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Clean and Prepare the Drain Pipe — Install the New Flange

Intermediate

Part of project

How to Replace a Broken Toilet Flange · Step 4 of 5

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In this video

After all the pieces of the old flange have been removed, use a rag to wipe the inside of the main drain pipe clean. If there are any rough spots or remaining bits of old glue, you can use sandpaper to smooth the surface. Once the pipe is clean and smooth, carefully retrieve the rag and all the collected PVC debris from the drain. The opening is now prepared for the installation of a new toilet flange.

Goal: Plumbing

  • Do not forget to remove the rag from the drain pipe before installing the new flange.

Used in this video

  • Sandpaper · optionalSmoothing the inside of the drain pipe.
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This Old House

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FAQs

How long does a toilet flange replacement typically take for a DIYer?

This intermediate DIY project usually takes between 2 to 4 hours to complete, assuming no major complications. Factors like severely rotted subfloor or rusted bolts can extend the timeline, so allocate extra time if you anticipate these issues.

What are the absolute essential tools and materials I need for this job if I don't have everything on the list?

You will absolutely need an adjustable wrench, screwdriver, putty knife, and a level. For materials, a new DANCO Perfect Seal Toilet Wax Ring with Bolts is critical, and a new toilet supply line is highly recommended to prevent future leaks.

What are the most important safety precautions I should take when replacing a toilet flange?

Always shut off the water supply to the toilet and flush it to drain the tank and bowl completely before starting. Wear gloves to protect against unsanitary conditions, and use caution when lifting the toilet as it is heavy and can be awkward, potentially causing back strain or damage.

What's a common mistake beginners make when installing a new flange, and how can I avoid it?

A common mistake is not ensuring the new flange is level and at the correct height, flush with the finished floor. This can lead to an improper seal with the wax ring and subsequent leaks. Use shims if needed to achieve a perfectly level and secure installation.