Fire Separations and Fire-Stopping for Wall-Mounted Screens

In multi-unit buildings, many corridor walls, elevator lobbies, stair enclosures and service rooms are fire separations: walls built to slow the spread of fire and smoke for a specified time. Cutting into one to recess a screen, or drilling through one to run cables, can compromise that protection unless it's done properly.

This is general information. Requirements depend on the specific wall, the building's design and the Ontario Building Code; your contractor and, where needed, a fire protection professional determine the right approach.

How to know if a wall is a fire separation

• Architectural drawings and life-safety plans, if the corporation has them
• Labels above the ceiling on some rated walls
• Location: walls between suites and corridors, around elevator shafts and stairs, and around electrical and mechanical rooms are often rated
• Your building's fire safety plan or previous consultant reports

When in doubt, treat the wall as rated until confirmed otherwise.

What can compromise a fire separation

• Openings: cutting a large recess removes material from the wall assembly
• Penetrations: drilling through for power or data cables creates paths for smoke and fire
• Back-to-back boxes: recesses on both sides of a wall at the same spot can create a weak point

What proper work looks like

Fire-stopping penetrations

Every cable or conduit that passes through a fire separation must be sealed with an approved fire-stop system appropriate to the wall type and the penetrating item. These are tested assemblies, not just any caulk. Installed correctly, the separation keeps its rating.

Rated enclosures or protection for recesses

Where a screen is recessed into a rated wall, the recess may need to be built with rated materials, wrapped or backed with protection, or sized and located so it doesn't reduce the wall's fire resistance. Sometimes the right answer is to choose a different wall, or to build out a furred section in front of the rated wall instead of cutting into it.

Documentation

Keep a record of what fire-stopping systems were used and where. Building inspectors, fire safety auditors and future contractors will want to know.

Why this matters to a board

Fire separations protect residents' lives. A recessed screen that quietly compromises a corridor wall is a real hazard, and it's often invisible once the screen is mounted. Boards should explicitly ask contractors how they will handle rated walls, and expect a specific answer. See questions to ask a contractor.

Other fire-safety considerations

• Keep fire alarm devices and exit signs visible. Screens shouldn't block or distract from life-safety signage.
• Don't obstruct sprinkler heads or their spray pattern.
• Respect corridor clearances for evacuation; recessed screens help here.