I recently installed some weathered boards taken from an old barn as wainscoting in our dining room. In doing so, I used several tricks that may be helpful to others who want to use this rustic but fragile material.
First, nail it to a solid underlayment. Although furring strips will work, a layer of 1/2-in. plywood is better. It lets you tighten up a board with a nail wherever it’s needed. I painted the plywood a medium grey, which minimized the impact of empty knotholes and the cracks between the boards. I also used a spray can of grey paint to touch up the ends of freshly cut boards. Left unpainted, these ends have a nasty way of showing.
Cupped boards can be trouble when you’re using weathered material for paneling. I got around this problem by making two or three saw kerfs down the length of each board. The cuts come to within about 1/8-in. of the good side, and they allow you to bend the cup out of the boards as they are nailed to the wall. You can expect to waste a few boards with this method, but the ones that survive will give the desired rustic effect without looking shabby.
Dale Nichols, Toledo, OH