Help with grouting and silicone at bottom of wall onto shower tray - Tile Advice

[ashurst]

Hello,

I noticed recently that my builder may have made a mistake when tiling some little mosaics ( Polished Marble 2.5cm x 5cm) in between large wall tiles in the middle of the shower enclosure area area (wall behind where the rain shower comes out from) I noticed some of the grout was going a bit brown and the tiles were movable as some of the grout had cracked. I removed the bottom row of tiles and noticed it was a bit wet behind (no problem on the ceiling on the floor below) and also they had used silicone to bond the mosaic tiles onto plywood which I know is not ideal, as firstly they should have maybe tiled onto the bare wall or cement fibre board or something similar. The reason why they used ply I think was because the mosaic tiles are thinner than the wall tiles so the ply was used to bridge the gap.

Furthermore I noticed that the builder had not completely grouted all the vertical lines on the bottom row of mosaics and instead used silicone here.

The builder then siliconed the entire bottom area.

I removed the entire row, filled the area behind with grout as there was almost a 5mm gap behind tray to wall behind So water could seem down if it leaked through.

Next I have waited 24 hours and now used Bal Max Flex adhesive to fix tiles onto the plywood. After 24 hours I have used Bal micromax grout (I removed grout on verticles and bottom of the row above which I left alone and did not remove as they seemed ok.

My understanding is not to grout the bottom of the tiles where they meet the shower tray and next is to silicone this so the silicone can fit into the bottom bits where the tiles meet the shower tray.

Also the large wall tile has a slight chip where it meets the first mosaic tile and I have used grout to fill this area as before the builder simply used silicone in the gap.

I am hoping that this is the correct course of action

You opinions please would be most welcomed.

Ashurst

 

[SJPurdy]

How long since the builder did this?
I assume it is a while since you are trying to rectify it rather than get him back.
Using ply to make up for the difference in tile thicknesses is not a good idea in my opinion (I think it's awful). Tiles/ mosaics should be fixed with a solid bed of tile adhesive in wet areas, I do not think sticking the mosaics on with silicone is appropriate even if it would set in a solid bed. It is also recommended that in shower areas the substrate should be tanked to protect against water damage, and I think this is particularly important where mosaics are used because there is a lot more grout to potentially let water through.
Where you have filled the gap between tray and wall with grout that would have been better done using a flexible sealant because the grout will crack if (when) there is movement in the tray.
You are right to fill all the joints between tiles and mosaic tiles with grout (not silicone). The joint between the tiles/mosaic and the tray is the one that should be filled with silicone as should any vertical corner joints. Make sure that the silicone used is suitable for marble tiles.
Also the marble should be sealed to make it water resistant.

 

[ashurst]

Hello,

It has been about 4 months now.

With regards to the bit at the back of the tray towards the wall where I filled it with grout, if I use my dremel tool to remove some of it and then silicone on top - I am assuming that would be good to try? I can remove the tiles and put them back and re-grout as it is only like 4 mosaic tiles to remove

I have included a photo of what it was like

 

[WetSaw]

You ought to get the builder back to rectify his work. It looks terrible and by your description it's not going to last very long.

 

[Kevbos]

Get a piece of wood cut out 2 notches depth of mosaics .use wood to bed out adhesive between the 2 tiled edges .let it dry then fix mosaics

 

[SJPurdy]

That looks terrible.
Is the plywood fixed solidly. If there is any movement in it when pressed then you have no hope without making it solid first.
The grout line up the left side of the mosaic looks a bit suspect which could be due to some movement in the ply. I'm only judging it from the one photo and your description but I suspect that it may need the whole mosaic on ply strip removing and redoing (without any wood based filler being used).
4 months is not a acceptable life span for tiling to last without needing to be partly redone. You should try to get the builder back to put his work right. Not sure what legal position would be now that you have partly redone it though.

 

[One Day]

The builder now doesn't have any legal obligation to come back as the customer has started repairs - that's "affirming the contract" by acceptance. Not fair I know, but that's it.

It looks so bad I wouldn't attempt a repair.
It really needs a complete rip out and re-do by someone competant - i.e. not a builder.

 

[Stef]

Typical builder.
As stated that needs ripped out & redone.
That isn't going to hold water & is going to lead to issues downstairs.

 

[White Room]

Has any of the walls been tanked....

 

[Jason D]

I have a similar problem, where the tiles meet the bath, there is no grout between the bottom tile and the top of the bath edge, I was wondering if this is normal, the silicone seperates from the bath, and eventually let's in water down the wall and through the ceiling. I'm about the seal for the second time, I fill the bath as well, it's so frustrating when tradesmen don't do things properly. And you end up spending more money.