Ontario Building Code Part 9 — Foundation Drainage Requirements
The Ontario Building Code (OBC) establishes the minimum legal standards for foundation drainage in Ontario. Part 9 of the Code (Housing and Small Buildings) applies to most residential properties and includes specific requirements for foundation waterproofing and drainage. The full Code can be referenced at Ontario Regulation 120/332.
Key foundation drainage requirements under OBC Part 9 include:
- Foundation walls below the local water table must be designed to resist hydrostatic pressure
- A perimeter drainage system must be installed at the footing level to collect and remove groundwater
- Drainage tile must be surrounded by at least 150 mm (6 inches) of clean gravel or crushed stone
- Filter fabric or another method must prevent soil migration into the drainage system
- The drainage system must discharge to a sump pit, storm sewer, or other approved location
- Dampproofing or waterproofing must be applied to foundation walls below grade
These requirements apply to new construction and to any renovation that involves excavation or modification of the foundation drainage system.
Permit Requirements for Waterproofing Work
Whether a building permit is required depends on the scope of the waterproofing project.
Exterior Excavation Waterproofing
Any project involving excavation around a foundation typically requires a building permit in Renfrew County municipalities. The permit ensures that the excavation does not compromise the structural integrity of the foundation, that proper drainage is installed, and that the site is properly restored. Municipalities in Renfrew County — including Pembroke, Petawawa, Renfrew, Arnprior, Deep River, and the County — have building departments that can advise on specific permit requirements.
Interior Drainage Systems
Interior drainage system installations that involve cutting the concrete floor slab and installing a sump pump generally do not require a building permit in most Renfrew County municipalities, provided no structural changes are made to the foundation. However, if the sump discharge is routed to the municipal storm system or involves breaking through the foundation wall, a permit may be needed.
Crack Injection
Crack injection — whether epoxy or polyurethane — is considered a repair rather than construction and typically does not require a permit. However, if the cracks are structural in nature and require carbon fibre or other reinforcement, the work may require an engineered assessment and a permit.
How to Check
Each municipality in Renfrew County has its own building department:
- City of Pembroke: Building Services, Pembroke City Hall
- City of Petawawa: Building Department, Petawawa Civic Centre
- Town of Renfrew: Building Services, Renfrew Town Hall
- Town of Arnprior: Building Department, Arnprior Town Hall
- Town of Deep River: Building Services, Deep River Municipal Office
- Renfrew County (rural areas): County of Renfrew Building Department
A quick phone call to your local building department before starting any waterproofing project can save significant time and expense later.
Contractor Requirements
WSIB Coverage
Any contractor performing waterproofing work in Ontario should have valid WSIB (Workplace Safety and Insurance Board) coverage. This protects you from liability if a worker is injured on your property. Always request a WSIB clearance certificate before work begins. You can verify a contractor's WSIB status through the WSIB website or by asking the contractor to provide proof of clearance.
Liability Insurance
Reputable waterproofing contractors carry general liability insurance, typically $2 million or more in coverage. This protects you if the contractor damages your property during the work. Ask for a certificate of insurance and verify that the coverage is current before allowing work to start.
HST Registration
Contractors must be registered for HST in Ontario. A valid HST number indicates the contractor is operating as a legitimate business. You can verify an HST number through the Canada Revenue Agency.
Provincial Licensing
Ontario does not have a specific trade licence for waterproofing contractors. Unlike electricians, plumbers, or HVAC technicians, waterproofing is not a regulated trade under the Ontario College of Trades. This means that verifying a contractor's qualifications, insurance, WSIB, and references is entirely the homeowner's responsibility. A written contract with a detailed scope of work and warranty is essential.
Discharge and Environmental Regulations
Sump pump discharge water is considered clean groundwater and can typically be discharged to the ground surface, away from the foundation. However, in some urban areas in Renfrew County, discharge to the municipal storm sewer may be regulated. Discharge to the sanitary sewer system is generally prohibited because it can overwhelm the treatment plant during wet weather.
Key rules for sump pump discharge in Renfrew County:
- Discharge must be directed at least 6 feet (2 metres) away from the foundation
- Discharge must not flow onto neighbouring properties
- Discharge must not create icy conditions on sidewalks or driveways in winter
- Some municipalities require discharge to be to a dry well or splash pad rather than directly onto the ground
Permit and Code Summary
| Work Type | Permit Likely Required? | Regulatory Notes |
|---|---|---|
| Exterior excavation waterproofing | Yes | Building permit; may require engineered drawings for structural work |
| Interior drainage system | Typically no | Check if sump discharge or foundation penetration requires permit |
| Crack injection (non-structural) | No | Repair, not construction |
| Carbon fibre / wall reinforcement | May require | Engineered assessment often required |
| Sump pump replacement | No | Replacement of existing equipment |
| Weeping tile repair (exterior) | Yes | Excavation triggers permit |