Clarifying Differences in NAFS and Canadian Building Codes

November 30th, 2012 by DWM Magazine

Fenestration Canada hosted a webinar this week in an attempt to educate everyone from building officials to architects about the various changes to the building codes. It was evident from the dozens of questions asked at the webinar’s conclusion that those involved are working to understand the various codes and how they differ from one another.

Jeff Baker, WestLab, conducted the webinar and started out by outlining the National Building Code (NBC) of Canada and pointed out that one of the changes is incorporation of the North American Fenestration Standard (NAFS). “In the past you would have seen CSA A 440 cited,” said Baker. “But NAFS covers everything for windows, doors and skylights.” (Storm doors are not covered in NAFS.)

However, it is important to know that in Canada there is a supplement to NAFS which has additional requirements, said Baker. For example, regarding the water penetration test, in the U.S., the amount of water is capped but not in Canada. “In Canada you have to meet infiltration and exfiltration as opposed to the U.S. where it is just infiltration,” said Baker.

“We have been working very closely with other associations including AAMA and WDMA to help companies understand that there are different requirements in the U.S. and Canada,” he added.

In the NBC, he said key sections for the industry are: Section 9.6—glass and 9.7–windows, doors and skylights. A change is that the glass requirements are now separated out from doors, windows and skylights.

“One key thing is that in main entrance doors there are only four requirements,” said Baker. “Missing from that is structural load and water load. That has been omitted and we believe that was an unintended change and we think that will go back in in 2015.”

Additionally, he noted that in the NBC, the minimum level of performance class required is R.

“A 440 only had one performance class while under NAFS there are four (R, LC, CW and AW),” said Baker.

One of the many questions asked related to changes in glass thickness. Baker said there is more information on this that will be posted on the Fenestration Canada site shortly. “It’s not new. It’s a clarification. It’s a simple table about how to come up with glass thickness.”

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