Building New Bathroom - Damp Proofing

[DevlinT]

Hi all

We will soon be completing on the purchase of a Victorian-built house. It’s in need of total renovation so we have the opportunity to do things right first time.

One area I’ve been thinking about is the bathroom. We will be stripping the wall back down to brick.

My question is what material(s) would you recommend in this environment to apply to the walls before any tiling is done? Assume there is no penetrating damp. Would simple plastering be OK?

Thanks.

 

[Swwils]

Schluter KERDI-BOARD

 

[DevlinT]

Thank you Swwils

I’ve also read about HardieBacker tile backer boards. You or anyone else here used them? Are these things even necessary? Can you simply not use tabled plasterboard?

I ask these questions as if I know what I’m talking about.

 

[Swwils]

They are cheap, but heavy and create mess.

KERDI-BOARD is not cheap, but it's light, clean and arguably quicker.

Do you not want to do any thermal renovation whilst the room is stripped?

 

[DevlinT]

Thanks Swwils

Sorry you’ll need to forgive my ignorance. What kind of thermal renovation do you mean? I’m intrigued and as mentioned originally I’d like to get things right now whilst I can.

 

[oldbutnotdead]

If you're taking the walls back to brick then you must consider upgrading thermal performance of the walls. Technically the work would be notifiable to Building Control. If you can afford it/eligible for grants etc/house suitable then external wall insulation is the way to go (avoids all sorts of issues). Otherwise you need to look at internally insulating the wall- min 80mm of PIR or 160-odd mm of rockwool to achieve the renovation U value.
After that you can look at tile backing board- don't use plasterboard, if it gets wet it loses all its strength. There are all sorts of systems (cementitious boards like Hardiebacker, polystyrene based like Marmox), most of them the main cost is in the jointing tapes etc needed to seal the joins/edges.

 

[cdbe]

Would simple plastering be OK?

Yes. Perfectly ok in my Victorian bathroom for 20 years before I sold it.

 

[DevlinT]

Thank you all. I came across this thread:

https://community.screwfix.com/threads/bathroom-insulation.194734/

What is being suggested here sounds logical to my mind...strip the wall back, batten the walls, fix the insulation between (or over the top?, not sure), then backer board on top.

What do you think?

 

[DevlinT]

Sorry to bump this up but any feedback on my previous post?

 

[JP_]

I used HardieBacker for my shower, then tanked. Would not want to use it for a whole bathroom.

Looks like KERDI-BOARD might be similar to Marmox?

Are the walls solid? If so, I'd suggest either Marmox/Kerdi with insulation, or maybe kingspan it, tape, then overboard with tile backer for better moisture control.
Although I guess you can just tape the Marmox/Kerdi boards befpre tiling to stop moisture penetrating between the gaps?

Re the link, I am not sure if battening with wood is the best option when there are good adhesives and mechanical fixings for the job. But handy if you are running pipes or electric cables behind it I guess.

 

[JP_]

some good info here

http://www.tileandstonejournal.com/featured-articles/what-lies-beneath/

Mentions all the major boards

 

[DevlinT]

Hi Djangobanjo

That link was really useful, going through it now. I see what you mean about the batten thing, right now I'm not sure whether would be running pipes or cables. I guess having a batten plus the boards you'd then attach on top is the loss of space. The one thing I though it might be useful for is when I want to screw something into the wall like a cabinet, seems like having a batten would make this even stronger. Just thinking aloud.

 

[JP_]

Yeah, hanging things on the wall would be easier. For my bathroom, the external wall is insulated so nothing hung on there, things go on the internal walls that are all solid.

But you can screw through the insulation into the bricks with long enough screws - I've done this for radiators.