Can a cooker extractor hood and a bathroom extractor fan share external ducting?

catt_2

I'm going to have a chimney style cooker extractor hood with external ducting installed.

I'm also installing a fan in the bathroom ceiling.

These two fans are almost back-to-back on the same wall and I want to duct them to the outside, going upwards through the roof. They can't duct sideways due to the position of the GCH boiler. Both rooms are partly in the roof space so the ducting won't be that long.

I want to use rigid not flexible ducting as it is more efficient. I don't want to clutter the exterior with too many vents, etc. So my question is could these two extractors share the ducting? Anyone know about the building regs and the practical side?

Would appreciate some advice on this. Thanks in advance.

catt_2

I'm hoping someone knows about this....

djheath

I am not sure on the building regs side, but if its possible, I would want to make sure each had a valve integrated just before they join. This way, when your extracting plumes of smoke from the burnt toaster, you're not just sending it into the bathroom!