History of Treehouse Attachment Bolts

How were Treehouse Attachment Bolts Developed?

The Treehouse Attachment Bolt has only come into the spotlight only since the late 1990s. However, the theory behind it runs back for centuries in the form of split ring and shear plate connections (Wood Handbook, 1935). The collars are what make TABs unique, and the idea for the collars is essentially the same as a split ring or shear plate: to get more shear strength from a single attachment point instead of pumping a small area full of bolts which weakens wood too much, according to principles both of dead timber and live wood.

The idea to use this well established technology for treehouse building in the 1990s is credited to Jonathan Fairoaks, an arborist who also builds treehouses. The idea was further developed by others, including chiefly Michael Garnier and Charley Greenwood. The shear collars got longer under Greenwood's influence which influenced the major North American treehouse builders of the 1990s and the new century. Dan Wright (Tree Top Builders, Inc) built upon Greenwood's publicly posted STF model by making adjustments to the thread count, sizes, and installation markings.

Not every model of Treehouse Attachment Bolt prototypes is still in existence. Fairoaks created a behemoth of an aluminum bolt with a 2" stud with a special end that was three times as strong as other bolt prototypes created by others such as the GL. The problem was that it cost four times as much to produce, and it was difficult to install. Though not recommended by any professionals in the treehouse building industry, several versions of all thread welded "Fake Limbs" have been created over time. They are a lot cheaper, but of much lower quality and reliability. The chief reasons to avoid this method are the normal machine stresses in all thread, absence of a stress transition area in the weak spot, and potential weak spots created by the welding.

Treehouse Bolt Timeline