Cooker hood extraction.

[Thomo39]

Hi, I'm installing a cooker hood in an extension at my house and it needs mechanical extraction, am i ok to run solid 100mm ducting above the ceiling clipped to the joist and then core drill outside and put a vent on?
Or does it need to be a bigger sized duct?
The joists are 8"x 2".
Thanks

 

[^woody^]

Follow the guidance of your hood manufacturer. There will normally be a required size, maximum distance of duct, and deductions for each bend.

Fit rubber pads under fixings to prevent vibration noise and insulate the duct.

 

[JohnD]

Older hoods used to have 100mm duct, but more modern ones seem to be 125 or even 150mm.

It will be a lot if work if you need to upgrade the duct later.

As woody says, look at the instructions. Presumably you are using a reputable major manufacturer.

 

[Thomo39]

I'm going to run 125mm ducting and then covert to 150mm flexi for the short piece down the wall, yes i will use a decent brand