basin gurgling upstairs

[handsomejackuk]

have a washbasin upstairs in the house, and since connecting it up to my new shower waste downstairs it is gurgling as the shower empties....

i realise that as the shower empties it is essentially pulling out the water out the upstairs trap...due to vacuum...

the both items are connected to the same 40mm shower waste...pipe

the upstairs basin has a long waste going at a very steep angle due to construction constraints at my house...

would fitting a air admittance valve with some sort of non return valve to this long waste section help with

a.... stopping gurgling in upstairs...when shower tray emptying

b.. empty shower tray quicker as the vacuum acting on this long waste pipe would open air admittance valve.....and send air down waste pipe instead of draining upstairs trap...

c.... if waste is emptied upstairs... the air admittance valve would remain closed due to the water pressure travelling down long waste pipe....and the nature of the air admittance valve stopping water coming out remaining closed....

does this mae sense....?

 

[SimonG]

Stick an anti syphon trap on the basin.

 

[REDSAW]

the trap seal is not deep enough

 

[Billy Bob Bob]

fit a bottle trap to the basin with a aav built in

 

[Simon F]

:iagree: with all the previous replies, you need to prevent the negative pressure in the pipe from pulling the water out of the trap. there are a various traps that will sort this as already mentioned, a hepvo valve is another option. It sounds like that should have been fitted anyway if there is an excessive length of pipe, also best to avoid joining wastes to avoid the problem you now have. Would it not be possible to fit the new shower waste direct to the stack/gulley?

 

[old_skool55]

In line Hep 20