Hi, we just moved to a new build. There is a dreadful 'sewer' smell in the house. No outside soil stack. AAV is sited behind bath panel in family bathroom upstairs. Had this replaced as plumber thought may be faulty, no change in smell. We are one of three houses and there is a joint pump station to the main sewer. There doesn't appear to be a vent on the pumping station, should there be? I have read advice and put all the plugs in downstairs sinks and covered with water to form a seal. This does seem to have stopped smell but obviously not answer to problem. Can't get builder to take notice! PLEASE can anyone advise what the problem could be.
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ROGER12345
Thanks, yes drain covers have lifted and no blockage. Water/toilets drains freely and not slow.
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ROGER12345
Thanks, we have plugged all sinks, opened one by one and it seems to be the kitchen sink that's the fault. That does have a small AAV attached to it since the problem started but didn't stop smell.
Agreed. Then get plumber to replace the trap on that sink or washbasin with an air inlet or resealing trap. Could be a DIY job if you're handy.
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ROGER12345
Hi, just to add. We didn't block the overflows but it (so far) has stopped the smell by plugging sink and leaving water in sink. Seems to be kitchen sink. Have unplugged utilities and downstairs toilet sinks.
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ROGER12345
Thank you, he did put a small AAV on under sink but that didn't stop smell. Do you think a resealing trap would do better? Also our next door neighbour has same smell in family bathroom, do you think it could be connected as they were built at same time, only months ago?
Replied but not shown....New to this! Did as you said but not covered overflows. The kitchen sink seems to be culprit. Plumber did put a small AAV ON but smell continued. It has a u bend (p trap?) Should I change that to an actual trap one?
A (U bend) P trap IS a trap! So what do you mean by a conventional trap?
I was going to mention overflows, but you stated use of plugs had stopped the smell. So my guess in the dark is that it's something that doesn't have an overflow.
Can't you use your nose to smell the plugholes and overflows to find the source of the problem?
Failing that, if you're still stuck, pictures of your undersink plumbing might show something interesting...
I've seen better, but I've also seen worse and I can't see a smoking gun, sorry.
You smell it from the sink itself? I'm wondering if it might not be sewer gasses, but a smell from whatever may be sitting in the pipes upstream of the trap, seeing as looks like you have 2 sinks and a washing machine (?) all on one trap.
You smell it from the sink itself? I'm wondering if it might not be sewer gasses, but a smell from whatever may be sitting in the pipes upstream of the trap, seeing as looks like you have 2 sinks and a washing machine (?) all on one trap.
No don't smell directly from sink but smell seems to be stronger about 30ft from sink where no evident plumbing is. It's an intermittant smell and quite disgusting. We were away for a couple of days and house was terrible, had to take deep breath run in and open all doors/Windows & run all taps. It's a double sink, big & small with a dishwasher. Could it be a problem with shared pumping to main drain, just 3 houses. Next door has a smell too but in their main bathroom. Any thoughts would be welcome!
Drains are indeed smellier when not all houses have an open soil and vent pipe, and where lots of houses use them, but the point is that if the traps are there and working and all pipework is airtight then the foul air in the pipework should not be able to escape into the building.
30ft away and you are still blaming the sink? You must have a large house! But speaking seriously, if it's that far away, I'd be more inclined to suspect a leaking joint in the waste pipework somewhere (perhaps under the floor?) rather than a trap at 30' distance. Would recommend a plumber be called to carry out a pressure test (it's not a high pressure, but it'll tell you if there is a duff joint somewhere) of your waste plumbing (which you'd have hoped would have been done already seeing as it's a newbuild).
Thanks for the thought, will bring it up with builder....if EVER we see him. Unplugged sink and let water out after 3 days of no smell...and its back. It starts with an edgy light smell turning to intermittant disgusting one. It's so frustrating, we are not plumbers or builders and bought a new build to avoid problems. I have researched so much but feel I am going in circles. Thanks for your input.
Stand by the kitchem sink and get somebody to let a full bath water run out or flush the toilet and run the basin, use the upstairs appliances, you should be able to hear if you listen to the plug hole of the kitchen sink gurgling or bubbling. New builds shouldn't have the need for anti vac traps, it's obviously badly designed.
We think its coming from the kitchen sink, we did as you suggested and when unplugged kitchen sink the smell came back but its intermittent but its disgusting smell. We now have heard through the grapevine that the builder intends to put a vent onto holding tank next door. Apparently it was suggested by the Building control inspector (agent from the local council) that this may be the problem. What do you think? Any suggestion will be welcome, its really getting us down!
