Moving Bathroom waste pipe question

[Tixx]

Hi all,

Im about to undertake a bathroom reno, and am looking at a cheaper way to install a wall mounted vanity with draws (not cupboards) The problem is that my waste pipe is offcenter and about 120mm off the back of the wall. Rather than core drilling the slab to run the pipe up the wall, i was thinking about just running the pipe back to the wall as per image below. image depicts an angled pipe for better water flow, or at worst case a perpendicular run using some 90deg elbows.

Once inside the actual vanity unit, i can use either an S or bottle trap.

Id like to hear from anyone in the know whether this is a good/bad idea and why?

https://imageshack.com/a/img922/9982/q9Z3HP.jpg

from the aesthetic point of view, i would hide the piping by boxing it so it wont look bad. its more about potential issues with water flow, leaks, etc etc?

 

[TomFOhio]

Set your vanity in place and then take a picture of it inside the vanity where the problem is. I'm sorry but those numbers you
sent don't mean a thing to me. Maybe this way you will get some responses.

 

[jwwing]

It is a little hard to tell what you are talking about - so please do as suggested by TomFOhio. I think that you are asking whether it is permissible to run the pipe back to the wall and then around on the surface. I think it is, but it might become a nightmare if you ever have to repair it or work on it for another reason. You also have to be very certain that the pipe remains level or only a very slight downhill to the drain pipe. As long as the pipe is protected and not too unsightly, the method for getting to the vanity is not usually a concern.

It also would be nice to see what you are referring to as the 'waste pipe', eg, pvc, abs, cast iron, copper, clay - if you are talking about a vertical pipe that is substantially larger and that you have to connect at a fitting, I would opt for 45's rather than 90's if it looks better to you because it will drain better too.

It also depends on your local codes.

 

[petedavies]

Had a similar issue.. Great information here.