Tree houses are fun, bonding activities you can do with your friends or family, and can provide a unique and ideal hangout spot surrounded by Mother nature. One of the biggest differences in my opinion, between tree houses and other on-ground add-ons you can build on your property, is the fact that a tree house sways – to varying degrees depending on the height and size of the tree and branches – and thus can add that “rocking”, soothing feel.
There are several prerequisites that must be met before this particular project would be considered feasible for you. The first ones are also the most obvious:
- Do you have a suitable tree within your property on which you can construct your tree house? This question may be ambiguous to some, as what kind of tree exactly is considered suitable? Well, this depends largely on the size of the tree house in question, as well as the expected load – number of people, furnishings, etc. The larger your tree house is, the larger your tree needs to be.
- How are you with heights? Now is not a good time to kid yourself or anyone else if you happen to be abnormally scared of heights! We’re all scared of heights to varying degrees, but if you lack the courage or ability to comfortably work at the needed height, this project may not be for you. Granted, a tree house can be built relatively low to the ground as well and still be called a “tree house” – in which case, this may not apply.
Now that we have those out of the way, we can get into the other aspects of building a tree house. When compared with a structure on the ground, a tree house may somehow seem like a simpler project due to the fact that some of us have grown up “throwing” little makeshift tree houses up here and there. However, it’s important to remember that any halfway decent structure, whether on the ground or up in a tree, requires careful planning and implementation of standard safety code.
Here are some other questions you should ask yourself before commencing the planning stage:
- What will I use the tree house for? Depending on your answer, you may want a roof and walls, or you may find it unnecessary. In either case, a rail and/or walls at least a meter high is recommended for safety.
- How long do I want my tree house to last? You may think that the answer to this question is obvious, but you should understand that the lifespan of your tree house depends largely on the materials you use and the quality and number of layers of your protective stain. Tree houses, by virtue of their definition, stand within and under the canopy of the tree in which they are built. Because of this, they are more susceptible to premature rot due to the prolonged shade and humid nature of their environment. The fallen leaves and branches scattered across the deck also serve as decay-accelerators unless they are regularly swept off.
Tree house Foundation and Floor-shape
One of the unique beauties of a tree house is the fact that you can simply build around the various branches leaving them exposed within your tree house, enhancing the “natural” atmosphere. As with an on-ground structure, you should start with building your base and floor. You may face complications with the shape of your floor due to the limitations of suitable branches to base off of.
Because of this, there’s a possibility you may have to settle for a non-square shape. This may be what you want, or this may be a problem for you. In any case, you should understand that there are some limitations placed upon you by the particular tree you’re working with. All branches used for a foundation should be able to single-handedly carry several hundred pounds, and more if you’re expecting higher traffic.
Tree Wood Density and Fastener Quality
Large tree houses that weigh more than the collective weight of their occupants should be designed carefully, as various factors such as the hardness of the tree and fastener quality and design come more into play. Wood will compress where the fasteners connect to the tree to varying degrees based on the hardness of the tree in question, causing a sinking of the tree house.
Professional-grade Tree house Fasteners – Are they Necessary?
There are various tree house fasteners available on the market today manufactured specially for the unique needs of tree houses. However, the question invariably arises as to how necessary these customized bolts and brackets are in comparison to normal ones found in home centers due to their price. They often cost between one and several hundred dollars each!
The first thing to bear in mind when contemplating the pros and cons of these rather pricey pieces of hardware is that trees are living organisms, and are still growing, moving, and changing shape. Therefore, your tree house and the hardware on which it is mounted must accommodate this movement. Simply bolting the beams of your tree house into the tree’s branches results in a fixed attachment that will force the tree to either pull the screw through the beam or try to grow around the beam.
The first of the two will result in a sudden and dangerous failure of the tree house, while the second will result in an unhealthy and unnatural growth around the beam, potentially causing disease and decay to set in. Custom tree house bolts and brackets are made with a certain allowance for tree growth, with a section of the bolt that is embedded deep in the tree’s heartwood and a large shank that allows axial movement coupled with a female part that is attached to the tree house beam.
So to answer the question of whether these expensive custom parts are necessary, the short answer is yes, and no. Yes, if you lack the know-how to find parts that will accomplish the same purpose as the professional parts do, and no, if you do, and don’t require your tree house to last for fifty years. Home centers sell bolts and hardware with large diameters and lengths which can be used for tree houses, but the entire shank cannot be threaded.
The half or so that is embedded into the tree must be threaded, but the remainder that acts as the cushion to compensate for tree-growth must be smooth. You also need a female piece that fits around the smooth shank that has a bracket which can be screwed into your beam. This female bracket then has the freedom to slide along the axis of the smooth bolt shank as the tree grows in girth. All parts should bestainless steel as well – others may corrode to failure.
Obviously, the big tree house building companies would disagree with the above opinion, and the ideal is to buy these parts. I’m just offering an alternative for those who don’t have a large budget but still want to construct a safe and environmentally-friendly tree house. There is also a chance you won’t be able to find hardware that meets the criteria, leaving you with no other choice.
The professional criterion when it comes to fastening your tree house to your tree seems to be “perch, don’t pin”. I agree whole-heartedly with this principle and any alternative I gave above shouldn’t contradict this. But not everyone looking to build a tree house is willing to spend tens of thousands of dollars, thus, your budget is a primary factor in determining the quality as well as what kind of tree house you would build.
In any case, your tree house should be a safe and fun place to accommodate whatever activities you envision. Taking into consideration the damage inflicted on the tree as well as future complications that may arise such as those mentioned above when planning your tree house, is simply the responsible and considerate course of action. Any attachment method that causes girdling of the tree is strongly discouraged as this will almost certainly kill the tree. Instead, direct fastening into the tree’s heartwood is the recommended method.
*Here’s some additional information on tree house supports and when to use flexible or inflexible joints and fixtures – The Treehouse Guide.