Decking Installation | Eco Pro Planet Eco.Decking Installation Guide. Step 1: Drill joist onto the subfloor drill down screw onto the joist. Step 2: Keep joist approximately 12-16 inches apart. Keep every screw on the joist approximately 12 inches apart from each other. Step 3: Attach starter clip at the end of every joist with a screw. Step 4: Slide the first decking board.