Lime plaster wall in bathroom. Renovate or replace?

[Dan watts]

I’m stripping our bathroom and found that behind all the layers of skin and tile over the years, we have lime plaster on the external solid wall. My initial plan was to just leave it be, but annoyingly it is blown from about 300mm above where the top of the new bath is going to be. The wall is only about 4m2.

Reading into this has opened a can of worms. I gather I need to use a breathable plaster if I repair it to prevent long term damage from damp. But the finish layer of the wall is going to be waterproofed with panels or tanked and tiled anyway, so it’s never going to breathe. Plus surely above a bath, my main moisture concern is keeping the walls internally water proof rather than breathable?

Any one got any advice?

 

[dontbelieveawordofit]

is this a ground or first floor?
how much weather exposure outside?
solid brick or solid stone?
is the existing plaster/wall bone dry ?
any signs of dampness?

 

[Dan watts]

It’s first floor. Solid brick. And fairly exposed. Never noticed damp in there. Always been dry apart from when the other half forgets to open window for showers.

 

[dontbelieveawordofit]

suppose it depends what your finish will be, if it’s wall board ,you could batten and board it.
or you could dot and dab it and tile over.
your not bound to lime or cement render it unless you really want to.