Bloomin' compression joints

Joined
25 Jan 2004
Messages
6,317
Reaction score
4
Country
United Kingdom
OK, so I have pretty much finished installing a new bathroom. It has been a lot of work but hopefully worth it.

Now, I have been having problems with compression joints. I read that you should wind PTFE on the thread, put on the olive and nut, push the pipe in then do it up finger tight. Then give it a half turn with a spanner and it should be done.

I followed that advice and they ALL leaked. So I went around with a pair of adjustable spanners and just did the bu**ers up tight. And I mean tight. Looking down a pipe that I later replaced I can see that the olive is clamping down on the copper and "necking" the pipe.

Is this bad? I don't want the joints to fail or leak later on. In fact I am tempted to remove all the new pipework I did and redo it all with plastic pipe and push fittings. I know o-rings don't last forever, but I am beginning to think they have better odds than my plumbing!
 
Sponsored Links
No need to use PTFE on threads with compression joints. I replace the brass olives with copper olives, and smear some jointing compound just in front of the olive. They need doing up and just increase the torque 'til the drips stop.

You could use copper pipe with push fits as well.
 
Where exactly do you mean to smear the compound? Between the olive and nut, or the olive and the fitting, or both?
 
Between the olive and the fitting. (Though you shouldn't need any, I only put it on to avoid having to go back to a job).
 
Sponsored Links
Wish I had asked before starting the job! :LOL:

Cheers oilman, off to buy some compound.
 
remember that a joint done too tightly will leak as badly as a joint not tight enough.
 
'remember that a joint done too tightly will leak as badly as a joint not tight enough.'

As badly? often worse.

Compression joints should be assembled dry, Where did you read that they should be wrapped in PTFE tape? (Some foreign ones benifit from a SMEAR of silicon grease between nut and olive to stop the squeeking as they are tightened).

Tightened so that they just nip the pipe and then a further quarter turn or so. Make sure the pipe is reasonably clean first and not distorted.

I sometimes find the odd one leaks occasionally and a little more tightening cures problem.

Common problem with DIY'ers is they get this urge to keep on tightening using 10 foot wrenches!!

Another of their common urges is to put lashings of Boss White, or similar, on immersion heaters - and then post questions in various forums later to ask how to remove them!!

Alan
 
you can always tell a diy plumbing job by the ptfe on the threads. i've stopped explaining to people that there's no seal made on the threads
angry-smiley-034.gif
. in fact you can always tell a diy plumbing job by the overuse of compression fittings. i think sometimes it would've been cheaper to get a plumber put in soldered joints than buy all those comp fittings.
 
....i think sometimes it would've been cheaper to get a plumber put in soldered joints than buy all those comp fitting.

It's cheaper now, use push-fits on copper tube, quick, and no plumber needed (until you need the problems sorting of course, but it's all work).
 
Remember those first few minutes of "Four Weddings and a Funeral"? Well, that is what I am now thinking. Whilst I APPEAR to have the drips under control I am seriously considering ripping the lot out and doing it again. Possibly with pushfit. So that is a £50 lesson learnt!

I can't use solder joints throughout (plastic bath... not good near a torch!) Anyone have experience of using pushfit (I am thinking the copper ones) with a shower pump? Mine is only 1.5 bar, 18 litres/min, do you think that would pose a problem? I know, o-rings don't last forever but then bathroom tastes change just as frequently! I would be using a mix of 15mm copper and 15mm plastic. I would prefer to use copper throughout but I have some complicated bends that I could do with copper and a pipe bender in half a day, with lots of trial and error and wasted pipe, or in half an hour with plastic.

Common problem with DIY'ers is they get this urge to keep on tightening using 10 foot wrenches!!

Only cos the bu**ers who sell the fittings include misleading instructions on how to use them, so the only conceivable way to fix the drip is to use a tyre lever to do them up!
 
I'd bet that if you use Conex compression fittings (the ones Wickes sell) you wouldn't have any trouble. They don't need cmpound or tap. Finger tight, then the instructions say 1 to 1 1/4 turn iirc, but that is very tight.

I use compound if I'm rejoining to an old pipe, say.
 
I like Boss Blue on the thread and ptfe around the olive on old fittings. But new fittings shouldnt need anything. If you are having problems I would use speedfit fittings on copper pipe. Use an adjustable spanner and whack it against the compression nut and olive to get the olive off if it is stuck on the pipe.
 
peter anderson said:
Use an adjustable spanner and whack it against the compression nut and olive to get the olive off if it is stuck on the pipe.

Believe me, the olives aren't going anywhere! They were done up so tight that they constricted around the pipe and formed a "neck". Great fun!

The leaks appear to have been cured now. I am tempted to put some of that pipe fixing compound around anything that COULD leak. I know it would make removing the joints later on impossible, but it would give better protection just in case.
 
AdamW said:
Anyone have experience of using pushfit (I am thinking the copper ones) with a shower pump? Mine is only 1.5 bar, 18 litres/min, do you think that would pose a problem?

Most showers have pushfit connections these days...speedfit copes easily with a 3 bar incoming pressure and are guaranteed for 25 years. Personally I much prefer pushfit to compression but the cost of the fittings and extra continuity bonds is steep...mind you I much prefer end feed to pushfit!
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top