Things You'll Need:
- ¾-inch plywood subfloor
- Tape measure
- Compass
- Drill
- Drill bit
- Jigsaw
- 4-inch ABS drain pipe
- Wood screws
- Copper pipe
- Quarter-turn shut-off valve
- Flooring
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Step 1
Install ¾-inch plywood subfloor, and fasten it securely to the floor joists with 1-5/8-inch wood screws.
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Step 2
Measure 12 inches from the back wall and 15 inches from any side obstructions (cabinets, walls, tubs) so there will be enough clearance for the toilet and its future users. Mark each measurement onto the plywood with a pencil. Look at the pencil marks on the subfloor create the center point of the toilet drain in the floor.
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Step 3
Draw a 4-1/2-inch diameter circle onto the plywood with a compass and a pencil. Drill through the plywood with a drill bit, and use a jigsaw to cut the circle out of the plywood.
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Step 4
Run 4-inch acrylonitrile butadiene styrene (ABS) drainpipe to the hole, and glue a toilet flange to the ABS drainpipe. Mount the toilet flange to the plywood subfloor with wood screws to keep it stable.
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Step 5
Run copper pipe to the area where the toilet will be installed for a water supply line. Set the end of the copper pipe in the wall so it will be 4 to 5 inches to the left or to the right of the center line of the toilet. Install a ¼-turn shutoff valve onto the end of the water supply pipe.
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Step 6
Install any number of flooring types to cover the plywood subfloor. It is always recommended to install flooring before installing a toilet.
