I have a company working with us in fitting a new kitchen. When they removed the old tiles, the plasterboard was damaged. They fitted new plasterboard. Should they have done anything to the new plasterboard to finish it before hanging cabinets? Also I am getting the backsplash tiled and in a couple of areas (as shown in picture with my hand) there is a considerable gap between worktop and plasterboard. How on earth does that get tiled without having to try fill the gaps with sealant/ silicone?