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How to Choose a New Toilet Seat

Ask This Old House plumbing and heating expert Richard Trethewey discusses the basics of choosing and installing toilet seats

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Cost: $15 and up

Skill Level: Beginner

Tools List for Choosing a Toilet Seat:
Measuring tape
Flathead screwdriver
Socket wrench
Putty knife

Shopping List:
Toilet seat

1. Start by measuring the length of the toilet seat. They come as either round seats at 16” or elongated at 18”. Be sure to buy the correct size seat.
2. Unscrew the bolts at the back of the toilet seat holding it in place and remove the old toilet seat. Depending on how old the toilet seat is, this may require a screwdriver if the screws are on top of the toilet. If they’re underneath, it’s safest to use a socket wrench to unscrew the bolts.
3. If the old bolts have become deformed and won’t loosen up, carefully cut them off with a hacksaw. It will be easier to cut them from the top. Place a putty knife underneath the saw to protect the china of the toilet from being scratched.
4. On the new toilet seat, place the holes on the back of the seat over the holes on the toilet.
5. Insert the screws that come with the toilet seat into the holes on the toilet. Put the nuts on the underside of the toilet.
6. Tighten the screws with a flathead screwdriver.

Richard distinguishes between Round (16”) and Elongated (18”) toilet seats. Replacement seats must match the existing toilet seat.

The seat with a potty training seat built in is the NextStep Children’s Toilet Seat, manufactured by Bemis Manufacturing Company ( This is available at home centers.

The elevated seat with grab bars is manufactured by Glacier Bay and is available at home centers.

The artistic seats that Richard showed are available in many styles and can be found at online retailers.

The high tech toilet seat with the bidet that Richard demonstrated is the Advanced Clean AC 2.0 Spalet Bidet Seat, manufactured by American Standard (

Ask This Old House TV
Homeowners have a virtual truckload of questions for us on smaller projects, and we’re ready to answer. Ask This Old House solves the steady stream of home improvement problems faced by our viewers—and we make house calls! Ask This Old House features some familiar faces from This Old House, including Kevin O’Connor, general contractor Tom Silva, plumbing and heating expert Richard Trethewey, and landscape contractor Roger Cook.
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Keywords: This Old House, How-to, home improvement, DIY, ask this old house, richard trethewey, kevin o’connor, toilet, toilet seat,

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