silicone over grout

[rhinosaw]

I'm sure that this has been covered before and seems to be a grey area
On my walk in shower I have a tiled on 1/2 inch ply which abuts the top of shower tray. Is it ok to grout first and when dry put silicone over the grout, slightly larger gap than normal and I don't want to re tile, does silicone stick to clean dry grout?
thanks

 

[lostinthelight]

silicone no grout for me every time but it will stick to it .

 

[rhinosaw]

Ok, so u are saying no silicone, only grout??

 

[lostinthelight]

Ok, so u are saying no silicone, only grout??

No, just silicone , I didnt think it was that confusing but then I knew what I meant

 

[Paul C.]

I think the silicone is the least of your problems. Tiling on wood, in a shower??? Hope you're not standing in it when it comes down!

 

[rhinosaw]

Well its been there since the flats were built some 40 years ago.
If its sealed there should be no problem for the wood, the wood is ok anyway, not rotting I mean

 

[Paul C.]

Oh thats ok then. Because it hasn't done it in 40 years, must mean its future proof . Joking aside, plywood ain't what it used to be. Many imports use dodgier glues, thin veneers, oil based coatings that prevent the adhesive/primer adhering. Also its been taken out of British Standards as a suitable surface for tiling (adhesive manufacturers say to only use their products in conjunction with the relevant tiling standards, no guarantees otherwise). It can still swell with both heat and humidity, sealed or not sealed, but there are so many more more suited products to tile onto. Marmox, Wedi, Jackoboard, PCS. Personally wouldn't risk it but its up to you.

 

[rhinosaw]

I hear what u are saying, are these products available in B&q etc?

 

[Paul C.]

Yes, B&Q have their own version called Aquadry along with all the waterproof tape for the joints, fixing etc:
https://www.diy.com/departments/bathroom/wet-rooms/tile-backer-boards/DIY1102708.cat