I wish to convert my garage to a habitable room. The walls are 9" solid
Regs require walls to have a U value of 0.3
I looked at the following site and the products are rated in R values.
Can anyone please tell me which one I need.
U lets you calculate how much heat you are loosing easily (U * area *
R = 1 / U, and has the nice property that R values add. That is, if
you have a 9" brick (R value 0.5), and 50mm celotex (R value about 2),
then the R value of the two together is 2.5. Inverting to get a U
value gives you 0.4 (so you need a bit more celotex).
You need an overall R of 1/0.3 approx = 3.3.
Don't forget that if you use 100mm sheeps wool between 50mm studs at
600mm centres, you will need to allow for the fact that 1/12 of the
surface is conductive wood rather than insulating wool.