Which material would you choose for rainscreen furring? – GreenBuildingAdvisor

Building Science Corp would tell you that anything over 1/16″ has pretty much exactly the same drainage potential. The additional depth provides additional ventilation potential. Is that necessary? I am not sure. Perhaps there are folks on here with more experience with the long-term durability of each who could tell you. To me, any drainage plane is massive upgrade from typical US residential construction. Unless you are in an particularlly wet location, either seems very reasonable to me.

The 1×4 may provide some additional support (especially if your framing is 24″ OC) by slightly reducing the span for the cedar lap siding. It will definitely be less likely to split.

You might price out 1×3 pine as well to see if there is a middle price option. In my area, that is sold in bundles as “furring” for relatively cheap.

I have used rips of 1/2″ CDX sheathing and been very happy with it. It has the advantage of using up leftover sheathing cut offs, and the disadvantage of more labor to rip them.

You are correct that 1/2″ or less typically means being able to trim out windows as “normal.” If you’re not using exterior insulation. Check your specific windows and doors. I think many come 1″ to the nailing fin, which would be enough to hide the 3/4″ furring as well.

https://buildingscience.com/documents/digests/bsd030-rain-control-theory