Raising loft boarding to increase insulation depth

[Mike]

The insulation in my 1930's house loft is thin compared to today's standards due to small close-spaced joist sizes and full boarding. I need to retain the existing boarding for light storage purposes; is there a cheaper option to adding conventional timber to raise the joists; I recall once seeing an advert for "I" section MDF joists? Any ideas appreciated. Mike

[John Rumm]

Could you not lay some ply bonded to PIR foam directly onto the existing boarding? The stuff intended for building warm deck roofs should do what you want.

[:::Jerry::::]

appreciated.

Bad enough getting ordinary flooring into the average loft space, I can just imagine the fun with that stuff !...

[John Rumm]

A large circular saw is your friend ;-)