New combi = No more shower curtain + Waterproof walls

[DrDan]

Morning all,

I'm after some guidance, mainly about tanking, but here's where I am.

I have a circular shower rail/curtain and an electric shower (gravity fed heating system) but since a new Combi was fitted the pressure has shot up and I now want to redo the shower above the bath. Here's what i looks like at the mo, the tiles are just stuck straight onto the plaster behind.

View media item 93519
I want to keep the electric shower for emergencies but move it about a foot to the right. I'll chase the pipe into the wall to the right then up the wall, this way it'll be outside of the shower screen I intend to fit.

View media item 93522
So the plan is to: -

1- Remove the tiles from the back and side of the bath, probably all the way to the end of the bath and 2 ft above the shower head.
2- Chase out some pipe runs for the hot and cold water pipes. Not quite sure how I'll attach to the existing pipes under the bath yet. Can I use plastic pipes or do they have to be copper?

View media item 93526
3- Put up some form of waterproof boards like Hardibacker from Trav Perkins - 12mm I guess. How would these be attached to the plaster wall?
4- Get some form of tanking system like Bal or Ardex to seal the gaps inbetween the boards, the boards themselves and the sides of the bath
5- Tile with some waterproof adhesive and grout, silicone around the base of the tiles, leaving some small gaps for any water that gets behind the tiles to run down and into the tub. I'm guessing it's best to go with much bigger tiles than the mosaic ones already on there?
6- Not thought about the shower screen, should that go on top of the waterproof boards or straight onto the wall with the boards butting up and silicone down the edge?

The tough bit as I see it is to get the holes in the boards lined up with those in the wall for the shower mixer and the shower rail

As the existing bathroom tiles will be a good 15mm lower than the new boards and tiles I'm not sure what to do about this gap, put some trim on it I guess...hmm.

Anyway, that's my plan for the Bank holiday...any pitfalls, advice would be much appreciated. I'm very capable of doing DIY but I'm very good at bodging things . Because of that, and for my wife's sanity, I thought I'd ask you knowledgeable people on here before I get started.

Cheers...Dan

 

[TeaTime]

Test for leaks at every stage of a new connection if possible.
Once they are in the wall, and covered you are at the mercy of the Gods.

Can I use plastic pipes or do they have to be copper?

Plastic or copper, no one will see it so it wont bother anyone. Just remember to protect copper from concrete as it eats it up.

I'm guessing it's best to go with much bigger tiles than the mosaic ones already on there?

Only if you are having problems creating a seal at joint on the bath, a fuller flatter surface is easier to work a nozzel over.

 

[DrDan]

Thanks, in that case I'll be using plastic pipe and compression fittings for the feeds to the mixer.

What's the best way to tap into the existing valves under the bath? At the moment there's just a 22mm flexihose up to the bath taps, shown on the pic. I guess I'll put a reducing T below the existing valve and attach the 15mm shower feed from the side of that. I'll use another compression elbow in the wall behind the shower with either plastic or copper coming out the shower, no idea what's best but hey ho!

Chasing out the channels looks like a dusty business with an angle grinder, I might drill and join-the-dots like I've done before a few times.

 

[TeaTime]

Your pipework arrangement seems to be a good design, but see if you can pipe with soldered fittings instead, since it will all be in the wall.

Either way, I highly recommend fitting individual isolating valves on the shower supplies as well.

 

[longdogs]

Not a problem using backerboard and tanking but I can't help feeling that it's a bit OTT for a bath with tiled walls. Correctly fitted tiles using waterproof adhesive and waterproof grout on a plastered wall will be fine.

 

[DrDan]

Thanks for the comments!

Isolation valves - Good point, I'll isolate each pipe up the mixer, the missus will go mental if I have to turn off the water completely because a balls up on my part!

Soldering - 100% agreed. This would be my preferred way of doing things but firstly I don't have any tools/experience of doing this and secondly I don't really want to pay someone £200 to do it for me (London prices) when compression fittings would do the job just fine.

Tanking - I've been doing some research (very dangerous I know) and everyone seems to bang on about tanking walls, water ingress and tiles falling off if it's not done correctly. It's a Victorian house and quite cold so any water isn't likely to evaporate in a hurry. From what I've read about "waterproof" grout and adhesive it seems to be only water "resistant" so eventually water gets through. I think it might be (ok, is ) OTT but to be safe I might go for backerboard and tanking, it'll be a trip into the unknown anyway!

Oh, do you think I can use small mosaic tiles over the backerboard to match the rest of the bathroom or should I use bigger tiles to minimise the water exposure? Teatime mentioned that I should use bigger ones only if there's an issue of sealing around the tub but I don't think that'll be an issue, my main worry is about water getting behind because of the area of grout exposed to water and everything falling off - I guess this comes back to squeaky's comment of "waterproof" grout and adhesive.

Thanks for your help and advice, it's much appreciated by a cack-handed eejit like me.

