Swapping to rigid ducting?

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Hi all,

Recently discovered a little bugger of a mouse had gotten into the attic eaves and, for whatever reason, decided to chew the aluminium flexible ducting used for the cooker hood. I'm presuming it could smell food and tried to make its way to the kitchen. Either way, it has chewed a good few holes in that thing. Rather than just replacing it like-for-like, I'm wondering about converting it to a rigid setup.

The duct itself basically begins in the kitchen ceiling, where it does a 90 degree bend into the eaves via the room above's floorboards, and then terminates into another couple of 90 degree bends and out the wall. Total length is around 2m or so (if even that), so I believe the 90 degree bends aren't too harmful to the performance.

I was thinking of swapping it out for rigid PVC ducting, slapping around foam pipe insulation, and then foil taping it all up (foil tape is much thicker and sharper when cut compared to that flexible tubing crap, so I hope that deters any further rodents from trying their luck).

This will be my first time having a go at rigid ducting, so any advice for connections/cementing the PVC (good idea, bad?) and things to keep in mind if maintenance or disassembly is required in future. Cheers. Will likely give this a go on the shower ducting as well, which as a similar setup and distance.

Attached a crude drawing showing how the ducting generally looks like.
 

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If you have a TLC Electrical store near you they stock a wide range of flat channel duct. As standard I fit 204mm x 60mm through lofts.

You may have to take the cowl off of your extractor hood and start again, the 204x60mm can be used with 5 inch or 6 inch flexible duct out of the extractor and then connects to either a 5 inch or 6 inch flat channel connector, which connects to the flat channel which is available in 1 & 1.5 mtr lengths. You'll need a flat channel connector or two depending on the length.
If your ducting comes out in the soffit you'll need a rectangular to round adaptor to continue out with flexi duct.

I.Sells is another ducting supplier, Toolstation & Screwfix do 204 x 60 but you won't get the rectangular to round from either.
 
If you have a TLC Electrical store near you they stock a wide range of flat channel duct. As standard I fit 204mm x 60mm through lofts.

You may have to take the cowl off of your extractor hood and start again, the 204x60mm can be used with 5 inch or 6 inch flexible duct out of the extractor and then connects to either a 5 inch or 6 inch flat channel connector, which connects to the flat channel which is available in 1 & 1.5 mtr lengths. You'll need a flat channel connector or two depending on the length.
If your ducting comes out in the soffit you'll need a rectangular to round adaptor to continue out with flexi duct.

I.Sells is another ducting supplier, Toolstation & Screwfix do 204 x 60 but you won't get the rectangular to round from either.

Sounds good but as mentioned I don't want to use flexi duct again.
 
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Use round pipe not flexi.

How big is the difference between 150mm round pipe and 204x60 square pipe? I ask because 150mm may be a tight fit under the floorboard space. Wondering if it might be worth it to just be all rectangular ducting.
 

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