bath waste issue. water not draining away.

[Specren]

hi gents and girls.

I have a problem.

Bath waste water wont flow down the waste pipe. Bath backs up when taps running.

(this is a whole new bath refurb and no, grout and adhesive residue was not washed in to bath)

So far, Ive taken off the trap and examined the pipe work for sediment. (hair etc) Both clean and clear.
However, whilst there is water in the bath and not draining, Ive noticed if i undo the trap cap nut slightly on the 40mm pipe side, i can hear air being sucked in and then the waste pipe clears?????


This bathroom is in a block of flats. yes its on the ground floor. (Positive pressure)???

Over to you professionals,

 

[ShaunCorbs]

Is there a fall on the waste to the stack ?

 

[Vee]

Is the drainage stack sufficiently ventilated?

 

[Specren]

I believe so.

It's a block of flats. Built in The 2000s.

Ground floor. He bathrooms wall in between. However, the bathroom I installed , changed from a shower room to a bathroom.

Waste has a fall into the ground about 4oomm away into the branch boss.

Funnily enough the other bath is draining badly.

But toilets and basin in both bathrooms are ok.

 

[Vee]

Try a ventilated trap, else it still looks of blockage.

 

[Specren]

Thank gents.

Looks like it was blockage after all.

Historic build up through the years of sludge and silt around the boss coller below the branch at ground level.

Drain company came out. A cctv probe put in and then you could see the problem.

Brilliant evidence to prove it wasn't adhesive or grout the customer accused it of being.

Thanks for your comments.

Friday 13th has been good so far.