance from Factory Mutual (FM) Global, one of the world’s largest insurers of commercial buildings and manufacturing facilities.

So how did FM Approvals become such a powerful voice in the construction industry? This blog will answer that question by providing deeper insight into who FM Approvals are, where they came from, what they do, and why it matters to commercial contractors.

The History of FM Approvals

Factory Mutual Laboratories which became FM Approvals has roots dating all the way back to the 19th century. At that time, fire was the largest concern for buildings and testing fire-protection devices was the company’s focus. This continued to be the case until 1954 when the lab began testing roofing assemblies.

Over time, FM Approvals has evolved to become a worldwide leader in testing and certifying property loss prevention products. Since the publication of the company’s first approval guide in 1897, the laboratory has shaped acceptable loss prevention practices on an international scale. FM Approvals laboratories can now be found around the globe, and the company’s findings and certification standards influence building codes for municipal, state, and national governments.

What Does FM Approvals do?

FM Approvals are involved in virtually every step of the construction process. On top of the rigorous testing performed to certify materials for use, FM Approvals leverages their findings to publish standards with required compliance. Contractors must submit drawings and installation plans to FM Approvals in the bidding process for certification before construction can commence. Once approval is received, contractors can start the process of ordering materials and scheduling work.

To share their knowledge and maintain heightened awareness among the various trades, FM Approvals is involved with over 100 national and international standards committees including the American National Standards Institute (ANSI), American Society for Testing and Materials (ASTM), International Electrotechnical Commission (IEC), International Organization for Standardization (ISO), and the National Fire Protection Association (NFPA). In addition to providing regulatory input, participation on committees like these enables FM Approval engineers to update manufacturers and contractors on updates or changes to testing standards and procedures so products can be designed to comply with evolving national and international standards.

How Does FM Approvals Certify Materials?

FM Approvals has a stated goal of providing an efficient process when it comes to certifying materials. If manufacturers are truly making safer products that excel in loss prevention, then Factory Mutual wants them to be available as soon as possible. The rigorous testing process is performed in state-of-the-art facilities designed to accommodate large-scale, thorough examination of property loss prevention products, and the engineers performing the testing are mindful of emerging industry trends.

The Factory Mutual Approvals certification for manufacturers is awarded based on a 5-step process:

  1. Manufacturer Request: The manufacturer contacts FM Approvals in writing to request approval for a product or assembly. This request is to include model numbers, specifications, and any applicable sales literature. If it is a new product being requested, there is an application for manufacturers to request a quote.

  2. Proposal Issue and Manufacturer Authorization: FM Approvals reviews the manufacturer’s request and replies with a proposal letter. The response includes a scope of work for testing, cost estimates, and an estimated schedule. It also outlines the tests the lab deems necessary and a request for samples to perform the tests. Once reviewed, the manufacturer authorizes the proposal in writing, submits any necessary material, and clarifies any additional requests for information identified in the proposal by FM Approvals Engineers.

  3. Review, Testing, and First Audit: FM Approvals finalizes testing plans using drawings, specifications, and product comparisons. When the lab receives all necessary items, testing is scheduled and conducted. First-time manufacturers or manufacturers working out of a new facility will also be visited by an FM Approvals auditor to review quality control procedures before approval is granted.

  4. Report, FM APPROVED Mark, and Listing: Upon successful completion of testing, a report is prepared and reviewed for quality and technical accuracy. Samples may be retained and archived or disposed of by the manufacturer’s suggestion. The final report is sent by FM Approvals to the manufacturer. If the product is approved, the approval is effective as of the report date and the manufacturer can label the product as FM Approved. The product will be listed in the online Approval Guide with approved roofing assemblies listed in RoofNav, a web-based software roofing contractors use to seek FM Approval of plans and projects.

  5. Surveillance Audits: FM Approvals must be continuously maintained. FM Approved manufacturers and their facility (or facilities) will receive periodic visits to ensure quality control procedures and manufacturing standards are being upheld.

