10 weeks ago, I went to re-tile my bathroom upstairs around the bath (with a power shower), suspecting that they needed to be done as a few were starting to come loose and there was a very slight water patch on the ceiling downstairs below.
On taking off the first few tiles on the first wall directly underneath the shower, I discovered that the plaster wall behind had rotted and fallen away.
I removed the rest of the tiles, called in a builder, who replaced all the plaster wall with aqua-boarding.
I then tiled, taking great care with the grouting and sealant. I am very confident that this was done well.
4 weeks ago, I noticed mold growing on the top of the inner wall in the room below the bath. I cleaned this off and looked for the source of the moisture but could not find one apart from a leaky shower head which was causing water to drip down onto the bath right where the taps are.
I have fixed the shower head so that it no longer leaks in case the water was getting under the bath through the tap fixtures (which happen to be directly above the mould patch) and I have cleaned the mould downstairs.
However, I am now worried that I need to rip the wall out and replace it to really solve the problem. If there is no more leaking and I have cleaned off the mould, will this be the end, or is the wall inside likely to be too damaged and stay too damp that mould will just keep growing?
Can I dry it out sufficiently from the outside?
I have not yet repainted over the original molded area.