 

[TeaTime]

Thanks for your help and advice, it's much appreciated by a cack-handed eejit like me.

Don't put yourself down. You have the good idea to seek advice and thats more than alot of people do.

As far as the tiles are concerned, don't worry too much about it. If you use the correct adhesive and grout, you will be fine, but larger tiles are easier to work with and there is inevitably less grout to use and less area for error.

 

[DrDan]

Don't put yourself down. You have the good idea to seek advice and thats more than alot of people do.

Thanks, I'm always a bit nervous coming into forums like these with only a thimbleful of knowledge. I'll add some more photos as I progress...probably combined with a lot of exclamation marks and angry emoticons I hasten to add.

 

[longdogs]

I love the look of mosaic tiles but my experience of them is that after a few years when the grout starts to discolour (particularly around wet areas), there's a lot more grout to clean or sort out than with bigger tiles.

If you do go for mosaics, try to get tiles that are the same thickness as the other bigger tiles, otherwise it will be harder to keep them flush on the wall.

 

[DrDan]

Yep, I tiled that bathroom in mosaics about 7 years ago and it wasn't a pleasant experience. A good point regarding discolouration, I don't really want to deal with re-grouting if I don't have to, it'll happen quickly in my place anyway due to humidity/cold.

I think I'll go with something much bigger, I just need to decide on tiles that match the rest of the mosaics I'll be leaving on the wall.

 

[DrDan]

Morning,

Bath and panels, screen, waste, rain shower, mixer, taps, shower mounting bracket all bought, there's no turning back now!

OK, I'm going to batten and plasterboard the side wall as it's not exactly flat, and the same at the end of the bath - no chasing to hide the pipes, moving electric shower will be easier.

My 4 questions are: -

* What size battens should go on the side wall, I'm thinking 50 by 25 (1x2) as I don't need to hide anything there, but 50x50 (2x2) at the end. Is this enough to route the pipes up to a mounting bracket?

* Where do you get the battens from and what type of wood? Untreated, soft, planed, roofing, CLS, C16? Jewson and Wickes seem to have so many options. I thought wood was wood, more fool me!

* Should I plasterboard from the floor or butt the bath up to the bare wall and just board above the bath? Obv I'll support the side of the bath on some battens either on the wall or attached to the floor to ceiling plasterboard?

* The side wall is external, Victorian about 2-3 foot thick, do I need to put anything behind the boards, insulation, vapour membrane etc?

Still not decided on MR boards with tanking or Aquapanel yet though, when considering the tanking kit with the MR the price is about the same.

Thanks for your help, chaps and chapesses.

Dan

 

[DrDan]

Is there anybody......out there?

 

[TeaTime]

Might be worth posting any question that aren't specifically related to plumbing in the appropriate forum.

You are more likely to get a specific and timely answer from people in their specific forum.

 

[DrDan]

Thanks, TeaTime... done.

 

[SFK]

As a DIYer (so expert please correct me if I have made any mistakes) these are my comments from doing a similar job.


* What size battens and Where do you get the battens from
If you are talking about stud work for a stud wall, the normal to use is: 38x63x2400mm. Fill the stud wall with rockwool or loft insulation to provide some sound dampening of toilet use.
http://www.wickes.co.uk/Products/Bu...rcassing-Timber/CLS-Studwork-Timber/c/1000201

* Should I plasterboard from the floor or butt the bath up to the bare wall
Make all the walls finished to stop drafts, dust etc. So the Platerboard should be to the floor behind the bath.

* The side wall is external, Victorian about 2-3 foot thick, do I need to put anything behind the boards, insulation, vapour membrane etc?
Don't have to, but I found stops cold spots on the walls and so minimises damp areas). If you use 25mm by 38mm treated wood battons (use frame screws to attach to wall) at 40cm or 60cm centers. Then fill the gap with 25mm of insulation (wickes plystirne if on budget, kingspan/celotex for higher the cost but double the insulation.
http://www.wickes.co.uk/Products/Bu...rcassing-Timber/Treated-Sawn-Timber/c/1000202

* Pipe valves
To stop any pressure loss I Suggest you use full flow isolation valves rather then the normal ones that can slightly impede flow.
http://www.screwfix.com/search?search=full+bore+isolating+valve

*skirting
I found the uPVC skirting was great for use in bathroom as no issues with damp ingress (although the idea of UPV skirting horrifies me).

* shower screen
Not quite sure what you mean hear. But it should go on last on top of the tiles. You can put a batton on the wall where the Screen will go for the screen to screw though the tiles, through the plasterboard and into the wood batton.

* Tanking
I used the bal tanking. But I noticed that the tape costs about £15 got 5mx10cm (=0.5m2) and the sheet costs about £6 for 1mx1m (=1m2). So I bought a sheet and cut it into 1mx10cm lengths. This did mean overlaps every meter, but was happy with cost saving.

Hope this help a bit, SFK