What is a fire-rated wall assembly?
A wall or ceiling assembly built with fire-resistant materials, such as specified drywall ratings, designed to slow the spread of fire from an attached garage into the home.
A fire-rated wall assembly is a barrier built between an attached garage and the living spaces of a house to resist the spread of fire and hot gases. In Ontario, the National Building Code mandates a one-hour fire-resistance rating between the garage and the house interior, which is typically achieved using fire-rated drywall (often 5/8-inch Type X drywall), rated framing, and sealed penetrations for any pipes, wires, or ducts that pass through the wall.
The assembly protects occupants by giving them time to evacuate and limiting damage should a vehicle fire or fuel vapour ignition occur in the garage. All transitions between materials, including around door frames and mechanical penetrations, must be sealed to prevent flames and smoke from finding gaps in the barrier.
Ontario builders must inspect and document compliance with fire-rating requirements during construction, as this assembly is not optional when garages are attached to homes. Homeowners considering a garage addition or renovation should work with experienced builders who understand these code requirements. Garage builders familiar with Ontario code will ensure all fire separation details are properly installed and inspected.