Flooring roof space & insulating 1st.Does compression affect efficiency of insulation

[stephenc]

My roofspace is going to be used for storage, but before I put down boards, I want to put some more fibreglass insulation on top of the existing rather dozed stuff

My question is, when I then put the flooring down and compress the insulation, will this affect the efficiency of this insulation? I'm thinking on one hand that the chipboarding will also help the insulation but on the other compressing the insulation removes the air gaps which trap the heat

Anyone any ideas please? :confused:

Thanks, Stephen

[Richard A Hetzel]

Owens-Corning publishes a chart on their website which explains the effects of compressing fiberglass insulation. Generally, it is something like when you compress R-19 by 2 inches, it becomes the same as R-13. What you can do is screw 2x2s, 2x3s or 2x4s to the top of the joists up there, to raise your flooring and allow the full depth of insulation.

The chipboard flooring won't add enough insulating value to worry about.

[stephenc]

Thanks Richard , I appreciate your advice
Stephen