I am planning to squeeze under suspended timber floors tomorrow to insulate with PIR boards (celotex). What I am not sure about is whether I should insulate between the joists or under them.
I know kingspan instruction state between joists but there is plenty of advice which states that its better to insulate underneath the joists to avoid condensation on the bottom of the joists e.g.
http://www.buildingscience.com/documents/insights/bsi-009-new-light-in-crawlspaces/#Photo_05
Any thoughts on which is the right advice?
I know kingspan instruction state between joists but there is plenty of advice which states that its better to insulate underneath the joists to avoid condensation on the bottom of the joists e.g.
http://www.buildingscience.com/documents/insights/bsi-009-new-light-in-crawlspaces/#Photo_05
Any thoughts on which is the right advice?