Smell coming up from Sewege Tank

BnB

Hi all

I am having a problem with a bad sewege smell in one of the my bedrooms.

It is the closest room to the sewege tank and I think the smell is traveling from the sewege tank back up through the pipes and getting out at the nearest point - the en-suite of this bedroom.

Its a new house and we are only in a few months. I noticed the problem even before we moved in.

There is a manhole just outside the window of this room and there is no back up of sewege or anything like that. I tried leaving this manhole open for a few days and it definately helped. So on the suggestion of a plumber, I drilled a load of holes in the cover of it to make it into a vent. I though this helped for a week or two, but this weekend it was as bad as ever.

The man that did the outside piping for me told me that he has a pipe going down to meet the main sewege pipe in my lawn. He said he left it there in case there ever was a problem and we even needed to rod it. The pipe comes up about 1 foot below the lawn. He suggested we bring this up over the level of the lawn to make a vent of it.

Has anyone even had a similar problem and if so, did they find a solution.

What do ye think of the proposed vent in the lawn ?

Has anyone ever heard of any kind of "valve" that you can fit that will allow sewege to travel down the pipe but will not allow the smell to come back up...? Does such a thing exist (I only dreamed it up myself)

I have attaced a fairly crude diagram to try and show what I am talking about.

Thanks in advance

youtheman

Your idea of a valve is a 'no no'. A vent in the lawn is also a 'no no', and I'd question the qualifications and mental capacity of anyone who would recommend same (Is there a mental asylum nearby missing a lunatic ???).

The complete sewage system is a vented system. The outlet from your WC goes out through the wall and into a 'tee', one end goes upwards to a high point vent (and the building regulations stipluate how high it must be, and how far from the nearest window is is allowed to be). The other end goes downwards and underground to your sewage tank.

There is a U-bend in the WC to stop smells coming back up the pipe. Make sure there is still water in it.

There is most probably a shower or bath connected to the same system. Make sure the water trap is intact in these (I had a tiny leak in the U-bend in my bath once and this allowed the bend to dry out and the smell back through the system).

Also, you need to see how near the vent is outside your window.

And, of course, you need to ensure the system is not blocked.

Mike2006

I would 2nd that...

Try to find the offending fixture in the bathroom. There will be a few possibilities:

1. Toilet
2. Shower Tray
3. Wash Basin

Get the nose in to 'see' if the smell is stronger around the waste pipes of any of the above.

1.Toilet - most likely cause here would be a perforated flexible wick (if used).
Get plumber to pull out toilet to check.
2. Waste trap not holding water or insufficient bend in waste to create water seal.
3. Same as 2.

These are all easy to see so check them out first.

Mike.

William Powell

youtheman wrote: »

The complete sewage system is a vented system. The outlet from your WC goes out through the wall and into a 'tee', one end goes upwards to a high point vent (and the building regulations stipluate how high it must be, and how far from the nearest window is is allowed to be). The other end goes downwards and underground to your sewage tank.

That does assume the system was installed correctly? Maybe best if OP can locate the current vent (stench pipe) and report where it is in relation to his picture. Is there any vent at all? btw great pic OP helps a lot

BnB

Thanks very much for the replies so far. They are very much apreciated.

You have given me a lot to think about here.

The sytem is vented at it's highest point. This is through two vent tiles in the roof at the back of the house. The house is a 1 and 1/2 story and these 2 vents tiles are coming up from the two upstairs en-suites in the house. A long way from the problem room.

I know the pipes for the vents were ran into the roof. The roofer came back to conect the vent tiles to the end of them. Now, teh roofer was a bit of a sod, and I wouldn't be surprised if he didn't connect them right. But if that was the case, I would expect the problem to be upstairs.

It sounds to me from your replies that you think the problem could be more to do with the local plumbing in the room. i.e. The fact that this room is the closest to the Sewege tank is merely a conicidence.

The room is a fairly standard En-Suite.

Standard Toilet. Standard Sink.

