The National Building Code of Canada (NBC) includes requirements for the protection of foamed plastics for both combustible and noncombustible construction in Part 3. Depending on the application, current acceptable solutions to achieve this protection include a variety of prescriptive options (e.g., interior finishes) or performance test methods.

Currently, the options in Part 9 for the protection of foamed plastics (Sentence 9.10.17.10.(1)) mirror those in Part 3 for combustible construction (Sentence 3.1.4.2.(1)). Furthermore, both Clauses 9.10.17.10.(1)(c) and 3.1.4.2.(1)(c) currently include a cross-reference to Sentence 3.1.5.15.(2), which provides additional (more stringent) protection options for noncombustible construction (on the basis that these options are also acceptable for combustible construction, as reiterated in explanatory Note A-3.1.4.2.(1)(c)).

A related proposed change (PCF 1967) introduces an additional compliance path in Sentences 3.1.4.2.(1), 3.1.5.15.(2) and 3.1.5.15.(3). The proposed compliance path provides an option of performance test method for the evaluation of assemblies that incorporate a protective covering (e.g., intumescent coating) by introducing a reference to a new standard, CAN/ULC-S145:2018, "Standard Method of Test for the Evaluation of Protective Coverings for Foamed Plastic Insulation – Full-Scale Room Test."

As more options for protective coverings enter the market, it becomes more critical to provide manufacturers, regulators and Code users with an additional compliance path that specifies a minimum level of performance for these products to be considered acceptable solutions where incorporated in a tested assembly. Furthermore, regulators and authorities having jurisdiction continue to struggle to accept such products, which could cause economic hardship within the foamed plastics industry.

In order for the same compliance path to be extended as an option for Part 9 buildings as intended, a cross-reference is needed in Sentence 9.10.17.10.(1) to proposed Clause 3.1.4.2.(1)(d) (PCF 1967). Otherwise, there would be no link from Part 9 to the proposed new compliance path for combustible construction in Part 3, and the only option for evaluating these types of products in accordance with CAN/ULC-S145 for Part 9 buildings would be the more stringent requirement provided in proposed Clause 3.1.5.15.(2)(f) (PCF 1967). This Clause also introduces a reference to CAN/ULC-S145, but requires an increased classification, which was found to be justified for buildings required to be of noncombustible construction. 

This proposed change introduces new Clause 9.10.17.10.(1)(d) to provide cross-references to proposed Clause 3.1.4.2.(1)(d) and its explanatory Note, which harmonizes provisions for the protection of foamed plastics.

As stated in PCF 1967, the proposed change in Part 3 introduces a reference to CAN/ULC-S145 on the basis that it offers a suitable performance-based approach to limit the contribution of foamed plastic insulation to early fire growth. PCF 1967 provides Code users (including manufacturers, designers, regulators and authorities having jurisdiction) with an additional compliance path that outlines an acceptable level of performance for protective covering products to be considered acceptable solutions in assemblies, which facilitates enforcement.

The proposed new compliance path is consistent with the existing intent statements of the NBC. Performance-based room corner tests provide a clear indication of the onset of flashover, which impacts both the time available for egress and the potential contribution of a material to fire growth and spread. These tests are recognized and relied on worldwide in building code regulations. Feedback from many Canadian fire experts indicated that the proposed classifications for protective coverings in CAN/ULC-S145 relate directly to the hazard that the Code intends to limit.

This proposed change also updates Clause 9.10.17.10.(1)(c) on the basis that "protective coverings" should not necessarily be qualified as "thermal barriers". This change is needed in Part 9 to incorporate the correct technical language and remain consistent with the equivalent proposed changes in Part 3.

This proposed change provides a cross-reference to proposed Clause 3.1.4.2.(1)(d), which benefits Code users by keeping Sentences 3.1.4.2.(1) and 9.10.17.10(1) aligned.

The proposed compliance option in Clause 3.1.4.2.(1)(d) provides flexibility to designers and fosters innovation without compromising safety by allowing a broader range of material to be used for the protection of foamed plastics.

This proposed change benefits manufacturers and Code users by clarifying a minimum level of performance required for assemblies incorporating a protective covering, which facilitates enforcement for regulators and authorities having jurisdiction.

Because the introduction of a reference to CAN/ULC-S145 is not intended to replace the existing options for acceptable solutions, there are no new forced costs for builders with respect to meeting the requirements for the protection of foamed plastics.

Furthermore, any additional costs associated with the testing of materials when using this proposed option could be offset by avoiding the cost of needing to pursue this option as an alternative solution.

This proposed change could be enforced by the current enforcement infrastructure for the Code and would harmonize Part 9 with the newly proposed changes in Part 3.

Regulators are familiar with assessing compliance through product testing in accordance with referenced standards. Having a performance-based requirement in the Code facilitates the interpretation and enforcement of the requirement and ensures consistency of the application throughout the country.

Furthermore, in jurisdictions where alternative solutions have been sought for protective covering products, it is anticipated that there is already familiarity with these types of products.

Architects, engineers, designers, regulators, manufacturers and builders would benefit from this proposed change as explained in the impact analysis.