Bathtub gurgling noises getting on my nerves.

[Tazz5010]

Bathtub pipe work done by companies own fitters, looks dodgy.
I had a new bathtub and sink installed 9 months ago by a well known company. Every time I drain the sink I get gargling noises coming from the bathtub. This also happens the other way around. Looking underneath the bath, the pipework angle looks correct for the water to flow towards the outlet/vent pipe. My question is, should the pipe have an upward bend leading out of the wall? See photo.

 

[footprints]

The trap under the bath would be OK, but if that bit going up through the foam filling is to outside it's certainly wrong, water does not run uphill in this universe. As Scotty from Star trek would say "Ye canna defy the laws of physics, Captain!"

 

[mikeyd]

Do the wastes from the sink and bath join before getting to the stack? If so then the gurgling is always likely to happen. That's why it is normal to take each waste pipe all the way to the stack. You can get round the problem with anti-syphon traps but the installer should have thought of that first.
However if this picture is your waste going out to the stack and it does run as the photo suggests then it's just plain wrong.
View media item 79136I'm not a plumber, and don't know what to suggest but I have asked for this to be moved to the plumbing section, where I hope you will get some advice.

I couldn't see your pictures until I searched your album, here is the other one:
View media item 79137