Bathtub Plumbing near you

Under every tub is a drain-waste-overflow assembly. The drain shoe connects to the outlet at the bottom of the tub, the overflow elbow connects to the opening below the rim, and the two meet in a tee that runs down to a trap under the floor. The stopper, whether lift-and-turn, toe-touch, push-button or trip lever, is part of the same assembly.

Most tub drain problems start here: a dried-out gasket at the drain or overflow, a slip joint that has worked loose, or a trip-lever linkage matted with hair. Because the assembly sits behind the tub, a leak tends to show up as a stain on the ceiling below or damp flooring beside the tub rather than a visible drip. When a tub is replaced, fitting a new assembly is part of the job; reusing an old one saves little and risks a leak you can't easily reach.

With a freestanding tub, the drain has to rise through the floor at exactly the spot where the tub's outlet will sit, so the tub is usually bought and its drain position confirmed before the floor is opened. The trap goes between the joists below, or into a cut in the slab on a concrete floor, and the waste and overflow on these tubs is often a finished piece that stays in view.

A floor-mounted filler needs supply lines brought up through the floor and a solid mounting to the framing, with its valve reachable for service; a wall-mounted spout needs the tub close enough for the water to land inside it. Leave room to clean around the tub, and decide how the drain will be reached later, from the ceiling below or through an access panel. New drain and supply routes are plumbing alterations, so they belong with a licensed plumber and may need a permit.

A full tub concentrates the weight of the tub, the water and the bather on a small patch of floor. Cast iron and stone tubs, deep soakers and large freestanding models weigh far more than a standard acrylic alcove tub, and older houses may have joists that earlier renovations notched or drilled. A floor that sagged, bounced or cracked tile around the old tub is a warning sign.

Before ordering a heavy tub, get the manufacturer's filled weight and share it with your contractor. If there is any doubt about the joists, especially for a tub placed mid-span or on an upper floor, a structural engineer can assess the framing and specify reinforcement, which is far easier to add while the floor is open.

Swapping a tub for a shower changes more than the enclosure. The tub drain sits at one end, while a shower base or tiled pan usually needs its drain in a different spot, so the trap is often relocated and the drain fitting changed to suit the new base. The valve usually stays in the same wall, but the spout and diverter come out and the showerhead may move higher.

It's also the natural moment to replace an old two-handle or non-balancing valve with a pressure-balancing or thermostatic one. The waterproofing, tile and glass that follow are part of a bathroom renovation, and families with young children may want to keep one tub somewhere in the house.

Tubs are where young children are most exposed to hot water, since they sit in it and may reach for the tap. The Government of Canada recommends automatic mixing valves on tubs, showers and faucets, or an anti-scald mixing valve at the water heater, set to deliver 49°C (120°F), and advises starting and ending with cold water when running a bath and testing it with your elbow before a child gets in.

A tub valve with pressure balancing or thermostatic control guards against sudden swings, and its limit stop should be set at installation. If the bath seems hotter than it used to, have the mixing valve or limit stop checked, particularly after the water heater has been replaced or adjusted.

When stepping over a tub wall becomes difficult, the answer ranges from small changes to a new fixture. CMHC's list of low- and no-cost accessibility modifications includes a safety mat and grab bars in the tub, and a water alarm that warns when a tub or sink is overflowing, useful for anyone who might forget a running bath.