How to Make a Tree Fort With Wood

Mark the floor plan of your intended tree fort on the ground directly beneath the tree. Determine whether there are enough branches to fully support the fort. If not, dig a 2 1/2-feet deep hole, pour 6 inches of concrete in the base and stand a 4-by-4-inch upright support beam inside it, filling in the hole with dirt. The beam should be tall enough to support a corner or edge of the future tree fort, when finished.

Screw a 2-by-8-inch beam, the length of your intended tree fort floor, between two branches. Cut diagonal shims and insert them between the branch and the beam if necessary to keep the beam parallel to the ground.

Screw another beam of the same length to another branch, or pair of branches, parallel to the first. Install two more beams perpendicular to these, one at each end, forming a rectangular frame supported by the tree. If your fort has a vertical support beam, screw it to the adjacent horizontal beam.

Add floor boards, laying them in place between the two initial beams and screwing them securely to the frame. Leave a small gap between each pair of boards for rain to fall through. Cut the boards to leave room for any branches that rise up through the middle of your fort's floor or saw off any such branches, as desired. If you want to locate the entrance to the fort in the middle of the floor, leave a hole for it as well.

Construct a railing for your fort, screwing 4-by-4-inch vertical beams into the four corners of the base and connecting them with four more 2-by-4-inch horizontal boards. Fill in the gaps with 2-by-2-inch balustrades for safety, leaving a space in one railing if you want the entrance to be on the side.

Bore round holes near both ends of a 1-by-3-by-12-inch board, to make a rope ladder rung. Repeat the process for many rungs as you'll need, assuming about one rung per foot. Tie a knot at one end of two thick ropes and thread the first rung onto it. Tie another pair of knots a foot up and slide on another rung, and so forth. Tie the top of the ladder around one of the beams of the fort or branches of the tree to let you into your arboreal stronghold.