I'm renovating the larder in the kitchen and I have started work on the cold shelf. It is made of concrete and was covered in tiles. The tiles have now been removed (that's a different story!) but the remaining concrete shelf is not level. The area is not very big, about 0.5m2 in a L-shape. I would like to ensure the shelf is level before re-tiling, what compound would be best for this job?
Grateful for advice as I'm new to this DIY game.