Sealing soil pipe

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may well be helpful...

The copper waste pipes from the bath and bathroom sink were installed so that they intrude into the dining room just below the ceiling. Not good.

As I'm refurbing the bathroom I wanted to reposition them into the void between the dining room ceiling and bathroom floor. There is enough space but I'll be left with two holes in the soil pipe.

Firstly, how do I remove the two copper coloured plastic joints between the copper pipes and the grey bosses?

And secondly, what's the best way to seal the remaining holes securely - the toilet outlet will be above them!

If it helps: the distance between the vertical face of they grey bosses and the inner face of the boxing-in is only ~2mm.

(And no doubt the upward sloping sink waste is the source of the gurgles when it's emptied?).

TIA

Reply to
F
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Depends. If they are "push fit", a tug should shift them. If they are solvent weld (ie the copper pipe isn't copper but just copper coloured) I'd decide how to seal first, see below.

Measure the pipe and pop along to a proper plumbers' merchant who will stock a range of caps. If you have a solvent welded boss, you'll nee a cap that fits the inside and you can cut of the pipe flush with the boss.

Brian

Reply to
Brian Reay

The copper pipe is copper and the end of the copper coloured plastic join that takes the pipe looks like it's probably push-fit. It's the end that goes into the boss that concerns me as I've not come across anything like it before. I wondered whether or not the face of the boss that's visible in the image might even be threaded?

Will they fit 'inside' the hole in the boss? I've only got ~2mm to play with between the front face of the boss and the inner face of the boxing-in.

Looks like it might be cut-it-and-see and then a trip to the local merchant.

Thanks for the help.

Reply to
F

The copper coloured fittings are almost certainly pushfit waste fittings. The colour was popular in the DIY market a fair few years ago. I'm pretty sure I had some waste plumbing using that colour piping in a house a good few years ago, before I moved onto solvent weld. I'd be 99.99% certain that type of fitting was not a solvent-type plastic, so they might have been put in with solvent, and that may have hardened up, but they won't actually be welded in.

Can you get your fingers around the sides of the main soil pipe? The grey bosses look as though they might be solvent-weld saddle bosses. These are usually used when joining into an existing pipe. They will probably have a strap as part of their construction, which goes from each side of the boss around the back of the main pipe.

I *think* ( I'm not 100% sure) that the bosses are intended for push-fit fittings. I'm guessing there's a rubber ring secured by the inner ring of the boss, IYSWIM.

It should be quite possible to get something that could be adapted to fit. Your problem seems to be the minimal clearance between the face of the boss and the finished wall surface. What you need to guard against is using something that protrudes too far into the soil pipe, otherwise you'll get problems with blockages!

Your best bet is to go and visit some of your local builders' merchants, until you find one where they keep all their waste and soil pipe fittings in bins for self-service. That way you can get a good look at what's available before you have to start buying. It's also best to go mid-morning or mid afternoon, to avoid all the professionals getting their stuff.

The alternative, can you get a clear working area immeiately to the bottom of the two bosses, even if it means a bit more making good? Much the better option would be to cut through the soil pipe immediately under the bosses and replace the soil pipe right up to the junction for the toilet connector. That way you'll know there's no chance of a leak at some time in the future.

Assuming also that you're using solvent weld for the new waste pipes, don't forget to secure them at reasonable intervals, looking at the length of the existing pipes. Over time plastic can sag, and if you get too much gunk, you could possibly get a blockage in the section through the void a few years down the line. (Speaks the voice of experience!)

Reply to
The Wanderer

Possibly unavoidable though, as the falls to the soil pipe must be of a certain slope, and, if there is a bog sitting on the top of it, there may be no other way to get the couplings low enough.

Pull hard?

Don't. Take out the whole soil pipe section and replace with a new one.

Probably.

Look. Rip out everything - the bog, basin, bath and the pipes and the boxing round them - and then cut the soil pipe (I assume its plastic) somewhere suitable and redo the whole ruddy thing properly. Experience shows this is usually quicker...you don't have to ask questions here for a start - you are installing new stuff to proper standards and that's it.

Reply to
The Natural Philosopher

Between you and The Wanderer I get the message: pull it out and do it properly!

Thanks: appreciated.

Reply to
F

To be honest, I learnt that lesson years ago when repairing cars.

After several sessions on my back underneath cars trying to fix brake pipes, prop shafts and the like, we eventually had the brainwave 'let's take the whole lot off, get it on a bench' - and by gum its easier to simply hacksaw out seized bearings or use a blow lamp, and stick in new bearings, brake pipes, wheel cylinders and the like..and its not even that expensive.

I fitted a new kitchen to me old mums old place about 2000, and she insisted on keeping a shoddy knocked up cupboard. I spent more time fitting stuff around that than I would have re-making an identical one by about a factor of ten.

Reply to
The Natural Philosopher

I usually do that too, but sometimes, just sometimes, it bites you back and you end up working your way backwards through a whole series of dismantles!

I learnt a long time ago that it's easier by a factor of at least 10 to start from scratch than to alter something that's already there.

