Smelly internal bathroom - Soil vent pipe problem?

[RSE]

Hi all, we have a smelly ground floor bathroom and I think it has to do with the positioning of a soil vent pipe that was installed when we had the bathroom renovated a few years ago. The soil vent is both angled within the the toilet cistern box and the vent is below the highest trap (a sink) - the attached images may help illustrate the situation
I wanted to get some opinions as to whether the vent angle, the fact that the vent below is below the sink trap, or a combo of both is going to be the cause of the smell to escape, and then how to resolve the problem. Thanks

 

[Newboy]

Well that's a bit of a lash-up!

1) There may be other reasons for the smell - basin (you don't have sinks in bathrooms ). The basin or shower trap may be being 'pulled' - worth checking that there is water in both of the traps.

2) The AAV is way too low and maybe getting wet every time the WC is flushed- I'd extend the pipework vertically and reduce to 2" and fit an AAV as high as possible - it should be 300 mm above the height of the basin rim.


Edit - I can't quite make out how the AAV has been fitted to the soil pipework - it looks like a large space around the AAV - any chance of a clear photograph?

 

[it's not that hard]

It seems that the angle of the AAV is causing the problem,I would have have reduced the soil down to 32mm on the branch and extended the pipe up as high as possible and fitted a 32mm AAV,because of the angle when the AAV closes it can't sit correctly making a seal.
Although your bathroom looks very nice,maintenance plumbers are faced daily with the problem of builders boxing in everything then tiling over and giving no thought about access,if the AAV is pushfit not glued then there's a chance that this can be altered reasonably easily.

 

[Madrab]

The problem with that is going to be access I'm afraid. How long is the bathroom in? Do you have any call back with the installers? An AAV needs to be accessible for maintenance and that isn't.

As you have also pointed out, it isn't high enough, was never going to be unless they extended a box section up the wall beside the toilet. Even then though worst case is they could have popped in a reducer, 50mm pipe and added a 50mm AAV at the top of that box section as Newboy mentions.

 

[it's not that hard]

A 32mm AAV is sufficient and bit more convenient considering the limited space

 

[Madrab]

Granted a 32mm may be easier given the space but depending on what else is connected onto that stack, it may not be enough to stop the traps being pulled.

I'd always look to get the largest vent in as possible and it looks like there's enough space. Regs do ask for a 50mm vent as a min on a discharge stack tho I believe.

 

[RSE]

All, thanks for feedback so far - I have done some more investigation and here's what I have.
- Access to the boxed in section will be via two tiles that I intend to cut out (one is cracked by the metal side trim anyway) and then cut through a section of the hardboard carcass; sadly these two tiles are on the shower side so will need to be replaced and the access point sealed (so no easy access from the side should the need arise in the future); I'm thinking removal of these two tiles should allow sufficient space to get access to the 110mm pipe to remove the existing AAV, add a reducer and run the pipe vertically up in the box to the highest point.
- Internal width between the boxed side and the cistern is 7cm (or 2.75 inches); so I think a 50mm vertical waste pipe can neatly fit in that space...
- Height of vertical 50mm pipe could extend about 20-25cm above the line of the washbasin's (noted: not a sink) trap top in the boxed in section
- How does the existing AAV connect to the 110mm pipe? Sadly I can't tell, but it may be evident from the photo I took by squeezing my arm down into the boxed in section.

Thoughts? Constructive comments welcome. Thanks

 

[Madrab]

Not clear how that's fitted into the 45Deg, the adapter, if there is actually one there, I can only guess is some type of internal rubber fixing, is in shadow.

All that sounds tickety boo to me

 

[Newboy]

Sounds like a decent plan.

I'm not convinced that the existing AAV is securely fitted to the soil pipe - it looks as if it has been pushed in to the open end of the pipe with possibly a rubber reducer and may even have fallen/been pushed out of position.

You need to reduce the diameter of the exposed end of the soil pipe - it looks as if it would be possible (although very tight) to fit a 135/45° fitting (either solvent or push-fit) and then reduce to 50mm with an AAV as high as possible.

 

[it's not that hard]

The AAV is a pushfit,pull it out and the rubber washer,can you reach it,If so what I would do is get a 110mm flexi pan connector,fit the AAV into it and push into the pipe,save hacking off tiles and could e just a 5 min job, flexi pan connectors come in different lengths.
This way you would create a rodding point if it ever blocked.

 

[dilalio]

The AAV is a pushfit,pull it out and the rubber washer,can you reach it,If so what I would do is get a 110mm flexi pan connector,fit the AAV into it and push into the pipe,save hacking off tiles and could e just a 5 min job, flexi pan connectors come in different lengths.
This way you would create a rodding point if it ever blocked.

+1!
Try the path of least resistance first! If you can get a flexiconn onto it and it works... Job done

You could also put an anti vac trap on the whb as belt and braces.
If you do have to go the route of removing tiles to get access, you can always make good after, using silicone rather than grout in such a way that silicone can be easily cut for future servicing... I do this quite often on installs where client doesn't want to see access panels or screw caps.

 

[Newboy]

,If so what I would do is get a 110mm flexi pan connector,fit the AAV into it and push into the pipe

And pray tell us - who is the supplier of the flexible pan connector able to fit through a 70 mm gap?

This way you would create a rodding point if it ever blocked.

Rod a blockage through a flexible pan connector?

 

[it's not that hard]

,If so what I would do is get a 110mm flexi pan connector,fit the AAV into it and push into the pipe

And pray tell us - who is the supplier of the flexible pan connector able to fit through a 70 mm gap?

This way you would create a rodding point if it ever blocked.

Rod a blockage through a flexible pan connector?

you should have went to spec savers,anyone can see that's a 110mm pipe and it's blatantly obvious it's fully fitted,I think that you can't see an easy way,wouldn't want you to work in my home if you want to make a simple job into a long winded exercise

maybe take up stamp collecting instead of plumbing if you can't work out how to rod a drain by removing the flexi

 

[it's not that hard]

Apologies, yes you are right about the 70mm gap

 

[Newboy]

1) Obviously it's 110mm pipe
2) The gap available for fitting anything is 70 mm as the cistern is obstructing access - see the photos posted by the OP
3) So with a blocked soil pipe you'd suggest pulling out the flexi to gain access despite the connection being below pan level. OK genius, tell me what happens when you remove flexi, any chance the contents of the soil pipw would pour out into the boxing?

wouldn't want you to work in my home

I'm pretty sure that you shouldn't be working in anybody's home with a cowboy approach like yours