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.

Away from the top and bottom. A fall of 1 4 inch per lineal foot is the best slope for drainpipes. Well you only need an inch of drop for every four feet for a pipe 2 1 2 or smaller. That gives you a 5 1 4 in.

So just measure carefully to maintain the minimum slope following the joist manufacturer s rules and you ll be fine. 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. Area in the middle of the 2 10 joist where the hole can go. And you can cut holes in the joists within the permitted range.

Where and how to drill joists for electrical cables or plumbing runs depends on what type of floor framing you have. An important step in running drain lines occurs on paper before the actual plumbing begins. 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. That s only 4 over 16 feet.

From the top and the bottom if it s a dimensional lumber joist. Keep the hole at least 2 in. Drill holes with a diameter of no more than one third the depth of the joist staying 2 in. The slope should be about 1 4 for each foot of pipe.

When you run your pipes through a joist you will have to be careful with your work. 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. 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. Mark where the overflow at the top.

Step 4 cut the holes. And most abs toilet drain piping i ve seen is 4 not 3. Good luck with your project. Area provided there are no other holes in the joist or notches along its top or bottom.

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. 3 pipe is 3 1 2 od and 4 pipe is 4 5 od. How to install drain lines through the floor layout. 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.

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.