Firestopping involves sealing joints and penetrations in fire-rated walls, ceilings, or floors to maintain fire separation integrity. Ontario building code requires firestopping for any equipment passing through these rated separations. It is mandatory for both new builds and retrofits, and failure to comply can delay building occupancy and inspections.

Proper firestopping ensures smoke and fire cannot pass through fire separations, protecting the building and occupants. Without it, penetrations by mechanical, electrical, HVAC, or IT systems can allow fire and smoke to spread, increasing damage and danger.