Canadian building code question

What are the building code requirements for impact sound insulation in Canada?

The building code requires floor-ceiling assemblies between dwelling units to meet minimum apparent sound transmission class (ASTC) ratings. While the code focuses on airborne STC, impact sound (FIIC) performance is critical for occupant satisfaction and is addressed through assembly design rather than a separate FIIC requirement in most code editions.

Impact sound transmission through floor-ceiling assemblies is one of the most common complaints in multi-unit residential buildings. While the building code sets minimum STC (Sound Transmission Class) requirements for airborne sound, impact sound performance depends on the floor-ceiling assembly design including the floor finish, underlayment, structural system, and ceiling treatment. Understanding how to achieve both airborne and impact sound performance is essential for multi-unit residential design.

What to check first

  • The building code sets minimum STC ratings for assemblies between dwelling units.
  • Impact sound performance (FIIC) depends on the complete floor-ceiling assembly design.
  • Hard surface flooring without proper underlayment is the most common cause of impact sound complaints.

Jurisdiction notes

National baseline

The NBC sets minimum apparent STC requirements for assemblies separating dwelling units.

Provincial amendments

Some provinces may have additional sound insulation requirements or reference different testing standards.

Condominium standards

Condominium declarations and bylaws may set sound performance requirements beyond the building code minimum.

Work through it in this order

  1. Identify all floor-ceiling assemblies between dwelling units that require sound insulation.
  2. Select assembly designs that meet both the minimum STC requirement and provide adequate impact sound performance.
  3. Specify appropriate underlayment for hard surface flooring to control impact sound transmission.
  4. Consider field testing requirements and address flanking paths through walls, penetrations, and structural connections.

Common questions

Does the building code set FIIC requirements?

Most code editions focus on STC for airborne sound. Impact sound performance is achieved through assembly design and material selection rather than a separate FIIC threshold.

Can I install hardwood floors in a condo?

Hard surface flooring typically requires resilient underlayment to maintain impact sound performance. Check condominium bylaws which may set specific requirements.

What is the minimum STC between dwelling units?

The minimum STC rating between dwelling units is specified in the building code. Check the applicable edition and provincial amendments.