Main Water Line Replacement in Toronto

Signs of a failing service

The service leaves the main under the road, passes a curb stop at the lot line, and enters through the front foundation in most houses. In many older Toronto homes that pipe is lead, galvanized steel or narrow copper. Each ages badly in its own way.

• Weak pressure everywhere, especially when two taps run at once. Galvanized pipe narrows from inside as rust builds up.
• A grey, soft pipe entering the basement that scratches easily with a key. That is likely lead.
• Rusty or discoloured water after the system sits overnight.
• A wet patch in the front lawn or a steady meter reading with everything off.

For more on recognizing lead, read signs of lead pipes and our lead pipe replacement page.

Trenchless versus open trench

An open trench is simple: dig from the foundation to the curb stop, lay new pipe, backfill. It works well where the path crosses lawn but means disturbing gardens, walkways and sometimes a front porch.

Trenchless methods use small pits at each end. A boring tool or a pipe-pulling rig draws new copper or approved plastic tubing through the soil, or splits the old line and pulls new pipe in its place. Driveways, mature trees and stone steps stay mostly untouched. Soil conditions, obstructions and the depth of the existing line decide whether trenchless is practical; we check before promising it.

Upsizing for better pressure

Many older houses were fed by a half-inch or smaller line, sized for a kitchen, one bathroom and no lawn sprinkler. A family with two or three bathrooms, a dishwasher and a front-load washer needs more. Replacement is the right time to go to a larger diameter, usually three-quarter inch or one inch, subject to the City's connection rules. Low pressure has other causes too; our low water pressure page goes through them.

Inside connections

Once the new service comes through the wall, it needs a proper main shut-off valve, a meter connection that meets City requirements, and bonding for the electrical ground if the old metal pipe served that purpose. Many homeowners pair the work with repiping the old galvanized branches inside, since a big new line feeding narrow rusty pipe will not deliver the gain you expect.

Permits are required, and an inspector checks the work before backfill. Plan for the water to be off for most of a day.

Living with the work

Expect noise, a temporary pit at the foundation and a hose-length of mud by the door. We protect floors inside and restore the soil outside to grade, but sod and paving restoration should be discussed up front. If you also have hard water concerns, the new service is a convenient place to plan room for a softener or filter.