I had my en-suite completely re-fitted at the end of May and within a couple of months noticed that in places the grout in the shower had become badly discoloured & in fact looked worse than the 12 year old stuff it replaced. The staining is only on one wall of the shower, the one to which the shower is attached. The shower is cleaned thoroughly every time I use it which is probably 3-4 times a week and has never been left wet or dripping after use. I have tried to remove the staining with both neat bleach & limescale remover - without success.
Having checked DIY Doctor for a solution, the likely cause seemed to be a leak from the shower behind the tiles on that wall, although there is no sign of water damage to the adjoining room or downstairs. I called my installer back last week who raked out the affected grout, but he said that it was only the top surface of the grout which was affected and that it was white underneath which seems to rule out the possibility of a leak behind the tiles. He replaced the grout & I did not use the shower for 3 days as instructed, but there are still dark/dirty looking areas of grout which look terrible in a newly installed bathroom. I cannot understand why it is only parts of some grout lines which are affected, some vertical some horizontal and mainly below the level of the shower valve, although there is one quite bad section above the valve, adjacent to the riser rail. The installer tried to tell me it was something I had used either in or to clean the shower, but as only one wall is affected and the problem remains after re-grouting & before I’d even used the shower again I cannot to accept this as a plausible reason.
I have contacted the tile suppliers to see if they have any suggestions, but have drawn a blank here as they can offer no explanation. It is not a power shower and the rest of the room which has the same tiles is fine.
Can anyone offer me any advice please?
