How to Replace a Toilet

Tips for a trouble-free, leak-free installation

Whether you're installing a better-flushing toilet or resetting the old one after remodeling, these tips will help you do it faster and with fewer problems.

By the DIY experts of The Family Handyman Magazine

Measure before buying

If you’re buying a new toilet, you need to know the “rough-in” measurement of the old one. For the vast majority of toilets, the waste pipe is centered about 12 in. from the wall. But with a few models, that measurement is 10 in. or 14 in. To check the rough-in, just measure from the wall to the toilet’s hold-down bolts. If that measurement (plus the thickness of the baseboard) isn’t approximately 12 in., toilet shopping will be a bit harder. Most home centers carry only one or two 10-in. models and no 14-in. models. If you have to special-order a toilet, be prepared to spend much more. If there’s a door near the toilet, also measure how far the bowl protrudes from the wall. If you replace a standard bowl with an “elongated” model, the door may not close.

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Brass bolts are best

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Cut hold-down bolts

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Lock down the bolts

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Flange fixes

A rock-solid toilet flange is the key to a leak-free toilet. The flange is the only thing anchoring the toilet to the floor. If the flange is loose or damaged, the toilet will rock. And a rocking toilet will distort the wax ring and cause leaks. So be sure to scrape off the old wax ring and inspect the flange. Here are some solutions for broken, corroded or loose flanges.

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Eliminate rocking with shims

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Sit on the toilet to squish the wax ring

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Don't overtighten the water connections

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Cut the bolts last

To make positioning a toilet easier, new toilet bolts are extra long. That means you have to cut off the protruding ends later with a hacksaw. But first connect the water line, flush the toilet a couple of times and check for leaks. Leaving the bolts uncut until you’ve done these final checks lets you easily remove and reset the toilet if you find any problems.

After cutting, double-check the bolts for tightness. Cutting often loosens the nuts a bit.

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Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

  • 4-in-1 screwdriver
  • Adjustable wrench
  • Caulk gun
  • Cordless drill
  • Locking pliers
  • Hacksaw
  • Level
  • Pliers
  • Rags
  • Shop vacuum
  • Slip joint pliers
  • Utility knife
  • Tape measure

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

  • Wax ring
  • Brass toilet bolts
  • Toilet flange
  • Plastic shims
  • Caulk
  • Flexible water supply