Soil pipe

[Ramprat]

Hi

 

Looking for some advice before the plumber comes next week its a bit long winded but please stick with it. 

 

3 years ago he refitted our bathroom, about a year later we started getting intermittent cabbage smells in the bathroom but because myself and my partner do shift work we rarely noticed it or only one of us was at home and because it wasn't bad convinced ourselves it was either outside or in our heads as I'd checked everything I could access and it all looked ok. Last March some construction took place nearby and the smell became worse and more frequent but we were told by a plumber sent by the drainage company who unfortunately came on a day when it didn't smell that it was due to the workings going on and it would be completed soon.

 

February this year the work was completed but by this time the smell was eye watering but again only at random times but id had enough and was planning to call the plumber back to have a look, unfortunately lockdown hit and my partner had to shield so we couldn't do anything about it, last month I was furloughed so I decided that as I had the time I'd research the problem and see if there was anything I could do even if it was temporary, I knew we didn't have a roof vent and i remembered the plumber saying something about a durgo valve in a box in the bathroom so I presumed that had failed and decided to take look, turns out the plumber had cemented the box closed and after serval hours of carefully taking the box apart I discovered that we don't appear to have an AAV at all, on speaking with the plumber whos saying he rembers the job well as it was a pain to do (never said that to me and charged enough anyway) he said that there wasn't a vent to start with and when he replaced everything he just did like for like and that because we are a terraced house we don't need one as we would be using our neighbours vent? 

 

Now for my questions, 1) is he talking bullshit about sharing our neighbours vent because we are a terraced house, I know the house at some point before we brought it a vent pipe as when we had the roof repaired they found the old pipe cut off and covered with mdf so it was removed it. 2) would any skilled plumber replace like for like even if it was the wrong thing to do? and what do the building regs say about this set up? 3) how much would i be looking at cost wise to fix this mess roughly, I think i know what parts we'd need and guessing non trade price is around £60 and I'm guessing a couple hours labour so am I right in thinking £150ish max 

 

I'm hoping he will sort it and fit the AAV for free but im just planning for the worst as its been 3 years im excepting the old "it worked fine when I finished its a new issue story"

 

I've attached pictures in case im totally wrong and missing something but to my amateur eyes it doesn't look right, even the pipes don't look sealed correctly.

 

Please help so I have the correct information and confidence to be able to deal with this when he comes next week, im already unwell due to a fair up of a chronic illness and I could do without the stress of fighting this or the cost of fixing it as like many others im sure im also at risk of redundancy so im trying to save what I can in case the worst happens.

 

Finally if all else fails how difficult a job would this be to attempt myself, im an ok DIYer I've never done any plumbing but I've learned electrics and wood work and willing to try or is this one I should leave to the experts.

Edited September 18, 2020 by Ramprat
Spell was terrible ha ha

[MJNewton]

If you don't have an AAV what do you have? Or is the toilet connected straight in to the end of the soil stack (i.e. not branched into it)?

 

An AAV serves to allow air *in* to the system (without letting smells out) and its absence could certainly lead to smells if there was just an open pipe (which doesn't appear to be the case here) or if any traps were being sucked dry because of negative pressure from flushing.

 

I think you need to find the source of the smell - is it coming from the toiler, the sink, bath etc - rather than just pinning it down to the room. With it being so strong I would expect you to be able to pinpoint the source.

 

Hopefully it's a trap being siphoned dry in which case an acceptable fix might simply be a deeper or waterless trap.

 

Finally, they do say if you want a job doing well do it yourself so I think I'd be focussing on diagnosing/solving it myself in the first instance rather than allow the stress of chasing and poking plumbers to add to the stress of the problem itself.

Edited September 18, 2020 by MJNewton

[Temp]

+1

 

Without ventilation water rushing down waste pipes  can suck water out of traps leaving them empty enough to let gas back in when the water stops running. That could be happening anywhere there is a trap - basin, bath, shower or even the WC.  Ideally there should be an AAV on that WC stack but if i understand the photos correctly it was difficult for him to connect the WC to the stack in the available space. 

 

If you can trace the smell to a basin or bath it might be possible to add a small AAV to the waste pipe near the trap being affected but I think they are meant to be located above the height of the WC pan.

 

https://www.screwfix.com/p/floplast-af32w-air-admittance-valve/42968?tc=IB6&ds_kid=92700055281954514&gclsrc=aw.ds&ds_rl=1249404&gclid=Cj0KCQjwtZH7BRDzARIsAGjbK2ZEICwkuS-RCIxTkjp8GPoo1URMcKhDx2zoXfiMi6z9IcABgSPJF6QaAltvEALw_wcB

 

 

 

 

 

 

 

[Ramprat]

5 hours ago, MJNewton said:

If you don't have an AAV what do you have? Or is the toilet connected straight in to the end of the soil stack (i.e. not branched into it)?

 

An AAV serves to allow air *in* to the system (without letting smells out) and its absence could certainly lead to smells if there was just an open pipe (which doesn't appear to be the case here) or if any traps were being sucked dry because of negative pressure from flushing.

 

I think you need to find the source of the smell - is it coming from the toiler, the sink, bath etc - rather than just pinning it down to the room. With it being so strong I would expect you to be able to pinpoint the source.

