To replace a toilet flange, you must first remove the toilet, cut out the old damaged flange, and install a new one that sits flush with the finished floor. This guide will show you how to replace a toilet flange safely and correctly, whether you are dealing with a broken plastic flange, a corroded metal ring, or a flange that sits too low. This task is common in older homes where the flange has rotted or cracked, causing leaks and an unstable toilet. Before starting, turn off the water supply valve behind the toilet and flush the toilet to empty the tank and bowl. Then disconnect the water line from the fill valve. Have a towel or a small bucket ready for residual water.
Tools and Materials You Will Need
- Adjustable wrench or basin wrench
- Screwdriver (flathead and Phillips)
- Utility knife or putty knife
- Hacksaw or oscillating multi-tool (to cut the old flange)
- New toilet flange (PVC, ABS, or cast iron – match your existing piping)
- Stainless steel or brass closet bolts (T‑bolts)
- Wax ring or wax‑free toilet seal
- Level
- Safety glasses and work gloves
Signs You Need to Replace the Toilet Flange
Not every toilet leak means a bad flange. Look for these common indicators:
- The toilet rocks or feels unstable when you sit on it.
- Water seeps out from the base of the toilet after flushing.
- You see a worn, cracked, or broken flange when you lift the toilet.
- The flange is corroded (common with cast iron flanges in older homes).
- The floor around the toilet is soft or rotted (signs of long‑term moisture).
Step-by-Step Instructions to Replace a Toilet Flange
1. Remove the Toilet
Unscrew the two closet bolts at the base. Rock the toilet gently side to side to break the wax seal, then lift it straight up. Place the toilet on a drop cloth or old towels in a safe area. Stuff a rag into the drain opening to prevent sewer gas and debris from coming up.
2. Remove the Old Flange
If the flange is screwed to the floor, remove the screws. If it is solvent‑welded to a PVC pipe, use a hacksaw or oscillating tool to cut the flange ring away from the pipe. For cast‑iron flanges, you may need to use a hammer and chisel or a special flange–removal tool. Always wear eye protection when cutting metal or plastic.
3. Prepare the Pipe and Floor
Clean the cut end of the pipe so it is smooth. Remove any old wax or adhesive from the floor around the opening. The new flange must sit flush with the finished floor. If the floor has been tiled above the pipe, use a flange repair ring or a spacer to raise the flange height.
4. Install the New Flange
Slide the new flange over the pipe. For PVC, apply primer and PVC cement to both the pipe and the inside of the flange hub, then push it down firmly. Make sure the flange is level and that the slots for the closet bolts are aligned correctly (usually parallel to the wall). If you are using a repair–type flange that does not glue inside the pipe, follow the manufacturer’s instructions. Once set, screw the flange into the subfloor using the provided screws or stainless‑steel screws.
5. Install the Wax Ring and Replace the Toilet
Place the wax ring (or wax‑free seal) on the flange. Insert the new closet bolts into the slots of the flange. Carefully set the toilet over the bolts, pressing it down evenly to compress the seal. Tighten the bolts alternately until snug – do not overtighten or you could crack the porcelain. Attach the water line and turn on the water supply. Flush the toilet and check for leaks around the base.
Common Causes of Flange Failure
| Cause | Description | Prevention |
|---|---|---|
| Corrosion | Metal flanges (cast iron or galvanized) rust over time | Use a PVC flange or a stainless‑steel ring |
| Improper installation | Flange installed too high or too low | Ensure flange is flush with finished floor |
| Wax ring failure | Wax dries out or shifts due to toilet movement | Use a wax‑free seal if the floor is uneven |
| Physical damage | Cracks from impact or overtightening bolts | Use a flange repair kit or replace with a heavy‑duty flange |
According to the International Association of Plumbing and Mechanical Officials (IAPMO), flanges must meet specific material standards to ensure a proper seal. The EPA WaterSense program also recommends checking for leaks after any toilet service to prevent water waste. For additional safety, consult the CDC Healthy Water site for tips on avoiding cross‑contamination during plumbing repairs.
When to Call a Professional Plumber
DIY flange replacement is doable, but some situations require expert help. If you discover rotted subfloor, extensive water damage, or a broken cast‑iron pipe below the flange, a licensed plumber should handle the job. Likewise, if the toilet flange is set in concrete or you are not comfortable cutting into the drain line, contact MyTownPlumber for toilet repair. Our technicians also offer drain cleaning and leak detection services to diagnose hidden issues.
Cost to Replace a Toilet Flange
The typical cost in the US ranges from $75 to $250 for materials and a DIY installation. Hiring a plumber will add $150–$400 for labor, but prices vary by region. A professional replacement includes inspection of the pipe, correct height adjustment, and a warranty on the work.
If you are not sure about tackling this job, call MyTownPlumber today. We specialize in pool heater repair, sewer line repair, water softener installation, and more. Our team is certified and insured. Book a service now at our special offer page to save on your first visit.