Foil insulation for ceiling / roof - good idea?

[jellycan]

I am thinking of putting in some sort of foil insulation in roof space on top of the loose fill stuff that is already in place. Came across a product called Silverline (www.silverline.com.au), a foil product with a claimed R value of up to 3.9. Light weight and easy to handle, seems ideal for DIY.

Anyone has experience with it? The company claimed it is not a reflective insulation material, so dust does not affect its performance. How plausible is this claim?

Any thought is appreciated.

[Bloss]

Do a search on the forum for 'insulation' or 'foil insulation' - plenty of threads and posts on it that should help.