Porcelain Mosaics on Floor Question

[rustylt2]

I have to tile a bathroom floor with Homebase Cobalt Blue porcelain Mosaics and was wondering if they need sealed? The tiles apear to be glazed - i.e. they are glossy and smooth and not matt. There is no mention of sealing in the instructions on the back of the box, but I suspect that the instructions are generic and they print the same on all of their tile boxes! There's also no point in asking the staff at homebase as they are mainly kids.

It is a fairly new house and the bathroom floor is made of ply sheeting rather than floorboards. Is this alright to tile straight onto or would it need another layer of ply on top? I was planning on using rapid set flexi adhesive and using a flexi additive to grey grout.

Thanks in advance.

Here is the link to the Homebase tiles below.

Link removed

 

[DHTiling]

Looking at the pic then they look glazed...so should be ok.....as for the ply floor ..how thick is it?....

 

[rustylt2]

Not sure how thick the ply is Dave - would need to check. Whats the mininum thickness you could get away with tiling onto before having to ply on top of?

 

[DHTiling]

I would say 18mm to 22mm and would need to be strengthened with noggins at 300mm intervals and screwed down.......