Hi All,

I'm splitting my unfinished laundry room into two rooms to add a small half bath. Currently the main vertical stack of my house comes down from an upper level into this room along the exterior wall. At about halfway down this exterior wall, the wall has a 4" lip where it juts in because it becomes cinder block, and at that point the main stack pipe has a 45 degree fixture bend in it to clear the cinder block. The 45 degree fixture bend is not just set perpendicular to the exterior wall, however, it's also rotated 45 degrees from the vertical plane of the exterior wall. Once the pipe clears the cinder block it has another 45 degree fixture to bring the pipe straight down through the concrete slab. My plan is to hide the main stack pipe in the dividing wall of the two rooms, but due to how the pipe runs it will pop through this dividing wall as it approaches the exterior wall. The idea I have is to cut the part of the pipe that juts in and over the cinder block into two separate 45 degree sections - one that goes 45 degrees parallel with the exterior wall, and another that is 45 degrees perpendicular with the exterior wall. Is this okay according to code, or will there be too many bends in the main stack? When I talked with an employee at Home Depot about my problem, he seemed to think it was ridiculous for my main stack to even have a 45 degree run in it, he said all pipes can only run completely 90 degrees vertical or at a horizontal with a slope of 1/8-1/4" per foot. I imagine that this is untrue, because I believe this is how my house was originally plumbed, but let me know.

I appreciate the feedback,

Tom (Ohio)

you will be OK. you don't really have trouble with 45 deg bends.
if you feel more comfortable put a cleanout tee in the wall and leave an access panel.

I know that it's important to have your solids flowing with your liquids in a waste pipe and so a horizontal pipe should have around a 1/4" drop per foot, but obviously a 45 degree or greater angle creates a far bigger drop per foot, so is it considered a vertical pipe once it passes the 45 degree mark?

45 degrees off of vertical is considered the same as vertical in the world of drains and vents.

Once again, the logic behind the advice given by an 'expert' in the big box store is just plain scary.

quote; he said all pipes can only run completely 90 degrees vertical or at a horizontal with a slope of 1/8-1/4" per foot

that is why HE is working at Home Depot, and not for a plumbing contractor. I cannot follow your description of all the 45 degree turns and how you want to do, so I cannot tell you if that is the best way or not.