Plumber Jobs in Ontario: Who Is Hiring Right Now

Ontario cannot pour a foundation, close a wall, or open a hospital without a licensed plumber on the water and the drainage. Every new house, every tower, every school and restaurant fit-out, every water heater that quits at minus twenty in January needs a 306A plumber or an apprentice working under one. The trade runs short of people almost everywhere in the province, and the work is spread from downtown high-rises to rural hookups on the edge of a growth town. The question is never whether the work exists. It is knowing which contractor is short a body this month, and getting your name to them before the crew is set.

That is what this page is for. The live strip above pulls the employers who just pulled a building permit or won a contract that will need plumbing, so you can chase real, current jobs instead of refreshing stale job boards. Below is the operator-level read on who hires plumbers in Ontario, when they need you on site, and how to actually reach them.

Who hires plumbers in Ontario

Plumbing almost never gets self-performed by the general contractor. It gets subbed to a licensed mechanical or plumbing shop, so your employer is usually one of these:

• Plumbing and mechanical contractors. The core of the trade. They run from a two-person residential service outfit to a large mechanical firm carrying dozens of plumbers and pipefitters across several sites. On bigger jobs the plumbing, heating, and sometimes the controls all sit under one mechanical contract, so the same firm may need rough-in hands, service techs, and gas fitters at the same time.
• ICI mechanical firms. Industrial, commercial, and institutional specialists who take on the hospitals, schools, towers, and plants. Bigger scope, tighter spec, more coordination and paperwork, and generally the best rates. Frequently unionized under the UA.
• Homebuilders' preferred plumbing subs. Production builders and developers rarely carry plumbers on staff. They run the same trusted rough-in sub subdivision after subdivision, so those shops get steady, repetitive volume as long as they hold the builder's account. When a builder ramps a new phase, that sub is the one scrambling for bodies.
• Service and drain companies. The 24/7 outfits doing leaks, clogs, camera-and-auger drain work, water heaters, sump pumps, backflow testing, and fixture swaps. Year-round, weatherproof, and almost always hiring, because both demand and turnover run high.
• New-home rough-in specialists. Shops that do little except underground and rough-in on production housing, moving crews lot to lot on the builder's schedule. Fast, repetitive work that rewards speed and clean layout.
• Site-services, watermain and sewer contractors. The crews that run water and sanitary services from the municipal main into the building, often overlapping with excavation and civil work. More seasonal and weather-tied, but steady in a growing corridor.
• Facilities and institutional maintenance. In-house plumbers and mechanical staff at hospitals, universities, school boards, municipalities, and large property managers. Stable, often pensioned, and the least exposed to the construction cycle.

One thing sets plumbing apart from most trades: a large share of the work is gas-fired. Water heaters, boilers, and combination systems burn natural gas or propane, so many shops want a TSSA gas ticket (a G2, or a G1 for the larger equipment) alongside the 306A. Carrying a gas ticket makes you far more useful on residential and service work, and it is often the single thing that decides a hire between two apprentices.

On the feed, the two signals to watch are permits (a builder or owner pulled a permit, so rough-in and finish plumbing are coming) and awards (a mechanical or general contractor just won a job that will need a plumbing crew).

The kinds of plumbing work

Where you land shapes your pay, your pace, and your ticket path. The main lanes:

• Residential new build. High volume, fast pace, smaller crews, heavy repetition. Underground and under-slab goes in first, then rough-in with the walls open, then finish and fixtures near the end. Tract housing, custom homes, and additions. This is the easiest lane to get into as an apprentice, and where most plumbers cut their teeth.
• ICI and mechanical. Bigger projects, longer timelines, tighter spec, and generally the best rates. Frequently unionized under the UA. Hospitals, schools, office and residential towers, water and wastewater plants, and large tenant fit-outs. Expect large-diameter pipe and cast iron, medical gas in health care, and heavy coordination with the other mechanical trades.
• Service and repair. Drains, leaks, water heaters, sump and sewage pumps, backflow prevention and annual testing, fixtures, and code corrections. This is the most year-round lane and the least exposed to the construction cycle, which makes it a stable place to ride out a slow winter. It is also the fastest lane to get hired into, because the shops are chronically short.
• Renovation. Kitchen and bath remodels, basement finishes, and commercial tenant work. A mix of tear-out, re-pipe, and finish, usually on older buildings where nothing is square and galvanized or lead surprises turn up behind the wall.

