Combining basin & bath waste

[Malutki]

Hi,

I’m currently planning replacing my bathroom & one of things involves moving the basin from the outside wall to an internal one. I’m trying to work out how to run the waste pipe for the basin. The waste pipe would be ~3m to the waste stack, longer than recommended as I understand it. I’d like to run the basin waste (32mm) around the inside of the bathroom (approx 2m) & then tee into the existing bath waste (40mm) which would then be the final ~1m to the waste stack.

I was going to fit an antivac trap (or Hepvo, not sure which is best?) to the basin, would this get around the longer pipe run? Will I be ok with 32mm still or do I need to go bigger?

Will teeing into the bath waste cause any problems? Its purely for convenience I want to do it, it happens to be in the right place if I combined the two wastes & would save me having to put another hole through the wall & another connection to the waste stack. If I did it is it necessary to fit an antivac trap to the bath as well?

Still at the planning stage so if I’m setting myself up for a disaster I can go back to the drawing board!

Any advice appreciated, thanks in advance.

 

[Hugh Jaleak]

It should be ok. I'd run as much as you can in 40mm to the basin, and fit the antivac trap there. This will stop the basin trap being pulled when bath is discharged.

 

[Gasop]

It should be ok. I'd run as much as you can in 40mm to the basin, and fit the antivac trap there. This will stop the basin trap being pulled when bath is discharged.

But there is a very good chance the basin water will push up into the bath momentarily leaving a grubby ring a few inches around the plug hole. (Women do not like to see this)

Would be best to keep seperate if possible.

 

[Nige F]

Both Hep .V. o`s and don`t use those horrible knuckle 90 degree bends ...As per Hugh`s post

 

[Hugh Jaleak]

I dont like the knuckle bends either. I think the swept bends allow better flow, and are a sight easier to get a snake round should it ever be needed.

 

[Malutki]

Cheers for the replies, much appreciated, two hepvo's, swept bends & as much 40mm pipe as I can manage it is.