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House grounding: when to redo it

Grounding electrode, bonding, plastic water service, two-prong outlets: what Québec’s Code requires, and the situations where you should have your grounding checked.

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By the master electricians of STM-ÉlectriqueRBQ licence 5815-0137-01Sources checked on October 4, 2026

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In short

The essentials.

Grounding connects your installation to the earth. It gives the whole installation a common reference and keeps the potential difference with the earth to a minimum.
It isn’t the same thing as bonding, which connects the metal parts of the house to each other. You need both.
In Québec, the municipal water pipe can no longer be used as a new grounding electrode. It’s a rule specific to Québec, which American websites ignore.
A water service replaced with plastic can make you lose the grounding without anything showing.
A three-prong outlet without a ground wire is allowed only if it is protected by a GFCI. It doesn’t become “grounded” for all that.

Jump to a section8

What it is
What you have at home
At the panel
The water pipe
When it’s lost
Two-prong outlets
What you can check
Frequently asked questions

What it is, and what it isn’t

People talk about it as a technical detail, hidden somewhere in the basement. Yet, along with bonding, it’s what keeps the metal parts of the house at a safe potential.

Grounding is the connection of part of your electrical installation to the earth, taken as a reference. The Office québécois de la langue française defines it as the connection of part of a circuit to a conductive mass “whose potential is taken as the reference” (translated from French).

Bonding (continuité des masses in French) is something else: connecting together all the metal parts of the installation (enclosures, outlet boxes, panel, piping) so they stay at the same potential. Québec’s Construction Code calls the green or bare wire of your circuits the “bonding conductor”.

	Grounding	Bonding
What it connects	The installation to the earth	The metal parts to each other
Where it happens	Between the service box and the grounding electrode	Everywhere: each box, each appliance, up to the panel
The wire	Grounding conductor	Bonding conductor (green or bare)
What it’s for	Giving the whole installation a stable, common reference	Keeping the metal parts at the same potential and connecting them to the panel

The Corporation des maîtres électriciens du Québec stresses the difference between the two to its members. For an owner, remember this: bonding connects the metal parts to the panel, and grounding connects the installation to the earth. They are two different wires, and you need both.

What you have at home

In a house, the chain is short:

The service box, most often your main panel with its main breaker.
The grounding conductor, a large wire leaving the box. In Québec, it is at least 6 AWG copper or 4 AWG aluminum, in principle without splices, and protected against damage or placed out of harm’s way.
The grounding electrode, at the end of that wire: for example rods driven into the ground, a buried plate or a conductor embedded in the concrete of the footing, depending on the house.

The number, length and spacing of the rods, or the area of a plate, are set by the Code. Your electrician chooses the solution based on the soil, the foundation and what’s already in place. It isn’t a figure to apply yourself: it’s the kind of detail settled on site, and measured.

The 2026 Code changed its numbering: grounding electrodes now fall under section 10-102. Work started before October 17, 2027, may still follow the previous edition, where the numbers differ. American websites’ rules don’t apply here.

Grounding at the electrical panel

At the service, grounding is done by connecting the neutral to the neutral block of the service box, most often your main panel.

It is done only once in the installation, at the first disconnecting point of the service. The grounding conductor leaves that neutral block and runs directly, without interruption, to the grounding electrode.

That’s what keeps the house’s neutral at the same potential as the electricity distributor’s.

If your meter is on a meter base with a breaker, that meter base becomes the service box, and that’s where grounding is done.

In a downstream panel, like the panel of a unit supplied by the main panel, the RBQ considers it non-compliant to leave the neutral connected to the enclosure by the brass screw or the jumper. The neutral current then flows continuously in the bonding wires, without any protection acting. This RBQ interpretation was published under the 2010 edition of the Code.

An exception specific to Québec: when at least two buildings are supplied by a single service, the 2026 Code allows the neutral to be connected to a grounding electrode at each of them.

The water pipe: Québec’s rule

For decades, the metal water service was used as a grounding electrode. That’s still what many American websites repeat. In Québec, it can no longer be used as a new grounding electrode. Québec’s Construction Code says so plainly:

“It is prohibited to use a municipal metal water distribution pipe as a new grounding electrode.” (translated from French)
Construction Code of Québec, Chapter V, Electricity, s. 10-102 6)

Québec goes further: the metal water piping inside the house must be connected to the installation (bonding), but a dielectric union, installed as close as possible to the water service, isolates it from the city’s pipe. In an installation done under this rule, the grounding therefore doesn’t depend on the municipal pipe. An older house may still depend on it.

