Basic pipework facts please?

[Roger465]

OK, time for me to learn some basic plumbing skills in a hurry. I’m fitting a new toilet, and here’s a pic of the existing water pipe. It will be close to the inlet on the new cistern, but alas, not close enough – it’s both a little short, and slightly off to one side.

So I’ll have to cut it, I guess, make some sort of joint, and extend it. The existing isolator tap works fine, so could be retained, but no big deal to replace it with one of the little ones, I guess, if it was desirable to cut the pipe below that (except then I’d have to drain the big water tank in the attic etc).

Thing is, I know there are compression joints, push-fit joints, copper pipes, and plastic pipes, and I haven't a clue what sort of configuration to use – could somebody advise me what to do, and what bits I need to buy, in really simple terms please?

Thanks guys

 

[terryplumb]

Probably easiest thing for you to do ,is to use a flexible hose . You would need to isolate the supply and drain out. Cut the supply pipe low down ,fit an isolation valve. Into the iso valve fit an adaptor then the flexi to the WC inlet .
Or engage a plumber !

 

[Roger465]

Probably easiest thing for you to do ,is to use a flexible hose . You would need to isolate the supply and drain out. Cut the supply pipe low down ,fit an isolation valve. Into the iso valve fit an adaptor then the flexi to the WC inlet .
Or engage a plumber !

Thanks... I haven't had much success getting plumbers to come out for jobs like this, which is why I thought I might bite the bullet and learn the real basic stuff myself.

When you say "flexi", do you mean the stainless braided ones like this?

 

[terryplumb]

Yes Roger

 

[mrStat]

Or one like this with a valve built in (be warned, these are suitable for emergency isolation only really as they often leak if turned too much)....

https://www.screwfix.com/p/flexible-tap-connector-with-valve-15mm-x-x-300mm/3558g

 

[Roger465]

Or one like this with a valve built in (be warned, these are suitable for emergency isolation only really as they often leak if turned too much)....

https://www.screwfix.com/p/flexible-tap-connector-with-valve-15mm-x-x-300mm/3558g

Right... so... is one end of that suitable to attach to the cistern, and the other a compression joint?

Thanks

 

[mrStat]

Yes bud, the valve end is 15mm compression and the other end is 1/2” female BSP for tap connection.

I always advise binning the cheap “thrown in” full valve with a brass shank fluidmaster - but that is up to you.

 

[Hugh Jaleak]

Flexi's are fine, but dont strain or kink them, (they can and do split, resulting in a flood if improperly installed.) To pick up on what mrStat has said, exercise extreme caution if attaching to a plastic tail on the new fill valve, plastic threads can and do cross thread very easily. I'd try and screw the nut on by hand very gently, only using a spanner when your confident its on square, and watch it still doesn't cross thread as you tighten it.


Can do a rigid connection, but you'll only need a short piece of pipe, hardly worth buying a length just for that job.

 

[Roger465]

I should point out here that I am the Master of Crossed Threads, so thanks for the advice

PS I have a roll of PTFE tape somewhere... somebody once told me that I should put a couple of turns of it round the copper pipe before tightening the olive onto it - what do you think?

 

[Hugh Jaleak]

PTFE is used for making the joint on parallel threads, i.e. male to female screwed iron joints. With compression fittings the olive should make the joint, although a smear of jointing compound always helps. PTFE shouldn't be needed, although if you want to put a turn round the olive before tightening, I doubt it'll hurt anything.

 

[mrStat]

[edit] Hugh beat me too it. +1

No!!!! Sorry, never put PTFE on the pipe before an olive, you can sometimes find the olive just grips the PTFE and when you sit back and crack open the beer - pop goes the connection and voila - indoor sprinkler.

I personally do not advise PTFE for this kind of job. Some will. Never put PTFE on plastic threads, ever.

Make sure your pipe is clean of paint, use the nut if needed and some wire wool or pipe cleaning mesh, then olive can bite nicely into the copper pipe. You can put a wrap of PTFE over the olive, but never under.

 

[Roger465]

Okily dokily chaps... will do. Just didn't fancy buying a £33 can of jointing paste for the occasional tiny job.

 

[mrStat]

You don’t need jointing paste. The olive makes a mechanical seal and a 1/2” tap washer between the shank of the fill valve and hose.

 

[Hugh Jaleak]

If you did want some.... https://www.homebase.co.uk/boss-green-jointing-compound_p946933 At £33 a pot I'll start shipping it over.....

 

[Roger465]

If you did want some.... https://www.homebase.co.uk/boss-green-jointing-compound_p946933 At £33 a pot I'll start shipping it over.....

Wow - it was Screwfix too! I think they only do enormous pots...