I have a tarp zip and they leak light BAD. They have a light proof zipper now on their website. I have a tarpzip in the center of my tent and the bottoms are cut horizontal from end to end and those are velcrowed to the 2x3 wood that makes up the floor. The zipper leaks light really bad so I took a piece of panda film and tapped it from top to bottom of the zipper but just on the right side so I can still open the door. Its much better that way but no way perfect. Id build a door if I was making a perminate structure with wood pannels.