To me it's a case of fix it and get it right or hope and pray that history doesn't repeat and you have to do it again. It's always more expensive to do it right once but cheaper than doing it wrong a multitude of times. You must without fail remove the plasterboard to allow what's behind it to dry out as well. If its timber, as I suspect, and you seal it up with dampness in the timber you will not only be revisiting it too soon but it will be a much larger and more expensive rectification job because you will be replacing timber framing, relining, rewaterproofing and either tiling or sheeting over the wall once more. If budget is really tight, consider Aquapanel by Laminex.

Sorry I wasn't clear , but I think you have misunderstood what I was getting at . If you kept the shower in the position you showed it , with the 1000 long glass and the 490 opening , and a lip across the opening -- the 'accepted' thing would be to place the showerhead at the far end . BUT if you had it on the right wall , angled down obviously , but pointing towards the glass side , you would get less water splashing out , thereby possibly avoiding the need to have a door ? Ironically too , having that shower narrower ( 800 wide ) will help contain the water .

It wouldn’t put me off if the price was right but you need to decide what is right for you. A mould treatment service probably isn’t what you’re after. You need to see what is under the surfaces. The plaster needs to be pulled off the walls that are effected. Plaster is cheap. The carpet needs to pulled up. Carpet can be relayed but unless you’re sure it’s totally mould free it will need to be replaced in that room. Carpet prices vary. The skirtings will need to be replaced. This isn’t expensive either. The wooden frame behind the plaster may only have a small section of damage but you won’t know. Overall it’s not hard but it is a lot of diy or trade coordination. And yes if you have another bathroom you can live there while the work was done. But I’d definitely remove all the damaged surfaces and materials and clean before moving in.

Thank you for the article! Unfortunately, I have faced it 2 days ago... Is there a basic humidifier(I got this one) enough here? Or better take a look at pro equipment?