Need a few tips for my new bathroom

Hi all, sorry if this a bit long winded !

Ok - I'm going to COMPLETELY revamp my bathroom starting in 3 - 4 weeks when all the goodies are delivered by Wicks, I just have a few points I'm not 100% sure on & hope some kind sole will steer me in the right direction !

1st thing to mention is I'm NOT a plumber, BUT I am a fine limits engineer and also spent 20 years twisting wrench's as a mechanic (so general instaliation, pipework & sparks is no problem - it's system design I know nothing about !)

I'm installing a Wicks ASMARA thermo mixer shower unit (no probs on adding the 2bar brass pump & Surrey valve etc to the airing cupboard - I'm also upping the hot tank capacity to cope as I have a gravity system and want more then a 30 second shower) BUT I'm a tad unsure what I need to do to the feed pipes for the mixer unit, obviously the feeds will be sunk into the wall (internal wall is breezeblock with plasterboard over (so easy enough to chase out)) the existing bath filler pipes are @ 22mm & already just below where the shower will go (that was a stroke of luck) and luckily the new tub has the filler in the corner (old tub was in the middle) so I can tee off the originals to the new filler & extend the originals up to the shower, the bit I'm unsure on is do I need to insulate the new pipe run (within the wall) to the shower, if so with what ? (the chase will be re-plastered and tiled over), also what do I do about expansion of the copper (never sunk copper before but assume I can't just plaster it over as the expansion/contraction of the copper will obviously crack/burst any plaster that's in contact with the copper.

OR should I be using Poly for this part of the run (prefer copper if there are no major issues (Im just a oldie who believes traditional is better then new fangled stuff ))

Hope this makes sence to you

Lez (aka FriedFreddy)

mate i think the copper just plastered over will be fine I've done that hundereds of times and not had any problems... *touch wood*

if its an internal wall I dont think insulation would be 100% required because
I would imagine it would be difficult to bury insulated pipes in the wall

well.. im prepared to be slaughtered by people who think differently!

Hi Ismellgas

Many thanks for the speedy reply

The wall in question is a external wall (brick outside, cavity, breezeblock then plasterboard 'dolloped' on)

I have seen other houses where the copper 'appears' to just go straight into the wall but not having seen it installed did'nt know if it was lagged inside before the surface was made good.

I was also a little worried that the copper would sweat with temp changes causing a damp patch over time.

Regards

Lez

your concerns are understandable mate, i'm just saying i've not seen a pipe to a shower inside a wall lagged.

You could always have a look about and see the thinnest insulation you can get and see if it would allow you to bury the pipe without taking too much of the block away..

let us know what you end up doing

Thermal expansion isn't usually a problem over a short length.

the 'sweating' is condensation from the atmosphere - with the pipe enclosed, there should be no humid air in contact with it, and no condensation.

Salts leaching from the render or plaster over the pipes may eventually cause problems, but nothing wrapping the pipes in, say, duct tape before interring them won't avoid.

Avoid burying compression joints in the wall - have you noticed it's only the ones you can't get at that leak?
Soldered should be OK, but clean the flux off after soldering, and protect as above.

Plastic pipe should be OK, but I regard the fittings as a form of compression joint, so I would avoid putting them anywhere inaccessible.

Many thanks for the replies pep's.

I didn't think about the lack of air round the copper meaning no condensation so thats one problem outta the way, and as I'll be forming the lower S bend to exit the wall it'll leave only 1 joint for the 22mm elbow at the top so I'll solder that one to be sure.

Thanks again and I'm sure I'll be back for other queries, till then it's off to read the other forums to see if I can be any help to anyone else on this most excellent site.

Regards

Lez

FriedFreddy said:

also what do I do about expansion of the copper (never sunk copper before but assume I can't just plaster it over as the expansion/contraction of the copper will obviously crack/burst any plaster that's in contact with the copper.

Click to expand...

It will almost certainly crack & wont do the copper much good in the long term either; this in turn will crack the grout, water gets in & there go your tiles & your wall if it’s just plasterbosrd; what you need to do is cap over the pipes & then plaster over that; but plaster is not the ideal tile base anyway, especially if using large format tiles. Not familiar with the Wickes thermo valve but if it’s recessed, don’t go chiselling everything out or you run the risk of ending up in the cavity; in many cases you have to construct a false wall & run everything behind that.

Have a read through the Tiling Forum archive for information about suitable tiling bases; plasterboard (even MR) is not a suitable tiling base in t wet area unless it’s tanked.

You can get coated/plastic covered copper if required, best if burying in plaster OR Speedfit plastic pipe is best.
Have had no problems with either.
Always try pipework before covering just to be sure no leaks.
BUT may I suggest if your doing bathroom look at Plastic Cladding instaed of tiles.
This stuff insulates the walls and is totally waterproof and it stays warm to the touch/room temp.
B&Q do it as well as others, just take care of what adhesive used.
Rgds