Exterior Insulation and Vented Rainscreen
We will start framing our cabin soon. It is in the Columbia Gorge, in Skamania County, WA. Zone 5B. Please see drawings (attached, and additional posts). My section drawings show insulation, air barrier, layers, etc. Rigid foam outsulation and rain screen. I have read the Pretty Good House book, by Michael Maines, and others, and several articles at GBA, and in Fine Homebuilding, including this one by Justin Fink:
My cladding/siding will be rough-sawn plywood, with battens. Breckenridge, or similar.
Question 1: If I run the plywood siding vertically, do I need to run the strapping horizontally?
Comment 1: Notching the horizontal wood strapping seems time-consuming, and having water drain through untreated wood doesn’t sound that great either. So, my drawings show Cor-A-Vent Sturdi-Batten and SV-3.
Question 2: In this article, https://www.greenbuildingadvisor.com/article/how-to-combine-board-and-batten-siding-with-exterior-rigid-foam, Peter Yost is talking about connecting the furring(strapping) to the studs and the cladding to the furring(strapping). But with the Cor-A-Vent, there is no wood strapping to fasten the cladding to. So my drawings show 4 1/2″ nails going though all the layers, all the way to the framing. Are there guns and gun nails for fasteners that big? Fastening all of the cladding through all the layers with screws sounds slow. Are there other solutions I should consider?
Questions 3: I’ve read this article:
For my climate zone, I should go beyond the drainable housewrap, and create a ventilated rain screen, correct?
Some comments on my drawings:
Question 4: Basement: I know that the vapor barrier should be on top of the rigid foam that’s on the floor. But the vapor barrier is already installed, and the rigid foam is not. Is it OK as shown?
Comment 2: Air Barrier on the walls: It should have gone underneath the mudsill on the concrete, but the mudsill and floor joists are already installed.
Question 5: Air Barrier on the walls: Should I interrupt the wall sheathing, in order to connect the wall air barrier to the ceiling air barrier?
Comment 3: I should be using advanced framing, with studs at 24″ on center. But I am already getting my framer/carpenter up to speed on two new techniques (outsulation and rain screen), and paying him by the hour as he learns these new techniques, so I’m not ready to embrace a new framing technique on this project. Plus, I don’t know enough about it myself.
Question 6: Do I have all the control layers shown correctly?
Question 7: Are there any changes to my details that you would recommend?
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