Where should I put an air barrier on a log home insulated from the outside only?
The house we bought is like a log house (post and beam). It was insulated only on the outside with a 1 inch air gap between the wood and foam insulation. This allowed for cold air to come in easily and for a major bug infestation. We are re-doing the outside insulation.
We will put soft rockwool (batten) right against the wood beams on the outside. Then an air barrier- WRB (as sealed as possible), then another layer of continuous rockwool board, followed by an air gap with diagonal furrings. Then we will attach vertical wood siding. Is this a good plan? Is the location for the air barrier right?
To clarify - a post and beam home (timber frame) would have support posts with wall openings between them, from what you say I will assume stacked logs, but correct me if that is wrong. based on that - yes, the air barrier location if perfect.
I would point out that some air barrier materials allow moisture to pass, and some stop it. to install an air barrier on the outside of the insulation you need to be sure not to trap moisture, so be sure you have a vapor permeable membrane, read more here -
Choosing the Right House Wrap / Weather Barrier, Which is Best?