Toilet Drain Through Floor Joist

Do not even think to drill a hole for your toilet drain on your floor joist.

Toilet drain through floor joist.

An important step in running drain lines occurs on paper before the actual plumbing begins. Mark the area of the tub footprint on the subfloor with crosses at each corner if it differs from that of the removed bathtub or if you are relocating the tub. Where and how to drill joists for electrical cables or plumbing runs depends on what type of floor framing you have. The slope should be about 1 4 for each foot of pipe.

Although notches aren t allowed in the center third of a joist s length you can drill holes anywhere along the length of the floor joist in that 5 1 4 in. And you can cut holes in the joists within the permitted range. Running drainpipe through joists calls for meticulous work. That gives you a 5 1 4 in.

Drill holes with a diameter of no more than one third the depth of the joist staying 2 in. If joists are 16 inches on center and pipes run across them at a right angle holes should differ in height by about 3 8 inch. The holes must follow a straight line across the floor and must ascend or descend so the pipe will be sloped 1 4 inch per foot. Area provided there are no other holes in the joist or notches along its top or bottom.

So just measure carefully to maintain the minimum slope following the joist manufacturer s rules and you ll be fine. Area in the middle of the 2 10 joist where the hole can go. Keep the hole at least 2 in. How to install drain lines through the floor layout.

Mark where the overflow at the top. While plain water will drain with. Away from the top and bottom. And most abs toilet drain piping i ve seen is 4 not 3.

The holes will have to follow a straight line that goes across the floor and has to either go up or go down so the pipe has a slope. A fall of 1 4 inch per lineal foot is the best slope for drainpipes. The bigger hole you can drill on 2x10 it will be 1 inch and you need at least 4 try to build some how a bulk head downstairs if it is possible. So your hole sizes will need to be a bit greater than that.

Well you only need an inch of drop for every four feet for a pipe 2 1 2 or smaller. Good luck with your project. That s only 4 over 16 feet. 3 pipe is 3 1 2 od and 4 pipe is 4 5 od.

Step 4 cut the holes.