I am planning on building a platform deck near our in ground pool. The frame will be 8 feet wide and 24 feet long. How do I join the boards to create the 24 foot length of the frame? I am assuming I will join two 12 (maybe three 8 foot lengths???) foot boards and I am unsure how to join them. I will obviously have to do this on the back side of the frame as well as the front side.
You don't have to join them, have them both sit on top of one of the support posts at the center, so put your support posts every 6 feet. If you could find a 24' long beam, it would never make that span unsupported anyway.