Large gap for grout - OK?

[Niscars]

Hi, I am trying to fix an old problem where shower tiles have not been properly sat on top of the shower base. I am going to be left with a gap above the bottom row of about 15mm which I plan to just fill with grout like the other joints. Putting aside the look of it (which I can live with inside the shower), is there a risk that this large joint full of grout will allow in water more than a small joint would?

Thanks in advance,
Oscar

 

[Richard C]

Bad idea; even wide joint grout can only be used for joints up to around 12mm. Additionally, apart from expensive epoxy products, waterproof grout is only waterproof in the sense it won’t disintegrate when wet, it’s not impervious to water. You will also need a flexible silicone joint between at the tray & the wall to accommodate movement, grout will crack & let water through.

TBH you’d be better off sourcing a suitable sized UPVC profile & silicone that into place around the tray.

 

[Niscars]

Richard, thanks for your reply. The final gap is 13mm and my local tiling place recommended the grout below for upto 20mm applications.
http://www.bal-adhesives.co.uk/products/micromax

The shower is not tanked but I did seal with PVA prior to retiling the bottom row.

If this is still a worry, then I am back to square one!

 

[joe-90]

The shower is not tanked but I did seal with PVA prior to retiling the bottom row.

That will impress Richard no end.

 

[Trazor]

The shower is not tanked but I did seal with PVA prior to retiling the bottom row.

PVA is water soluble, not good at all for shower areas.

That row of bottom tiles should have been raised to give a normal gap for grouting.
Then use silicon and a suitable tray sealing strip, for the gap at the bottom.

 

[Richard C]

I use BAL products all the time but Micromax is not one I’ve used or am familiar with; the spec does say up to 20mm so in theory at least, should be suitable.

However, as the others have pointed out, you have made the biggest mistake possible by using PVA as a primer. It should never be used as a tile primer anywhere but can be a complete disaster in a wet area. Standard PVA is not waterproof & remains water soluble; when moisture gets at it, it will re-emulsify & your tiles will fall off. I advise you remove the tiles, clean off all traces of the PVA & refit as trazor suggests; it will also look much better than in your photograph.

 

[stewartlaura67]

Hmm probably that would be the case, why take a chance get some other idea.