Sewer Gas and odd solutions

[allthegearandnoidea]

I purchased a home a few months ago. Unfortunately I found a truly foul smell in the bathroom, at least after running any water.

A bit of nasal investigation revealed that this smell was (at least partially) coming from the bath u-trap, clearly escaping sewer gas. Unfortunately I couldn't find a u-trap that fit so I ended up trying to re-do the seal on the old one. This may or may not be working.

Unfortunately, I've found that's not the only was sewer gas is coming from. The wc pan connector on the toilet was leaking. Whilst investigating this I ended up ripping out a lot of wood work that was covering the pipes from the toilet. This revealed that one of these pipes, after the toilet's u-bend, has a large and seemingly deliberate hole (I'll refer to it as devhol1) in the top. This of course is also leaking sewer gas.

In summary I think its high time to redo a lot of this work. The screws in the old toilet are so rusted that I'll have to destroy them the get the toilet out, and new toilets aren't that expensive so I think I'll get a new one and replace all the interior pipes.

Now what's bothering me is why someone put devhol1 there in the first place. Seemingly, to act as some kind of escape for sewer gas. There doesn't seem to be anything wrong with my soil stack but I've not looked very thoroughly and to be honest wouldn't really know what I'm looking for.

I want to get cracking with ripping the old stuff out and getting shiny new porcelain and pipes in but I'm not sure if there's some deeper underlying problem I should be fixing first?

Any advice or tips welcome,

atgbni

 

[Newboy]

A photo would help.

The only reason I can think of that somebody would cut a hole into a soil pipe would be to relieve back pressure - it can relieve the symptom of a partial blockage bu is (clearly!) not a cure.

Alternatively has an appliance been removed and the connection point not made good?

 

[allthegearandnoidea]

Hi newboy,

Please see picture of the hole in the pipe:

Holeinsoilpipe

• allthegearandnoidea
• 13 Nov 2016
• 2

I've now had another look around my house and I'm not sure if I have a soil stack or an air admittance valve. Either way the location of what I've found seems odd. I've found something which I've indicated in this picture:

Building_soilstack

• allthegearandnoidea
• 13 Nov 2016

As you can see its on the opposite side of the house to my bathroom which seems odd. As such I'm more confused than ever and not sure what the situation is. Perhaps I have an internal air admittance valve somewhere or (hopefully not) there isn't a proper venting system installed.

I'll keep googling and my next step seems to be trying to work out exactly how the systems working as potentially this hole in the pipe is being used to stop back pressure/as a venting system (albeit a rubbish one).

 

[JohnD]

pictures not attached.

you can copy and paste them if not too big, otherwise upload them to your album and use the "picture of a camera" button

 

[Newboy]

1) When you flush the WC does any water come out of that hole in the soil pipe?

2) Do you have a photo of the bath trap

3) Are there any other WC's in the house and, if yes, where are they in relation to the bathroom?

 

[Hugh Jaleak]

Wondering if that was for a former overflow, now new WC has been fitted with an integral overflow, it is surplus to requirements, although should always have been done using a proper boss connection, if they had do it that way and not take it out the wall.....


I'd look at either cutting that pipe back beyond the hole, fit a coupler and extend back to where you need it to be, or alternatively enlarge the hole, strap boss on the pipe and a plug. I'd do the former though, will look better.

Vent position isn't too odd, pipe from WC clearly runs under the floor to meet it, so don't worry about that. Doubt there's an AAV's either, at least one of those vents out the roof is likely to be the soil, cant see the other behind to judge the material its made from.

Bath, any standard 40mm trap should fit unless you've got a weird Ikea type waste on it? Pic might help of underneath bath showing current waste set up.

 

[allthegearandnoidea]

1) No; but you can see water flowing through the pipe by looking through the hole; the flush just isn't powerful enough to spit water out.
2)
I couldn't find a new one that fit so I cleaned out the old one and applied a highly technical solution of taping plastic bags around the waste end. I'm going to get another one that fits at some point but either way sewer gas is also coming from the hole in the soil pipe.
3) No other WCs.

I've now tried covered up the whole in the soil pipe and flushing the toilet; gave it a solid five or six flushes; water draining out of the pan at normal speed. So seemingly even with the hole covered air is getting in to ensure low pressure doesn't develop. So even though I haven't gotten to the bottom of my ventilation system it seems its working...

 

[Hugh Jaleak]

Is that waste leaking from the outlet end? Look for either missing or knackered washers, (should be a black rubber tapered washer and a plastic O ring then the nut), or the waste pipe is on an angle preventing it from sealing correctly. Looks a standard bath trap, although ideally should be a deeper seal P trap if connected to a stack.

Toilet is working as it should, I'd only expect back pressure if there a blockage. Air passing over the stack will cause pressure fluctuations in the soil pipework, that's to be expected. Normally you don't have an open hole in the internal pipework....