How to Measure for a New Toilet, Faucet or Water Heater

Three measurements that save a second trip to the supply house.

Toilet: the rough-in

Measure from the finished wall to the centre of the closet bolts — the bolt caps at the base. Measure from the wall itself, not the baseboard, or you'll be off by half an inch.

You'll get roughly 10", 12" or 14". 12" is by far the most common. Skirted toilets, where the base is enclosed, hide the bolts — those sometimes have to be lifted to measure properly, and their base width varies enough that the supply line may need moving.

While you're there, note whether the bowl is round or elongated, and measure the clearance in front and to each side.

Faucet: count the holes

Look at the sink or countertop from underneath.

• One hole — single-hole faucet.

• Three holes, 4" apart centre to centre — centerset.

• Three holes, 8" apart — widespread.

• No holes in the deck — wall mount.

Measure centre to centre on the two outer holes. Mounting style is limited by what's already drilled, and we don't drill countertops.

Water heater: measure the path, not just the space

Capacity matters, but so does the box it comes in. Energy efficiency rules changed in 2015 and manufacturers added insulation, which made tanks wider. A 50-gallon heater today may not fit where the old 50-gallon sat, and some no longer fit through a standard doorway.

Measure the height and diameter of the old one, the alcove or closet it lives in, and the width of every door and turn between the front of the house and that spot.

While you're at it: find the model and serial number

Usually on a sticker on the side of the tank or behind a cover panel. Photograph it. If you ever file a warranty claim, that's the first thing you'll be asked for, and it's a lot easier to read before the unit fails.

When to call us. A rough-in that doesn't measure to 10, 12 or 14. A skirted toilet you'd rather not lift. Or a replacement heater that won't fit the path — there are usually options, including a different form factor.