Q I have had two attempts at painting my concrete garage floor. On each occasion the paint has flaked after a short time. On the first occasion I scrubbed the floor with normal washing-up liquid, rinsed it and then used Wickes garage floor paint. On the second occasion I tried to be more rigorous. I used Sugar Soap as the cleaning agent and Leyland garage floor paint. I have seen perfectly good results elsewhere so I must be doing something wrong. Any hints and tips that you can offer that would lead to a successful outcome? GH, by email
A Concrete or screeded floors can be difficult to paint, especially when relatively new, because of a weak surface layer of cement that is brought to the surface by trowelling when wet. This is known in the trade as “laitance”, and can be tested for by scraping the edge of a coin across the surface to see if this produces a fine powdery residue. So, while we think of concrete as being a very hard, dense material, it can have this soft surface layer that flakes off easily, taking any applied paint coating with it.