My house no 7 gable is higher than no9.no9 had it roof replaced and flashing the flashing are of the up stand type thay then hacked off my render and only replace about 12incc to cover their flashing thay also rendered the chimney that had flashings on their new roof this render has now fails and thay say its my chimney and gable and want me to rerender the chimny and gable were do I stand ?