Can I use overflow pipe as en-suite bathroom sink waste

[ex_directory]

I have a small ensuite in the eves of a town house which has a sink waste which currently is boxed in and looks awful. Toothpaste is about all that goes down the trap.

Thinking to run the waste + hot/cold feed through a couple of studs and then in to a large accessible void which is where the main soil pipe is. The stud is 65-70mm, i am still not keen to chuck a 35mm hole (32mm plus a bit) for the waste in the stud.

I could however use a 1m length of overflow pipe with a solvent weld 32mm adaptor at each (from the trap and back to 32mm before boss in to main soil pipe).

Overflow external diameter maybe 22+2mm? That should be fine in stud if I double up the joist.

I appreciate flow will not be the same but thinking that caravans were for years on 19mm and all manner of things go down a caravan kitchen sink.

I would appreciate your experiences/thoughts on this idea?

 

[Hugh Jaleak]

Its not recommended or good practice, but if you want to do it and not tell anyone, then it's up to you.

 

[ex_directory]

Its not recommended or good practice, but if you want to do it and not tell anyone, then it's up to you.

Not recommended because of risk of blockage or reduced flow (or both) or something else I am not thinking of!?

 

[Hugh Jaleak]

Blockages. Flow will obviously be slow, (and even more so if it slowly gums up with residue), but if you are only planning on brushing teeth in it, then it will probably take a long while to gum up. (Excuse the pun...)

Under normal circumstances I'd say no, soap, hair, and general muck form washing would soon start to build up, and block the smaller pipe quite quickly. Reducing waste pipes never works out well.

 

[dilalio]

If the stud wall is just a room divider then drilling holes for 32mm waste would not be an issue... The meat left on the studs plus the plasterboard would be sufficient to keep the wall in tact.

 

[denso13]

As above, I'd double up the stud and put a hole through for a 32mm pipe.

 

[ex_directory]

Yes it is a room divider, I will cut away 1.2m high of plasterboard from the floor so I planned to double up the stud as much as I can and then add almost a full plasterboard sheet back on the wall. If it turns out to be 70mm stud (which i hope it will be) then maybe 35mm will be ok. Maybe I can buy a nice new hole cutter to get a nice clean cut.