Soil pipe -- to replace or not to replace

[James]

Hello -- first post here after reading for a long time and picking up lots of valuable advice.

I'm going to completely replace our bathroom over the next few weeks. Before doing anything internally I was planning to replace the soil stack. The connection to the toilet is a mess -- years of bodging and putty and a cheap loo that wobbles and leaks because it hasn't been screwed to the wall. Here's a picture. Note that I didn't install this!

now I find myself thinking how much easier it would be if I didn't have to get rid of the whole thing. The external pipework is old but sound.

I don't want to fit a new toilet to a knackered pipe -- but does anyone have any thoughts about reusing what's there already?

If I could saw/grind off the collar on the pipe and clean up the end then would a flexible pan connector make a decent seal? Would it help to use a long connector and push it further down the pipe than normal?

The current (badly fitted) toilet is on a wooden plinth which will come out before the new toilet goes in. Is there likely to be a problem with the angle of the connector? Clearly the new one will need to be closer to the wall so it can be fixed in place. I'd rather not have to have a bit of wood between the back of the cistern and the wall.

Any advice would be much appreciated. Two small children in the house mean that the quicker I can finish the project the better -- but if I'm going to have to bite the bullet and replace the whole thing then I might as well get on with it.

Thanks in advance.

James

[ARWadsworth]

Is that a lead waste pipe to a cast iron soil stack?

[James]

Thanks for the reply. I don't think it's lead, although having never knowingly seen a lead waste pipe I'm happy to be proved wrong.

For some reason that TinyPic link brings up a zoomed-in version of the photo. If you click on the image then you get a better view.

There's a modern pan connector shoved into what looks like a bit of plastic pipe, which goes into the collar at a strange angle, then loads of putty and sealant packed around them all.

I'd assumed everything except the plastic bit was cast iron, but I've just been up and tried to stick a fridge magnet to it, and it doesn't stick. It doesn't stick to the soil stack outside either.

Abestos? Or maybe I need a stronger magnet...

James

[ARWadsworth]

A photo from outside might give more clues.

Where does the shit pipe go to?

[newshound]

Looks a bit like an iron waste pipe to me; don't recognise the collar at all. What happens outside? One option might be to fit a new plastic pipe through the wall to an existing iron stack outside (which is what I have). Then you can have nice modern unbodged pipework inside the house.

[James]

Not much to see out there at the moment, but I'll take one when it's light.

It goes out through the wall then straight into the soil stack via a swept tee. The soil stack is outside, just to one side of the pipe.

[fred]

In article , newshound writes

Agree it is likely cast iron, I have seen one with a similar collar from a 60's build, the collar was sealed using lead wool compacted with an offset compacter/chisel type tool.

I'd cut it off 2" or so from the wall to get a lower entry and use a flexible pan connector to mate with the inside of the pipe. They're meant to be self sealing but I'd add sanitary silicone to the compressible vanes to make sure.

No need to disturb a cast iron stack in good condition, it should last a century. Hopefully the building is not 99yrs old ;-).

[newshound]

Cement asbestos used to be used sometimes for things like rainfall downpipes in factories and garages, but I have never come across it used in soil pipes. If it's not magnetic my money would be on (relatively) modern plastic (usually ABS or PVC). I *think* the sizes for soil pipes are to a British Standard so modern parts should mix and match. This isn't true for sink wastes which were a real dogs breakfast when they came in in the 1960's and 70's. Who was it made the awful brown stuff?

[The Natural Philosopher]

i've cut one vertical back to the floor and fitted a 90 degree univesral to it

But it was brand new and unencrusted

[The Natural Philosopher]

Looks like clay to me.

Could be a bugger to cut without shattering

[PeterC]

My house was council-built c. 1950 and the soil pipe is asbestos cement with lead through the wall. My main fear, after 60+ years, is that the lead will start leaking into the cavity.

[Nightjar]

On 03/07/2012 22:07, James wrote: ...

You can tell how much heat treatment cast iron has had by changes in its magnetic properties, so don't expect it to react like mild steel. Thick layers of paint also reduce the grip of most magnets. I suggest a *much* stronger magnet.

