FM certification and wind load calculation
The three most common FM concepts
FM Approvals is a global certification mark from the industrial insurance company FM Global. It stands for the quality and (fire) safety of the products and assemblies used. The certifications are recognized worldwide by leading companies in the construction of roofs and façades. FM Approved products and assemblies undergo strict testing for safety, fire, wind load, and more. As a result, not only does FM Global require this approval, but increasingly, local insurance companies do as well
To obtain the FM certification and mark, tests are conducted in Boston, USA. These tests take place at the FM Approvals facilities according to the FM-4470 guidelines. There are often misunderstandings about how FM Projects should be approached in Europe.
Therefore, we explain the three common FM concepts in this document.
There are often misunderstandings about how FM Projects should be approached in Europe.
Schematic overview
Full FM Approved Assembly |
FM (Accepted) |
FM Approved Products |
|
| Your project is FM Approved: | ✔ | ✘ | ✘ |
| Your project meets FM standard: | ✔ | ✔ | ✘ |
| You use FM Approved products: | ✔ | Depending on the situation | ✔ |
Full FM Approved Assembly
This is the approach for FM Global approved wind load calculations. Here we are referring to an approved FM system according to an FM Assembly number, All products including the steel deck must conform with the description in the Assembly, which can be found in RoofNav. This is not very common in Europe when most assemblies are tested on American steel decks.
The calculation is made according to FM Datasheet 1-28 . The starting point is the achieved ratings according to testing guideline FM-4470 in Boston, USA. Calculation values according to European tests (EN-16002) are not accepted
The total safety factor must be at least 2.0, consisting of |
| Safety factor on the component side Ym=1,5 |
| Safety factor on the load side Yq=1,34 |
| Total safety minimum: 1,5x1,34=2,0 |
Insulation fastener:
In case of an insulation fastener, FM-4470 paragraph 3.3 refers to the product data sheets from the suppliers. Therefore, no separate tests are required for the insulation fasteners. The number of insulation fasteners per insulation board as pre-securement is defined in FM datasheet 1-29.
FM (Accepted)
This is the approach for FM Global approved wind load calculations. Here we are referring to an approved FM system according to an FM Assembly number, where one or more products do not conform with the description in the Assembly, which can be found in RoofNav.
This approach must be approved by a FM Global project engineer. This approach is very common in Europe.
The calculation is made according to FM Datasheet 1-28, section 2.8 “Use of the Eurocode”›. The starting point is the achieved ratings according to testing guideline FM-4470. Calculation values according to European test standard (EN-16002) are not accepted.
This wind load calculation method requires approval from the FM engineer for the specific project!
The total safety factor must be at least 2.0, consisting of: |
| Safety factor on the assembly side Ym=1,5 |
| Safety factor on the load side Yq=1,34 |
| Total safety minimum: 1,5x1,34=2, |
FM Approved Products
In this case, only the products are FM approved and listed in RoofNav. There is no FM assembly number referring to this specific roof build-up. The calculation is made according to European standards (EN 1991-1-4 & CEN/TS-17659) with the accompanying national annex. Calculation values are based on European tests (EN-16002).
The total safety factor is conform European standards (Eurocode): |
| Safety factor on the component side Ym=1,5 |
| Safety factor on the load side Yq=1,27 (depending on country e.g. Netherlands, EN-1990 standard states Yq=1,5) |
| Total safety minimum: 1,5x1,27=1,90 (depending on country |