When grounding is lost, or has to be redone

Grounding is often lost because of another job, without anyone noticing:

Your situation	The risk	What to do
The metal water service was replaced with plastic	If it served as the grounding electrode, the link is cut: plastic doesn’t conduct.	Have the grounding electrode checked, and install another one if needed.
A plastic water meter or water softener was added	Same effect: the continuity of the piping is interrupted.	An electrician restores the link (jumper) or another grounding electrode.
You’re increasing the capacity of the service entrance	An old grounding conductor that’s too small may have to be replaced.	Have the grounding checked during the service entrance work.
Old wiring, two-prong outlets	No bonding conductor in the circuits.	See the next section, and our guide on knob and tube wiring.
Basement renovation	The grounding conductor may be cut or damaged during the work.	Locate it before closing the walls: the Code requires it to be protected against damage.

We found no official list of signs of faulty grounding. An installation without grounding can seem to work normally: a few clues can be seen (see below), but only a check confirms it. That’s why it’s worth having it checked during a service entrance or panel replacement, and after plumbing work that touches the water service.

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Two-prong outlets

A two-prong outlet is the trace of wiring from another era, with no bonding conductor. The Code doesn’t require changing an existing installation that isn’t being touched. The problem is replacing it with a three-prong outlet without changing anything else. The third slot then gives the illusion of a ground that doesn’t exist.

The Code provides a solution: a three-prong outlet is allowed without a bonding conductor if it is protected by a Class A GFCI (a GFCI outlet, or a GFCI breaker at the panel). The GFCI cuts the power as soon as it detects a leak, which protects the person.

What the GFCI doesn’t do: it doesn’t create a ground. The ground slot stays without a reference. A device that depends on it, like a power bar with a surge protector, no longer protects against surges. For a real ground, the circuit has to be redone with a bonding conductor.

For the details of where a GFCI is required, see our guide GFCI outlet or breaker: what it protects, where you need it.

What you can check yourself

Without opening anything, you can already spot a few clues:

The wire leaving the main panel towards the ground, a rod or a clamp: is it there, is it intact, wasn’t it cut during a renovation?
The water service: metal or plastic? Has it been redone recently?
The outlets: two or three prongs? Were the three-prong outlets in an old house installed without redoing the wiring?

The rest isn’t a do-it-yourself job, and it isn’t a matter of skill. In Québec, the Régie du bâtiment is clear: a person isn’t allowed to work on an electrical installation, even in their own home, without the appropriate licence. Redoing a grounding electrode, replacing an outlet or adding a GFCI is electrical work.

Frequently asked questions

How do I know whether my house is grounded?

Locate the large wire leaving the main panel towards a rod, a plate or the foundation. If it’s missing, cut, or was connected to a water service that is now plastic, have it checked. Only a check by an electrician confirms that the grounding and the bonding are good.

Is a two-prong outlet illegal?

The Code doesn’t require changing an existing installation that isn’t being touched: a two-prong outlet is the mark of old wiring, without a bonding conductor. What to avoid is replacing it with a three-prong outlet without GFCI protection or new wiring.

Can I install a three-prong outlet without a ground wire?

Yes, if it’s protected by a Class A GFCI: that’s what the Code allows. But it doesn’t become grounded for all that: a surge protector plugged into it no longer protects against surges. And the work must be done by an electrical contractor.

Is my water pipe used as my grounding?

In an old house, it’s possible. But in Québec, the municipal water pipe can no longer be used as a new grounding electrode, and the Code now requires a dielectric union near the water service. If your water service was replaced with plastic, the grounding may have been lost.

How much does redoing the grounding cost?

It depends on what we find: a simple jumper to restore, a new grounding electrode to install, or a conductor to redo with the service entrance. We price it after seeing the installation, and the price is written down before the work.

What about grounding sheets?

These sheets plug into an outlet, but they aren’t part of your installation’s grounding. We found no Health Canada advisory about them. The grounding this guide talks about is a Code requirement for the safety of the house.

Do I need an electrician to redo the grounding?

Yes. According to the Régie du bâtiment, any work on an electrical installation, even in your own home, must be done by a contractor who holds the appropriate licence.

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Sources

The requirements cited in this guide come from the official pages below, consulted on October 4, 2026. The Code changes: check the page’s update date before committing to any expense.