Damp - Does all plaster board need to be replaced?

[sandeepB]

Does all the plasterboard need to be replaced following a damp issue due to leaking shower in en-suite?
There is a cupboard adjoining which houses the unvented hot water cylinder.
This had damp which was showing in the cupboard but is obviously worse on the reverse of the plaster board - the sides in the en-suite and bedroom. Pictures below.
If this plaster can be left in place this would obviously save having to get a plumber to remove the water cylinder!
Can I treat the wall using another way instead? I have used vinegar to clean the surface damp so far.
Maybe I need somebody to have a look as the damp came through underneath the floor joist along the floorboards but which trade do I need?

Further details:
En-suite shower room which has been leaking inside the wall where the built in shower mixer had been leaking.
I think this has been on-going for at least 6-8 months but did not notice until damp penetrated into the adjoining bedroom! My house is a bungalow so most of the water has been going down into the foundations.
I have removed the shower and capped the water supply, will be getting someone in to re-board, plaster, fit new shower etc.
I had removed the plaster in the en-suite but realised there was also damp inside the cavity of the bedroom wall which I have removed too. The last picture below shows what is was like before I removed most of the plasterboard.

Thanks in anticipation of any advice.
Sandeep

[GALLERY=media, 104922]1 - Damp in bedroom by sandeepB posted 22 Jul 2020 at 6:03 PM[/GALLERY]
[GALLERY=media, 104925]2 - Damp in en-suite by sandeepB posted 22 Jul 2020 at 6:10 PM[/GALLERY]
[GALLERY=media, 104924]3 - Slight damp in hot water cupboard by sandeepB posted 22 Jul 2020 at 6:03 PM[/GALLERY]
[GALLERY=media, 104921]4 - before removing plaster board by sandeepB posted 22 Jul 2020 at 6:03 PM[/GALLERY]

 

[KenGMac]

You could have made an Insurance claim against your home insurance policy?

All and any soft or heavily stained Plasterboard will need to be replaced.

Allow to dry and have a really close look at the timber some may need replacing.

Never easy to make a call from images?

Ken.

 

[sandeepB]

Thanks Ken.
All soft plaster is out, its just the stained plaster making up that corner that I'm concerned about.
If it needs replaced, the hot water cylinder would need taken out which would be a bigger expense.

As it was a slow leak over time which caused the damp, my insurance was not going to cover it.

Do I need a general builder or a damp specialist or who to sort this out?

Sandeep