Ecofriendly Tree Forts

Building a tree fort with your kids is a great way to bond and show them a good time that will last throughout the years. Tree forts are fun and safe, as long as they are built correctly. But when tree forts are built into a tree, nails and screws that hold the tree fort in place can damage the tree. Over time, screws and nails will rust, damaging the tree, causing rot and even death. Use this guide to building green tree forts and you'll be sure to get the best fort possible for your kids and a long life for the tree that it's built in.

Using the Trees' Natural Features

The tree that is perfect for your tree fort is one that is naturally growing in a split crown shape. A tree that is squat and split with multiple trunks coming out of one section is the ultimate tree fort tree. Here, a triangular, square or rectangular deck band can be built from 2x6 or 2x8 pressure treated lumber. You'll need to allow the structure to free float in between the tree branches at the desired height. Tie a few ropes around the trunks to help hold the platform in place.

Next, attach a few 2x4 or 4x4 posts down to the crotch of the tree to under the 2x6/2x8 frame. This will support the weight of the joists. Add 2x6/2x8 joists in between the frame at 24 inch intervals. Install a few metal joist hangers and nail them off. Surface the deck with plywood, 2x4 walls and the like and you have a tree fort that is built into the tree without using a single nail.

Custom Work

Sometimes, tree forts are limited to one peculiar tree. With a little imaginative thinking, you can create a few unique tree forts that will hold against a tree without nailing into it. One such method works well for single branch trees like a pine tree. Build a deck frame around the base of the tree. Add four joists with 45 degree angles cut on each end. Two going one direction across the joist frame, the other going the opposite direction, underneath the opposing joists. Each joist is attached to the frame with a bolt that is just hand tightened.

Next, lift the deck to the desired height and set a few temporary posts under the frame to hold it in place. Attach the four bolted joists around the tree. Now tie a series or ropes around base of the joists, tying them and the rope tightly to the tree. Now build and top the deck with the tree fort. Eventually, the tree will grow around the rope and the joists, causing the rope to rot away and the tree fort to stay in place forever.