Plumbing help with bath taps

Plumbing help with bath taps

Author
Discussion

Mojooo

Original Poster:

12,720 posts

180 months

Thursday 8th October 2015
quotequote all
I need to replace a bath mixer shower (but same theory as replacing standard bath taps).

I have ordered the new shower and I have had a look at the current pipework.

The cold water is a 15mm pipe with a soldered tap connector nut and the hot water is 22mm which then appears to go down to 15mm pipe at the last second and then also has a soldered tap connector.

Here are some photos -

The hot water is the one that is furthest away - you can see it has a T where it goes down to 15mm pipe where it goes to the left of the photo to the basin.

http://1drv.ms/1L9kGdT

OPTION 1

Now I could be extremely lucky and find my new shower tails match the length of the old ones - in that case all I will need are a couple of fibre washers and I can just re-connect as is.

Screwfix sell fibre washrs specifically for tap connectors so I suppose this is what I need?

http://www.screwfix.com/p/fibre-washers-for-flexib...

If you buy a new tap connector it seems they come with a rubber washer

http://www.screwfix.com/p/flexible-tap-connector-1...

Which is best?

OPTION 2

If the tails are too long or too short then I guess I will have to cut the pipes and use flexible tap connectors. This gives me an opportunity to fit isolation valves.

With regards to the 22mm pipe, this is where my concern is. I will have to cut it back at 22mm and add in some sort of downsizer - like this http://www.screwfix.com/p/reducing-coupler-compres...

I will then have to have some 15mm pipe sticking out of it before adding an isolation valve. Can I just re-use some of the 15mm pipe from the cold water tap as I only need about 10cm I spose.

Then I just need to buy flexi connectors (3/4 to 15mm?) and connect them onto the isoaltion valves.

I ahve the 15mm pipe cutter and a deburring tool and some wire wool - so all I would need is a 22mm pipe cutter.
Any comments?

Mojooo

Original Poster:

12,720 posts

180 months

Thursday 8th October 2015
quotequote all
having thought about it, on the hot 22mm pipe I coudl use a 22mm isoaltion valve and then a 22mm to 3/4 flexi hose liek this

http://www.screwfix.com/p/flexible-tap-connector-w...

I've never done a 22mm compression joitn before so that concerns me a little.

jagnet

4,111 posts

202 months

Thursday 8th October 2015
quotequote all
Mojooo said:
Now I could be extremely lucky and find my new shower tails match the length of the old ones - in that case all I will need are a couple of fibre washers and I can just re-connect as is.
You'd have to be extremely unlucky to find that they aren't the same length. On very very rare occasions that I could count on one hand with digits to spare I've come across basin taps with an odd length, but have yet to come across bath taps with non standard length tails.


Mojooo

Original Poster:

12,720 posts

180 months

Thursday 8th October 2015
quotequote all
Thanks

Well I was going to go down the plubmers merchant and buy the bits in the morning before work

but I may chance it and just hope its a straight fit - in which case all I need to do is go down to screwfix and buy some washers.

I spose I just need standard washers then 3/4?

http://www.screwfix.com/p/fibre-washer-pack-of-20/...

jagnet

4,111 posts

202 months

Thursday 8th October 2015
quotequote all
That's the ones thumbup

herewego

8,814 posts

213 months

Friday 9th October 2015
quotequote all
Any hardware shop should have those or you can get them on ebay and have them on the doormat next day.

Gingerbread Man

9,171 posts

213 months

Friday 9th October 2015
quotequote all
It's not unheard of for the tap tails to vary in length, but if they do, it's typically not by much. If you wanted to fit an isolation valve, this could gain you 15/20mm anyhow if you just cut the pipe and added it in. Or you can obviously reduce the pipe length/ keep it the same overall length using this joint. If you do add an isolation valve, go full bore.

Therefore in regards to your flexible hoses, you'd regret fitting them as they throttle do the flow rates as their internal bore is quite reduced compared to bare copper pipe. Looks like you might have a 28mm hot and 22mm cold. The pictures are hard to tell, probably the two differing 3/4" tap connectors playing tricks with my eyes.


