Bath waste trap

[marlb]

Hi I am about to fit a new bath which will have no access once it is fitted. The bath plug hole is directly above a joist. Can I use a low profile bath waste? I have read that they can cause issues with smells etc. The bath will be on its own pipe work all the way to the soil stack, in 40mm plastic pipe. The bath is one of these, all the way to floor types and there is a void under the bath of about 10cm which will give me some room to play with.

 

[Newboy]

Current regs for discharge into a stack are 75mm seal, into a hopper 50mm.

You may find that a shallow bath trap doesn't give you any problems - there are thousands of them fitted regardless of regs.

If you've got space and access then fit a deeper trap (in addition to one on the bath waste) further down the run - I'd avoid the waterless traps on a bath waste.

 

[Madrab]

Hi I am about to fit a new bath which will have no access once it is fitted.

Regardless of the finishing, I'd always suggest that access should always be part of the design. I have found that there is always a way that an invisible or design feature can be create to allow a process to get access.

It's either asking for trouble or a big bill in the future if things need to be broken to get under a bath to the invariably blocked or restricted bath trap.

Good design of the bath run is needed if the only option is to use a shallow trap, shortish runs, not too much fall, if possible nothing else on the run etc as it's much easier to (self) syphon a shallow trap.

 

[marlb]

Thanks for the replies. I am going into a stack but I have put in a manifold and all of my wastes are going into separate slots in the manifold. Is this classed as a hopper?

 

[Newboy]

No - a hopper is external and open to the air thus reducing the risks of traps being pulled by other appliances.