CSA A123.21 standard was officially introduce in the National Building Code of Canada in march 2015. But, where does the difference stand between CSA A123.21 and FM?
1. The difference lies in the testing protocol definition
2. The nature of these organizations differs in itself
FM, on the other hand, is an insurance company that has elaborated test protocols to verify products in its coverage range. FM is testing all kinds of things ranging from fire to hail resistance. Wind is only one component of the testing program.
CSA A123.21 is a standard developed to evaluate the wind uplift resistance of a roofing system.
3. The length of the test is totally different
The FM protocol takes 5 minutes per systems, while CSA A123.21 takes 5 hours per systems.
4. The safety factor (SF) is also part of that difference
FM safety factor is 2. CSA A123.21 is 1.5.