Treehouse Platform Construction
1. Small 1-tree platforms
GTS Free – For the very small ones:
The GTS Free is our low-cost solution for small decks, children’s treehouses and simple playhouses in the garden. All you need are 4 x GTS Free to attach a small triangular construction to the tree! As the GTS Free goes directly through the wooden beam (without Supports and Accessories), the GTS Free has less load capacity and is therefore only suitable for the smallest platforms:
Minimum trunk diameter:
- for two opposing GTS Free: ø > 30 cm (12 in)
Size of the platform:
- < 6 m² (65 sq ft) in softwood (spruce, pine, etc.)
- < 10 m² (107 sq ft) in hardwood (oak, beech, maple, etc.)
- The tree should be centred and the platform should not project far.
- Reinforce your support beams around the GTS Free with fully threaded screws.
- Use lots of screws and wood glue or better PU glue to stabilise your lower triangular connection around the GTS Free.
- You are welcome to build a children’s playhouse on top of it, but it should be really small and light.
Your tree trunk is very thin – move the Screws!
With this trick, the treehouse can also be anchored in very thin trunks. However, the trunk should not be thinner than ø < 25 cm (10 in) at the attachment point. The Tree Screws damage too much tissue, the tree still grows a lot in width and a thin tree still sways very much in the wind.
If the trunk is thinner than ø 25 cm, we recommend waiting or building the treehouse on stilts.
Trick: Move Tree Screws
If your tree is very thin, stagger the height of the opposite screw on one side by at least 10 cm (4 in) – this way the screws can’t get in each other’s way (see picture 1 & 2). The support beam on one side is simply doubled.
Variation: Only one triangle + stilts
This solution (see picture 3) is especially suitable for small trees that are very close to the property line and where the treehouse would otherwise protrude over the fence to the neighbour. With the supports set in concrete, you can build a slightly larger platform. Don’t forget to brace your supports with small stirrups / headbands, otherwise your treehouse will tip over towards the neighbour.
Remember that small, young trees still want to grow properly – plan your treehouse so that this is possible!
Building a treehouse on a tree stump
Of course, you can also attach your platform or part of it to a freshly sawn-off tree trunk. Since the tree is either dead or no longer expected to grow thicker, you can attach your beams directly to the trunk with ordinary wood screws (ø 8 mm galvanised). If you protect the freshly sawn-off trunk from direct water, your trunk will certainly stand for another 10–15 years – if it is no longer stable, you can put your tree house on stilts instead. Caution: Never build in rotten, fungus- or pest-infested trunks!
GTS Friend – For solid projects in small trees:
Instead of the upper GTS Free, for example, a GTS Friend + Static Support + Distance Rings can also be used: This way, the support beam can be mounted with more distance to the tree and the mounting of the wooden beams becomes even easier. Especially with crooked and laterally inclined trees, this gives you the necessary leeway!
If you want to get the maximum out of a thin tree trunk < ø 30 cm (12 in), it is better to use the GTS Top instead of the GTS Friend (the trunk must be very straight at the mounting location!).
GTS Free, Friend and Top are only suitable for small platforms. Especially in softwoods (spruce, fir, pine) and with lateral torsional loads, the load-bearing capacity is limited.
2. Medium-sized 1-tree platforms with GTS Side and wooden brackets
Another way to attach a platform in the tree is with the GTS Side and Brackets. The side-mounted “open” triangles made of wooden beams are easy to prefabricate and assemble. In some situations you are more flexible with single wooden brackets than with ready mounted triangles, you can avoid branches better and adapt to the peculiarities of the tree.
Minimum trunk diameter:
The trunk diameter of 4 brackets should be ø < 35 cm (14 in)
- Softwood < 12 m² (130 sq ft)
- Hardwood < 16 m² (170 sq ft)
- The consoles should be loaded as evenly as possible.
- Pull-out loads on the upper GTS Side must be avoided at all costs, preferably by means of an opposite Screw.
- Lateral torsional movements should also be avoided by design.
- Here, too, it is possible to build in somewhat thinner trunks by offsetting the height of the opposite brackets (see above).
Variant 1 – Screw struts directly to the trunk:
This is a quick and inexpensive solution for temporary treehouses.
Moisture can accumulate at the point of contact between the tree and the beam, and the beam can rot there. If your tree is still very small and young (< 40 cm (16 in)), we advise against screwing wooden beams directly to the trunk – the trunk still wants to grow strongly in width and will be prevented from growing or your brace will be “pushed away”.
