A Canadian Plumbing Service Contract is a legally binding agreement between a property owner and a licensed plumber for the installation, repair, maintenance, or modification of plumbing systems. Unlike general handyman work, plumbing is a compulsory trade in every Canadian province — meaning only holders of a Certificate of Qualification (C of Q) or registered apprentices working under supervision may legally perform plumbing work.

In Ontario, plumbing (Trade Code 306A) is regulated under the Building Opportunities in the Skilled Trades Act, 2021, administered by Skilled Trades Ontario (formerly the Ontario College of Trades). In British Columbia, the Industry Training Authority oversees Red Seal plumbing certification. In Alberta, the Apprenticeship and Industry Training Act (R.S.A. 2000, c. A-42) governs plumbing certification. In Quebec, plumbing is regulated by the Régie du bâtiment du Québec under the Building Act (CQLR, c. B-1.1), and contractors must hold a specialized licence.

The legal consequences of hiring an uncertified plumber are serious. The property owner may face denied insurance claims, building code violations, mandatory demolition and re-installation at their own expense, and liability for any resulting water damage or health hazards. This contract ensures that certification, permits, insurance, and WSIB/WCB coverage are verified before work begins.

A Canadian Plumbing Service Contract is required whenever a homeowner, landlord, property manager, commercial tenant, or building owner engages a plumber for any work beyond the most minor repairs. Even replacing a faucet — which technically does not require a permit — benefits from a written agreement specifying the cost, materials, timeline, and warranty.

The contract becomes legally essential for work that requires a building permit under the Ontario Building Code (O. Reg. 332/12) or the applicable provincial building code. This includes installing new plumbing systems, relocating existing fixtures, connecting to the municipal water or sewer system, installing water heaters, adding new fixtures (sinks, toilets, showers, laundry connections), and installing or modifying backflow prevention devices.

Landlords performing plumbing repairs in rental units must comply with the Residential Tenancies Act, 2006 (Ontario) regarding notice of entry (24 hours minimum under s. 27), the tenant's right to quiet enjoyment, and the landlord's maintenance obligation under s. 20. Property management companies that engage plumbing contractors for ongoing maintenance across multiple properties need contracts that clearly establish the independent contractor relationship to satisfy the CRA four-fold test.

Commercial properties, restaurants, and healthcare facilities have additional regulatory requirements — including backflow prevention testing (required annually under most municipal bylaws), grease trap maintenance, and compliance with provincial health and safety regulations.

A comprehensive Canadian Plumbing Service Contract must begin with the plumber's certification credentials — the Certificate of Qualification number, the issuing authority (Skilled Trades Ontario, ITA, Alberta AIT, or RBQ), and the Red Seal endorsement if applicable. The contract should also require proof of current registration and good standing.

The scope of work must be specific and detailed. List every fixture, pipe run, valve, and connection to be installed, repaired, or replaced. Specify the materials and brands to be used (copper, PEX, ABS, PVC), the grade and rating of materials, and whether the client or plumber supplies them. For renovation work, specify demolition and disposal responsibilities.

Building permit obligations must be clearly assigned. The contract should state who applies for the permit, who pays for it, and who schedules and attends municipal inspections. The plumber should guarantee that all work will comply with the Ontario Building Code (or applicable provincial code) and will pass inspection.

Insurance and WSIB/WCB coverage are critical. Require a minimum of $2 million in commercial general liability insurance and a valid WSIB clearance certificate (or provincial equivalent). Pricing should be in Canadian dollars — fixed price, hourly rate (with a not-to-exceed cap), or time and materials — with GST/HST clearly broken out. Include a change order process requiring written authorization before any additional work begins. The workmanship warranty should be at least one year, with manufacturer warranties on materials passing through to the property owner.