I noticed a couple of small patches of damp around the rear uPVC door in the extension leading to the garden. Additionally the extension is very cold with the floor in particular being cold. The step outside the door is built on a foundation of bricks that are exposed and the gutter above the step has been overflowing with water coming down onto the concrete step and bricks. I have fixed the issue with the gutter so no more overflow during the rain. I would like some advice on what to do next, I guess I should have the bricks removed and replaced with a more appropriate base with a damp proof membrane. I'm hoping this will fix the damp issue and also improve the temperature in the room. Any advice gratefully received.