One final note. You mention it is hard to gain access and swing a spanner - baths always bring this joy. You could get a basin spanner which is designed for vertical work over rotating a spanner horizontally which always help.




Just re-read your post again. Pipework never shows well in pictures scale wise. If your hot is 22mm fed, and your cold is 15mm fed, then your cold is likely to be mains pressure and your hot supply gravity fed I'd hazard a guess. Those differing pressures may play havoc with your mixer tap. You might be wise to fit a non return valve into the hot pipework if this is the case to save the cold overpowering the hot and back feeding down it.

Mojooo

Original Poster:

12,720 posts

180 months

Friday 9th October 2015
quotequote all
The house has had a combi boiler installed recently

I understand these feed hot and cold 15mm normally

I suspect the plumber has just re-use the old 22mm pipe the bath used for hot before

I figure that if I need to cut the 22mm pipe I can get a flexi which is 22mm to 3/4 - as you say that will reduce the size of the intenral pipe.

Can a flexi go straight onto a cooper pipe with its comprssion or is it aposed to thread onto a compression fitting/isolation valve?

Gingerbread Man

9,171 posts

213 months

Friday 9th October 2015
quotequote all
Ahhh okay, ignore my pressure differential worries.

I doubt you'll need a flexible, but they can go on to A threaded valve end, of attach to pipework by means of compression or push fit.

Mojooo

Original Poster:

12,720 posts

180 months

Saturday 10th October 2015
quotequote all
Bloody nightmare!

The tails of the new taps/shower SORT OF fitted the old rigid pipework - the problem is the 2 feeds sort of sit at an angle and the main shower the attaches to it - a massive faff to get them into position with the rigid pipework in the way - so in the end I cut the rigids off - as I need to get the taps in palce first withouth the rigid pipework giving me aggro. The old tap nuts seemed clogged up with some crap as well and I couldn't get easy access to clean them.

I have temporarily put on 22m isolation valve and 15mm isolation valve with an end feed on both pipes as extra measure - the 22mm is dripping VERY slightly - so I've turned the water off for now.

If you look at my first photo where the 22mm tees off into a 22m and a 15mm - I have cut the 22 past the first bend for now but its an awkward place to try and do a 22mm comrpession joint - the problem is if I come further back there is no nice place to get a cut on a straight piece of pipe as there are so many bends - the inital T has lots of solder under it so not sure it is ideal for a compression joint.

My thinking is to cut the T out and couple it from 22m to 15mm - then just take a new flexi from a 15mm T. I prefer to work in 15mm so if I do that at least I can do the 22m compression joint where it is easily the most accesible - just need to hope the nut doesnt interfere with my bath panel as the pipes are very close.

I have seen you can buy a T that is a 22mm with 2 15mm - which is liek the soldered T - so essentially could jus trepalce the soldered feed. I would need a bit of new copper then.

Edited by Mojooo on Saturday 10th October 04:35

Gingerbread Man

9,171 posts

213 months

Saturday 10th October 2015
quotequote all
How old is the house? Cast iron soil pipe I see. Is the 22mm pipe actually 3/4" pipe? With compression, this requires a different olive, but the same fitting.

Mojooo

Original Poster:

12,720 posts

180 months

Saturday 10th October 2015
quotequote all
Herer aret he measurements, even the 15mm looks a bit small

http://1drv.ms/1N5lALt

Mojooo

Original Poster:

12,720 posts

180 months

Saturday 10th October 2015
quotequote all
right got it

i have 1/2 inch and 3/4 inch pipe - which is around 13mm and 19mm

my only problem now is hopign b and q or screwfix sell olives for 3/4 as that is all I am missing




Gingerbread Man

9,171 posts

213 months

Saturday 10th October 2015
quotequote all
15mm uses the same fittings just fine, might just be a tad tight. 22mm needs converting.

Mojooo

Original Poster:

12,720 posts

180 months

Sunday 11th October 2015
quotequote all
I went to B and Q with my cut offs and compared them to the 15mm and 22m pipes

If I didn't know that imeprial pipes existed I would have said the pipes I had were the exact same same as the 15mm and 22m - the differences were minutes - maybe 1mm on both - and that could have been cuased by the rounding off of the edge by the pipe cutter.

