I just completed the demo of an old barn and I saved many of the old pine boards that were used as board and batten siding. They were in great shape and I'm planning to use them to build a new workshop. The exterior of these boards is weathered and grey on the outside but the inside of the boards is a much cleaner brown color. Does it matter which side I choose to face out on the exterior of my new barn? Thanks!
No, it doesn't matter which side is out. Heart pine barn board is heart pine barn board. Whichever side faces the sun and weather will weather gray fairly quickly (2-3 years), so unless you're going to stain, paint or seal it, you might was well put the weathered side out to begin with.
My home is a 1977 a-frame. I have authentic c1906 heart pine barn boards for kneewalls and boxed beams upstairs and down. They had a mix of board-and-batten gray and brown tone colors. Because these were used on the interior, we stained them all with a semi-transparent light gray stain and they all matched out.
You just have to make sure that the old barn boards don't have termites or powder post beetles, etc. Ours didn't have termites, but we had powder post beetles and had to shoot mineral spirits with a hypodermic needle into the boards wherever we heard scratching for a while. LOL