Reply to
F

I think you can get a feel for what kind of joints you have there before you dismantle by giving the ones near the stack a firm wiggle. The one about

6" from the stack def looks like a pushfit and should give a bit but not sure about the one direct into the stack, if that is firm then likely solvent which could be a pain to remove then repair but I notice the lugs on the boss which suggest something to unscrew, trouble is I've never seen anything similar to compare with or know where to get a blank version. If it's a simple boss fitting then BES have solvent or pushfit compatible bungs (or 'socket plugs' as they call them) or if that boss plate is removable then you could fabricate a blanking plate sealed with rubber or silicone and perhaps bolted through the holed boss plate.
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Good luck.
Reply to
fred

Given it a gentle wiggle and the pipe moves so, yes, it looks like push-fit.

It seems much more solid and doesn't move like the other end. I'm reluctant to lean on it just now as I'm not in a position to put things right if I get a problem.

That was my suspicion. I was hoping someone would come along and say they'd fitted them in the past (house is circa 1967) and then proceed to give me chapter and verse to help me get the bits that I'll need!

No doubt I'll find out if it unscrews when I've stripped out the bath, washbasin and toilet and can get to it more easily.

I took the opportunity to get a couple from Screwfix (34151 and 91427) with today's order just in case.

I've got silicone in stock!

However, a complete strip out and replace of that section of soil pipe is still the likeliest option.

Thanks. And thanks for the help.

Reply to
F

As an aside, why would the original installer have run two separate pipes? Why not tee the 32mm washbasin waste into the 40mm bath waste as it passes?

Reply to
F

This can possibly drain the trap of the washbasin as a bath is emptied due to suction (although not so likely as will a toilet). It also results in gurgles from the non-emptying plug hole, very annoying. When I finish the bathroom I will run two separate pipes such that they join at a vented point, which will happen to be the soil stack ! Simon.

Reply to
sm_jamieson

On Thu, 24 Aug 2006 19:09:34 +0100 someone who may be F wrote this:-

That depends. Bath, basin, shower and bidet pipes should not be connected within 200mm of the centre of a toilet connection to a stack. This is largely to guard against the smaller pipes being blocked by toilet waste. I haven't looked at the photographs, but this may be why the connections are where they are.

A few manufacturers make special adapters that allow one to avoid this restriction. They involve removing your existing toilet connection to the stack and replacing it with a new fitting.

Reply to
David Hansen

Didn't know that - thanks.

However, there's a spare 100mm under the floorboards but I suppose it was easier to drop under the ceiling. After all, whoever fitted it didn't have to live with it.

I'll be making the new connections under the floor but I'll make sure I stay outside the 200mm.

I've also found a waste manifold (Screwfix 12593) that should make connecting the bath and basin wastes separately much easier.

Reply to
F

On Sat, 26 Aug 2006 12:25:13 +0100 someone who may be F wrote this:-

It is 200mm from the centre of the toilet connection, which will give you a little more vertical height to play with.

Reply to
David Hansen

Thanks. I was assuming 200mm centre to centre which should be even better.

Talking about this over the weekend I was told that I might be able to make further improvements to the soil stack by bringing the top of it into the boxing-in in the bathroom and using an air admittance valve from Screwfix (95531).

The present stack is internal and exits the building through the roof above the bathroom. Where it passes through the roof tiles has been the source of a couple of serious leaks in the past that have damaged the bathroom ceiling so I would like to get rid of this weak point.

So, do these valves work? If they do, how low can I bring the top of the stack? Could it be, say, level with the top of the close-coupled cistern?

Removing the boxing-in in the upper part of the bathroom and reducing it to around 800mm would also have benefits as wall space is in short supply.

TIA.

Reply to
F

On Mon, 28 Aug 2006 11:41:05 +0100 someone who may be F wrote this:-

If the flashing is done properly there should be no leaks for a long time.

Usually. For a while.

Personally I would only use an air-admittance valve if very pressed, after discussing it with Building Control. These people know bugger all about electricity and hot water cylinders, but are a very useful source of information about drains and other building work.

Reply to
David Hansen

Yup. The general view is that a stack prevents overall positive pressure in a drain, and durgos can be used to prevent localised negative pressure that sucks traps dry.

They should be where they can be easily replaced.. Mine isn't :-)

However the worst that could happen if it failed would be a trap or two sucked a bit (fails shut) or perhaps a pong IN the bathroom wall (fails open), that probably would escape outside..

The important thing to remember is they do not replace the stack vents. They duplicate half of what a stack vent does, and you use them to prevent local vacuum, not pressure build up: the stack vent does both.

Reply to
The Natural Philosopher

An update...

The copper pipe meets the copper coloured plastic pipe at a push-fit joint.

The other end of the copper coloured plastic pipe screws into a thread on the internal face of the boss on the soil pipe.

The boss is fixed to the soil pipe by the circular knurled/keyed section visible in the photographs which screws onto another section which is placed within the soil pipe and comes through it to take the pipe fixing. There's a rubber/flexible plastic seal between the outer ring and the soil pipe. Trouble is, the boss can't be removed as the flange on the inside prevents it moving through the hole. Rotating it doesn't help so it'll have to wait until I cut out that section of soil pipe.

Hope that helps anyone who comes across the same fixings.

Reply to
F

I did exactly that but now regret it somewhat. The AAV doesn't seem to admit enough air so that when the toilet is flushed the water seal in the U bend is broken and air is sucked in through the toilet. The seal is OK after the flush finishes but the water is at a lower level than it would otherwise be.

MBQ

Reply to
manatbandq

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