Tree Screws, Treehouse Attachment Kits, Tools – 100% Made in Germany
Every treehouse project is unique – that’s why you need an individual set of hardware for each attachment point.
In our product overview we show you how you can combine screws and accessories to build a stable and safe platform.
6 Treehouse Screws
Our Treehouse Screws (similar to: ‘Garnier Limb’, ‘Treehouse Attachment Bolt TAB’ or ‘Tree Fastener’) are screwed directly into the tree, supporting the entire weight of the treehouse.
1. Range of application of the GTS Screws
The GTS Allstar is our heart and with 80% the most used tree screw in our online shop. It is the best choice because it can take huge loads both vertically and horizontally – even in softwood (spruce, fir, pine, etc.) it can manage up to 2.5 tons of vertical load capacity.
“In our treehouse carpentry ‘Baumbaron’ we always use the GTS Allstar as the basis for our projects. The other screws then widen the scope!” – Vitus W.
The GTS Top is an alternative to the GTS Allstar, especially in hardwood and with small log diameters. In softwood its load-bearing capacity decreases considerably, here it is only suitable for small and lightweight projects. The advantage: Since it does not have a thick cylinder, it is more tree-friendly than the Allstar. The disadvantage: The tree must be smooth and straight at the mounting point so that the steel plate fits well.
The Friend is our helper for low loads. It is often used to secure the position of triangular constructions, tree swings and secondary constructions. In softwood it should not be heavily loaded!
The GTS Side can be used to attach wooden beams to the side of the tree, making it ideal for smaller platforms, landings and stair constructions.
The GTS Free is similar to the GTS Friend, only it is made of stainless steel and has a slightly thinner shaft – this allows it to be mounted directly in the tree as well as in the wooden beam. Difference to the GTS Friend: you don’t need any screw accessories & no supports. Perfect for small DIY kids treehouses with light weight and low budget.
The GTS Safety is a supporting screw for rope fastenings, awnings, fairy lights, etc.. – It is not a load-bearing treehouse screw.
You can find more detailed information about the individual screws on the respective product pages.
2. Dimensions of the Screws in comparison
Our products are perfectly matched to each other:
3. Load capacity of the screws
The load capacity of the screws depends on the following factors:
- Tree species (general, see here)
- Individual tree characteristics (growth habit, strength, age)
- Local wood quality (in place of drilling)
- Lever arm (where the screw is loaded)
- Load direction (vertical / horizontal / compression / tension)
- Load type (static, jerky or oscillating)
- Assembly quality & precision
Vertical load capacity:
The values for the vertical load capacity of our GTS Screws can be found in the graphic. The values apply to a lever arm of about 10 cm. The load-bearing capacity depends strongly on the individual tree and its wood!
Horizontal load capacity:
The horizontal / lateral load capacity is about 1/3 of the vertical load capacity.
The pull-out resistance, i.e. the load required to pull a screw horizontally out of the tree, is about 300 kg in softwood and 500 kg in hardwood for the large GST Tree Thread.
Note: Our load values are for guidance only – a safety factor of >2 should always be applied, i.e. instead of 4 tons load capacity in hardwood (average value of our tests), the GTS Allstar should only be loaded vertically with 2 tons!
In addition to the wood properties, the lever arm in particular has a great influence on the load-bearing capacity of the screws; the lever arm is the distance from the bark to the centre of the support. The upper picture illustrates: the larger the lever arm, the lower the load capacity of the screws.
For static calculations: The pivot point of the screws is in the inner quarter of the tree thread (in the picture approximately at letter G of ‘GTS’).
Distance Rings are used to prevent the support and beam from slipping completely to the outside.
The accessory parts can be attached to the large GTS models (shaft ø 40mm):
- GTS Allstar
- GTS Top
- GTS Friend
1. Reinforcement of the GTS with ‘Strut GTS +’ and ‘Cable Suspension’
With a reinforcement you maximize the load capacity of the large GTS screws!
That’s necessary, if:
- the GTS reaches the limit of its load-bearing capacity
- your tree is very soft (poplar, willow, …)
- you want to be on the safe side right from the start of a large project
- your GTS is already overloaded
In our tests we were able to increase the load capacity of the GTS Allstar to almost double with only one reinforcement!
2. Supports and Distance Rings
To fix the wooden beams on the GTS Screws you need supports, these are pushed onto the shaft of the GTS.
The sliding Dynamic Support is used for treehouses in 2 or more trees – it gives the trees room to move so that they can swing independently in the wind. This prevents constraining stresses on trees and wooden structures.
The sturdy, thick trees are equipped with ‘Static Supports’, the smaller trees dance with ‘Dynamic Supports’.
Distance Rings are small metal rings (10 or 40 mm long) which are pushed onto the shaft of the GTS Screw. The rings are used to determine the exact position of the supports, their clearance and distance from the tree.
3. Triangular construction with Brackets
The supporting triangle is a frequently used supporting structure: Instead of mounting two bolts opposite each other in the trunk, one builds a triangular construction with two bolts lying under each other. This results in the following advantages:
- The span (surface for the platform) is significantly increased.
- The triangle is inherently stiffened and cannot tilt.
- The triangle can be freely dimensioned. The bigger the more stable.
- Screws placed one below the other have the advantage that fewer water and nutrient lines are injured (vessels in the trunk run vertically).
- The tree trunk can therefore be somewhat thinner.
The ‘Brackets’ are slid onto the lower GTS and hold the top of the wooden triangle.
Our struts open up more possibilities for the construction of your platform. You remain very flexible – mount several struts on one GTS or single independent struts on thinner trees. The struts can be firmly clamped with the height-adjustable plate. Instead of thick wooden struts, you can also attach elegant steel struts!
The tools (drill and ratchet) are necessary to install our Screws in the tree. It has been extensively tested by us and is perfectly matched to our GTS screws. You can either buy the parts individually or rent them in a toolbox.