Product Overview

Screws & Accessories for treehouse assembly – 100% Made in Germany

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Every tree and every tree house is unique – that’s why you need an individual set of attachments for every project.

In our online shop, we sell exactly these fasteners for a permanently secure connection of tree and treehouse. Here you will find a rough overview of our Treehouse Screws and the matching Accessories. You can find more details on the product pages.

Treehouse-fixation-tree-buy-assembly-products

6 Treehouse Screws

Dimensions in Comparison
Field of application
Load Capacity

Screw Accessories

Supports and Distance Rings
Triangle Construction with Brackets
Struts
GTS Back-Up with „Strut GTS +“ and „Cable Suspension“

6 Treehouse Screws

Steel screws for treehouse construction GTS Product overview

1. Dimensions of the Screws in comparison

German Treehouse Screw - Treehouse Screws Models Comparison Cross Section Tree

With its massive cylinder, the GTS Allstar has the highest load capacity and the widest range of applications; it is, so to speak, the “mother of all Screws”. The other Screws do not have a cylinder and are rather intended for smaller constructions and support applications.

comparison dimensions tree house screws gts models 2021

Low tool requirement due to optimally matched products!

All GTS Screws (except the small GTS Safety) can be pre-drilled with the same ø 36 mm Auger Drill.
All GTS Screws can be screwed into the tree with the same 1″ Ratchet + 46 mm nut.
For the GTS Allstar, the hole for the cylinder (Forstner-Pin Combo) must also be pre-drilled.

2. Field of application of the GTS Screws

In our shop you can choose from 6 Screw models, each Screw has its own special area of application.

GTS Allstar

The GTS Allstar is our flagship and the most frequently used Treehouse Screw. It is the best choice because it can carry enormous loads both vertically and horizontally – in softwood (spruce, fir, pine, etc.) it can reach a vertical load capacity of up to 2.5 tonnes. In combination with Strut GTS + or Cable Suspension, the GTS Allstar can carry 6–8 tonnes in hardwood (oak, beech)!

Because of the large cylinder, it should only be installed in trees ø > 35 cm (14 in).

“In our ‘Baumbaron’ carpentry workshop, we always use the GTS Allstar as a base for our tree houses. The other Screws then expand the scope!” – Vitus W.

GTS Top

The GTS Top specialises in medium vertical loads on small trunk diameters ø < 35 cm (14 in), where the GTS Allstar would be oversized. Instead of the large cylinder, it has a small support plate and is therefore gentler on trees than the Allstar. This advantage is particularly effective in hardwood. In softwood, on the other hand, the load-bearing capacity decreases considerably, and here it is only suitable for smaller projects.

GTS Friend

The Friend is our helper for light loads. It is often used as a lower anchoring point for tribeam constructions, tree swings and auxiliary constructions. It should not be loaded too much in soft wood!

GTS Side

The GTS Side enables the attachment of laterally projecting wooden beams to the tree and is therefore ideal for smaller platforms, landings and stair constructions.

GTS Free

The GTS Free is a slimmer stainless steel version of the GTS Friend that comes without Accessories. It is ideal for the smallest platforms and children’s playhouses < 10 m² (110 sq ft) where a small budget must be considered.

GTS Safety

The GTS Safety is a complementary Screw for rope fixings, awnings, fairy lights, etc.

3. Load capacity of the Screws

Tree Bolts Test and Development Laboratory FH Munich

The picture shows one of our numerous load tests, here in the laboratory of the Munich University of Applied Sciences.

The load capacity of the Screws depends on the following factors:

Individual tree (tree species, growth form, strength, age).
Wood quality in place of drilling
Lever arm (where the Screw is loaded)
Direction of load (vertical / horizontal / compression / tension)
Type of load (static, jerky or swinging)
Quality & accuracy of assembly

comparison load capacity german treehouse screws load capacity tree wood

Vertical load capacity:

The vertical load capacity of our GTS Screws is shown in the graph and applies to a lever arm of approx. 10 cm.

Horizontal load capacity:

The horizontal / lateral load capacity is approx. 1/3 of the vertical load capacity.

