[Jassmine]

I am wanting to tile over an existing concrete slab but need to raise it by about 10mm before laying the tiles. I am wanting to do this with a mix of sand and cement but do not know what the ratios are. Can you help

[KBC]

What are you reasons for wanting to raise the height? To level it? To smooth it out because of imperfections?

Is it exterior or interior?

Inside you could use 'Thinset'(to a certain height) Standard mortar(premixed) otherwise.

Exterior you could use mortar(premixed)

As far as making your own,I have used 2 spades full of mortar(type N),7 spades full of sand,and one spade full of lime.(this was a historically correct match for barn work,it is strong,but not a grey color like standard mortar)

Hope this is helpful,

Ken

[ballengerb1]

It may be easier to just put down a 1/4" hardibacker sub floor board. Modified thinset and the backer will give you 10 mm plus it will help to level the floor.