Should I use self-levelling compound?

[fiiido]

I have a new porch with a concrete floor. It is roughly flat. I will be laying granite floor tiles on top. Is it necessary to pour the self-levelling compound first before laying the tiles or just leave it and use the tile adhesive to lay a level granite tiled floor?

Thanks in advance.

 

[hotrod]

Define "roughly flat" as a variance in +/-mm per metre.

 

[fiiido]

using a spirit level it is generally flat. It is not slopping in any direction. It is more bumpy with small divots. It's like the concrete was poured in, spread around but no effort made to smooth it out entirely.

Would the levelling compound also help with dampness? Not that I am concerned as it has a plastic sheet, then insulation then concrete on top. I did install a door and sill straight onto the concrete and any levelling compound my fill the gap between the sill and the concrete.

 

[alexmorgan]

I'd say just use the adhesive. I had a levelling screed blister on me in my kitchen / breakfast area and it is a nightmare. Less layers the better I say.