Issues with wash basin and bath wastes

[nish75]

Hi Guys

I gave just installed a new bath and sink, and I have 2 problems.

(1) The bath takes ages to drain.
(2) When I drain the wash basin, there are gurgling noises in the bath drain and sometimes water even comes out of the bath drain.

The waste outlets of the wash basin and bath are both connected to the same pipe. I have a mcalpine bottle trap with anti syphon connected to the wash basin. See attached pictures.

(a) do you see any problems with connection overall?
(b) do I need to remove the cap from the anti syphon trap?

Thanks so much so much for your help as usual.

Kind regards

Nish

 

[muggles]

Problems with the installation? You've got a flexible pipe on there, which will block up as it appears to be going uphill before it goes down again, and is almost certainly the cause of the gurgling and water appearing. Get rid of it and do it properly in rigid pipe with the correct fall. You also appear to have insufficient fall on the waste pipe running from the chrome basin connection to where it goes through the floor - it should drop approx 44mm (the diameter of the pipe) in that distance, but it looks almost level to me.

Take it all out and start again

 

[nish75]

Thank for the great advice, will restart as you suggested. Regarding the anti syphon waste unde the sink, do I need to open/loosen the cap on top or will water leak. Thanks.

 

[Madrab]

Yup, as muggles mentions increase the fall from the basin waste where it reaches the bath to where it drops through the floor. Cut the wooden support for the bath where the Tee is and the pipe sits on so that the end where it drops through the floor drops a bit. You may also wish to consider increasing to 50mm from the Tee at the bath outlet.

Leave the anti vac the way it is, the top is meant to be tight

 

[nish75]

Excellent, thanks all.

 

[oilboffin]

I'd put a hep2o bath trap on that'll stop the gurgling and back flow

 

[nish75]

Another question to the decent people on this forum - Do the connection where the chrome pipe meet the white pipe needs to be higher than the top of the bath trap OR it does not matter?
Thanks again.

 

[Madrab]

It's all about where it meets the main waste pipe, so at the Tee connection it needs to be lower. Just go for the 45 - 50mm per meter drop as @muggles suggested along the main waste's length.

 

[Doggit]

Unusual setup to say the least, and it's be interesting to know why you designed your own bath trap, rather than use a standard one.

I'd actually say the the fall on the waste from the basin is sufficient, (as you only need a 1 in 40 fall, so 25mm over a metre) as the fall down the chrome pipe will create enough pressure on it's own, but once a low level trap has been fitted, he may find he also needs an antivac unit on the bath trap as well, so as Oilboffin suggests, a Hep20, (or Hepvo gives a better description for novices) would be the best solution under the bath.

 

[nish75]

Thanks again all. The trap I used is actually a McAlpine bath trap. The Hepvo is an interesting trap -never seen that before. I take it that it will replace the current trap rather than use together with it?

 

[Doggit]

Yes; then take it in to the waste from the basin, but as low as possible to stop it flowing back in to the pipe, and you may need to raise the pipe running under the bath to play safe.

I would be inclined to construct the bath waste first, and then see if you need to re-arrange the pipework from the basin.

 

[Madrab]

Yep, if you want to use it then remove the current trap and use a bent connector from the bath waste that connects to the HEPvO.

Nothing wrong with the trap you have mind you, just needs setup correctly.

 

[Doggit]

Madrabs got a point, but even if you bend the flexipipe down a bit, I suspect it'll still take time to drain out.

 

[Madrab]

As @muggles mentions at the start, take it out, really from the section from the tee down to after the 45. Take a slot out of the wood bath supports, middle and right, that the run is sitting on just now, that'll give the fall you need by the looks of it from the top of the bath. If it's still not enough raise the chrome end up a little till you get the desired fall (+/- 45mm/m), add in a new tee, pipe and 45 and dry fit it all so you have the correct fall down the length of the bath.
Then using rigid pipe and an elbow from the trap back and then across to the tee so it's dropping all the way to the join. Mark the pipe, disassemble and glue.

As suggested though, If you could take it up to 50mm at that point it would be so much happier