A few add-on tickets pay off across all four lanes. Backflow prevention and cross-connection control certification lets you install and test backflow devices, medical gas certification is required to touch hospital and lab gas systems, and a TSSA gas ticket covers the heating side. Each one opens work and rate that a plain 306A cannot bill for, and each one makes you harder for a short-staffed shop to pass over.

It also helps to know what systems a shop runs before you pitch them. Residential work leans on PEX and ABS, commercial and institutional work still runs a lot of copper, ProPress, grooved pipe, and cast iron, and older buildings mean galvanized and lead you have to cut out. If you are quick and clean on the materials a shop uses every day, say so when you reach out.

When plumbers get the call on a build

Reading the build sequence is how you time your outreach. Plumbing touches a job at three or four distinct points, and they are spread right across the schedule:

1. Underground and under-slab rough-in, first, before the slab is poured. The drain, waste, and vent below grade and the water service into the building go in while the ground is still open. Miss the window and it becomes jackhammer work later, so it is scheduled tight and early.
2. Top-out and rough-in, after framing, with the walls still open, alongside or just after electrical and HVAC rough-in and before insulation and drywall. Stacks, branches, and water lines go in and get pressure-tested and inspected. This is the biggest single labour draw on the plumbing side.
3. Finish and fixtures, near the end. Toilets, sinks, faucets, tubs, water heaters, and trim get set once the walls are closed and the finishes are in.
4. Inspection, the plumbing inspection before occupancy, plus the TSSA sign-off on any gas work.

So a fresh residential building permit signals rough-in plumbers will be needed roughly a month or two out, depending on how fast the builder gets to the slab and framing, with finish plumbers later still. Treat any specific timing on the feed as an estimate, not a promise. A water-service, backflow, or water-heater permit is the opposite: immediate, short-duration service work that a shop needs filled almost right away. An ICI award means the mechanical sub gets engaged at buyout and mobilizes on the project schedule, which can be weeks or months after the announcement lands.

Where the work is right now

Plumbing is mostly interior work, so it holds up better through the winter than exterior trades like roofing or masonry. Underground and site services are the exception: they follow excavation and the weather, so trenching and watermain work slows when the ground is frozen while rough-in and finish keep rolling inside heated buildings. New-build volume still tracks the permit cycle, but service and ICI fit-out work carry through the cold months, which is why a plumber who can swing between new construction and service rarely sits idle.

Geographically, the deepest pools are the GTA, Ottawa, and the Golden Horseshoe, with fast growth around Waterloo Region, Barrie and Simcoe County, and the Durham corridor. Institutional and industrial work follows the hospitals, campuses, and plants rather than the housing map, so eastern and northern Ontario carry their own steady demand off the big facilities even where new housing is thinner.

How to get in front of these employers

The feed gives you the who. Here is how you turn that into work:

• Reach out directly. Once you have the employer name and location from a card, look them up and contact them. Lead with your 306A ticket, your apprenticeship level and logged hours if you are still an apprentice, and any gas ticket (G2 or G1), backflow, or medical gas certification you hold. Add the site tickets that get you on fast: WHMIS and Working at Heights. Say plainly what work you want and when you can start.
• Go direct for residential and service. Those shops are almost always short-handed and hire faster, with less process, than the big ICI firms. A builder starting a new subdivision or a service company heading into its busy stretch is exactly when they register apprentices and take on hands.
• Work the union hall if you are UA. Plumbers and pipefitters locals dispatch to signatory contractors off the out-of-work list. Get your name on the list, keep it current, and stay in contact with your business agent. Each local dispatches within its own territory across the GTA, Hamilton, Ottawa, London, Windsor, Sudbury and the north, and the rest of the province.
• Lead with the gas ticket. On residential and service hires especially, a G2 next to the 306A often decides it, because so much of the day-to-day is water heaters and boilers.
• Time it to the signal. An employer who just pulled a permit or won a contract is staffing for that specific job. Reaching out in that window, before the crew fills, is the whole point of watching the feed.

Getting qualified

If you are still chasing the 306A Certificate of Qualification, that is the credential that opens the better-paid work and, eventually, your path to running jobs or your own shop. Our Last Mile to Certificate of Qualification guide for the plumber trade below walks the exam, the hours, and the union route from the apprentice's seat. It pairs naturally with the TSSA gas tickets most plumbing employers want you carrying alongside the 306A.