Asbestos cement fire resistance

[witsd]

Hi all. I've reached the 'banging head on wall' point with this one, so I thought I'd see if you guys had any answers or new angles to consider.

The scenario:

Residential multiple floor building, penetrated between floors by a ventilation system, consisting of asbestos cement ducting.
Investigations have determined that the ducting is 7mm thick.

How can I determine (or reliably estimate) the fire resistance in terms of minutes of this material?

I've heard plenty of anecdotal descriptions of asbestos pipework being the only thing left after serious fires, but ultimately that sort of thing isn't much help in making any definitive statements...

For reference, my best source so far has been this: http://www.fireriskheritage.net/wp-cont ... atings.pdf However the suggestion of just 10 minutes' resistence for ~5mm, and 45 minutes for ~19mm seems far too low for common sense.

[Messy]

That's quite a tricky problem

Can I suggest a post on this forum http://www.crisis-response.com/forum/in ... ion=recent

I have to be honest, there are a few characters there that can be a bit rude at times and the atmosphere isn't a friendly as here. But there are some very capable people including some who have been around for a while. They may be able to point you in the right direction. Alternatively, if you want, I will post the question on your behalf?? Just let me know

Cheers

[witsd]

If you wouldn't mind posting on my behalf it would be greatly appreciated, but I'll save the link as well for potential use later.