 

That is the top of the soil pipe so no vent or anything.

 

The smell comes from the toilet area, sometimes from behind the toilet near that pipe and some times the toilet itself (its clean ?). I can only assume from what you said about traps and from what ive read that because we have no air inlet or vent when we flush its causing a vacuum and then this is being filled with sewer gas that's finding its way out?

[Ramprat]

37 minutes ago, Temp said:

+1

 

Without ventilation water rushing down waste pipes  can suck water out of traps leaving them empty enough to let gas back in when the water stops running. That could be happening anywhere there is a trap - basin, bath, shower or even the WC.  Ideally there should be an AAV on that WC stack but if i understand the photos correctly it was difficult for him to connect the WC to the stack in the available space. 

 

If you can trace the smell to a basin or bath it might be possible to add a small AAV to the waste pipe near the trap being affected but I think they are meant to be located above the height of the WC pan.

 

https://www.screwfix.com/p/floplast-af32w-air-admittance-valve/42968?tc=IB6&ds_kid=92700055281954514&gclsrc=aw.ds&ds_rl=1249404&gclid=Cj0KCQjwtZH7BRDzARIsAGjbK2ZEICwkuS-RCIxTkjp8GPoo1URMcKhDx2zoXfiMi6z9IcABgSPJF6QaAltvEALw_wcB

 

 

 

 

 

 

 

 

Thanks but unfortunately I don't think that would help the sink and bath drains both run to a separate foul water drain pipe which actually dumps out into an open drain by the kitchen (old raf house and the plumbing is a bit odd, along with most of the electrics? which is why we used "professionals" when we renovated it) so I'm positive its not these that are the issue, the toilet is the only thing connected to the main soil stack directly and into the sewer but what you've said has given me an idea, it could be the trap on the toilet that's being drained, ive never noticed it really low but maybe its low enough to allow the gas to escape?

 

The plumber actually built that box after removing a taller one that was already there so if its too small that's his fault ?

[Nickfromwales]

10 hours ago, Ramprat said:

1) is he talking bullshit about sharing our neighbours vent because we are a terraced house, I know the house at some point before we brought it a vent pipe as when we had the roof repaired they found the old pipe cut off and covered with mdf so it was removed it.

Not entirely, but he is using it in the wrong context. You can petition the BCO on a signed off job to take the factor of 5 or factor of 10 ( if they've been lucky in love that morning ) where OPEN vents to atmosphere are required to vent the network sewerage system and each dwelling must participate in that duty. If the BCO looks at the topology and agrees that losing the vent ( aka stench pipe ) is not going to be to any detriment then you may get permission to do away with it.

NOW;

As jerk-face aka your plumber has simply said you don't need one, some questions arise.

1) Is this ground or 1st floor?

2) How many bathrooms T into that one stack?

 

Building regs will stipulate that  you cannot omit an AAV on a vertically downwards discharging stack if the fall attains a drop of 1299mm or more ( from the bottom of the WC pan outlet to the bottom of the horizontal sewerage pipe at the manhole that it discharges to ) which is referred to as the "invert". The logic is, that after you discharge your Sunday roast plus 7 pints of Guinness and flush the loo, the contents of the pipe travelling south will, if travelling south for more than 1300mm, create a vacuum behind it as it falls. That creates a deficit with some welly behind it in the above waste network. That force, albeit it only momentary,  literally sucks the water out of the basin / bath / shower trap ( whichever is the one with the path of least resistance ) and then that leaves a clear path from the sewer gasses in the street and your nostrils ( can be hugely exacerbated  by a windy day for good measure too ).

So, the issue you have is allowing a bit of air into that cycle to alleviate the 'drop''. Can be done easily by T'ing in a small AAV ( 40mm ) behind the bath panel ( 9as long as the bath is connected to the same stack in the same room as the WC ) and also, if the issue persists, the basin trap can be changed to one with an integrated mini-AAV.

DIY for this is certainly do-able   

[Nickfromwales]

20 minutes ago, Ramprat said:

 

That is the top of the soil pipe so no vent or anything.

 

The smell comes from the toilet area, sometimes from behind the toilet near that pipe and some times the toilet itself (its clean ?). I can only assume from what you said about traps and from what ive read that because we have no air inlet or vent when we flush its causing a vacuum and then this is being filled with sewer gas that's finding its way out?

Fill the WC pan by flushing the loo gently, like part flushing it, or by filling the pan with a jug. Note the 'resting' water level. Then put a wedge of bog roll, ( folk often refer to this as 'toilet' or 'loo' roll, ( in the same way Hyacinth Bucket is pronounced bouquet lol )), and flush it fully. See if the resting water level is now down much lower, eg as low as the throat of the WC pan. If it's lower after flushing ( products + water btw is important for this test so don't be shy with 'the roll' ) then the stench will be coming from the WC.  

Edited September 18, 2020 by Nickfromwales

[Nickfromwales]

10 minutes ago, Ramprat said:

after removing a taller one

Was that higher than the top of the WC cistern?

[Temp]

I can see a jubilee clip where the wc connects to the stack. I wonder if that joint is gas tight?

 

Pressure testing the drain would tell you if there was a leak but not where it was. The kit to do a pressure test is about £40.

 

Edited September 20, 2020 by Temp