German Treehouse Screw ‘GTS’
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Whether it’s a large platform, a kid’s treehouse, a hunter stand or a swing beam – if you want to attach something heavy directly to a living tree, Tree Screws are the best solution!
1. What is a Treehouse Screw?
Without Treehouse Screws (or Treehouse Bolt), modern treehouse construction would not exist. The technology was developed more than 20 years ago by the American treehouse pioneers Charles Greenwood, Michael Garnier (Garnier Limb – “GL“) and Pete Nelson (Treehouse Attachment Bolt – “TAB“). Based on these American bolts, we have further optimized our Treehouse Screws and adapted them to the European market – we proudly present:
Example of “German Treehouse Screw GTS” (also known as “Tree Attachment Bolt TAB”, “Garnier Limb GL”, “Treehouse Fastener”, “Treehouse Bolt” or “WorldTreehouseOrganisation Bolt”)
2. What makes Tree Screws so special?
Treehouse Screws (or treehouse bolts) are extra-large screws which have been developed for mounting in the living tree. They can carry extreme loads of up to 8 tonnes.
The advantage over other attachment methods is that the wooden beams keep their distance from the bark and do not pinch the tree (see picture). In this way, the tree can continue to grow unhindered and wrap the screw tighter year after year – a kind of artificial branch is created.
The area of application is wherever heavy objects are to be permanently and securely fastened to the tree trunk: Treehouses, platforms and installations in tree adventure parks, aerial forest parks, high ropes courses, and tree top trails.
3. Why shouldn’t you use normal wood screws?
Attention:
Ordinary wood screws and threaded rods with a ø < 40 mm should not be used for fixing in the living tree – this is for the following reasons:
- The material is not designed for the load:In contrast to normal timber construction, large swinging and twisting loads occur in the living tree (storms). This continuous alternating stress can lead to fatigue fractures in normal screws.
- The tree grows with great force in width: wooden beams that are screwed directly to the trunk can rot and break; screws can bend and break off.
- If the trunk is pinched over a large area and prevented from growing (clamping technique), predetermined breaking points can develop there.
See: Advantages and disadvantages of the different fixing methods
4. How exactly do Treehouse Screws work?
Our “GTS Allstar” has three segments:
- a: Coarse thread
- b: Cylinder
- c: Shaft (+ support + beam)
First, a precise hole must be pre-drilled; the coarse thread (a) and part of the cylinder (b)are screwed in. The part of the screw that sits in the tree transfers the load of the treehouse(F) into the trunk.
The other half of the cylinder and the shaft (c) are outside the tree. The supports including the wooden beams are mounted on the shaft.
Good to know:
The screw remains at the same height in the tree throughout its life, like an incised heart; only at the buds does the tree grow upwards.
Example of “German Treehouse Screw GTS” installed in tree (also known as “Tree Attachment Bolt TAB”, “Garnier Limb GL”, “Treehouse Fastener”, “Treehouse Bolt”)
Around the screw, the tree forms resistant wound and reaction wood . Over the years, the screw is further surrounded and becomes a permanent part of the tree.
See here, whether Screws harm the tree?
5. Load capacity depending on tree and lever arm
The load-bearing capacity of our Treehouse Screws depends strongly on the wood properties of the respective tree. In general, it can be said that screws in hardwood (oak, beech, maple, …) are about twice as resilient as in softwood (spruce, fir, pine, …).
See here: Is my tree hardwood, medium hardwood or softwood?
The following table gives an overview of the load capacity of the individual GTS Screw (the values were determined during load tests):
Also, the load capacity depends on the lever arm, the place where the load rests (centre of support + beam). The closer you get to the tree with the construction, the higher the load-bearing capacity of the screw becomes! For normal loads, we recommend about 10 cm (4 in) distance between beam and tree.
The load capacity can be almost doubled with Screw Accessories!
6. Advantages of our “German Treehouse Screw GTS”
- Proven fastening technology for over 20 years!
- 100% Made in Germany – Bavaria!
- Lifetime warranty on all our GTS Screws!
- Extremely high load capacity (in tests with rope backup, up to 8 tons vertical load)
- High safety & lasting stability
- Free thickness growth for tree
- Very low maintenance
- We sell 6 different Screw models, there is a suitable tree screw for every situation.
- Many Accessories
- Low tool requirements thanks to perfectly matched products.
- Work cordlessly: Thanks to the advanced screw geometry and sharp tool cutting edges, pre-drilling is effortless with a powerful cordless drill. Disturbing cables are thus a thing of the past.
- Screw and Accessories were assembled for the European market, i.e. metric dimensions, time-saving tool and spare parts procurement, no expensive special tools.
Technical details:
- Special Tree Thread: Specially developed coarse thread for tree guarantees high pull-out resistance about 500–1000 kg (1100-2200 lbs) & optimal power flow.
- Max Load Cylinder 74: The massive cylinder (ø 74 mm) transfers even the heaviest loads safely into the tree trunk.
- Seal +: The larger cylinder seals the drill hole, the screw fits snugly and tightly. Slight indentations show you how deep the screw is in the tree.
- Natural Transition: Over the years, the tree will to cover the screw. This process is facilitated by the parabolic cylinder transition. The flowing transition makes the overall look more aesthetic – like a natural branch.
- Shaft 40: With a diameter of ø 40 mm (1.57 in), the shaft can withstand even the greatest alternating stresses – peaceful sleep is guaranteed.
- Seamless: We fabricate without weld seams, this makes the screws indestructible!
- Black KTL Coating: The environmentally friendly coating process ensures optimum corrosion protection and excellent sliding properties. Thanks to the black look, the GTS disappears inconspicuously in the tree.
7. Step-by-Step Installation Tutorials
Take a look at our assembly videos in the Service-Section and on YouTube!
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