You should start the treehouse with a durable hardwood such as pine, cedar, or redwood because they are safe and water-resistant. Softer wood, such as spruce, birch, or poplar, can shrink faster because they contain more moisture. Treated wood is stronger and won’t decay as easily. You get the idea of a sturdy foundation. Here are more suggestions for the flooring of the child’s new play house.

Floor Basics

It is advisable to begin with 2x4s or 2x6s plywood or decking. However, don’t use chip boards including oriented strand board (OSB) because it can absorb water and easily swell. The slats should provide air flow of approximately ½” apart that have been pretreated with a wood preserver. The flooring can also be protected with an extended roof. The joists should be 12″ apart with a minimum thickness of 1″ for safety.

A drainage slope is advisable of 1 in 12 (5°) that can help drainage and remain safe. Floor coverings shouldn’t be used unless the floor remains dry.


Plywood can be used over the beam crosses and adhered with adhesive and screws. However, it is necessary to use marine plywood because it is seven or eight layers thick and uses a waterproof epoxy to bind them together. The plywood is also treated with a waterproof sealer and has no gaps/voids in between the layers like regular plywood. It is faster than using regular boards for the flooring since it can be cut to fit the area of the treehouse.

IPE Decking

This is a durable and strong choice that originated in South and Central America. It resists mold and fungus growths and will remain cool since it is heat-resistant. It is also slip-resistant and will repel rot and decay. It is perfect for children to play on because it is also resists slivers and scratches. It is easily cleaned and you can apply a decking oil to give it a boost to help repel UV rays and water damage.

Maintain the Flooring

Wood products should be protected from elements whether they are directly in contact with them or not. For the exterior floors, like the ones in a tree house, you should apply a clear sealant every one to three years for protection. All wood has a lifetime, and protecting the surface will make them last much longer.

Even though you might want to place carpet in your child’s treehouse, you should probably settle for some throw rugs that can be easily cleaned. You can also remove them before the floors get wet. As you see, there are several options to make the play haven safe for your child.