Loft boards have insulating effect on their own?

[JamesA]

Does adding a layer of loft boards have a significant insulating effect on its own?
I can get by without adding boarding, but might do the job sooner if it will add insulation.

There are other topics covering raising the floor level to add more insulation that I'll have to think about, but as it stands I would just add boards to whats there already.

 

[JohnD]

The boards have a slight effect, but nowhere near as much as another layer of fibreglass or foam.

You can get tables of "U" values and "R" values to work it out, but an inch of fibreglass is as good as three inches of wood or ten inches of concrete blocks.


*I expect someone will be along in a minute with the accurate figures