Underlays and Impact Noise Reduction

Manuel

We've been to many hardware shops about timber flooring and asked about the best underlay to use upstairs to reduce the banging of footfall for the poor unfortunates downstairs.

A lot of them looked at me like I had two heads. I would have thought this would be in the top 5 considerations for anyone putting down timber floors over plywood upstairs. Anyway, I came away with a few cut samples of underlay, none of which *looked* like they would be terribly effective.

Then browsing through B&Q we came across packets of underlay sheets of various materials (rubber, layers of paper, etc.) with - hallelujah - actual quoted figures for impact noise reduction in dB.

Has anyone used any of those products from B&Q or anywhere else? Some of these were quite thick, the paper based one was about 8mm I think. Can anyone quote me the best dB rating for reduction that they've come across?
Or better still, has anyone laid a product that turned out to be good?

Thanks!