Air admittance valve, will it help

[Skinszo]

Hi all,

I've just been to look at a job, the customers shower trap has got air coming up so I'm assing there's no u bend.

There is no way of getting to the underside of the tray without major works as it's stuck down onto a basement floor, tiled all around.

I can can get access to the basin waste and the toilet wastes by cutting a hole on the other side of the wall in a bedroom, and both of these are higher up than the shower.

Nothing appears to to have an air admittance valve installed and I'm wondering if I installed these on the loo and basin if it would stop air coming through the shower .

Thanks

 

[josh]

Im guessing you mean its bubbling up?
The tray will be trapped and as you mention its in a basement the top of the stack should be vented so if the stack goes up to serve another bathroom it may be vented up there.
I would look to see if the drain is partially blocked, if not i would say its probably a pipework issue, waste pipes tee'd together or compression at the bottom of the stack if it carries on up to other bathroms.