Colin Bignell

[Tim]

stronger magnet.

I think TNPs right though. Looks like a clay pipe to me. Scraping a bit of paint off would be a good start.

Tim

[James]

Ok -- here's a couple more pictures of outside:

's noticeable that there's no rust on the pipework, which I suppose may suggest it's not cast iron. Look at the top section of the second picture where the paint has come of. It doesn't look like metal to me, at least from a distance. Next door's soil stack is identical but has lost a lot more paint, and that hasn't rusted either.

The white plastic pipe is coming from a Saniflo at the front of the house and will be removed when I do the bathroom.

As an aside, and for the benefit of future readers searching the archives for helpful advice about macerating toilets:

If you move into a house with a Saniflo, assume that you'll want to put it in a skip within the first year of living there.

Anything you read online about them being (quite literally) full of shit is entirely true. Unless you live in a converted basement, you do not want a Saniflo, however badly you need another bathroom. Move house instead.

[James]

Thanks for the reply. I've just posted links to another couple of pictures of the outside -- see my reply to Adam.

Your idea sounds promising, if I can get the old joint apart on the other side of the wall without damaging it. How did you fit the new plastic pipe into the old joint?

[James]

I'm still not sure. Other than a magnet, is there a test?

That's pretty much what I had in mind. How far down the pipe would you aim to get the flexible connector? Does further = better? I suppose there's a danger it won't seal properly if it's halfway round a bend instead of in a straight section.

Probably about 120! But I suspect the first bathroom was installed in the 1930s...

Thanks for the advice.

[James]

Predictably enough, the "much stronger magnet" that I remember salvaging from something a couple of years ago has completely disappeared.

Good idea. This is what it looks like under the paint:

's not cold to the touch. I'm beginning to suspect that Tim and TNP are right.

If it's clay, how practical is it to cut without damage? Chain-style pipe cutter?

Failing that, is the outside joint likely to come apart?

[fred]

It wont bend until it is through the wall so you have at least 4" straight there so nowt to worry about.

You want the pan connector to go into the pipe until it bottoms out or until all the fins are in which could be 2-4" depending on type.

From your other pics it's def a cast iron stack, that straight vent section at the top may be something lighter.

Other comments about the pipe being brittle and cracking are valid hence my suggestion to cut it 2" from the wall so that you can have another go if it breaks. Maybe start further away then re-cut closer once you have more confidence also noting that the further from the wall the higher the pipe will be and that it will need to match your new pan. My choice could be a 110mm angle grinder with cutting disk, mark your cut line, score round first a mm or 2 with the grinder then go progressively deeper until it is cut.

Chose the right distance and you can use a straight pan connector, which is better than flex. Smart move would be to get a few likely bits in from a place like BES, they're not expensive and it means you have exactly the right bit to hand no matter what.

See the bottom of this page:

from the wall will be set by your pan/cistern combo, close coupled?

Re comments about breaking into cast iron joints/stacks, just don't go there unless you have to, there is a high risk of breaking the collar if you do as it is all so brittle. When you do have to do it, you smash the ingoing pipe with a hammer, stuff newspaper in the hole to catch the bits then have to chisel out the stub of the pipe form the socket so not unsurprising that it often ends in tears.

You're welcome and good luck!

[The Natural Philosopher]

well a diamond wheel would probably do it.

I used a very non H & S compliant way to cut my pipe: I mounted a cutting wheel on a bolt and stuck it in a drill chuck and worked away from inside.

If its clay you can bust it with a hammer and remove it from wherever.

I'd save that as a Plan B if you break it trying to cut it.

[newshound]

In my case, I only replaced the vertical "vent" pipe (previous owner had replaced the angled one carrying fluid). As I recall, once I had removed all the old iron (a bit fiddly as you don't want to crack the junction) the new pipe "bottomed" on a step in the collar, which makes it fairly easy. Pack the bottom part of the joint with something like newspaper, string, baler twine, rope, etc and create a seal using suitable mastic or silicone. You can finish off the top with silicone, mastic, or even a cement filet. Since it never really sees positive pressure (even if there is stuff flowing down) the seal does not have to be brilliant.