Stench pipe removal

ed110220

I need to refurbish my bathroom and due to it being small I'm thinking of removing the stench pipe in order to make the layout easier (basically to avoid the handbasin being jammed up against the bath or even overhanging it).

At the moment the stenchpipe is boxed-in so I was thinking of cutting it off just above the toilet join and replacing with an air inlet valve. Is there any significant disadvantage to this or anything I should watch out for?

keystone

ed110220 wrote: »

I need to refurbish my bathroom and due to it being small I'm thinking of removing the stench pipe in order to make the layout easier (basically to avoid the handbasin being jammed up against the bath or even overhanging it).

At the moment the stenchpipe is boxed-in so I was thinking of cutting it off just above the toilet join and replacing with an air inlet valve. Is there any significant disadvantage to this or anything I should watch out for?

1. 1970's property?

2. You must have one vent open to atmosphere on your soil system.

3. When fitting an AAV it must be fitted above the flood level in the room. For you thats the basin.

Your proposition is definitely knackered on 3 and almost certainly on 2.

A pic or two might yield suggestions as to how layout can be improved.

Sorry.

Cheers

ed110220

Thanks for the reply.

It's a British Iron and Steel Federation (BISF) house, so steel-framed dating from the late 1940s. Due to the construction the stench pipe, soil stack below and chimney flue are all boxed-in internal pipes.

The reason I asked was this is what the neighbours have recently done, which is not to say it's advisable!

I'm a little confused though as I thought the whole point of a durgo-type air inlet valve was to allow the removal of a stench pipe and act the opening to the atmosphere?

Here's a plan of the house, bathroom included (at the moment there is no bath, removed by previous owner):

ed110220

Here's a photo, but due to the small size of the room the plan gives a better idea I think. You can see the boxed in stench pipe with mirror tiles on it (for some reason the previous owners had them in almost every room) and the urgency of refurbishment!

To the right is a shower enclosure on part of the area where the bath would have been (a bath shaped area of missing carpet). I imagine this was removed as the previous owner was in his nineties and perhaps couldn't get into or out of a bath.

keystone

ed110220 wrote: »

It's a British Iron and Steel Federation (BISF) house, so steel-framed dating from the late 1940s. Due to the construction the stench pipe, soil stack below and chimney flue are all boxed-in internal pipes.

Ah thank you.

The reason I asked was this is what the neighbours have recently done, which is not to say it's advisable!

Do you have a linked drainage/sewer system in terrace of houses?

I'm a little confused though as I thought the whole point of a durgo-type air inlet valve was to allow the removal of a stench pipe and act the opening to the atmosphere?

But an AAV only works one way and the drainage system needs to be able to vent as well as suck. Its all about pressure balance. There has to be one vent stack open to atmosphere on a drainage system. If you have two stacks you can get rid of one and fit an AAV as long as said AAV is above the flood level.

Here's a plan of the house, bathroom included (at the moment there is no bath, removed by previous owner):

I'll look at that and the photograph later.

Cheers

WestonDave

Hi Ed - we did exactly what you are suggesting in a previous house. Boxed in soil pipe, cut it off at bath top level with a durgo valve in the top of it. Ours went out through the roof to a cowl top above - we left that part in place and stuck an extractor fan which vented out through this top pipe. Never had a problem with it and was suggested by a bathroom installer (I can PM you the name if you like as you are local to Bath I seem to recall).

WestonDave

Actually on thinking again - what we did was to cut it off at sink level and hide it under a worktop that ran across the width of the bathroom and across the end of the bath. No reason why you couldn't do similar if you enclosed the remaining soil pipe and valve in a unit with the sink set into a work top on top of it. (By the way if you are looking for cheap bathroom stuff - worth checking out Total Bathrooms on Locksbrook Road.)

ed110220

Thanks Keystone and Dave. That's exactly what the neighbours have done, except they have cut the stench pipe off lower, just above floor level above the soil pipe (definitely below basin level) and even got the stuff from Locksbrook Rd!

The drainage systems may well be connected as the houses are semi-detached but linked by outhouses with a WC in them. As the outhouse WCs would be back-to-back, it would make sense for them to use the same system, but I do not know this for a fact.

keystone

OK then Dave has his above the flood level which is what you have to do. Cutting it off lower is non-compliant (!!!) whether the neighbours have done it or not.

It is a REQUIREMENT whether the neighbours have done it or not to have one vent stack on a drainage system open to atmosphere.

Yours might be the only one left if its a common system!!!!!

Oh and based on the plan and the pic swap the loo and the basin for each other. Plenty of room twixt vent and bath for the loo and more space on LHS for the basin. Alternatively fit a smaller more modern basin in current location.

Cheers

docmatt

keystone wrote: »

But an AAV only works one way and the drainage system needs to be able to vent as well as suck. Its all about pressure balance. There has to be one vent stack open to atmosphere on a drainage system.

I didn't know this. But now you say it of course it makes sense, this could be why I get a weird kind of splash back water dribbling from under my downstairs bog sometimes when it's flushed.

keystone

BTW in case you think I'm being too dogmatic one thing that's always mystified me is that it's perfectly OK to have an Anti Vac trap on your Basin which is below the flood level but it's not OK to fit the AAV below it.

Cheers