Our home was built in 2004 from hand hewn logs. We’ve only been living here 6 months and I’ve noticed that black, vertical lines have started to appear on the interior logs. Most run from ceiling to floor. The walls have never been treated inside. I’m afraid sanding may be our only option to remove them. But I’m most concerned with what is causing them. Any ideas?

waterloop Changed status to publish April 8, 2024