If it stayed like this and no additional framework was installed it looks like I may have a clear run to the fascia?
It should have insulation in it, so maybe above that. There's probably some reg about how close ducting can be to insulation, but it's not like anyone is gonna check.
The fact I'm hearing the hose flop about up there when the fan is turned off is not filling me with confidence, but next weekend I'm going to pull out the current pvc hose and stick a camera up there for a look. Exciting times! Thanks for the reply.
Found a pic of the flat roof construction. The far end is where the cooker hood is now installed.
If it stayed like this and no additional framework was installed it looks like I may have a clear run to the fascia?
I've no knowledge on roof construction, will it simply be the plastic external fascia board and then access into the void?