A cracked and slightly uneven concrete floor can be made suitable for wood-block flooring or tiles by smoothing it with a 3mm 1 in layer of screeding. Various compounds are available and are normally sold in powder form to which water has to be added. Always follow the manufacturer’s instructions to make up the mix. Wash the floor with water and detergent to remove any dirt and grease and pour the mix over it. Work from a corner of the room towards a door and spread the compound with a metal float to a thickness of about 3mm 1 in. Do not worry if slight trowel marks are left in the surface – these will disappear as the compound settles and dries. Allow at least two hours of drying time before walking on the surface, and at least twenty-four hours before starting to lay wood blocks or tiles.