I am building a treehouse deck and realized I installed the lag screws incorrectly into the ledger board I attached to my treehouse tribeam.

It is a 4x6 tribeam attached to the tree. A 2x8 ledger attached to the face of the tribeam with 5” 1/2 lag bolts. Then joist hangers attached to the ledger. Why I didn’t just rest the joists on top of the tribeam, I will never know; know I’m losing the structural advantage of the beam itself and relying on the strength of the bolts.

Since this is the most critical loadbearing part of the treehouse I’m wondering if I should carefully relocate the lag screws so that they are properly staggered and/or just build a new support column and beam a few feet away for peace of mind.

enter image description here

enter image description here

enter image description here

  • What kind of "stagger" would you have used?
    – FreeMan
    Commented Apr 7, 2022 at 13:18
  • I read you are supposed to have ledger lag screws not on top of each other, in more of a crisscross diagonal pattern
    – Chris
    Commented Apr 7, 2022 at 13:21
  • That would be true if you used half as many. :) Pairs are fine.
    – isherwood
    Commented Apr 7, 2022 at 13:24

1 Answer 1


Your screw location provides plenty of stagger and spread. That's not a concern. And yes, you could've simply added joist hangers to the member behind. That's water under the treehouse, though.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.