However I tried the 3/4 olive and it is slightly more snug than a 22mm one (on the 22mm pipe obviously).

However the 22mm olive was only slightly bigger than the 3/4 pipe - the same difference relativley as the 15mm on the 1/2inch so not sure why one is interchangeable and one is not.

When I make my comrpession joints I am going to use Fernox jointing compound after reading about it - not using PTFE.

Once I have done up the olive can I just untdo the nut to make sure it done - what should I be looking for? Obviously if i put thej ointign compound on it will not be that visible - and I cannot put the joining compound on after as it seems everyone puts it onto the front of the pipe that goesi nto the fitting.

Thanks for your help

I will tackle this tomorrow as I am trying to re-do the silicone sealant around the bath tonight!

Gingerbread Man

9,171 posts

213 months

Sunday 11th October 2015
quotequote all
Yep, 3/4" olives look similar, but are that all important difference. Sorry I didn't think about it before when you showed a picture of your cast iron pipe. I could have saved you the hassle if I engaged my brain.

You can get 3/4" to 22mm solder couplers also. Slight difference in size.

It's the olive that creates the seal. You don't NEED compound but it can help. I used to put a bit around the olive so both mating surfaces were taken care of. Once you compress it with your spanners and grips, it should be fine. You can turn the bath isolations off, then turn the mains water back on, so that you're less live joints, then check them, then turn on the isolation to check the next set of joints. You'll be fine.

Mojooo

Original Poster:

12,720 posts

180 months

Sunday 11th October 2015
quotequote all
thanks

a couple of other queries

am i right in thinking that if it leaks it will do so in the first 15 minutes? what is teh best way to test - put some tissue under it? I wil lwant to get the bath panel back on ASAP and silicone it back in place.

is there any problems with having a short run of pipes between joints? for exmaple if I have a T can I then put and isoaltion about 10cm away or would i be better using longer pipes? can't see why it woud make a difference as long as the pipes connect.

Gingerbread Man

9,171 posts

213 months

Sunday 11th October 2015
quotequote all
With mains pressure you'll typically see a leak quicker. You can test with tissue paper. I typically run my hands over all joints. Then pack up, then check again before leaving with my tools, heading for the van.

You could leave it a few minutes then check again if you're not confident, maybe have a cuppa before boxing it back in.

Isolation can go anywhere. You should minimise any dead end runs, but flowing pipework, the isolation can go anywhere.

Mojooo

Original Poster:

12,720 posts

180 months

Monday 12th October 2015
quotequote all
All done - no leaks as far as I can see - but will leave the panel off for a day or two.

I had to do some elaborate bends in order to get my isolation valves in and my also to try and prevent the flexi tails from kinking.

I ntoe the flexi tails really reduce the size of the pipe - not sure what difference this makes in practice as I am not comparing liek for like. The flow from the shower seems reasonable.

I have 2 further issues though

I notices the overflow was leaking when I was testign the show - its a plastic bit on the bath side and a black plastic bit/pipe on the other side - no there is no sealant or anything. I note some peopel use silicone to seal it whereas others say use putty.

I have silicone and jointing compound - any of those any good?

Also the shower I got, the holes were exactly the same size as the odl shower but i have a feelign the rubberm ay have mvoed when putting the shwoer on meaning there may be a small gap - I put silicone around the nut undeneath - is this good enough? I figure if I stop the water going underneath thats all that matters - it will make it hard to get the backnut off later but thats another issue.

A belt and braces would be to silicone around the base of the taps.

Gingerbread Man

9,171 posts

213 months

Monday 12th October 2015
quotequote all
The overflow should have a rubber seal. I personally silicone them and have never really used plumbers mait or similar compounds. It might slide slightly with the silicone, but should be fine. Then wipe any excess silicone away.

I'm assuming you mean the rubber gasket that sits on the bottom of your bath taps/ shower mixer which is sandwiched between the taps and the top face of the bath? Ideally this should stop the water from going under the bath. All the more important when you have a shower above the bath, as water is more likely to spray onto the top ledge. You could silicone around the taps but it may start to look ragged/ discoloured in time, your choice. I'd recommend clear if you did it to minimise it's impact.