DIY Doctor UK DIY Forums

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.

Please help!

Hi there, its difficult to comment without seeing the problem first hand. I also understand from what you have described that your shower runs into you bath? However from experience, when working around baths, tiling walls, fixing showers the weight of people working whilst stood in the bath could of made the plastic pipes/ bath u-bend trap come loose. Have you checked behind your bath pannel for leaks in this area?...also ive never done this myself but when tiling and sealing around a bath a tip i once read was your menat to fill you bath with water before sealing it around the tiles so the wieght of the water holds the bath down as it would when in use....hope that makes sense and is helpful? Cheers

as well as the above, did you dry any of the water from the leak?? if not its still going to be there. Timber is hygroscopic and plasterboard can be like blotting paper. it needs ventilation and air changes to dry properly and if its all boxed in and sealed it cant. Pop the bath panel off and get a fan heater and dehumidifier running. if you dont, this proplem may go on for some time, potentially leading to a rot problem.