With thick, mature trees, there is nothing to be said against screwing individual beams directly to the tree. Use sturdy wood (oak, robinia) for the beams and several wood screws ø 8 mm (0,3 in).
Variant 2 – Fix struts with Strut Support Safety:
With the Strut Support Safety you can also adjust the height of the strut afterwards and thus wedge the platform firmly (see pictures). The advantages are obvious:
- you have more room to manoeuvre during assembly (unevenness on the trunk is irrelevant).
- the length of the struts can be adjusted later, the cutting does not have to be so precise.
- you give the tree more time to adapt to the new construction
- the tree can simply wrap around the small GTS Safety and continue to grow undisturbed.
- Waterlogging at the struts is not an issue for the time being – so you can do without expensive and difficult to work with oak and robinia.
Variant 3 – With large “GTS + Support” instead of GTS Side:
This construction is also a classic! The two parallel beams at the top form the basic framework of your platform. Depending on the load, you can freely choose which 2 GTS Screws you use at the top.
As you can see, there are many possible combinations of our products – there is a suitable attachment for every platform and every treehouse!
Find the right hardware for your project!
Example for illustration – loading of a platform without a treehouse:
1 – The front strut (1) must take a lot of compression load: It should be strong; possibly brace in the middle with an intermediate strut diagonally upwards; a second strut parallel would also be useful.
2 – The upper GTS bolts are pulled strongly in the direction of “arrow 2”. The platform wants to tilt down with the load. If we didn’t have an extension on the right, the upper GTS would be very strongly loaded on extension (2)! This is exactly why we have the upper Screw opposite, which is now pressed into the tree and absorbs the tensile load.
3 – All the Screws on the left together transfer the vertical loads into the tree trunk.
4 – The large lever arm on one side also creates lever forces upwards (4, 5, 6) on the opposite side. Especially the strut (6) is subjected to tensile loads. These parts should be specially bolted, glued and reinforced with angle plates.
Assessment of the attachment of the example platform:
In hardwoods (oak, beech, maple, …) this construction is possible with low loads (e.g. platform + small children’s playhouse).
In softwoods (spruce, fir, pine, …) or when building a large tree house, larger GTS Screws (GTS Allstar) should be used. In general, we always recommend using the large GTS Allstar as soon as the trunk diameter is > 35 cm (14 in). This also makes a stable 3D triangular construction conceivable! More about this below!
When planning your platform, think about where the loads will be transferred to and what forces will occur at the connections. Also think about horizontal loads (storms) and rotational movements – with a staircase or slide firmly embedded in concrete, you can additionally stiffen your construction!
3. Large 1-tree platforms with triangular constructions
If you want to build a big tree house, stable 3D triangle constructions are the best choice! If possible, use our tree screw GTS Allstar – especially with softwoods you are on the safe side.
The advantages of triangular constructions with our “Brackets” and “GTS Allstar”:
- The triangles are very stiff in themselves
- The “GTS Allstar” can also take horizontal loads in softwood
- Cantilevered platforms are thus easily possible
- The long shaft allows the beams to be positioned further out – the tree can grow undisturbed.
Minimum trunk diameter:
At the height of the upper attachment ø > 35 cm (14 in), at the height of the lower attachment ø > 45 cm (18 in).
Size of the platform:
- Softwood < 20 m² (215 sq ft)
- Hardwood < 30 m² (320 sq ft)
Example – Large platform with 2 x Triangle Set – 45° Heavy
Rough instructions for assembling the triangles in the tree:
The easiest way is to prepare the wooden triangles (white) on the ground.
- First mount the upper Tree Bolt (GTS Allstar)
- Lift the triangle (or part of it) onto the upper GTS and align it so that everything is in the water.
- Temporarily fix the triangle with 4 wood screws to the support (Static Support), so you can correct it later.
- Now mark the position for the lower drill hole
- Tilt the triangle to the side and install the lower Tree Screw.
- Finally, slide the whole triangle (incl. Distance Rings) onto both Screws – done!
Always consider the leverage and rotational forces on single-sided overhanging constructions! Install diagonal braces – these stiffen the platform and transfer the forces directly to the tree.
In this example, the lower Screw, for example, is heavily loaded horizontally. In hardwood this is OK as long as you don’t build a heavy treehouse on top.
In softwood, you should also use the GTS Allstar instead of the small GTS Friend – it can better absorb the lateral forces and rotational movements due to the large cylinder!
Tip – components that project strongly on one side:
In the case of structures that rotate easily, such as this one above, it is better to install 2 Static Supports per GTS Screw by doubling up the support beam at this point. This way the connection can withstand strong shear and torsional loads.
