looking for BS 476 part 20

[Ductmate]

I've been searching the net most of this morning looking for someplace where i can download or purchase BS 476, part 20, Method for determination of the fire resistance of elements of construction (general principles.

Can anyone tell me where to find it, or at least give me the general gist of it?

Thanks
Vince
p.s. I know this isn't NFPA, but it's the only forum that came up under 'fire' stuff.

 

[samuelliu]

$153 to purchase it @ IHS