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How to Replace a Toilet

Replace that old toilet with help from these instructions.

In this article, you will find:

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Step 2: Preparing the Drain and Attachment

It's time to jump in—not literally—to the only tricky step: preparing the drain and attachment for the bowl.

Analyze Your Drain

Building Smarts

If your toilet has been flushing without enthusiasm, the replacement is a great time to call in drain-cleaning wizards. You may save money in the long run. You will definitely save those anxious “will-it-or-won't-it” moments after the flush.

The new toilet mounts to a floor flange that fits in a 4" (inside diameter) drain. The ideal toilet drain is a 4" closet elbow, connecting to a drain system that is sound, open, and strong. If you have a 3" drain pipe, install an expanding fitting to connect to a 4" pipe at floor level. This will, we regret to say, involve cutting into the floor—or the ceiling below. After repairing the drain, screw rot-proof 2 × 4 or 2 × 6 blocking around the drain, making a square box tight to the drain.

The Floor Attachment

Even if the drain passes inspection, you also need rot-free framing wood around the drain. If you can't tell whether such wood is present, try driving screws through the floor in the area that will be covered by the new toilet. If they grab solid wood, you are in good shape. If not, you need to tear into the floor and replace the framing.

Using a monster drill called a rotary hammer, which drills by repeatedly banging onto the bit, we drilled through tile to attach the new floor flange. The flange is a disk that slips inside the 4" drain pipe and rests on top of the finish floor.

Hefty stainless-steel screws are ideal for holding the floor flange onto the framing hidden in the floor.

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