Hi, We have a single story rear kitchen extension. It was a self build built approx 20 years ago by previous owners. It was not the best build and had a flat roof with tar and felt (Typical of that time). 2 years ago we put on a pitched tiled roof over the flat roof. My question is could there be an issue with the extra weight from the tiled roof on the kitchen walls. I am not sure what the original foundation was like on this extension? Also I am seeing a lot of the plasterboard joints from the kitchen ceiling crack but I believe this to be from the joints themselves. Any words of wisdom appreciated..