Simple treehouse plan
Fasten the roof supports to the verticals using 4 inch nails or screws. To avoid the wood splitting when hammering a nail at the end of a piece, it is important to first hammer the point of the nail so it is blunt. It will then break through the wood fibres in its path, rather than forcing them apart. Better still is to drill pilot holes for the nails with a drill bit slightly narrower than the nail. Cut the ends of each roof support at 45° so that each corner is supported from the post below. Add a bracket to strengthen the joint as shown below.