Trapped water behind tiles?

[D1nhs]

Hi guys!

Setup:

Corner shower enclosure, aqua panel, tanked, and tiled, siliconed along edge of shower tray and up vertical corner.

Observation:

Mould has developed over approx 12 months in the silicone, bottom row of tiles are a darker shade almost as if they are damp from behind. I removed the silicone which in some parts came off very easily (worrying)

Question:

Could there be water getting through the grout and running down the back of the tiles and gathering at the bottom? Getting trapped between the tanked wall tile and gathering behind silicone?

Also the gap between the shower tray and tiles is grouted, then siliconed ontop. Should i remove this grout and fill the gap with silicone? Think this would help?

Ta muchly!!

 

[Richard C]

Does looks like classic symptoms but you’ve got a good base & 12 months is rather quick to be getting such a problem; what adhesive & grout did you use? Did you fix the tiles on a notched bed of adhesive? I assume you haven’t got a shower valve/pipe leak behind there!

I don’t grout between the tray & the bottom tile run; I inject silicone into the gap between the tray & bottom of the tile first, wipe off flush & then run a final bead between the tile edge/face & tray as normal.

 

[D1nhs]

Used Bal powerderd grout, said it was suitable for swimming pools!

Yes fixed with notched trowel for flat bed of adhesive. All othe tiles are fine, just the bottom row.

I like the sound of your technique regarding the gap. I siliconed using dow corning around the shower tray between the tray and wall, so i hope thats all still good.

Maybe i should dig out the grout and do it again with silicone

 

[Richard C]

Thought I’d already posted a reply to this one once but obviously not.

Used Bal powerderd grout, said it was suitable for swimming pools!

Which one?

Yes fixed with notched trowel for flat bed of adhesive.

Which one?

Maybe i should dig out the grout and do it again with silicone

Not sure how much that will help unless the water is being siphoned up between the tray & the bottom row of tiles? If you do dig it out leave it to dry out thoroughly (& don’t use the shower either) far several days or you’ll just seal the moisture back in there.