Unpopular opinion: Packed wool insulation in cold countries is asking for trouble
I was in Norway a while back and saw how they stuff wool into log cabin walls with no real seal. The locals said it breathes well and handles their dry winters. But I spotted moisture stains and a musty smell in a cabin we visited. In my concrete work, I see how water damage creeps in, and insulation is no different. I think skipping a proper vapor barrier is a huge mistake, even in dry climates. One wet spring and you've got a mold farm inside your walls. We should share tips, but not copy methods that ignore basic moisture control. Always tailor your install to the actual weather, not just tradition.
Tbh, wool insulation done properly doesn't trap moisture like that. My cousin has it in her Montana cabin with a solid vapor barrier, zero smell issues after heavy snow melt. If the wool gets wet during install or the logs can't dry out, that's when problems start. Sounds like a bad seal or no rain screen.
What type of vapor barrier did your cousin use, because that seems like the key difference? A lot of folks skip the right barrier for the climate and then the wall can't dry inward or outward. That might explain why some setups fail while others last.