Cooker Hood Extrator needs to go through the roof to vent

The Klober unit doesn't look like it is rated for extractors and is mainly for roof space ventilation. If you are going to go through the roof you will need a small upstand pipe. Any roof level vents will cause several problems - wind will rattle down the pipe and blow through the baffles inside the cooker hood and not only will it be noisy but you will get a huge draft. Secondly within the air extracted you will get amounts of fat/oil and these will settle on the slates around the opening. A short pipe will allow the wind to disperse the extracted air over a greater distance.

Do not put foil based insulation alongside your flue. Foil based insulation is highly flammable and if you have a small fire on the stove and the fan is on the flames will spread really quickly especially in a roof void. The only thing to use for insulation is a stone based mineral wool - e.g. like a rock wool product

 

Warm air +condensation = mould & maybe smell.

And rigid ducting,use tape (alumimun tape) all the joins to get a airtight seal, & had Sos mentioned insulation, that is a stone based mineral wool - e.g. like a rock wool product, you don't want the warm air cooling in the ducting to form moisture.

 

Was me that mentioned insulating the vent pipe .... just a humble diyer !

 

By insulation was thinking something like the foil wrap blanket , roof membranes. Sure they are fire retardant now days - doesn't most insulation materials have to be now days ?

Academic really as the vent pipe will likely be plastic. Industrial applications will be all metal but this is a domestic situation

I could be wrong of course, just DIY
me

 

Some foil insulation is indeed fire retardant but not all.

My uncle used to be in the fire service and he used to loathe kitchen extractors with a passion. One of the common things he used to find was people would put a chip pan on the stove, turn the extractor on and then wander away. Then when the thing caught fire the extractor would be funneling the flame and smoke up the flue. So all the kitchens I have fitted I have used metal pipe and then wrapped it in plasterboard just in case.

 

Get a roofer in to do your roof penetration. Use a piece of soil pipe with a cowl on top and a condensate trap with overflow pipe