How to Fix a Cracked Cast Iron Pipe Under My Toilet
- 1). Crawl into the crawl space directly underneath the toilet, if possible. If the toilet is on slab, tear up the floor around the toilet to access the drain pipe underneath. Position a ladder underneath the ceiling directly beneath the toilet, if the toilet is not on the first floor. Remove the ceiling tile underneath the toilet to expose the pipe, or cut a hole through the ceiling with a keyhole saw.
- 2). Cut out and remove the section of damaged cast iron pipe. Use either a Sawzall, which is a reciprocating saw, or use a hacksaw, which takes a little longer than the Sawzall.
- 3). Measure the inside diameter of the section you removed from the pipe and the length of the section, using a tape measure.
- 4). Measure a section of PVC pipe that has same 3- or 4-inch diameter as the cast iron pipe. Cut the section of PVC pipe to the right length, using a hacksaw.
- 5). Wipe the drain pipe clean and dry, using a dry rag. Twist the screw clamp of a rubber boot counterclockwise, using a screwdriver, to open the boot up. Slide a boot onto each end of the cast iron drain pipe. The rubber boot is basically a rubber sleeve that creates a watertight seal between the sections of pipe.
- 6). Position the piece of PVC pipe into place within the rubber boots, with the boots covering the ends of both the cast iron and the PVC. Tighten the screw clamp on each boot, using a screwdriver.
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