Cooker hood ducting

[Grommit]

Hi,

I'm moving the kitchen into another room in the house and i'm intending to duct the cooker hood out between the ceiling and the upstairs floor. The nearest external wall is directly opposite where the cooker hood is(with joists running in the same direction).

I've been told by building control that a fire collar(or similar) should be fitted where the ducting goes through the ceiling(I thought this was only for flats etc). I've been looking at fire sleeves instead of collars to do this, but I cant find anywhere that sells them except to trade.

Does anyone know where I might find one, or a better alternative?

Thanks

[wine~o]

Toolstation..

http://www.toolstation.com/documents/se ... &submit=Go