From this page you can find all awesome stuff that you can create with BARN DOOR. BARN DOOR belongs to farm category. Plant 40, harvest 40, brake all the blocks, repeat. You get experiance points for breaking BARN DOOR. Hitting it will break it but you need to count the hits yourself. Seed mathematics is very complicated, but you should get at least 1 seed back from splicing BARN DOOR. Profiting with this might be questionable. Will you get enough blocks to build something? You just have to find out yourself.