What is fire separation for secondary suites in Ottawa?

Understanding Fire Separation Requirements for Secondary Suites

Fire separation is a 45-minute fire-rated barrier required between your main dwelling and secondary suite in Ottawa. This means the wall, floor, or ceiling assembly must be able to contain a fire for 45 minutes, giving occupants time to safely evacuate and emergency services time to respond.

What Fire Separation Actually Means

Fire separation isn't just about thick walls - it's an engineered system that includes the wall assembly, insulation, drywall thickness, and crucially, all penetrations must be properly sealed. Every electrical outlet, plumbing pipe, HVAC duct, or cable that passes through the fire-rated assembly needs fire-stopping materials to maintain the rating.

The Ontario Building Code (OBC) requires this separation because secondary suites create two separate dwelling units in one building. If a fire starts in one unit, the other occupants need guaranteed time to escape safely. This is especially important since many secondary suites are basement units where escape routes may be limited.

Ottawa-Specific Implementation

In Ottawa's older homes (pre-1980s), achieving proper fire separation often requires significant structural work. You'll typically need to install 5/8" Type X drywall on both sides of the separating wall or ceiling, with appropriate insulation between studs. The ceiling assembly between a basement suite and main floor usually requires the most attention.

Common areas requiring fire separation in Ottawa secondary suites:

• Ceiling between basement suite and main floor


• Any shared walls between units


• Around shared mechanical rooms or utility areas


• Stairwell separation (if accessing through main house)

Professional Requirements and Permits

Fire separation work must be inspected by the City of Ottawa Building Code Services. This isn't DIY-friendly work - improper installation can void your insurance and create serious liability issues. Licensed contractors understand the specific products, installation techniques, and documentation required to pass inspection.

The building permit process typically takes 4-8 weeks for secondary suite applications, and fire separation details are heavily scrutinized. Inspectors will check that all penetrations are properly sealed with approved fire-stopping materials and that the assembly meets the 45-minute rating.

Next Steps for Your Project

If you're planning a secondary suite conversion, have the fire separation requirements assessed early in your planning process. The structural work required can significantly impact your budget and timeline - typically adding $8,000-$15,000 to a basement suite project depending on the existing conditions.

For a comprehensive evaluation of your fire separation requirements and secondary suite feasibility, contact Justyn Rook Contracting for a free consultation. Our team specializes in Ottawa secondary suite conversions and works closely with the city's building department to ensure full compliance.