I've just knocked my kitchen into the adjoining utility room to create a bigger kitchen. The kitchen has a nice old quarry tile floor, the utility room floor was concrete and about an inch higher than the tiled floor. I've got some matching salvaged quarry tiles (0.5" thick) to extend the tiled floor into the new section, and have dug out the concrete to allow sufficient depth for a 20mm sand/cement mortar bed and the tile, including painting a liquid DPM onto the concrete first.
My question is, can I leave the concrete in its current bumpy rough state, given that the sand/cement mix will fill any depressions and even out the floor anyway, so I will be laying the tiles onto a level mortar bed? Or do I need to use a levelling compound first? The concrete currently has a cobbled effect with lots of raised gravel, but it will all be buried under the mortar with no stones sticking through into the backs of the tiles. The concrete is about 50 years old but in good shape.
I've laid paving before so have a reasonable idea what I'm doing.
Thanks.
