How to Replace a Toilet: Flange Height, Wax Ring and Bolts

A toilet that weighs about 50 lb and still holds water is easy to spill, and the hole around the flange leads straight to the ceiling below. In a 1984 house, a renovator working alone shows how he removes an old toilet and installs a new one, claiming 90% of toilets in remodels are installed incorrectly.

Emptying the toilet first

Before the water is shut off, he pours in a pail of water quickly to shock the system, which creates a vacuum and pushes much of the water out of the bowl. A shop vac then removes the rest, including the tank, whose water he notes is clean city water. He wants the level near zero so nothing pours onto his leg or through the flange hole when he lifts the toilet.

The tank comes off by removing two bolts, using a large flathead screwdriver on top and holding the nut underneath. He explains the bolts sit under compression against a rubber gasket.

A stuck closet bolt

The closet bolts use a nut and brass washer. If the nut and washer spin, he suggests needle-nose pliers to hold the thread, or a grinder. Here the bolt itself turned with the nut. His fix was 3-in-1 oil with compression, pushing the nut up and the washer down. Lifting the toilet to create compression also works.

What was under the toilet

He states the flange needs to be as high as the floor. In this bathroom it was not. The wax was swollen and almost nonexistent, an economy ring rather than the $5 type with a plastic mold and diverter. Someone had added plywood and cheap laminate over old vinyl. He says there is no such thing as waterproof laminate, and that he can count on one hand the times he has lifted a toilet that was installed correctly.

New supply valve

He removes the old valve from 1984 by turning the bottom nut counterclockwise. The new valve has the same thread size and valve body, but sends the supply straight up. He tightens it by hand first, then holds the valve body while snugging the compression nut, which compresses a flared copper ring onto the pipe. He then turns the water back on to test it.

Raising the flange

The existing PVC ring had been flush with the old floor but is now lower because of floor leveler, Ditra and tile. He uses a 3 in. PVC twist and seal replacement flange, sold at Lowe's or Home Depot, with a flared rubber gasket. With minor downward pressure he twists it in until it is hard to turn, aligning the bolt slots at 9 and 3. The gasket keeps sewer backup from coming into the house. He pre-drills and screws the new flange to the old one so the toilet cannot rock, which protects the wax seal. The rule he gives is that it must be at least flush or up to 1/4 inch higher, which he says is met all the way around.

Setting the new toilet

A washer with a plastic holder keeps each bolt standing upright. Only an extra-size wax ring was available, which means more wax in the way. He attaches the tank to the bowl first, hovers the toilet over the bolts and sets it straight down. Leveling clips on the floor mean there should be no wobble. Seat bolts twist on, get cut off and are capped.

For an uneven floor, he suggests grouting the toilet area with leftover sanded grout as a stabilizer, finished with a clear silicone bead.