Of course, you can build a treehouse on a sawed-off tree trunk, but you should pay attention to the following: The tree trunk must not be rotten or brittle and must be able to hold the treehouse securely. The cut surface must be constructively protected from moisture (build a kind of roof). Support your platform from below with struts and triangular constructions. You usually don’t need special Treehouse Screws for this – fix the beams directly to the tree with wood screws, use many long wood screws ø 6-8 mm. Since the tree is already dead, you can do this as an exception Normally, a reasonably healthy, freshly cut tree should remain standing for another 10 – 15 years. After that, either the children are too big, or the children have to support their little house with wooden stilts.