The directors (the ladies of the house) selected 47.5" by 5.5" 3/8" decorative boards to run horizontally. The wall is down to studs on nominal (some markedly "nominal") 16" centers. I need to make the lateral joins nicely patterned across the wall. This means the ends of quite a few joins will not be backed by a stud. The boards will be attached by ringed panel nails. I am not going to fit a layer of ply over the whole wall. This is already more committing than I desired, but I got hugs and snuggles, and I am easily led around by pretty women.

What is the standard method of doing this?

1. Vertical 6" section of 2x4 behind the join, held in place by hand and then nailed into

2. Horizontal 2x4 pieces between the studs providing real structural support

3. Some other magic easier method you are going to tell me.

Thanks a bunch!