Is airtec insulation any good? This - http://www.screwfix.com/p/airtec-double-insulation-1-05-x-25m/21112
It say it is equivalent to 55mm polystrene. Can I use 2/3 layers to have a good U value? Any pitfalls?
It say it is equivalent to 55mm polystrene. Can I use 2/3 layers to have a good U value? Any pitfalls?