The Shower is a wet floor shower as opposed to a shower tray. But we have the same shower trap in our own room and it doesn't give any trouble.

How would I go about diagnosing the problem.

I presume... Check for leaks around the U-Bend of the Toilet

Do the same around the sink.

If I can't find anything wrong, would it be an idea to try blocking the shower up completely for a few days to see if that is the source of the problem ?

Mike2006

When you lift the grate on the shower tray, can you see water in the trap?

If you can, then it is probably ok...

yeah, you could masking tape all the opes and if it the smell goes away, open each one 1 day at a time until smell returns and then you have the culprit..

Mike.

William Powell

One more thing to add to your list . Check the outlet from the sewage tank (assuming it drains into a percolation area) is below the inlet level. If it isn't you can get s-h-one-t building up in the inlet pipe and that can cause a right stink, that should be vented back to the roof vents but will be noticable at every inspection cover thats not totally air tight.

martin46585

hi there, looking at your diagram, if the tank has no vent between it and the wc, the negative pressure create from a full flush may empty the traps in the basin or shower, a vent at the tank is first, then depending on the length of the branch from the aj, another beside the window,
the valve which you refer to is an air admittance valve which opening and closes to eqlize the pressure in the pipes to counter act the syphon.
hope this is of some help..........

andrew cross

hi i had the same problom when we moved in to new house i will check tomorrow with my son in law as to how we fixed it , we cut sewer pipe put in y bend, so that sink,and shower, flowed into one part of y bend, let me check that tomorrow to see if my memory is correct ill get back to you;)

William Powell

martin46585 wrote: »

hi there, looking at your diagram, if the tank has no vent between it and the wc, the negative pressure create from a full flush may empty the traps in the basin or shower, a vent at the tank is first, then depending on the length of the branch from the aj, another beside the window,
the valve which you refer to is an air admittance valve which opening and closes to eqlize the pressure in the pipes to counter act the syphon.
hope this is of some help..........

If that is the case the OP might might be able to hear the water getting sucked out of the traps when the flush is pulled, emptying a full basin of water out might create a guggling noise in the shower trap as the water is sucked out due to the same negative pressure but on a smaller scale.

BnB

Lads. Thanks for all the suggestions here. They really have been brilliant.

I did as suggested this evening when I got home and started looking in earnest for the source of the smell inside the en-suite as opposed to looking at vents outside.

Tried the shower first as I had suspisions of that. But there was water in the trap and no sign of a smell.

Moved onto the sink - Same thing - no leak - no smell.

Stuck my head right down the loo.. not even a wiff of a smell (within reason)

Started looking around the floor.... and bingo......



Where the outlet of the toilet goes down into the floor, there was a right stink. Something obviously isn't sealed properly here down here and the smell is coming back in here.

I'm going to give the plumber a call tomorrow and get him back.

Sincere thanks for all your help. I really was barking up the wrong tree with my messing around trying to create more vents outside. I'll keep ye posted on how I get on with the plumber.

Mike2006

Well done.

Saved yourself a few bob there as well not having to mess around with the sewage system.

Mike.

andrew cross

BnB wrote: »

Lads. Thanks for all the suggestions here. They really have been brilliant.

I did as suggested this evening when I got home and started looking in earnest for the source of the smell inside the en-suite as opposed to looking at vents outside.

Tried the shower first as I had suspisions of that. But there was water in the trap and no sign of a smell.

Moved onto the sink - Same thing - no leak - no smell.

Stuck my head right down the loo.. not even a wiff of a smell (within reason)

Started looking around the floor.... and bingo......



Where the outlet of the toilet goes down into the floor, there was a right stink. Something obviously isn't sealed properly here down here and the smell is coming back in here.

I'm going to give the plumber a call tomorrow and get him back.

Sincere thanks for all your help. I really was barking up the wrong tree with my messing around trying to create more vents outside. I'll keep ye posted on how I get on with the plumber.

congrats thank god it was just the seal no digging up pipes