White grout dries brown after a few hours - Tile Advice

[Chris B]

Hi everyone

A newbie here, needing some professional advice please!

We have a shower that was installed in an upstairs bathroom about 8 years ago. It's all been fine until now, but we are finding that the white grout around a few of our mosaic tiles is turning brown about 10-12 hours after we shower, ie as it dries out. As soon as it gets wet again it goes back to white.

The affected patch is on a partition stud wall and is half way up. It's below the hose inlet for the hand held shower attachment but not directly below - probably a couple of inches to one side.

We've scrubbed using bleach, cif, limescale remover and mould remover (on separate occasions, not together!), and as soon as the grout gets wet it's white again, but the discolouration still returns.

It's been like this for the last couple of months. We wondered initially whether there could be a leak behind the wall but the patch is half way up the wall, so you would think that any water would run down and that the tiles below would also be affected. Nor is any water coming through the ceiling. We've also put a tissue against the grout but there's no obvious sign of damp.

3 photos added, one showing the overall position in the shower, one a close up of the marks when dry and the third showing how they clear when wet.

Any suggestions as to the next step would be greatly appreciated!

Thanks
Chris

 

[Dumbo]

Do you know what the background is on that wall . Could it possibly be ply .

 

[Chris B]

Do you know what the background is on that wall . Could it possibly be ply .

No, it’s definitely just a stud partition wall. I took a power socket off on the landing side to double check that.

 

[One Day]

Staining from behind, pulled through into the grout.
It's a sign that there is water damage behind that area.

Look closely at the top grout joints in the 2nd and 3rd photos.
They have opened up, allowing water in.

 

[One Day]

Your next step:
You could rake out and re-grout that area, also check the silicone joint which looks compromised too.
Check behind the shower valve that it's sealed too.
That might last a while.

Proper solution though is cut out and replace damaged areas.
Two problems - 1) Any sheets of mosaic left over? 2) It's a job for an experienced pro only.

 

[Chris B]

Your next step:
You could rake out and re-grout that area, also check the silicone joint which looks compromised too.
Check behind the shower valve that it's sealed too.
That might last a while.

Proper solution though is cut out and replace damaged areas.
Two problems - 1) Any sheets of mosaic left over? 2) It's a job for an experienced pro only.

Oh no, I was hoping you weren't going to say that lol.

Just had another look in the shower with my glasses on(!) and it looks as if there's quite a lot of minor cracking in the grout.

We've not got any spare mosaics. Do you think they are likely to get damaged if they are removed and refitted? Presumably it's going to be a massive job to redo the whole shower? We were concerned about using mosaic tiles when we first had the work done. And of course, the company that did it are no longer in business . . .

 

[One Day]

Oh no, I was hoping you weren't going to say that lol.

Just had another look in the shower with my glasses on(!) and it looks as if there's quite a lot of minor cracking in the grout.

We've not got any spare mosaics. Do you think they are likely to get damaged if they are removed and refitted? Presumably it's going to be a massive job to redo the whole shower? We were concerned about using mosaic tiles when we first had the work done. And of course, the company that did it are no longer in business . . .

No, you can't remove and re-fit. Impossible.
Best brace yourself for a rip-out!
Get someone in who can also do all the prep. It could need new wall boards, so plasterboard (tanked) or Wedi board (or similar).
If I used mosaics like that, I would have specified an epoxy grout which as well as being easier to keep clean, is 100% waterproof.

 

[Chris B]

My day can only get better ....

Thanks for your advice though, it’s appreciated.

 

[On one]

Do you know what the background is on that wall . Could it possibly be ply .

That was my first thought.

 

[On one]

No, it’s definitely just a stud partition wall. I took a power socket off on the landing side to double check that.

Yes,it may be a stud partition,but fixed to the studwork is it plywood or plasterboard?

 

[Bill]

Aren't these the tiles that had preformed grout lines in that were grouted in when fixed?

If so then it is possible that you could just rake out the the grout back to the tile backer and regrout.

 

[One Day]

Aren't these the tiles that had preformed grout lines in that were grouted in when fixed?

If so then it is possible that you could just rake out the the grout back to the tile backer and regrout.

View attachment 94838

Well spotted! If they are then it becomes a lot easier.

 

[Qwerty]

The grout joints look too inconsistent for it to be that type of tile? Plus, the vertical grout joint on the left is silicone!

 

[Chris B]

I'm not really sure if they had pre-formed lines but they are definitely Villeroy and Boch Bernina Creme 3.3 x 7.5cm Mosaic. It looks from the web site as if they come in a large square like your image above but I thought they pulled apart into individual mosaic tiles.

Example link here if it helps:

Villeroy and Boch Bernina Creme 3.3 x 7.5cm Mosaic - https://www.tilesandbathroomsonline.co.uk/villeroy-and-boch-bernina-creme-3-3-x-7-5cm-mosaic

Thanks everyone, can't believe how helpful this forum has been!

 

[Bill]

Arghhhh .... these are Mosaics on a mesh...just checked with Waxmans who sell them.

I would be tempted to try and remove the grout first and regrout before ripping them off. A multi-tool should take this gout out quite easily, worth a try and possibly money saving.