Pull-out resistance:

The pull-out resistance, i.e. the force required to pull a screw horizontally out of the tree, is approx. 300 kg (660 lbs) for large tree threads in softwood and approx. 500 kg (1100 lbs) in hardwood.

Lever arm:

In addition to the wood properties, the lever arm has a major 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 greater the lever arm, the lower the load-bearing capacity of the Screws.

This means: the closer the support beam is mounted to the tree, the higher the load capacity!

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’).

Important note: The load capacity of the Screws depends strongly on the individual tree and its wood! The load values are only guide values – a safety factor >2 should always be calculated, i.e. instead of 4 tonnes load capacity in hardwood (average value of our tests), the GTS Allstar should only be loaded vertically with 2 tonnes!

Screw Accessories

The Accessory parts are the links between the tree screw and the wooden beam. They are attached to the large GTS models with shank ø 40 mm: GTS Allstar, Top, Friend.

(The smaller Screws, Side, Free & Safety, do not need accessories).

1. Supports and Distance Rings

The main elements for fastening the wooden beams to the GTS bolts are supports, these are pushed onto the shaft of the GTS.

Static Support

Every treehouse needs a static anchorage point, this is always the Static Support. This anchorage point is always located on the strongest tree.

Dynamic Support

The Dynamic Support can slide back and forth on the shaft of the GTS and is used in treehouses in 2 or more trees – it gives the trees room to move so that they can swing independently in the wind. This avoids constraining stresses in the trees and the wooden structure.

Static supports are used for strong, immobile trees. Dynamic Supports are used for thinner trees that are susceptible to vibrations.

Distance Rings

Distance Rings are small metal rings (10 or 40 mm long) that are pushed onto the shaft. The Rings are used to determine the exact position of the Supports, their clearance and the distance to the tree. They are very important because they prevent the Supports from slipping outwards and thus overloading the Screw by giving it too much leverage.

2. Triangle construction with Brackets

The Triangle Construction is a frequently used Support Element. The Screws are mounted one below the other on the trunk.

The Tribeam Construction offers the following advantages:

The span (supporting surface for the platform) is considerably increased.
The triangle is inherently stiffened and cannot tilt.
The triangle can be freely dimensioned. The larger, the more stable.
Screws that lie below each other have the advantage that fewer water and nutrient lines are damaged (vessels in the trunk run vertically).
The trunk can thus be somewhat thinner.

45° Diamond Bracket

The 45° Diamond Bracket is designed for large triangles and heavy loads, the struts have a fixed angle of 45°. The closed back wall allows for the attachment of forward cantilevered beams (3D), making even larger platforms possible.

V-Bracket

The V-Bracket is intended for smaller constructions, the variable angle offers a lot of leeway and design possibilities. Thus, disturbing branches can be bypassed and single-sided cantilevered decks can be built.

3. Struts

Our Struts open up additional possibilities when building your platform. You remain flexible – mount several Struts on a GTS or individual independent Struts. The beams can be firmly clamped with the height-adjustable plate. Instead of thick wooden struts, you can also mount elegant steel struts!

Strut Support GTS

This strut connector is pushed onto the ø 40 mm shaft of the large GTS – for example, up to 5 Strut Support GTS fit onto a GTS Allstar.

Strut Support Safety

This Strut is pushed onto the ø 30 mm shaft of the GTS Safety. The Strut Support Safety can be loaded in hardwood up to 1000 kg. Perfect for point support of the platform from below!

Strut Support Platform

The Strut Support Platform is the counterpart to the GTS Struts – it is attached directly to the platform. This saves you complicated angle cuts at the top of your strut. Or you can use it as a component for your steel struts.

4. Reinforcement of the GTS – Maximise the load-bearing capacity!

With the Strut GTS + or the Cable Suspension you get the maximum out of your GTS Screws.

This makes sense if:

the GTS is overloaded (too heavy a tree house)
your tree is very soft (poplar, willow, …)
you want to be on the safe side right from the start of a big project!

Strut GTS +

From below you reinforce the GTS with the Strut GTS+.

Tree screw secured from above and reinforced with rope suspension

Cable Suspension

Secure the GTS from above with a Cable Suspension.

The good thing is that you can add these reinforcements at any time. In extreme situations, you can even secure a GTS with several reinforcements.