Plumbing Checks Before Buying an Older House

Why it matters in Toronto homes

Many older houses in Toronto have been renovated several times, and plumbing upgrades tend to stop at whatever was visible. Behind new tile and drywall you may find original cast-iron stacks, clay sewer laterals, galvanized supply lines and, in some cases, a lead service pipe from the street. None of these is a deal-breaker on its own, but together they can add up to a serious budget item. Knowing in advance lets you plan, negotiate, or walk away.

Step-by-step what to do

1. Check the incoming supply pipe beside the meter in the basement. Dull grey, soft metal that scratches shiny may be lead; see our guide on signs of lead pipes.
2. Trace the supply lines visible in the basement. Grey steel with threaded joints is galvanized and likely nearing the end of its life.
3. Run every tap at once and flush a toilet to see how pressure holds up on upper floors.
4. Book a sewer camera inspection of the lateral. It is the only way to see roots, cracks or sags under the lawn; our sewer camera guide explains what it shows.
5. Check the water heater label for age and whether it is rented.
6. Look for a backwater valve and sump pump, and ask whether the basement has ever flooded.

Mistakes to avoid

• Trusting a new bathroom to mean new pipes. Often only the fixtures and the last metre of pipe are new.
• Skipping the lateral inspection because drains seem fine during a showing. Partial blockages often show up only under heavy use.
• Overlooking unpermitted basement plumbing. Our article on plumbing permits in Toronto covers why that matters.
• Ignoring the age of the house's era; see knob-and-tube-era plumbing for what tends to come with it.

When to call a plumber

Bring a plumber in during your conditional period, ideally after the home inspection flags any concerns. We can run a camera through the lateral, check the visible supply and drain piping, and tell you what is likely hiding behind the walls. If repairs are needed, a written description of the scope helps you and your agent discuss price with the seller. Where hidden leaks are suspected, slab and wall leak repair covers how we locate and fix them.

Budgeting after you buy

Even with good inspections, set aside money for plumbing in the first few years of owning an older house. Prioritize anything that affects safety or flooding, like a lead service or a damaged lateral, then plan galvanized replacement and fixture upgrades around other renovations so walls are only opened once.

Common questions