Europe's first online shop
for tree house builders
HOW TO: Attach
1. German Treehouse Screws – Overview and application range
In our Onlineshop you can choose from 4 screw models:
We use the GTS Allstar most frequently (approx. 90%) – it stands for maximum load-bearing capacity, safety and stability, and is easy to install in any tree. It can carry vertical loads of 2.5 – 4.5 tons. Due to the large cylinder, it can also be loaded horizontally. Horizontal – i.e. lateral – loads are generated, for example, by wind fluctuations or tensile loads from suspension bridges.
Are you looking for the ultimate resilience? In combination with a Cable Suspension from above, we have achieved vertical loads of up to 8 tons in hardwood! If you support the construction from below with a Strut Connector, loads beyond 8 tons are possible!
Our newly developed GTS Top is primarily intended for vertical loading with small log diameters. It can also handle loads of 3 tons in hardwood! The big advantage: No cylinder – minor injury – very easy assembly – the tree thanks – the people cheer!
The GTS Friend is primarily intended for position securing and supports the larger screws that carry the main load; it is a tree, strength and budget-friendly helper and is used:
- when small loads occur (< 1000 kg)
- for triangular constructions as lower screw (with V-Bracket and 45°-Diamond Bracket)
- for mini platforms, supporting structures, stairs, bridges, …
- for very small trunk diameters (because less tissue is injured)
Our GTS Safety has two areas of application:
- To amplify the GTS Allstar in combination with the Cable Suspension
- To secure the position of the platform (tilting, wobbling) & to suspend small loads (< 500 kg).
2. Loading 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, firmness, age)
- Local wood quality (instead of drilling)
- Lever arm (where the screw is loaded)
- Load type (static, jerky or oscillating)
- Quality & precision of installation
It is difficult to make accurate statements about the load-bearing capacity, since these are living trees with completely individual properties, and not standardized timber.
Our load values therefore serve only as an orientation – a safety factor >2 should always be used, i.e. instead of a load of 4 tons (average value of our tests), the GTS Allstar should only be vertically loaded with 2 tons.
In addition to the properties of the wood, the lever arm in particular has a major influence on the load-bearing capacity of the screws; the lever arm is the distance from the bark to the support point of the bearing. The following figure illustrates: the larger the lever arm, the lower the load capacity of the bolts. Distance Rings help to limit the movement of the support.
3. GTS Safety & Cable Support System
The GTS Safety serves as a back-up for the large GTS screws. It is usually used to reinforce the GTS Allstar and thus guarantee maximum stability. Safety and GTS are connected to each other by a steel cable.
Read more about the Cable Suspension Set on the product page.
If you want to remove your tree house, or notice that a screw reaches its static limits, then the rope protection can also be retrofitted without any problems.
The rope safety device is also an excellent way to hang the platform from the side and to prevent it from tipping over and wobbling.
4. Accessories – Supports and Distance Rings
You will need a suitable support to attach the support beams to the screw. The supports are simply pushed onto the shaft of the GTS and hold the support beam in place. If you build in several trees, the trees must be able to move independently or “dance in the wind”. For this purpose, fixed bearings are attached to the most solid tree and movable supports to the other trees.
The “Static Support” is used for single-tree tree houses, triangular constructions and multi-tree tree houses as an anchor point in the most solid tree.
The Dynamic Support gives the trees room to move so that they can swing independently in the wind. This is very important: on the one hand, it prevents tension from being exerted; on the other hand, trees use their movement to identify where they need to grow wood in order to be able to compensate for the new strain on the tree house more quickly.
Distance Rings are small metal rings (10 or 40 mm long) which are pushed onto the shaft of the screw. The rings are used to determine the exact position of the supports, their clearance and distance from the tree.
5. Accessories for triangular construction
The support triangle is a popular construction element. Instead of placing two screws opposite each other in the trunk, a triangular construction is built with two screws lying one below the other. This results in the following advantages:
- The triangle is stiffened in itself and cannot tip over.
- The triangle can be freely dimensioned. The larger the triangle, the more stable it is.
- The platform rests on top of the triangle and can be fixed far outside.
- Screws lying one below the other have the advantage that fewer water and nutrient pipes are damaged (vessels in the trunk run vertically).
The V-Bracket is designed for smaller constructions, the variable angle gives plenty of design possibilities.
The 45° Diamond Bracket is designed for large triangles and heavy loads, the struts have a fixed angle of 45°. The closed rear wall makes it possible to fix beams that protrude forwards, making even larger platforms possible.