Who is responsible for mould in an Ontario rental unit?

Chapter 629 of the Toronto Municipal Code does not name mould. It sets the standards that the moisture behind mould usually breaks:

• The building is kept in repair so it prevents moisture getting in that would cause damage, decay or deterioration (section 629-16).
• Roofs are weather-tight and free from leaks, and eavestroughs and downpipes are water-tight (629-20).
• Windows and exterior doors are weather-tight to prevent drafts or leakage (629-21).
• Plumbing is kept free from leaks and defects (629-37).
• Every area has adequate ventilation, every ventilation system is cleaned and kept working, and every washroom has an outside opening or a fan that changes the air at least once an hour (629-39).
• Walls and ceilings are kept clean and free of damaged or deteriorated surface material (629-27).

Section 629-6 requires the occupant to keep the unit clean and sanitary and to co-operate with the landlord in meeting the by-law. A bathroom fan that is never switched on is part of the picture. Whether damp came from how the unit is used or how the building is built is a question of fact, and the evidence decides it.

Mould on a wall is a symptom. The source is a roof, a window, a pipe, the foundation, or condensation that a ventilation fan should be clearing. Cleaning the surface without fixing the source brings it back, and a record that only shows a cleaning does not show the cause was dealt with.

Record where the moisture came from, the fix, and photos before and after. That record answers the tenant and supports a claim under section 34 when the cause was the tenant's.

A tenant can apply for an order that the landlord breached section 20, within one year of the conduct. Under section 30 the Board can order the repair, a rent abatement, payment for the tenant's damaged property and other reasonable costs, or end the tenancy.

Roundhouse traces the water before anyone quotes the repair, and the findings, photos and invoice sit on one record. See basement leaks and waterproofing, plumbing repairs or request work.