It's possible that an open vent will help. Building regs say that a foul drainage system should have an open vent to atmosphere (as in soil stack) somewhere to relieve positive pressure.
AAV's only deal with allowing air into the system to avoid water in traps being sucked out. They don't help in the event of a higher pressure in the drain system (possibly created by the pumping station) that could push foul air through a shallow trap.
I wouldn't think so don't I wouldn't mention it to them see if it cures your problem end of the day it's your property .
Most new builds have 18 months - 24 months my son has a brand new property the shower tray is leaking been six months butwillget sorted eventually I suppose
We are doing a snagging list ourselves but it seems impossible to find the reason for the awful intermittent smell. The builder is far too busy and ignores us..and our next door neighbour who has same problem.
If all three houses suffer from the same problem it seems likely it'll relate to the pumping station. Flush some septic tank treatment down the toilet (preferably when nearer empty than full) and see if it delays the stink some.
Thank you for your reply. All 3 houses have same problem to a degree but we are worse effected. We are the highest property. The pumping station pumps to main drain so should I still put septic tank treatment down? Should the 'holding' tank be ventilated? Had a look and there is no ventilation at all. A tank in the ground and next to it a green metal box which has a hole in the top but nothing attached to the hole, looked into the hole and there is no vent. I really appreciate your knowledge and help, thanks.
They can stay but it far better to have em fitted from the start put one one the outlet from kitchen sink waste to start with if you're DIY handy there nothing to difficult , I'm just saying try it the easiest way which will be on the outlet pipe to the drain
Thanks for reply. No, none of us have an external vent of any sort. We all just have AAV's sited behind the family bath panel. The plumber originally changed ours thinking it must be faulty but it made no difference to the smell. We did think it would have been a coincidence that all three had faulty AAV's.
That's main cause of problem what sort of a idiot would do that?
Against building regs as well at least one property has to have drains vented.
Probably saved £100 per dwelling and caused endless problems!
Against building regs as well at least one property has to have drains vented.
Probably saved £100 per dwelling and caused endless problems!
Thank you! We have been trying to get info on the drainage but its impossible from the builder. We are also trying to get info from the Agent who on behalf of the building control at the council did (?) the final checks. So far this hasn't happened. We dont know about these things but always felt there should be a vent somewhere. Should this be on the holding tank at the pump station to the main drain. We have never lived in a house without an outside soil stack. Are AAV's not enough?
AAV'S are exactly what they say air admittance valves .
Drains need venting to clear any dangerous buildups of gasses if nothing else.
Methane,carbon monoxide , hydrogen sulphide are just some of possible nasties.
I've worked on pumped sewage systems each manufacturer has it's own instructions.
I still do a certain amount of new build so know somebody has issued a final certificate .Private building inspector seem to be favoured route of many small developers.
Drains need venting to clear any dangerous buildups of gasses if nothing else.
Methane,carbon monoxide , hydrogen sulphide are just some of possible nasties.
I've worked on pumped sewage systems each manufacturer has it's own instructions.
I still do a certain amount of new build so know somebody has issued a final certificate .Private building inspector seem to be favoured route of many small developers.
Experienced this for 4 years in a house that was a self build. Finnaly plucked up the courage to investigate fearing the worse and began dismantlement boxed-in pipes. There was an internal stack with an external vent. Replaced with durgo..smell fixed. Must have been a self certifying plumber as building control would never have allowed it
That all sounds like it could be our answer, thank you so much. So do you think a vent on the tank or a vent on the house is the best answer?
I've been involved with building drainage for over 50 years (also where my higher qualifications are) the drains should be vented at there highest point . A combined soil and vent pipe is perfectly acceptable.
As this problem affects all the properties I would suggest you get together to put pressure on builder to get it sorted.
As this problem affects all the properties I would suggest you get together to put pressure on builder to get it sorted.
Back in the old days, each and every house had a soil and vent pipe open to atmosphere. The vast majority of these systems are still giving good service and need no attention as there . I can, however, see a slight disadvantage in having such a system in that each house will have an inside pipe that becomes an outside pipe with associated thermal bridging, whether the stack runs externally or whether it runs internally and up through the roof.
Nowadays, it is common to have fewer open vents than houses. Those houses that do not have an open vent will have a 'durgo' or AAV at the top of the soil and vent pipe. This works until the valve fails and a smell comes up through the faulty valve. Provided there is easy access to replace the valve, and people don't do idiotic things such as box the valve in where you cannot see it, this is not a problem. But the system relies on the fact that at least one house (or more if required at design stage) has an open vent, and some people just don't understand this.
