First line the wood up with your rollers so they are even and mark in 3 spots where you want to put the wheels on each piece of wood, add 6 inches to each side of those and mark that off. Don't screw within those marks because that is where the wheels are going to roll. Place the PVC on the wood in the center with the wood laying flat. Countersink if you can then screw in. I put in 6 screws on each piece of wood and it is extremely sturdy.