What duct to use

[North]

Hi all,

I have just installed my cooker hood extractor fan unit and only need to make the connection to the aluminium ducting that goes into the wall.
Q1 Do I have to use aluminium duction for this? I can not find the right diameter in my local DIY shops 125mm.
Q2 How do I do the connection to the ducting on the wall? Is it enough to just insert one into the other?
Thanks

 

[flameport]

5 inch ducting and other accessories here: https://www.tlc-direct.co.uk/Main_Index/Ventilation_Index/Ducting_1/index.html
For joins, use aluminium tape, available from the same place as the ducting above.

 

[North]

Thanks!