Part of the problem is the (probably unavoidable) grey area between what work really needs a dedicated plumber and what does not. Obviously a general builder could construct a perfectly functional drainage system, but this relies on a fit for purpose building control system, which the UK currently lacks. As others have noted, private building control inspections often lack substance.
I am learning everyday about plumbing! far more than I ever thought I would need to know. I am grateful for all the interest and helpful replies. So far the opinion is that we need a vent, we are amazed that the builder, drainage people and building control have let this through. The builder is local and well respected, having build lots of properties in this village, so you would think this would have been avoided.
The problem lies now with getting him to correct this, meanwhile we live with the rotten smell.
No need if you do as I recommended ? it will work till Mr builder he's his act together
Unfortunately very few builders really understand drainage both below and above ground. Add to that plumbers who think aav's and anti vac traps cure poor design your in trouble!
I suspect what's happening in your case is as pump kicks in it causes enough of a vacuum to take seal out of trap before the aav can open.
I suspect what's happening in your case is as pump kicks in it causes enough of a vacuum to take seal out of trap before the aav can open.
current building control is the perfect example of feudalism in action in the 21st. The clergy (Capita plc) collect bribes (payments that are demanded each year) from the vassals (plumbers) so the Royal ministers (council) can have a recuring income from the peasants (you and I) by inflicting laws in exchange for taxes (forced payments) for everyday living)
Got a message today that plumber was coming to fit a 'deeper bath trap and a pan neck on toilet'..whatever that is.. We are not allowing this as we now agree with all on here that we need a vent.
Check out building regulations H1 section 2.18
Also even if the aav was suitable it needs to be above wash basin hight.
Keep it simple vent pipe fitted at highest point of drains .
Also even if the aav was suitable it needs to be above wash basin hight.
Keep it simple vent pipe fitted at highest point of drains .
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It needs to be above all waste outlets, visible and accessible
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Have looked, thanks very helpful. We have been told that the AAV although lower than the washhand basin wasn't a problem as its only in case of a flood? Would that cause smell? Is it a big job to put a SVP through roof?
So what your been told is if there is a blockage its ok for the aav to leak contaminated water inside boxing's ect?
Maybe not.
The s&v could be taken through the roof will depend on how easy route is.
Or a external vent pipe taken from inspection chamber at head of drain i think your in whatever is easiest territory!
Maybe not.
The s&v could be taken through the roof will depend on how easy route is.
Or a external vent pipe taken from inspection chamber at head of drain i think your in whatever is easiest territory!
I'd be inclined to agree that the height of the vent isn't the cause of the smell issue. The lack of accessibility is not something I would ignore. When the membrane in the AAV wears out (give it ten years), you'll be ripping out the panelling to get to the AAV. The drainage system needs to be ventilated at the head of the drain, which will be the house furthest from the pumping station.
If you are an intermediate house, why not have the AAV in the loft? Then it's hidden but easily accessible. You've only got to run the stack through a bit of plasterboard, presumably.
If you are the furthest house and need the open vent, then up through the loft, through the tiles, and terminate above the roof line, with a roofer to form a lead flashing to seal around the pipe. Or as #73. Make sure the distance from windows etc as in ADH are complied with as the open vent will be smelly if it serves several houses.
We only knew we had an AAV when we complained about the smell and the plumber replaced it, no change to the smell. I know it seems silly but we bought the house on 'good' advice, recommendation and reputation. We dont know what the drainage system is particularly and trying to find out is just so difficult. The building control company Stroma supposedly completed final check but they are not coming forward.
There are three houses number 1 is furthest, number 2 has the pump station and we are number three, we have the worst smell and are the highest (land wise).
We are so frustrated by the whole thing, I would move but my Husband wants to stay, we have only been here since January!
Oh yuk! 'They' said its only a warning sign and the flood would be water downstairs and we would notice it before it got to the bathroom...so gullible we are!
Where would the inspection chamber be at head of drain? Is that in the garden.
I hate new builds. They ought to be good but...
Normally, ICs will be something like this:
The red line is the sewer, the blue ones is each house's soil stack to the nearest IC, and there will be a vent either at green dot at the head (house 3) or a separate vent pipe to the IC (yellow). My terminology may not be exact, but you get the idea. I'm showing conventional 600x450mm IC covers, but yours may be small plastic round things as it's a new property. Basically, there will/should be access wherever there is a branch or abrupt change in direction.
