Hi all we currently have an old out building wich over the years we have converted into a sitting room of sorts put a few windows and doors in that was donated to us from a friend and rendered the outside we have power to it, its basically used as somewhere to sit in summer whilst in garden the advice im after is for the inside as we never actually really finished that as was just seen as a shed lol it has a wicker 3 piece sofa in a little stereo n tv etc... it has a standard concrete floor and for brick walls the front wall consits of the door in the middle windows to the sides the front wall and the 2 side walls are bone dry well as far as i can see but the rear is seriously damp no major worry as just initially a shed its not attached to the house in anyway im looking for advice in what i could do with the walls make it more complete i think plaster is out of the question with the rear wall in the state its in would you guys render inside ? line it out with some sort of kingspan ? or i believe there is some sort of plastic type sheets that slot together ? but i feel that would look some what cheap i dont think repairing the rear wall is at all possible i suppose at the start rebuilding it would have been best bet but back then we initailly wasnt going to build this sitting room type of thing untill doors n windows got donated an we had a slight brain storm Many thanks guys excuse the spellings grammar