Things You'll Need
3/4-inch drill bit
6- to 12-inch wood-cutting blade
A toilet flange is a fitting that allows a plumber to connect a toilet to the waste line. It consists of a short length of 3- or 4-inch waste pipe connected to a metal or plastic ring. The ring has holes so you can screw the flange to the floor, and it also has two slots for the toilet bolts. To install one, you need to make a hole in the floor so you can pass the flange pipe through to glue it to the waste line. Plumbers usually make the hole with a reciprocating saw.
Measure the position of the center of the flange from the back and side walls and make a mark with a pencil. The distance will vary according to the size of the toilet and the local code requirements, but is typically about 12 inches from the surfaces of the walls.
Place the flange pipe on the floor and center it over the mark. Draw the outline with a pencil, making sure it doesn't intersect any of the floor joists.
Put a 3/4-inch drill bit into a power drill and place the tip of the bit about 1/4 inch inside the line. Drill through the subfloor. The hole should just touch the pencil mark.
Fit a reciprocating saw with a 6- to 12-inch wood-cutting blade and insert the blade all the way into the hole until the base of the saw makes contact with the floor.
Saw around the outline, keeping the saw vertical as you cut. If you angle the saw, the blade may cut through a floor joist. When the saw returns to its starting point, pull the cut-out out of the hole.
If the subfloor is made with 3/4-inch plywood or 1-inch planks, you can also make the hole with a jigsaw.
After you cut the hole, make sure the flange pipe fits through it. Widen it slightly if the flange doesn't slide through easily.