It was suggested a HepVo valve could be fitted under your sink in series with the existing trap. This will certainly work if the issue is pressure developing and forcing through the trap. It's a one-way valve. They are expensive but work well. It may shift the problem elsewhere though (possibily to a neighbour...)
What if you find your IC and lift the lid slightly to allow some air to exit? Make sure to cover with a wire mesh though (rats...). This should have a similar effect to the yellow pipe in the above drawing. It's not a permanent solution and it will make the immediate vicinity of the garden smelly, but if it means your house doesn't smell of drains - which, long term, isn't going to be that good for you - it may just keep you sane while you arrange a permanent solution (and may be a good way of convincing your idiot builder that he needs to vent the head of the drain... which, by the way, is in the level 2 plumbing course, so not exactly a difficult concept).
So your house needs an open vent. Basically.
Normally, ICs will be something like this:
The red line is the sewer, the blue ones is each house's soil stack to the nearest IC, and there will be a vent either at green dot at the head (house 3) or a separate vent pipe to the IC (yellow). My terminology may not be exact, but you get the idea. I'm showing conventional 600x450mm IC covers, but yours may be small plastic round things as it's a new property. Basically, there will/should be access wherever there is a branch or abrupt change in direction.
It was suggested a HepVo valve could be fitted under your sink in series with the existing trap. This will certainly work if the issue is pressure developing and forcing through the trap. It's a one-way valve. They are expensive but work well. It may shift the problem elsewhere though (possibily to a neighbour...)
What if you find your IC and lift the lid slightly to allow some air to exit? Make sure to cover with a wire mesh though (rats...). This should have a similar effect to the yellow pipe in the above drawing. It's not a permanent solution and it will make the immediate vicinity of the garden smelly, but if it means your house doesn't smell of drains - which, long term, isn't going to be that good for you - it may just keep you sane while you arrange a permanent solution (and may be a good way of convincing your idiot builder that he needs to vent the head of the drain... which, by the way, is in the level 2 plumbing course, so not exactly a difficult concept).
One last question, hope you dont mind. The Agent for the Council building control (Stroma) now tell us its nothing to do with them and they cant check every detail on their final check. He did say that on the plans (which he wont give us) there is, or meant to be as he didn't check, an SVP in the small attic above our garden room. There is a small hatch in the ceiling but we have never looked in. He said that there should be a vent tile on the outside, there isn't. Any ideas would be great thanks. We are going to try to look inside that hatch later but it is very high!
If there is a vent tile or even a ridge vent easily identified from outside just looks different!
When you look in roof space if vent exists should be easy to see 110mm pipe.
As for building inspector absolute rubbish . They inspect buildings at a number of stages if vent exists it probably went in at first fix stage so should have been seen at pre plaster inspection.
When they sign a building off they are confirming its built to what the plans and specifications say and its to current regulations.
Maybe time for a word with the solicitor who did the conveyancing?
When you look in roof space if vent exists should be easy to see 110mm pipe.
As for building inspector absolute rubbish . They inspect buildings at a number of stages if vent exists it probably went in at first fix stage so should have been seen at pre plaster inspection.
When they sign a building off they are confirming its built to what the plans and specifications say and its to current regulations.
Maybe time for a word with the solicitor who did the conveyancing?
Well, we looked in roof space, nothing to see inside or out. Stroma have sent plans, there should be two svp with roof vents. No AAV on plan yet we have one. The conveyancor is on holiday! We e-mailed builder as its only way to contact him, no reply as yet. Stroma have said its not their job to sort this out. It's getting to the point of moving but how with this smell.
Absolutely dreadful Stroma do have a responsibility they signed of a property not built to plan that did nor meet building regulations.
Any back up guarantee n h b c or similar?
Any back up guarantee n h b c or similar?
Only an architects guarantee, that is not for 10yrs. We really dont want a fight but just to get it sorted out. With all the great info you have given us we have at least got an understanding of what should be happening. The plans are very different to what we actually have in many respects, build wise. We relied on local knowledge of the builder, we moved 500miles. Had the dishwasher on last evening and the smell drifted into the kitchen. Do you think a vent on the pump station would help, that is in the garden next door?
We really appreciate your time in helping us.
You really do need to have the vent on your own drains, and it's now obvious the original designer though so too.
As a very temporary solution I would follow the advice give by Ric on #78 and lift a inspection chamber lid slightly.
