HARDWARE FAQ
- What TAB bolts should I use for my design?
When we are choosing TAB bolts, we look at several factors:
- Determine the size of the platform
- The number and species of trees involved
- What do you plan to build/load on the platform
Architects typically use 40 lbs. per square foot for decks only and 65 lbs. per square foot for decks with structures on top.
Almost all our clients build a house on top, so here is a typical scenario that may help you.
14 x 14 Treehouse in 4 trees:
196 S.F.
196 x 65 lbs. per S.F. = 12,740 lbs.
12,740 lbs. divided by four trees = 3,185 lbs.
We tested our TABs in an oak tree to the point where the TAB failed.
(By failed, we mean it began to pull down or sag in the tree) Here are our results:
TAB 1x9 = 3000 lbs.
TAB 3x9 = 4500 lbs.
TAB 6x12 = 8000 lbs.
Keep in mind the softer the tree species, like pine, the lower these numbers will be vs. a bit more in a harder tree, like hickory, etc.
So in our example, we would recommend TAB 3x9’s for the 14 x 14 treehouse.
- Do the hardware kits come with lumber?
Lumber and Wood products are not included in our kits. The kits include tree attachment bolts & brackets and downloadable plans.
The plans include lumber lists you can take to a local lumber yard for a quote and local delivery.
- What size drill bit should I use to drill the hole for my TABS?
For our standard-size TABs, you will want to use a 3” speed bore, a 1” ship auger, and a 1-⅛” Ship auger.
On softer woods like pine, fir, spruce, or cedar, you may be able to use the 1” auger for the entire stem section of the bolt.
For very hard trees like hickory, pecan, and maple, you may need to ream out the 1” course section of the pilot hole using a 1-1/16” ship auger. This will enable you to turn the TAB into the tree.
- What weight are the Treehouse Attachment Bolts (TABs) rated for?
We tested our TABs in an oak tree to the point where the TAB fails (beginning to pull down or sag in the tree).
Here are our results:
TAB 1x9 = 3000 lbs.
TAB 3x9 = 4500 lbs.
TAB 6x12 = 8000 lbs.
Keep in mind the softer the tree species, like pine, the lower these numbers will be vs. a bit more in a harder tree, like hickory, etc.
Note: Due to all of the variables involved, we do not publish actual ratings on the TAB bolts – the ratings would be so high that the tree tissue would crush far before the bolt actually breaks so the numbers would be misleading.
We consider publishing ratings to be unethical for this reason. We have engineers on staff who can assess the situation and make certified hardware recommendations, which can help you design for commercial projects.
For simple backyard designs, our design team can make recommendations based on their long experience designing and building successful treehouse projects.
