Canadian building code question

What are the building code requirements for mass timber encapsulation in Canada?

Mass timber buildings in Canada may expose structural timber elements or require encapsulation depending on the building height, occupancy, construction type, and adopted code edition. The NBC 2020 introduced encapsulated mass timber construction as a defined construction type with specific fire performance, charring, and protection requirements. The NBC 2025 continues this framework with refinements.

Mass timber encapsulation is one of the most technically detailed areas of the current Canadian building code. The distinction between exposed and encapsulated mass timber determines fire protection strategy, construction detailing, and inspection requirements. Understanding which construction type applies and what fire performance is required is essential before committing to a mass timber design.

What to check first

  • Encapsulated mass timber construction requires all structural timber elements to be protected by noncombustible encapsulation that prevents charring for the required fire-resistance period.
  • Exposed mass timber is permitted under different construction types with different height and occupancy limitations.
  • The distinction between encapsulated and exposed mass timber affects cost, aesthetics, construction detailing, and fire protection strategy.

Jurisdiction notes

NBC 2020 baseline

The NBC 2020 introduced encapsulated mass timber construction (EMTC) as a defined construction type for buildings up to 12 storeys. Use this as the baseline framework.

NBC 2025 updates

The NBC 2025 refines mass timber provisions including fire performance requirements and construction type definitions. Confirm which edition is adopted in your province.

Provincial adoption timing

Not all provinces have adopted the NBC 2020 or 2025 mass timber provisions. Confirm the provincial code edition and any amendments before proceeding with a mass timber design.

Work through it in this order

  1. Determine the applicable construction type and whether the project qualifies for exposed or encapsulated mass timber under the adopted code.
  2. Confirm fire-resistance requirements and encapsulation specifications for all structural timber elements.
  3. Verify that the proposed mass timber products and connections meet the fire performance requirements.
  4. Coordinate with the AHJ to confirm acceptance of the proposed mass timber construction type and details.

Common questions

Can I leave mass timber exposed in a tall building in Canada?

It depends on the building height, occupancy, and construction type. Some construction types permit exposed timber; others require encapsulation. The adopted code edition and provincial amendments determine the specific limits.

What does encapsulation mean for mass timber?

Encapsulation requires all structural timber elements to be covered with a noncombustible protection system that prevents the timber from charring during the required fire-resistance period.

Is mass timber allowed above 6 storeys in all Canadian provinces?

Not necessarily. Provincial adoption of the NBC 2020 or 2025 mass timber provisions varies. Some provinces may not have adopted the taller mass timber construction types yet.