Hi folks, i am curious to get some opinions on a new construction project in climate Zone 4, northern coastal CA near the OR border. I’ve detailed my plywood sheathing as an exterior air barrier and while i haven’t gotten a blower door test, i’d like to think i did a pretty thorough job. Siding is cedar T@G over a 3/8 rainscreen. Walls are 2×4 and i am planning on insulating with rockwool (pathetic i know but it’s a tiny house on wheels… ).Roof assembly is vented, with “cut and cobble” polyiso insulation in the ceiling that’s thoroughly sealed on the interior plane with Siga tapes.

Assuming i’ll be using pine tongue and groove (with a water based poly clear coat) for nearly all interior cladding, do folks recommend the use of a second air barrier on the inside of the wall assembly? I have heard talk about convective loops happening within wall assemblies like this in the comments section of this article, though Martin suggest this is unlikely if the exterior air barrier is good: https://www.greenbuildingadvisor.com/article/one-air-barrier-or-two

Has the thinking on this evolved much since 2010 when the article was written? If it’s a yes on an air barrier, does anyone have recommendations? I was thinking some sort of membrane would be easiest, maybe even just basic Tyvek. 

Thanks a bunch!

-Tanner

P.S. there is always the possibility that the house will end up in a colder climate down the line