Treehouse Fasteners Explained: TABs vs. LAGs and How to Use Them

A treehouse attachment bolt (TAB) and a treehouse lag bolt are two different types of fasteners commonly used in treehouse construction today. Let's explore how they differ and when to use each:




Treehouse Attachment Bolt (TAB)

A Treehouse Attachment Bolt, also known as a TAB or a Garnier limb, is a specialized type of fastener designed for treehouse installations. It consists of a long, threaded steel rod with a large, round, or square plate at one end. The threaded portion is inserted through a pre-drilled hole in the tree trunk, while the plate rests against the outer surface of the tree. The bolt is secured in place by tightening a nut on the threaded end. TABs are typically installed higher up on the trunk, away from the ground. 

When to use TABs:

TABs are used when constructing treehouses that require a high load-bearing capacity. They provide exceptional strength and stability, making them suitable for larger or multi-level treehouses. TABs are also preferred in situations where the tree is expected to grow, as they allow for some flexibility and movement. 


Treehouse Lag Bolt:

A Treehouse Lag Bolt, also known as a lag screw or lag bolt, is a heavy-duty screw with a coarse thread and a pointed tip. Unlike the TAB, the lag bolt does not have a large plate attached to it. Instead, it relies on its thread pattern and self-drilling capabilities to secure the treehouse components. Lag bolts are typically shorter than TABs and are installed at a shallower depth.

When to use lag bolts:

Lag bolts are used for lighter or smaller treehouse structures that don't require as much load-bearing capacity. They are suitable for attaching beams, joists, and other framing components to the tree. Lag bolts are easier and quicker to install compared to TABs since they don't require the drilling of a large hole. However, they may not provide the same level of long-term stability as TABs.


Does your treehouse need TABS or Lags?

The simple answer: it depends on the size of your treehouse.


For Treehouses 75 square feet and under:

Our MINI treehouse hardware kits use Lag Bolts, and (depending on the shape of the structure you choose) will generally work for treehouses up to 75 square feet in size

For Treehouses larger than 75 square feet:

Our SMALL Treehouse Hardware Kits and STANDARD Treehouse Hardware Kits use TABs and (depending on the shape of the structure you choose) will generally be suited to treehouses over 75 square feet in size

NOTE: these recommendations are based on the quality and weight-bearing capacity of our TABS and Lag Bolts, which we have tested vigorously. Other products on the market may not match our quality and load capacity. Individual needs may differ and there may be exceptions to this recommendation. We recommend factoring in the live load and consulting an engineer as needed.


We've carefully developed our easy-to-use system of Treehouse Hardware Kits that combine with our Treehouse Construction Plans to construct the treehouse of your chosen shape and size (just add lumber and you're all set to master a DIY Treehouse project!). Our system of Plans and Kits makes the choice between TABs or lags that much easier- with a hardware kit tailored to the size of the treehouse you intend to build. 



To sum up, TABs are heavy-duty, large-scale fasteners designed for high-load applications and long-term stability. They are ideal for larger treehouses or situations where the tree is expected to grow. Lag bolts are more suitable for smaller or lighter treehouses and provide a simpler installation process.

The choice between TABs and lag bolts depends on your treehouse project's specific requirements and the structure's load-bearing needs. Still not sure what will work for you? Contact Us, we'd be happy to help!

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