I've lived in my end terraced house now for 4 years and just started to see water running down the upstairs chimney breast. Having had a builder to look at it he says the old chimney was taken out and badly closed up. The hole in the loft has only had a board placed over it and no air vents placed on the outside wall. he also tells me the roofing joists dont all rest against brickwork and have been patched up in places with wood. He says its gonna cost a fortune to fix and possibly could find more problems once he starts to inspect properly. Does anyone know if I could claim this on my house insurance or claim against the former owners for bad workmanship?