A staircase set in concrete can also help to relieve the load.
4. 2-tree constructions with parallel beams and Dynamic Supports
The construction with parallel beams is simple:
- The space under the treehouse can be used freely.
- Spans of up to 6 m (20 ft) are easily possible.
- Thanks to the Dynamic Supports, the trees can swing freely.
- Depending on the load and trunk diameter, you choose the appropriate GTS Screw.
- Also ideal for a platform between 3 or 4 trees.
The beam dimension can be calculated very easily (see photo), read more in our FAQs.
Tips for the design of the platform:
- Place Static Support on the thicker tree, it swings less and is the fixed point.
- The main load should be on the side of the Static Support.
- The treehouse (main load) should be as central as possible above the beam.
- Avoid lateral loads and large lever arms (see picture 2).
If your platform is nevertheless loaded laterally, there are two simple solutions to support the cantilevered parts:
1. From below – Strut Support Safety or Strut Support GTS
If you only need one strut and want to support smaller loads, the Strut Support Safety is your choice.
For larger loads, several Strut Support GTS can be mounted on the shaft of our large GTS bolts (Allstar, Friend, Top)!
Attenzione Sensazione!!! Work on the moving side (on the Dynamic Supports) without Distance Rings – this way the struts remain somewhat movable and can absorb the movements of the construction.
2. From above – with a Cable Suspension
If the struts at the bottom bother you, you can also secure your platform from above. The advantage of rope suspension is that it is easy to assemble and adjust.
A stable branch fork or a twig where you can attach a tree loop is suitable as an anchor point. Alternatively, you can hang the rope on one of our Tree Screws.
Fasten the steel cable to the wooden beam with a ring nut and carriage bolt and, if necessary, reinforce the platform construction there. Tighten the steel cable with a turnbuckle.
Alternative: Triangular construction – Spread your wings!
If you build a wooden tribeam, you pull the beams further out and your platform becomes more stable! The triangular construction can absorb and dampen slight vibrations.
The following 3 examples show which supports you need (see picture floor plan):
- Scenario: both trees thick (ø > 50 cm) & hardly any vibrations: Tree 1 – Static Supports.
- Scenario: Triangle tree very thin (ø < 35 cm) vibrates in the wind & tree 1 thick (see picture): Tree 1 – Dynamic Supports completely bounded laterally by spacer rings, Dynamic Supports can only move in the direction of Tree 2, not laterally.
- Scenario: Tree 1 thin & triangle tree thick: Tree 1 – Dynamic Supports, laterally limited with Distance Rings.
5. 2-tree construction with triangles
A supporting structure made of triangles opens up many possibilities for the design of the platform. Even cantilevered shapes and large base areas can be realised with it.
The structure usually works as follows:
- prefabricate the triangles on the ground
- fix the triangles in the tree (with our GTS Tree Screws)
- screw your platform construction on top (e.g. 6 × 12 cm beams) – this can protrude over the triangles.
- When the triangles and the platform level are firmly screwed together and braced, the platform is covered with the floor boards.
Minimum log diameter:
The trunk diameter for a triangle in a tree should be > ø 35 cm (14 in) for the lower bolt (with only one triangle per tree).
- Softwood < 30 m² (320 sq ft)
- Hardwood < 40 m² (430 sq ft)
Oh wind, oh wind – how do the triangles stay mobile?
- The triangles have some play on the shaft of the GTS Screws by default.
- As a rule, the wood of your platform construction will absorb the remaining movements.
If you want to build very high or in very thin, wobbly trees, you should think of a construction that can absorb these movements.
For example, you can decouple the platform from your triangular truss with “sliding shoes”: For this you can buy Sliding Plates made of PE-HD in our shop!
6. Treehouses in 3 or more trees
Congratulations! With the knowledge from the previous examples you are now ready to plan a treehouse in several trees. You can find more useful details in our article Support Elements. Finally, a few examples with multiple trees:
If you are still not sure how your treehouse should look like, then take a closer look at our article Planning and Building Treehouses!
Just like every tree, every treehouse is unique! Take your time, make sketches, combine our products and design the perfect platform as the basis for your dream house!
Here are the 5 most important rules for building a treehouse:
- Trees and their branches swing independently in all possible directions.
- The tree wants to grow – give it room to do so: The trunk diameter ø increases by approx. 5–15 mm (0,2-0,6 in) every year.
- Keep the balance: Watch out for leverage forces and torsional movements.
- Stiffen the construction with triangles, struts and diagonals.
- Distribute the loads as evenly as possible among the individual fasteners.