Treehouse Veteran Corbin Dunn’s Inside Tips on How to Avoid Treehouse “Fails”

Treehouse Structural Failure

Sometimes the best lessons are learned from our mistakes. Which means they’re not really failures at all (hence the quotations in the title), but opportunities for improvement. Corbin Dunn lived in a treehouse for five years before his girlfriend urged him to move out. They started using the treehouse for storage instead.

Which turned out to be a really good move, given what happened next.

One day Corbin arrived and most of the floor had fallen 40 feet to the ground, along with the storage items, most of which were damaged in the plummet.

 

He says he cut some important corners during the building process. Here, in his own words, are the no-no’s he warns us against:

1. HUGE 24′ spans with doubled up 2×6′s (not quite as strong as a 4″x6″), with ZERO 45 degree supports underneath the house. I initially had put a few 45 degree supports, but my lackluster attachment made them not do much, and they eventually just fell down. Now, douglas fir isn’t made to span that huge of a distance, and was prone to have a huge amount of support weight on the edges.

2. Non-floating foundation. Ideally, I should have made metal brackets that would allow one end of the attachment to the tree to “float”. Since I didn’t do that, the movement of the trees was slowly pulling the house apart. It was particularly worse when it was really windy out, and it made the whole house creak really bad. NOTE to self now that I can weld: make brackets!

3. Built-in foundation. Instead of having some joists that the real floor would be built upon, I just built it directly into the joists. That works for smaller houses, but for larger treehouses it wasn’t a good idea. The floor acted like a torsion box, and probably flexed the worse at the ends.

4. Related to #2 — “tree on wood contact”. The edges of the 2x6s had two 6-8″ lag bolts bolted into the tree. The wood-on-bark contact never would really dry out, allowing it to rot slightly.

By avoiding these – ahem – pitfalls, you can build a treehouse that will weather the storms for many years to come. See Corbin’s photos and full story.


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