On Mon, 04 Dec 2006 17:54:52 GMT Phil L wrote :
shows that 200mm of loft insulation has a w/mk u-value of 0.040.

While their compressed slabs at 25mm have a value of 0.034

Those are the k values, the amount of heat W that will pass through
a 1m thickness for a 1C/1K temperature difference.

If you look at the resistance values 200mm of loft insulation has a
thermal resistance of 5.00, 25mm slabs 0.70/0.75

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk