National Building Code


In order to fill a basic need that has lasted over 40 years, to include a normative test protocol known about the resistance of a dynamic roof system form.

A specialized committee was form within NRCC and was the foundation on which rests the work to establish this protocol, the first group of professionals, community and governmental bodies as view the day under the name of SIGDERS (Special Interest Group on Dynamic Roofing Systems) in 1994.

Through this group came out the first version in 2004, CSA A123.21.04, for mechanically attached systems.

2005 NBCC, all calculations of data were integrated into the portion of the user’s guide.

In 2010, a first amendment to the CSA standard A123.21-10 to integrate full adhered systems which led the responsible committee of the national code to ask a few additions to the protocol to officially integrate in the next edition in 2015 following few public comments to respond.

In 2012, as a reference of the technical bulletin issued by the SPRI dated November 5, 2012, no 1-12, stating that now that FM 4470 can no longer be the reference source in Canada since it does not meet the minimum requirements of National Building Canadian Code. The latter under test as static and not dynamique.

And In 2015, the CSA A123.21-14 standards is now integrated in the National Building Canadian Code 2015 »

Integration Determination of Wind Load

(See Appendix A.)

1. This Article applies to the determination of wind load to be used in the design of materials, including their connections, that separate dissimilar environments or are exposed to the exterior, where these are:
a. Subject to wind load, and
b. Required to be designed to resist wind load.
2. Except as provided in Sentence (3), the wind load referred to in Sentence (1) shall be 100% of the specified wind load determined in accordance with Article

3. Where it can be shown by test or analysis that a material, component, assembly or connection referred in Sentence (1) will be subject to less than 100% of the specified wind load, the wind load referred to in Sentence (1) shall be not less than the load determined by test or analysis.

4. Except as provided in Sentence (5), the wind uplift resistance of membrane roofing assemblies shall be determined in accordance with the requirements of CSA A123-21, “Standard Test Method for the Dynamic Wind Uplift Resistance of Membrane-roofing Systems “. (See Appendix A)

5. Membrane roofing assemblies with proven past performance for the anticipated wind loads need not comply with Sentence (4). (See A- (4) in Appendix A.