Tub fillers are one of the few bathroom purchases where a small measuring mistake becomes a big renovation problem. A model that looks perfect online can arrive and sit too low to clear your tub rim, reach too short to pour into the basin, or demand a rough-in your floor cannot accommodate. The good news is that fit comes down to a handful of dimensions, and every reputable manufacturer publishes them. This guide covers standard tub filler sizes, how to measure, and the fit mistakes we help buyers avoid, from condo retrofits in Vancouver to new builds outside Halifax.
Three mounting styles, three sets of numbers
Every tub filler is a floor-mount, deck-mount or wall-mount design, and each style lives or dies by a different set of dimensions.
Floor-mount fillers rise from the floor beside the tub and are usually paired with a freestanding bathtub. The critical numbers are overall height, spout height (the point where water actually exits) and spout reach. Most floor-mount fillers stand somewhere in the range of 85 to 115 centimetres, with spout outlets commonly 75 to 95 centimetres above the finished floor and reach around 15 to 25 centimetres.
Deck-mount fillers, often called Roman tub fillers, install through holes in the tub deck or rim. Here the numbers that matter are spout reach, the spacing between mounting holes, and the maximum deck thickness the hardware can clamp. Three-hole configurations are common, with many models adding a fourth hole for a hand shower. Confirm hole diameter and spread against the drilling template before anything gets cut.
Wall-mount fillers put the valve inside the wall and project the spout out over the rim. Spout reach, installation height above the rim, and the valve's in-wall depth range are the dimensions to check. The reach has to carry the stream past the tub wall and into the basin.
| Style | First dimensions to check | Typical territory |
|---|---|---|
| Floor-mount | Overall height, spout height, spout reach | Roughly 85 to 115 cm tall overall |
| Deck-mount | Spout reach, hole spread, max deck thickness | Reach often 17 to 28 cm |
| Wall-mount | Spout reach, mounting height, valve depth | Reach often 15 to 25 cm |
Treat these ranges as orientation only. The numbers that count are on the dimensioned drawing for the model you are buying.
Measuring your space before you shop
- Rim height. Measure from the finished floor to the top of the tub rim. New tile or heated floors raise the finished floor, so measure to the level the floor will actually be.
- Rim width. Measure across the rim or deck where the spout will cross it. Freestanding tubs with generous rolled rims need more reach than the photos suggest.
- Tub position. Confirm where the tub will actually sit once plumbed, including its distance from walls.
- What is under the floor. Floor-mount fillers need supply lines stubbed up in an exact spot, so check joist direction and below-floor access. On a concrete slab, this decision has to happen before the pour, or it becomes a concrete-cutting job.
- What is inside the wall. For wall-mounts, confirm stud locations, finished wall thickness, and whether the wall is an exterior one. In most of Canada, from the Prairies to the Maritimes, a tub valve in an exterior wall invites frozen lines, so plan for an interior wall or serious insulation detailing.
Clearance rules worth respecting
- Water should land well inside the basin. A spout that barely crosses the rim will splash and streak the tub wall.
- Plumbing codes generally require an air gap between the spout outlet and the tub's flood rim to protect against backflow. This is one reason spout height is a code matter, not just an aesthetic one.
- Leave real knuckle room around handles, and make sure a hand shower's hose can reach the far end of the tub without straining.
- Floor-mount fillers need standoff from the tub's curved body so the base flange sits flat and the column does not crowd the tub. Follow the manufacturer's stated minimums.
- Canada's National Plumbing Code is the model document, but provinces and municipalities adopt and amend it, so your local inspector and installer have the final word.
The fit mistakes we see most often
- Buying the filler before the tub. The tub sets the rim height and rim width, and the filler has to answer to both. Choose the tub first, or choose the pair together.
- Ignoring reach on a wide rim. A short-reach spout over a thick rolled rim pours onto the edge instead of into the water. Add the rim width to the required standoff and compare against the spec sheet's reach figure.
- Missing the rough-in window. Floor-mount supply lines have to be positioned before flooring goes down. If the trades are already tiling, your options narrow fast.
- A deck too thick for the hardware. Stone and thick composite decks can exceed a deck-mount filler's maximum clamping thickness. Extension kits exist for some models, but confirm before ordering.
- Forgetting flow rate. Spec sheets list flow in litres per minute at a stated pressure, and household pressure varies. A big soaker matched with a modest-flow filler means a long wait for a bath.
How to read the spec sheet
Once you shortlist a model, pull its dimensioned drawing. Established manufacturers such as Riobel, Kalia, Aquabrass, Rubinet and Kohler publish these for every tub filler they make. Look for five things: overall height, spout height (sometimes labelled outlet or aerator height), spout reach measured from the centreline of the base, rough-in requirements for supplies or the in-wall valve, and flow rate at a stated pressure. For Canadian installations, check for cUPC or CSA certification marks; reputable retailers list them, and your inspector may ask.
If a drawing is missing a number you need, ask before you buy. It is a five-minute question that prevents a return shipment, and nobody enjoys freighting a tub filler from Halifax back to a warehouse in British Columbia.
Where to go from here
Measure first, shortlist second. With your rim height, rim width and rough-in situation noted, browse our tub filler collection, where floor-mount, deck-mount and wall-mount options ship across Canada. For the rest of the room, our buying guides hub covers tubs, showers and faucets in the same fit-first spirit.
Frequently asked questions
How tall should a tub filler be?
Tall enough that the spout outlet clears your tub's flood rim with an air gap, and low enough that the stream does not splash on the way down. Freestanding rims commonly sit in the 55 to 75 centimetre range and floor-mount spout outlets between 75 and 95 centimetres, so most pairings work, but always check your specific tub against the specific filler.
What is spout reach, and how much do I need?
Reach is the horizontal distance from the mounting point to the centre of the water stream. You need enough to cross the rim or deck and land the water well inside the basin. Measure your rim width at the crossing point, add the standoff the filler needs from the tub body, and make sure the spec sheet's reach comfortably beats that total.
Can I install a floor-mount tub filler on a concrete slab?
Yes, but the supply rough-in should be planned before the slab is poured. In an existing slab, whether in a Calgary bungalow or a Montreal basement, the concrete has to be cut and patched, which adds cost and demands precise layout. Talk to your plumber before committing to the fixture.
Do tub fillers sold in Canada need certification?
Plumbing fixtures installed in Canada are expected to be certified to the applicable standards, most often shown by a cUPC or CSA mark. Requirements are enforced locally, so confirm with your municipality or installer, and buy from retailers that state certification clearly on the product listing.
