Wall prep advice for a shower

[Deborah]

Hi hoping for some advice as local tradesmen are suggesting various options for our bathroom - the walls in question will be where the shower will be installed....
We have a plaster (sand and cement i think with skim finish) wall that is partially blown.
Currently debating if to:
a) take this back to brick and re render with sand and cement - in this case am I correct in thinking it doesn't need a skim coat? Does it need tanking or is sbr coat enough?
b) remove blown sections and fill with hardwall (suggestion of 1 tradesman) to avoid drying time. In this case am I right thinking he shouldn't tile straight onto this? - it then needs a skim coat and tanking?
I know dot and dab with plaster board (+ tanking) or lining with wedi (or similar) board are also possibilities but we're reluctant to loose space.

Any advice much appreciated - Im not going to try to do the job myself but would like to be best informed to get tradesmen to do the job properly.
Many Thanks

 

[Rookery]

I'd remove old plaster as required, fix new plasterboard with dry wall adhesive then tank with a tanking kit. Quick, inexpensive, effective.

 

[jobdone]

As above ^^^^

 

[WetSaw]

What they said, but, if the budget allowed, Wedi board or similar would be my preferred choice.

 

[Deborah]

Many thanks for the advice.
If some areas of plaster/render are good and some blown with loose plaster removed it will leave us with an uneven surface - can board go onto that or do need to remove all plaster/render back to brick to make it even(ish)?
Thanks

 

[Qwerty]

Yes, remove all. Share the during & after photos with us. It's great when we get to see projects that members have helped with

 

[Rookery]

Many thanks for the advice.
If some areas of plaster/render are good and some blown with loose plaster removed it will leave us with an uneven surface - can board go onto that or do need to remove all plaster/render back to brick to make it even(ish)?
Thanks

You don't have to take all the plaster off. Remove that which has failed plus sufficient elsewhere to fix new dabs to blocks/bricks.

 

[Deborah]

Hello again
If we use Wedi board directly onto brick what thickness board do we need?
Is the same thickness appropriate to go on a stud wall and over plaster?
Also not sure how easy it is to get Wedi board locally - what are the other alternative boards
Thanks