As you main problem seems to be your kitchen sink I would be quite interested to know if the drainage to that is as per plan.
As a very temporary solution I would follow the advice give by Ric on #78 and lift a inspection chamber lid slightly.
As you main problem seems to be your kitchen sink I would be quite interested to know if the drainage to that is as per plan.
Would that ease the pressure, we have loads of drains in the garden, only one says inspection chamber, is that the one we should lift? The plumbing on the whole house was done by a lad of 21yrs, very nice but I do wonder how experienced he could be. He said he just followed plans given to him by the Boss. He did put a small AAV under sink a while ago which made no difference. The washing machine in the utility is making so much noise from the sink above it when it drains. I put the plug in and it seems to stop the noise, its a very loud sucking noise. We get the feeling that we should be enjoying our new home but sadly we are not.
Yes try the one marked inspection chamber.
The noise from sink is air being draged in to break the vacuum in waste.
All lines up with what we already know.
Nothing wrong with a young tradesman doing the work but maybe more supervision required?
The noise from sink is air being draged in to break the vacuum in waste.
All lines up with what we already know.
Nothing wrong with a young tradesman doing the work but maybe more supervision required?
If in doubt, open the chamber, run the sink taps, and see if you can see water run through it. Then flush the toilet: does water run thorugh it?
I would imagine the two will both run through the same chamber, but if not, let us know as it will give us something to scratch our chins over.
I would imagine the two will both run through the same chamber, but if not, let us know as it will give us something to scratch our chins over.
Well, just had a call from Stroma, they have contacted the builder {after we had the plans sent to us, which bears no resemblance to our house drain wise, and they were told that a SVP was being installed in our house next week along with venting of the holding tank at the pump station! We have not yet been informed by the builder so we wait to see. I think that Stroma have been very worried that they signed off something which was not correct, although he did add 'its not an exact science' when my husband questioned why plans were different to what we had. I will update you (if you like) if and when it happens!
I agree, the plumber is a really nice lad but he is THE only plumber there and he is only doing as he is told. Stroma have to take responsibility for the end checks surely not being done properly. Hoping this all gets resolved soon. Thanks for all your time and effort on our behalf,
I would agree Stroma are responsible for signing of a property not to plan or more importantly not to building regulations.
But the builder & plumbing contractor are responsible for not following what are fairly simple regulations, it really is there fault you are in this position.
Pleased you are looking like job will be sorted please let us know end result.
But the builder & plumbing contractor are responsible for not following what are fairly simple regulations, it really is there fault you are in this position.
Pleased you are looking like job will be sorted please let us know end result.
Interesting read. Bottom line is that somebody has signed it all off and it's not to building regs.
The real worrying thing is that this only came to light because of the smell, so what else doesn't meet the regs that hasnt caused problems, yet?
Think a strongly worded letter from yourselves or even better a solicitor to say that you intend to hire a professional to do a full survey on the house as the drain issue proves that either negligence or wilfull deceit is at hand and should anything else be discovered etc etc etc.
The real worrying thing is that this only came to light because of the smell, so what else doesn't meet the regs that hasnt caused problems, yet?
Think a strongly worded letter from yourselves or even better a solicitor to say that you intend to hire a professional to do a full survey on the house as the drain issue proves that either negligence or wilfull deceit is at hand and should anything else be discovered etc etc etc.
We only heard from Stroma that the work is in hand but the builder still is not responding to us. All the work is done by the builder and his guys. He does have a good build reputation but also one for not responding to problems, this we found out the hard way. I will keep you updated....
Quite! We are now worrying about the other hidden things. We have just retired and thinking that a new house would be trouble free. We really dont want a legal fight but also we want a safe home. Thank you for your thoughts. Do all new builds have to have outside vents? I have read somewhere in all the 'stuff' I have researched that not all houses do, what do I know I am a nurse not a builder.....
From memory, and it's getting old, 1 in 6 vented to atmosphere was regs. But as yours is a development of 3, then at least one should be vented to atmosphere.
Hope get sorted.
Hi
AAV do not relieve positive pressures in drain systems only negative ones, I have been called to many houses where the plumber has fitted AA valves which then causes a positive pressure and blows the traps.
A lot of modern plumbers were not trained when we actually use to fit soil and vent pipes for that reason.
Every house shouild have at least on vent pipe, if you have a unvented cylinder like a lot of modern houses then the regs say that the soil pipe needs to be vented, sorry just another fault that seems to be regulary occuring event now.
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