Water leaking from base of soil pipe

[freshman]

Hello all,

I have an external unvented soil pipe running from my bathroom wall at the rear of my house, down into concrete at ground level.

My partner and I always have showers and I didn't notice a problem until we had a guest who wanted a bath. When the plug was pulled and the water started to drain, I noticed water seemed to be coming out from the base of the soil pipe.

On closer inspection the soil pipe disappears into a larger pipe, and there doesn't seem to be any kind of seal between the two. The volume of bath water must have been great enough to cause water to rise up over the top of this larger pipe and spill out onto the concrete. (See attached pic)

It looks like there may have been a cement or concrete collar-like join between the two long ago but this has since fallen away. The house was built in 1901.

Untitled

• freshman
• 17 Jun 2008
• 1

Having never really inspected soil pipes before, is this a normal set up, and do you think would sealing the gap between the two pipes again solve the problem? Alternatively I suppose replacing the soil pipe with a new, vented one might help. The existing one elbows straight into the bathroom wall on the first floor.

Any tips advice would be much appreciated...

Thanks!

PS I'll try and take some photos when I get home later.[/img]

 

[tryitandsee]

The old joint has probably gone. This is what should have been there.

Caulked Joints. Caulk joints shall be firmly packed with oakum or hemp and shall have at least one (1) inch of pure lead properly caulked. Paint, varnish or putty shall not be permitted until tests have been performed for seal.

This is what you can put in, but I don't know who makes the stuff, may be standard Dow Corning off the shelf.

A multi-purpose, extremely durable polyurethane sealant. Excellent lead substitute for caulking cast iron soil pipe joints.Works with or without oakum. Single component polyurethane sealant that cures rapidly to a firm yet flexible, waterproof and weather resistant seal.

Forget the oakum, I would pack the pipe first with wetted newspaper first, so as to stop the sealant flowing down the pipe. Or you will end up using the whole tube!

 

[freshman]

Thanks tryitandsee, I'll have a look for some sealant, hopefully it'll do the trick.

 

[tonybhoy]

Soil could be blocked

 

[tryitandsee]

As Tony has said, the soil may be partially blocked below ground level.

As a precaution try and locate a manhole and lift the lid and see if waste water is running ok.

The joint on the soil pipe may have been purposely left so it could be accessed/lifted, to sort out previous unknown problems.

 

[tryitandsee]

Re reading your post, how many wastes pipes are connected/going to this soil pipe.

Bath, shower, wash hand basin, WC.?

If all these were connected, there would be some sort of vent/anti-syphon, as you would suffer syphonage from the traps when the loo was flushed/plug pulled.

Wildly speculating now, perhaps the joint was left open as a crude way of letting air out. As you mentioned in the first place, a vented soil would be better. Having said that, it's worked since 1901

 

[freshman]

Currently two pipes go into the stack; a 40mm waste and the soil pipe from the WC. I have a basin, bath, and WC (although have enough space for a separate shower which I plan to fit soon), so I assume the two wastes from these join somewhere under the floor before going out of the wall.

There doesn't appear to be an inspection chamber nearby, although it could be in next door's garden. I'll need to talk to my new neighbour and have a looksy.

Unfortunately the 1901 factor may be irrelevant; I've only lived here 4 months and this bathroom looks less than 10 years old, the property was extended 20 or so years ago and although the bathroom is in the original part of the house I'm not sure if this was its original location, and therefore whether this is the original soil pipe...

When you say siphonage do you mean the water in the traps would be "sucked out" when the toilet is flushed? I haven't noticed this happening but will do some testing tonight.

I have a large airing cupboard between this bathroom and the master bedroom so was thinking of converting to an en-suite with the waste running between the joists under the existing bathroom floor to the same soil pipe, so would I be right in thinking it would be best to replace with a vented one?

Thanks

 

[tryitandsee]

Venting the drainage system is a building regs issue, ideally toxic/flammable gases have to escape, thereby proper venting is required.

This can be achieved by extending the soil pipe above gutter line and leaving open ended preventing these dangerous build up of gases. Although other stacks in the system may be venting the system (neighbours etc.) adequately.

By the sound of it, your existing drop from the first floor to ground level is not up to standards, (others may know the regulations) so it would probably be best to replace the soil stack externally when you come to do your shower and taking it up higher then.
Adapting the existing cast iron would look 'messy' and in the end would be easier to replace in plastic with new fittings.

I'm not sure but if you are just replacing like for like, then I wouldn't get building inspectors involved

If the basin, bath and shower were all in line using all one waste pipe, then that is when siphonage can occur, the waste water pulls the 'trap water'. This is remedied by anti siphonage traps under the sink/bath/etc..