How to Change a Toilet Seat

In this video, This Old House plumbing and heating expert Richard Trethewey and host Kevin O’Connor share tips for removing rusted, stubborn toilet seats.

Steps for changing a toilet seat

1. Snap open the protective covers concealing the screws that secure the seat to the toilet.
2. Use a wide-blade screwdriver to loosen the screws. Remove the nuts and lift the seat from the toilet.
3. If necessary, reach underneath the toilet and prevent the nuts from spinning by holding them by hand or with a wrench or pliers.
4. For a toilet seat that’s secured with brass bolts, loosen the nuts from below using a ratchet wrench fitted with a deep socket.
5. If the nuts are rusted onto the bolts, squirt penetrating oil onto the bolt threads and wait 10 minutes. Then, try loosening the nut with the ratchet wrench.
6. When all else fails, cut the toilet seat free using a close-quarter hacksaw.
7. Protect toilet’s porcelain surface with a wide putty knife, and carefully saw through the two bolts.

Pro Tip: Richard Trethewey, This Old House plumbing and heating expert, advises patience when dealing with corroded bolts: “There are all sorts of ways to remove rusted toilet seat bolts, but using a Sawzall isn’t one of them because it’s likely to scratch the porcelain.” He notes that many modern toilet lids now use nylon bolts and washers precisely because they don’t rust.

When shopping for a replacement seat, you only need to know two things: the shape and the bolt spacing. Richard Trethewey explains that toilets come in either a round front, which measures about 16 inches front to back, or an elongated (pear-shaped) style that’s about 18 inches. The bolt spacing is always standard at 5.5 inches center to center, so you don’t have to worry about fit beyond choosing the right shape.

Pro Tip: Old brass-bolted seats are the most troublesome to remove. As Richard Trethewey points out, seats that have been in place for decades can become severely corroded: “Over time, urine and liquids can really corrode that.” He recommends using a deep socket to get underneath the nut and work it loose before resorting to cutting.

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