Installation & New Work

Kitchen Plumbing

Sinks, faucets, dishwashers, appliance water lines and kitchen drainage, from a single faucet swap to the full rough-in behind a new kitchen.

Request a Quote (742) 688-3747

Sinks, faucets and the drain that has to line up

The difference between a drop-in sink and an undermount is not just how it looks at the counter. An undermount hangs below the stone, so the strainer, tailpiece and trap all start lower. Add a deep single bowl and a garburator to a standard 34-1/2 inch base cabinet and the trap outlet can end up level with or below the branch drain in the wall, which leaves nowhere for the water to fall. That is a problem to catch before the counter is templated, not after.

Farmhouse and apron-front sinks bring their own issue, since the cabinet has to be cut and a support built under the bowl. With cast iron and fireclay that support is structural, not decorative.

Faucets are simpler, with one caveat: hole count and spacing are set when the stone is fabricated. A pull-down faucet, a separate soap dispenser, a filtered water tap and an air gap for the dishwasher each need a hole, and the fabricator drills them once. We would rather see the faucet spec sheet before the template than solve it afterward with a deck plate.

Dishwashers, fridge lines and appliance connections

A dishwasher needs a dedicated supply stop under the sink, a braided stainless connector rather than the old copper coil, and a drain arrangement that keeps waste water from siphoning back into the machine. That backflow protection comes either from a high loop fastened as high as possible under the counter or from an air gap fitting mounted through the countertop. The air gap is the more certain of the two, and it is the one we recommend where a hole is available.

The most common no-drain call on a new dishwasher is not plumbing at all. It is the knockout plug still sitting in the garburator inlet where somebody forgot to punch it out.

Fridge water lines should run in 1/4 inch copper or PEX off a proper tee and a quarter-turn stop. If yours is fed by a saddle valve, the little clamp-on device with a piercing needle, plan on replacing it. They restrict flow, clog with mineral scale, and seep behind cabinetry where nobody looks. Pot fillers are a similar story. Nice fixture, but it puts a supply line and a shut-off inside the wall behind the range, and in a Toronto house that is often an exterior wall with real freeze risk in January.

Island sinks and the venting problem

An island sink has no wall behind it to run a vent up, and every trap needs a vent. It is the most misunderstood point in kitchen plumbing, and where a lot of unpermitted renovations go wrong.

The conventional answer is an island vent, sometimes called a loop or bow vent. It rises from the trap arm to just under the countertop, loops over as high as the cabinet allows, then drops back below the floor and runs across to a vented line. The low point gets a foot vent and a cleanout, because the return leg collects water and has to be cleanable. It works, it is accepted, and it takes up room inside the cabinet.

The alternatives are narrower than people hope. An air admittance valve inside the cabinet is sometimes acceptable, but it has to stay accessible and it will eventually need replacing. Oversized combination waste and vent arrangements exist in the code for specific situations and are not a general substitute. If someone has told you an island sink just needs a studor cap and no further thought, get a second opinion before the island is built.

What actually blocks a kitchen drain

Kitchen drains fail for one reason far more than any other. Grease goes down warm and liquid, then cools and coats the branch and the stack, and coffee grounds, starch and food fibre stick to the coating. It builds in layers until the pipe is a fraction of its bore. That is why kitchen blockages come back on a schedule rather than as accidents.

Older Toronto kitchens make it worse. A 1-1/2 inch galvanized branch running twenty feet to a cast iron stack has a rough interior to begin with, and grease finds every bit of it. A garburator is a convenience, not a drainage improvement, and adding one to a line like that buys you an annual snaking.

Cabling clears a blockage. Hydro-jetting scours the pipe wall back toward its real diameter, which is the difference between a sink that works today and one that works for a while. Where the branch itself is shot, replacing it while the kitchen is already apart beats another service call.

Questions

Kitchen Plumbing, answered.

Why does my kitchen sink keep backing up?

Almost always grease. It goes down warm, cools, and coats the inside of the branch drain and the stack, and food solids stick to that coating until the pipe is barely open. Cabling opens a channel through it. Hydro-jetting scours the wall back toward the full diameter, which is why a jetted line stays clear far longer than a cabled one.

Does an island sink need a vent?

Yes. Every trap needs a vent, and an island has no wall to run one up. The usual solution is an island loop vent that rises under the counter, loops over, drops back below the floor and connects to a vented line, with a foot vent and a cleanout at the low point. An air admittance valve is sometimes accepted instead, but it has to remain accessible.

Can a dishwasher drain into the garburator?

Yes, that is a normal connection, but the knockout plug inside the garburator inlet has to be punched out first. A dishwasher that fills with water on a brand new installation is usually that plug. The drain hose still needs a high loop or an air gap regardless of where it discharges, so waste water cannot siphon back into the machine.

Do I need an air gap for my dishwasher?

An air gap fitting mounted through the counter is the most reliable backflow protection for a dishwasher drain, and it is what we recommend when a hole is available in the deck. A properly fastened high loop under the counter is commonly accepted as an alternative. What is not acceptable is a hose run flat from the machine to the trap.

Can you install a water line for a fridge or ice maker?

Yes. We run 1/4 inch copper or PEX from a tee with a quarter-turn stop, positioned so the fridge can be pulled out without kinking the line. If there is an old saddle valve on the existing line we replace it. Those piercing valves restrict flow, block with mineral scale, and tend to seep behind cabinetry where the damage goes unnoticed.

Is a garburator a good idea?

It depends on your drain. On a modern properly sized and vented kitchen line it is a reasonable convenience. On an old 1-1/2 inch galvanized branch running a long way to a cast iron stack, it adds solids to a pipe that is already narrowed by grease, and you will be calling for drain service regularly. We will tell you which one you have before we install anything.

Often needed alongside this.

Get a quote

Tell us about the job.

Send the details through the quote form and we will come back to you with next steps. For anything urgent, call the office. A phone call always beats a web form.

Call the office(742) 688-3747 Request a Quote

Mon–Fri 9:00am–5:00pm · Saturday by appointment. We do not advertise 24-hour emergency service. Messages received outside regular business hours are returned as soon as possible on the next business day.