Should feather-edge lap siding be installed directly on sheathing or on furring strips?

Question

I'm building a shed this summer. The plan is to use a stud frame construction. Cover it in 12mm OSB3 and a breather membrane to keep the interior dry and use feather edge as the cladding. The thing I am wondering is should I put the feather edge on rails or directly to the OSB3 through the breather membrane? I've seen it done it both ways online
It's pressure treated pine. I've planned a 20cm roof overhang so I am not planning for it to get soaked on a daily basis but I want to be on the careful side.
Using rails should mean there is a 40mm air gap between the backside of the feather edge and the breather membrane so if moisture accumulates on the backside of the feather edge there is some air movement to let it dry. This has the added advantage of meaning less holes through the breather membrane.
Without using rails mean less material will be required and I can use fence posts for the edge similar to this video on Youtube by Colin Furze. Seems like he knows what he's doing and lives in the same climate as me (UK - so moisture is gonna be a bit of an issue).
https://youtu.be/LP67MAoihZk?t=110
If anyone has got any experience doing it one way or another then advice would be greatly appreciated.
Cheers.

isherwood · Accepted Answer

It's really a matter of prerogative (which is why you get varied suggestions), but it sounds like you have your answer. You want to be "careful", which I interpret to mean you're willing to put in the extra expense and effort to get additional longevity. It might last 40 years instead of 30 if you let it breath.
In my experience, lap siding is installed directly over sheathing/house wrap. Wall shingles tend to be installed over strips, but that's because they tend to let more water through all the extra joints. Your mileage may vary.

Should feather-edge lap siding be installed directly on sheathing or on furring strips?

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