UPVC External Bathroom Pipe Replacement — DIY or Professional Job?

JRG123

Hello,

First time posting…

In our new (old) house I need to replace these two horizontal 40mm upvc pipes and the tee joint that connects to the 32mm vertical pipe as its leaking where the tape is.

It's the bath and sink outlets from the bathroom that connects to the soil stack on the right (second picture).

Connecting/cutting new pipes seems easy enough but I'm unsure how to remove the old pipes from the joints that are solvent-welded…

Do I cut the pipe at the top joint where it's going into the brickwork and drill out the pipe left inside or am I wrong there? same goes for the soil stack connection etc.

Best left to a professional?

Cheers!

grumpy_codger

Personally, I hate solvent-weld and prefer push-fit wherever possible. Hopefully, the pipe it's not solvent-welded to the boss.

I think there will be no need to drill out the pipe from the wall and you'll be able to extract it after disconnecting and cutting, especially if you cut it in a way making it easier to rotate the part sitting in the wall.

That said, IMO, the easiest, although not the most aesthetic way of repairing this is to keep the existing pipes and, e.g., to cut out the existing Tee connection and replace it using a new Tee, three short pieces of pipe and three straight couplers. Not sure if the existing pipes are compatible with push-fit. 

And do add brackets to support the pipes.

JRG123

Appreciate this @grumpy_codger very helpful!

sheenas

I recently did my bathroom and the pipe was 32mm which is not ideal as they block easily. The pipework connection is really easy, the soil stack is normally push fit and with some washing up liquid easy to connect. The 32mm pipe work I used and would recommend solvent, it the safest option and does move around. It's really not hard to use and drys instantly. 
The picture shows pipes above the window, not sure what height that might be, but it does make life harder. Further if the soil stack needs replacing thats further complications.
Now to answer the question about DIY or not. I think this is an intermediate DIY job and watching a few youtube vid's do able. 

WIAWSNB

This is a nice DIY project, JRG, and would have been as easy as falling off a ladder had the fittings been push-fit type.

However, solvent is far neater - does that matter to you on this wall? If not, then you can cut away with abandon, and make up a new pipe section using push-fits - provided you can find ones that'll suit that exact pipe thickness.

My only concern regarding DIYing the job is whether these fitting failures are down to sunlight-brittled plastics? It should be resistant, and they don;t look old (the soil pipe even has the paper label on it), but if the actual pipes themselves are also brittle, then you may find a nice wee job expanding more than you'd like, and possibly having to begin the new pipework from inside the house... Would that be problem?

I can't make out the manufacturer, but there is bound to be enough info on there to find out whose it is. That should make it easier to find the exact same parts.

Can you manage without that bathroom for a few days if needs be?!

If you are uncertain whether to tackle it yourself, there is always the option to give in half way through, and get a plumber in to finish it - this will be a doddle for them.

Anyway, your have a few options. The first is to attempt a repair of what's there - and that could well work - and the others involve more work, in replacing the broken fittings.

1) The easiest option of a repair will also require the addition of pipe clips on the wall to support the pipes in the correct position; I suspect this is something you'll need to do anyway, since there's a good chance the fittings failed as they were carrying all the weight. Once clips are fitted (one on each pipe length should be 'enough', tho' two would be much better - it depends on how easy it is to drill into the wall!), then the broken fitting parts should be aligned nicely. Then, a good adhesive should work to bond it. 

What I would do is first use the correct pipe solvent (available from Screwfix and others) to bond them together - you apply a good coat on the two mating surfaces, and immediately press them togther. You'd need to hold the parts firmly together for a few minutes until the solvent evaporates. Then you can add something like StixAll in a nice thick smoothed-off finish around the repair to reinforce them. It comes in black.

2) Proper repairs! These solvent fittings are not designed to be dismantlable, but often then can be. If you can, then you can resue the pipes, and just solvent on new fittings - the T and elbow. Usual methods are to use heat - a bit tricky when they are on the wall - or to slice through the outer collar, and prise it away. I would suggest that this is worth trying... Now't to lose :-)

First, cut right through the bottom 45o elbow where it's already broken in its middle. The pipe at the other end - at the T - is already broken clean through, so this should allow you to remove the 2-pipe section with the other (good) 45 elbow joining it in the middle.

Now look at what's left. Get a hacksaw, which is going to have to be used 'flat', and cut along the yellow lines shown - it's ok if you do this at a slight angle, but follow the curvature of the pipe. The idea is to cut right through the outer collar - the plastic of the T piece - but to not cut into the pipe underneath.

Do this on just one collar first, and see how you get on. If it doesn't work, then there's no point continuing with this method.

Repeat at the other end where the broken elbow is - cut into the two collars.

Now insert a flat-bladed screwdriver into that slot you have cut, and prise away. You'll likely have to be quite firm-but-gentle; ie it'll need a bit of effort to prise away the outer collar and break the solvented joint, but don't dig into the pipe underneath - you'll want the pipes intact! You may be surprised and it comes away surprisingly easy and cleanly :-)

3) Failing that, there should be the option of cutting the actual pipes feeding into the two broken fittings - the T and the elbow - and then using straight connectors to rejoin the pipes to new ones. This would likely end up looking like:

 

FreeBear

WIAWSNB said:

This is a nice DIY project, JRG, and would have been as easy as falling off a ladder had the fittings been push-fit type.

Being at height, I would recommend using a scaffold tower. Makes jobs like this so much easier & safer with no risk of falling off a ladder.

WIAWSNB

That LH pipe is for rodding? Does it have a wall clip?!

Whatever you do, JRG, this needs serious clipping;

And similarly at either side of the 45 elbow.

JRG123

@WIAWSNB I was sure I said thankyou, but can't see it on here.

Really appreciate your in-depth response, I'm going to give it a go this weekend, will let you know how I get on!