When I built my house I used white pine (T&G) throughout the living space. Then I decided to use rough cut 1x12's (also white pine) in the basement, just for a change. My problem is that after I have hung the wood and it has dried out, I have fairly large gaps between the boards. I ran them horizontally so I don't know about running a strip like you would when you board&batton. You can see the studs and insulation through the cracks and I am a little bit particular and it is driving me crazy. I need something to fill the gaps(some as big as 1/2").I need something maybe dark brown. Any suggestions would be appreciated. Thanks.