Toilet Drain Through Floor Joist

An important step in running drain lines occurs on paper before the actual plumbing begins.

Toilet drain through floor joist. So just measure carefully to maintain the minimum slope following the joist manufacturer s rules and you ll be fine. Away from the top and bottom. Drill holes with a diameter of no more than one third the depth of the joist staying 2 in. And most abs toilet drain piping i ve seen is 4 not 3.

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. Keep the hole at least 2 in. Good luck with your project. A fall of 1 4 inch per lineal foot is the best slope for drainpipes.

Where and how to drill joists for electrical cables or plumbing runs depends on what type of floor framing you have. When you run your pipes through a joist you will have to be careful with your work. And you can cut holes in the joists within the permitted range. That s only 4 over 16 feet.

That gives you a 5 1 4 in. Running drainpipe through joists calls for meticulous work. Mark where the overflow at the top. Well you only need an inch of drop for every four feet for a pipe 2 1 2 or smaller.

3 pipe is 3 1 2 od and 4 pipe is 4 5 od. While plain water will drain with. 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. Area provided there are no other holes in the joist or notches along its top or bottom.

So if you ve got a 2x10 you ll be able to squeak a piece of 4 pipe through if you carefully centre it in the joists from top to bottom. The slope should be about 1 4 for each foot of pipe. Area in the middle of the 2 10 joist where the hole can go. From the top and the bottom if it s a dimensional lumber joist.

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. 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. Do not even think to drill a hole for your toilet drain on your floor joist. Step 4 cut the holes.

How to install drain lines through the floor layout.