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Corner batten detail

pnwbuilder | Posted in General Questions on

I am building a house with the following wall assembly: conventional 2×6 framing with 5/8 plywood sheathing, 4″ exterior mineral wool, 2×4 untreated DF battens, hardie plank siding and hardie trim. At the outside corners I used 2×8 battens (also unterated DF) so they could be screwed into the corner studs. I am located in a relatively dry part of PNW with an annual rainfall of about 27″. The siding butt joints will be flashed with galvanized plates. I’ve applied two coats of primer on all sides of the corner battens before installing them but  I am wondering if some kind of flashing should also be installed to protect them should the caulk between trim and siding fail?

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  1. Expert Member
    Peter Engle | | #1

    In your dry climate, and with two coats of primer, the battens are already pretty well protected. Adding flashing is probably not necessary but it wouldn't hurt. Even a layer of #15 felt paper would be an improvement. Strips of #30 felt are traditional for the butt joints and routinely give 50+ year service, even in relatively wet climates. Lots cheaper than galvanized and easier to work with. I'd use #15 felt at the corners, as it bends more easily. Two layers if you're obsessive. If you're really obsessive, use self-adhesive flashing, like Vycor.

  2. pnwbuilder | | #2

    Thanks Peter, I'll probably go with felt paper.

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