Despite the hurdles in the certification process, FM Approvals’ control over standardization and the necessity for contractors to use FM Approved materials for many applications makes achieving the certification quite valuable.

What is the FM Approvals Guide?

As mentioned above, certified products receive a listing in the FM Approval Guide. For years this was a printed publication, similar to a catalog, that contractors purchased through Factory Mutual. The guide contained listings and information about all of the products that had received approval from the insurer.

Today, the Approval Guide is conveniently located online and contractors are provided complimentary access. Besides the cost-benefit to contractors, moving the guide online allows for real-time reporting on the tens of thousands of products and services that have been tested and approved by Factory Mutual. The online FM Approval Guide allows manufacturers to enjoy the benefits of being FM approved immediately, and ensures that contractors have awareness of the latest materials that address exposures and protect facilities.

How Does FM Approvals Review and Certify Proposed Roof Assemblies?

Factory Mutual has been heavily involved in certifying roofing assemblies since the 1950s. General roofing contractors who are seeking roof approvals from Factory Mutual must follow their stringent process. FM Approvals has developed an online tool called RoofNav where a proposed roof assembly must be created.

RoofNav contains a listing of products that have been certified in the laboratory based on FM Approvals’ criteria listed above including roof uplift testing and negative pressure testing in the laboratory. Roofing contractors review the approved products and select the proper materials based on the needs of their current job. The commercial roofing contractor compares their selections against all applicable standards, then submits their project along with any necessary mechanical drawings to the nearest FM Approvals office for certification to commence work.

How Does FM Approvals Certify Completed Projects?

Once approved to begin, commercial roofing contractors have two options for receiving final FM Approvals sign-off. One option involves paying a certified FM Approvals loss prevention engineer to be on the job site for the duration of the assembly of the commercial roofing assembly. This engineer oversees construction and submits detailed daily reports to Factory Mutual for review. The presence of such an engineer costs up to $1,000 per day and given the high price incurred by the contractor which must be passed to the customer, this is usually not a viable option.

The second means of approval involves standardized testing of the installed roofing system to ensure it was assembled to the standards of FM Approvals and the manufacturer. Just as in the lab, commercial roofing assemblies are tested to see how they withstand wind uplift, hail impact, and foot traffic while not allowing seam leakage.

Wind uplift is tested using a negative pressure dome on the corners and certain places in the field of the roof. The dome is mounted at the test location and then air is sucked out of it to simulate wind events of varying speeds. FM Approvals has documented acceptable standards based on the style of the commercial roofing system being tested and failures outside of certain tolerances can result in the reconstruction of specific sections of a commercial roof assembly, or in extreme cases, the entire roof.

There is concern among commercial roofing contractors regarding the cost and validity of the testing procedures. This generally stems from the fact that contractors have already been required to use approved materials and processes, but still sometimes fail testing despite following the prescribed procedures to the letter. There is an obvious difference between certifying a material or system in a laboratory versus doing the same thing in the field. In spite of documented concerns and discrepancies, FM Approvals stands by its certification and testing processes and will not issue the necessary certificates for Factory Mutual Global insurance until all tests are passed in accordance with their guidelines.

In Conclusion

FM Global and its subsidiary, FM Approvals, are powerful regulatory entities in commercial construction contracting. FM Approved commercial roofing assemblies have met rigorous testing standards in the laboratory and also must be approved once installed in the field. The process for both manufacturers and commercial roofing contractors is stringent and requires patience and attention to detail.

Developing a deeper understanding of FM Approvals’ history, purpose, and procedures is vital for building owners and contractors in order to mitigate loss and ensure completed commercial buildings provide maximum protection for their contents and occupants. FM Approvals sets high standards with the intent to achieve these goals.

Register Roofing has a long history of working within Factory Mutual’s prescribed framework. If you have a complex building need and your commercial roofing system will require an FM Certification prior to being insured, contact us and let our experts manage the process for you. 



Experience the Register
Roofing difference

Register Roofing

Request An Estimate