Insulating a Tiled, Solid Bathroom Wall

[It's me]

We have a 1950s property with solid brick walls without a cavity. The bathroom is cold and suffers from condensation. It has two outside walls.

We plan to replace the bath with a built-in shower which will need to go on one of the outside walls. Relocating it is not an option due to the shape and layout of the room.

Beneath the tiles, there is a thin skim of plaster, under which is thick, hard concrete, so hacking back to the bricks is not an option.

We wish to insulate the outside walls and then tile them. What would be the most viable option that would cope with the shower? We are considering gluing and screwing a board such as JACKOBOARD Plano Bathroom Insulation Board or PRoWarm BACKER-PRO Tile Insulation Board directly to the wall and tiling over it.

Would this be suitable and would it need a separate vapour barrier? Alternatively, is there a more suitable method?


Thank you.
Thank you.

 

[motorbiking]

Foam filled Tile backer is pretty good, but it's not much good at insulating. 5-10mm boards make bugger all difference to the U-Value. Really what you need is a big radiator and decent extractor. If you foam adhesive them on to the wall it can help as you get some air gap.

Can you lose some room space? 40mm insulation will start to make a difference. There is no need for a vapour barrier - its not that moisture is getting through from the outside, its because its a cold surface in a warm wet room.

 

[It's me]

Thank you for your reply. The Jacoboard that we are considering comes in thicknesses, 85mm or so being the thickest, I think.

 

[motorbiking]

If you can lose that space, then something around 40mm glued with plasterboard foam and screws will make a difference. It will roughly get the U- value of the wall down by a factor of 4. There probably isn't any benefit going thicker. Spend the extra money on a decent radiator and extractor.

Make sure you foam fill any gaps.

Be careful not to over tighten any screws and washers as it's easy to bow the board. Though not so much the thicker ones. Alternatively go 50mm celotex and 10mm board.

 

[It's me]

Thank you.

 

[motorbiking]

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