Several common Type X gypsum board products are available on the market and used across Canada. However, Article 9.29.5.2. of Division B of the NBC currently references only two standards for Type X gypsum board. This results in a limited selection of Type X gypsum board products that can be used to comply with the requirements of Subsection 9.29.5. If the list of gypsum board standards referenced in Article 9.29.5.2. is not updated, it will continue to limit the flexibility of design and construction.

The current edition of the NBC needs to be updated to reflect the standardized industry language and gypsum products that are currently used in Canada.

This proposed change would introduce references to two Type X gypsum board standards to Article 9.29.5.2., ASTM C1177/C1177M, “Standard Specification for Glass Mat Gypsum Substrate for Use as Sheathing,” and ASTM C1658/C1658M, “Standard Specification for Glass Mat Gypsum Panels.” These two standards are already referenced elsewhere in the NBC 2020, and referencing them in Article 9.29.5.2. is not expected to result in any conflicts.

This proposed change would permit Type X gypsum board with glass mat facer to be used in high-moisture environments where paper-faced products are not appropriate. This proposed change would also improve flexibility in the design and construction of buildings since more options would be available to Code users.

No additional costs are expected to be incurred as a result of adding references to these two standards to Article 9.29.5.2. The proposed change would simply add more options. Formally including more gypsum board products as desired by the construction industry will simplify enforcement and allow the use of gypsum board products that are more appropriate to the end use.

This proposed change can be enforced by the existing infrastructure. Since the two additional standards are already referenced in the NBC 2020, the industry and regulators are familiar with the products conforming to these standards. As such, no additional training is anticipated to be necessary for Code users. Formally including more gypsum board products as desired by the construction industry will simplify enforcement of the Code.

Builders, consumers, manufacturers, regulators, designers, contractors and building owners.