Removing and Replacing Your Old Toilet Part 2 of 3: Installing Your Low-flow Toilet

Jim Mallery

Editor's Note: This is article 2 of a how-to guide on replacing a toilet

You've removed your old toilet and you're ready to install the new, water-efficient model. Here are seven steps to get you started installing your low-flow toilet.

  1. First, make sure you have the right toilet. The standard distance from the toilet mounting bolts to the wall is a foot, but decades ago the distance was 10 inches. Fortunately, you can still buy toilets made for the ten-inch spacing. If your toilet did not include a mounting kit, you need to buy one from your local plumber or big-box store.
  2. To begin, install the wax ring on the horn (outlet) on the bottom of the toilet bowl--the ring will press against the mounting flange on the drain when the toilet bowl is in position. The ring has a flat side and a rounded side--the rounded side goes against the toilet. If your wax ring has a plastic sleeve, it points away from the toilet, into the drain pipe. If your mounting flange is the same level as the floor, a standard wax ring is all you need. If you have a ceramic-tile or stone floor and the flange sits below floor level on the subfloor, you'll probably need to buy an extra-deep ring. Hint: warm the wax ring slightly so that the toilet smooches against the flange more easily.
  3. Insert the long brass screws, thread end up, into the slots on both sides of the flange. They may have plastic disks that push down over the threads to hold the bolt in place, or you may want to dab them with a little plumber's putty to get them to stand vertically.
  4. With the aid of a helper, or if you have a very strong back, set the toilet bowl in place with the brass bolts through the holes in the toilet base and the wax ring sitting atop the flange. (Remember to remove the rag you stuffed into the drain pipe to block the fumes.) If you do not feel the wax ring hit the flange, the ring is too shallow, and you need to buy a deeper one. Do not twist and rock the bowl to set it; simply push down gently, maybe giving it a little squiggle, until the bowl rests on the floor. The wax is very dense and doesn't squish easily--that's why it's nice to have it warm for this process. Once you have deformed the wax, you cannot reuse it, so once you have placed the toilet, do not pick it up again!
  5. If the floor is not level, shim the bowl to level it. Non-corroding stainless steel washers work well for this.
  6. Your toilet-mounting set should include nylon washers, and probably also brass washers to fit over the mounting bolts. The nylon washer sits against the toilet base and the brass washer on top of it. (There may be a top and bottom to the nylon washer--instructions with the kit should tell you.) Tighten the nuts to the mounting bolts with a wrench, a quarter turn at a time until the nuts meet resistance. Keep the pressure the same on both sides. Don't overtighten: the toilet could crack! With a hacksaw or grinder, cut the bolt a couple of threads above the nut. In cutting, protect your toilet from scratches with a couple layers of masking tape. Snap on the decorative plastic bolt covers to the nylon washer.
  7. To finish, seal the base to the floor with a thin bead of clear silicone caulk.

That gets your toilet bowl in place. Next, we'll look at installing the tank and hooking up the water supply.



About the Author

Jim Mallery, a semi-retired journalist and onetime registered contractor, has extensive experience remodeling, repairing, and rebuilding homes.

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