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Clean and Prepare Drain Pipe — Remove Cast Iron Flange (Alternative)

Intermediate

Part of project

How to Remove an Old Toilet Flange · Step 6 of 7

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In this video

After removing the old flange, clean the inside of the cast iron drain pipe. Use a grinding wheel or a flap disc on the angle grinder to smooth any rough edges on the inside of the pipe where the new flange will seal. Vacuum out all debris from the pipe and the surrounding area. Stuff a clean rag back into the pipe.

Goal: Plumbing Pipes Installation

Used in this video

  • Angle Grinder (Tool Type: Power Tools)Smoothing the interior surface of the cast iron pipe.
  • Shop VacuumCleaning up all the dust and debris from the removal process.
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FAQs

How difficult is it to remove an old toilet flange, and how long should I expect it to take?

Removing an old toilet flange is generally considered an intermediate-difficulty DIY project. Expect it to take 2-4 hours, though this can vary significantly based on your experience, the flange material (cast iron is more challenging), and how easily the old fasteners come out. Patience and the right tools are key.

What are the essential safety precautions I need to take when removing a toilet flange?

Safety is paramount for this project. Always wear safety glasses and work gloves to protect against debris and sharp edges. Ensure the water supply is shut off and the toilet is completely drained before beginning. If working with cast iron, be cautious of flying fragments and use appropriate hearing protection when chiseling.

Do I absolutely need specialized tools like an inside pipe cutter or a cold chisel and sledgehammer for this project?

Yes, for PVC/ABS flanges, an inside pipe cutter (like The Plumber's Choice 1242R) is highly recommended to make a clean, safe cut without damaging the main drain pipe. For cast iron flanges, a cold chisel (e.g., Dasco Pro G419) and sledgehammer (like Estwing MRF3LB) are often necessary to break the brittle material without damaging the subfloor or surrounding pipe.

What's the most common mistake DIYers make when removing a toilet flange, and how can I avoid damaging the drain pipe?

The most common and costly mistake is damaging the drain pipe itself while removing the flange. To avoid this, always exercise caution and precision. When cutting PVC/ABS, ensure the inside pipe cutter is properly adjusted to cut only the flange. When breaking cast iron, direct your force carefully with the chisel to fracture the flange, not the underlying pipe or subfloor.

Clean and Prepare Drain Pipe — How to Remove an Old Toilet Flange (Step 6, Video 3) | Stesso