Will the New Toilet Fit?
Richard Trethewey explains how to measure for a new toilet
I’m replacing our old toilet with something more efficient. Will the new one have the same wall-to-drain measurement as the old one?
—Brian Van Tubbergen, Holland, MI
When it comes to plumbing, almost nothing is standardized, including rough-in dimensions: the distance from the wall to the center of the closet flange that connects your toilet to the drain. It usually ranges from 10 to 14 inches—12 inches is most common these days—but I’ve seen flanges even closer to a wall.
It’s easy to determine the rough-in dimension for any toilet, and you don’t even have to remove it. Simply measure from the wall to the nearest closet bolt, which holds the toilet to the flange. If there’s a baseboard, add its thickness to get the actual wall-to-drain distance.
If your measurement is close to 10, 12, or 14 inches, you’re in luck; you should be able to remove and replace the toilet yourself. Don’t worry if your rough-in doesn’t match these dimensions exactly. Anything within the 10- to 14-inch range can be accommodated by just setting the toilet farther from the wall than the usual 3⁄4 inch. Rough-ins a little shy of 10 inches can also work with the existing flange, if you don’t mind the toilet being closer to the wall.
For rough-ins between 8 and 9 ½ inches from the wall, you’ll need an offset closet flange, which can move the drain’s centerpoint 1 ½ inches away from the wall. That should be enough clearance for a toilet with a 10-inch rough-in. Installing offset flanges is a tricky job, however. Call in a plumber if you need to go that route.
Shown: Before Richard Trethewey installs a new toilet, he checks the distance from the wall to the center of the drain to make sure the new fixture will fit.