July 2016
28 July 2016
First there was bitumen felt – or nothing! Roofing underlays and insulation have evolved considerably in recent decades. Before the nineties the rafters over a room-in-the-roof would have had a bitumen felt on top and possibly a small amount of glas…..
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7 July 2016
A U value is a measure of how much heat is lost across an insulation build-up – insulation materials, rafters, air gaps and all. Materials by themselves e.g multifoil insulation don’t have U values; they have R values which are a measure…..
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