Hardibacker Board or similar for outdoor use

**Ajax123** · 20-09-2009

I built a covered walkway outside my house some years ago and quarry tiled the floor to it but a. ran out of tiles part way from the end and b. made a right mess of laying them. I used reject tiles so they were all sorts of slightly different shapes and sizes. (well they were cheap and I was strapped)

Anyway I now intend to take them up and relay new tiles although not yet sure if I will go for quarries again. I fancy a stab at a victorian style pattern. When I take up the tiles I know that I am going to have a poor sub base in terms of level. There is not enough room to lay a new screed and I have possibly 25mm to include the tile and anything I do to remedy the sub base. I am not confident in my ability to lay a self leveller so am thinking about a cement based backer board.

Question. Is there a cement based backer board which I could lay on a layer of blinding sand and then screw through to the ulutimate substrate and then tile onto it?

The sand is just to act as a levelling layer.

It is not truly outside as it is covered and only gets a tiny sprinkling of rain in the most inclement weather conditions.

I know about insitu substrates but this one I thought I would ask for opinions on from you guys. Thanks in anticipation....