We have just moved back into our completed renovation project in southern England. But during the last week, on two separate cold nights (approx 0 to 3 degrees centigrade) we were woken by loud cracking noises from the slate roof. The cracking sounds lasted an hour and then half an hour on the second night. We have looked at the slates and there do not appear to be any visible changes. They are new Camborne Mont Azul Superior Natural Spanish Slate purchased from a builders merchants and fitted last July by a local roofer. We have not contacted either yet because we want to gather information first. Thanks.