To follow up on my post about sloping ceiling insulation and the possibility of using Celotex I bought one of these from Amazon (if Brian is listening it's a hand held infra red thermometer by Etekcity):
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The sloping ceiling was reading just over 25 degree in the early afternoon and it seemed to be uniform from taking readings at about 2 feet centres. The cavity wall was 23 degrees uniformly.From what I can see there is fibreglass behind the plasterboard and since the readings were constant it seem it goes all the way up - otherwise there would have been a line where the temperature changed. Does that make sense? Any thoughts as to whether replacing the fibreglass with Celotex would make big enough difference to be worthwhile?
Nice bit of kit, good fun :-)