Canadian building code question

What is the required fire separation between floors in Canada?

The required fire-resistance rating for floor assemblies depends on the building's classification, height, occupancy type, and whether it is sprinklered, as set out in NBC Part 3 and Part 9.

Floor assemblies in multi-storey buildings must achieve a fire-resistance rating that prevents fire spread between storeys. The National Building Code addresses this through construction type requirements, occupancy separation rules, and specific assembly ratings that vary with building height, area, and sprinkler protection.

What to check first

  • Floor assemblies acting as fire separations must meet the fire-resistance rating required for the building's construction type under NBC Part 3.
  • Occupancy separations between different major occupancies on adjacent floors may require higher ratings than the base construction type.
  • Sprinklered buildings may qualify for reduced ratings or construction-type trade-offs in certain conditions.

Jurisdiction notes

National baseline

NBC Part 3 Division B sets fire-resistance ratings for floor assemblies based on building classification, height, and occupancy. Part 9 covers smaller buildings with simplified requirements.

Provincial variations

Provinces like Ontario (OBC) and British Columbia (BCBC) may adopt the NBC baseline with amendments affecting specific occupancy or construction-type thresholds.

Project-specific variables

Building height in storeys, floor area, occupancy type, sprinkler protection, and whether the floor is also an occupancy separation all influence the required rating.

Work through it in this order

  1. Classify the building by occupancy, height, area, and construction type under NBC Part 3.
  2. Determine the base fire-resistance rating required for floor assemblies for that construction type.
  3. Check whether the floor also serves as an occupancy separation requiring a higher rating.
  4. Verify whether sprinkler protection or other trade-offs affect the required rating.
  5. Confirm provincial adoption and any local amendments before finalizing.

Common questions

Is the fire separation between floors always the same rating throughout a building?

Not necessarily. Floors serving as occupancy separations between different major occupancies may require a higher rating than the base construction-type requirement for other floors.

Does sprinklering remove the need for a fire-rated floor assembly?

No. Sprinklers may allow construction-type trade-offs that reduce the required rating, but a fire-resistance rating is still required for floor assemblies in multi-storey buildings.

How does building height affect the floor fire-separation requirement?

Taller buildings generally require higher construction types with correspondingly higher fire-resistance ratings for floor assemblies.