screed not dry Advice and information on tiling and fixing tiles to a variety of surfaces

[welsh brickie]

i have been watching the tilers next door install a screed on a roof terrace they lay a sand and cement screed on a dry concrete base to get their level,and then tile directly onto it 2 hours later.Now its hard enough to stand on,But surely it should be left to dry.
Has anyone done this method as I have never seen it done and are there any complications afterwards.

[chris_on_tour2002]

hi welsh brickie,

never seen it done this way before but i guess it would be no different to laying slabs or bricks into wet concrete. why use another layer of adhesive, provided the tiles bond with the cement in the screed i suppose it makes sense especially as it's exterior.

wall tiles used to be set with a cement mix before tile adhesives came onto the market.

don't know why they left it for two hours though - i'd have thought that this technique would work better if the tiles were laid directly onto fresh screed.

[welsh brickie]

thanks chris for your reply,It seems to have set well enough I was just curious to see if the tiles would pop as time goes by

[TPTiles]

The wait for it to become walkable seems strange. you can lay some tiles into wet cement but its very unusual these days.