Page: Last modified: 2024-01-15
Code Reference(s):
NBC20 Div.B (first printing)
Building Fire Safety
New Part 9 Provision with Cross-Reference to a Standard for Testing of Protective Coverings over Foamed Plastic Insulation
This proposed change introduces Clause, and its cross-reference to Part 3, to maintain harmonization between proposed changes to provisions in Parts 3 and 9 for the protection of foamed plastics.
This change could potentially affect the following topic areas:


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 mirror those in Part 3 for combustible construction (Sentence Furthermore, both Clauses and currently include a cross-reference to Sentence, 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-

A related proposed change (PCF 1967) introduces an additional compliance path in Sentences, and 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 to proposed Clause (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 (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 to provide cross-references to proposed Clause 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 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.


[] of Foamed Plastics

(See Note A- CHANGE A-
[1] 1)Except as provided in Sentences (2) and (3), foamed plastics that form part of a wall or ceiling assembly shall be protected from adjacent space in the building, other than adjacent concealed spaces within attic or roof spaces, crawl spaces, wall assemblies and ceiling assemblies
[a] a)by one of the interior finishes described in Subsections 9.29.4. to 9.29.9.,
[b] b)provided the building does not contain a Group C major occupancy, by sheet metal that
[i] i)is mechanically fastened to the supporting assembly independent of the insulation,
[ii] ii)is not less than 0.38 mm thick, and
[iii] iii)has a melting point not less than 650°C, or
[c] c)by any thermal barrierprotection method that meets the requirements of Sentence (see Note A- CHANGE A-, or
[d] --)by a protective covering, incorporated in the assembly, that meets the requirements of Clause (see Note A- (PCF 1967).
(See Note A- CHANGE A-
[2] 2)A walk-in cooler or freezer consisting of factory-assembled wall, floor or ceiling panels containing foamed plastics is permitted to be used, provided the panels
[a] a)are protected on both sides by sheet metal not less than 0.38 mm thick having a melting point not less than 650°C,
[b] b)do not contain an air space, and
[c] c)have a flame-spread rating, determined by subjecting a sample panel with an assembled joint typical of field installation to the applicable test described in Subsection 3.1.12., that is not more than that permitted for the room or space in which they are located or that they bound.
[3] 3)Thermosetting foamed plastic insulation having a flame-spread rating of not more than 200 is permitted to be used in factory-assembled doors in storage garages serving single dwelling units provided that
[a] a)the insulation is covered on the interior with a metallic foil,
[b] b)the assembly has a flame-spread rating of not more than 200, and
[c] c)the assembly incorporates no air spaces.

Impact analysis

This proposed change provides a cross-reference to proposed Clause, which benefits Code users by keeping Sentences and aligned.

The proposed compliance option in Clause 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.

Enforcement implications

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.

Who is affected

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


[] ([1] 1) [F01,F02,F05,F01-OS1.5,OS1.1][F02-OS1.2][F05-OS1.5]
[] ([1] 1) ([a] a)
[] ([1] 1) ([c] c)
[] ([2] 2) [F05-OS1.5][F02-OS1.2]
[] ([2] 2) [F02-OP1.2]
[] ([2] 2) no attributions
[] ([3] 3) [F01,F02-OS1.2]
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