Q. "What are the "dos and don'ts" about protecting the tree?"
- Use single, large bolts or TABs (treehouse attachment bolts) for main supports.
- Line bolts up vertically on the tree if using more than one bolt - it's better to disrupt only one channel of nutrient flow. When doing this, keep the separation around 18 inches and never less than 12 inches. This way the tree will treat the second bolt as a separate wound. Both wounds will be compartmentalized separately by the tree, thereby reducing the risk of rot between penetrations. If the penetrations are too close to each other, the tree will treat them as one wound and rot could set in between the bolts, increasing the chances of pull-out.
- Use metal or metal faced brackets where movement is inevitable (like sliding joints).
- Drill the correct sized hole carefully with a sharp bit to avoid errors and leave a clean wound.
- Use angular blocks or brackets to provide flat vertical or horizontal surfaces for beams.
- Treat the tree with respect as a living thing.
- Do not use nails for main supports - they are much weaker than bolts, can work lose easier, and you usually need many more to do the same job which will cause more overall damage than a bolt.
- Do not use cables or ropes wrapped around branches for support - these wear away at bark and sensitive layers below and as the branch grows it will become strangled, again cutting off nutrient flow to the rest of the branch.
- Do not position bolts that penetrate the tree vertically closer than 12 inches.
- Do not cut away excessive amounts of bark or wood to provide a flat surface (like to ensure a beam is bolted on vertically).
- Do not use more nails or screws than you need to temporarily position supports.
- Do not let any part of the tree house touch the tree directly - it should all be resting on your support system. This stops friction burns as the tree sways in the wind. Like ropes and cables, this destroys living tissue and starves the branches of nutrients. A particularly bad practice is to rest one end of a support in a fork of the tree to allow it to move in the wind. This causes massive damage due to the motion and weight bearing down on the surfaces in contact.
Q. "Permitting: What are the permitting requirements/building codes for constructing tree houses?"
This varies widely according to your location. You will have to contact your local planning department to find out your specific restrictions. For a discussion about permit considerations, see our Planning/Design page
Q. "Many Nelson Treehouses I've seen use metal brackets. Can these be ordered?"
We use brackets a lot to provide a sturdy footing for supports. All the brackets we use are custom built to fit the wood and tree in question.
An alternative to full brackets are TABs (treehouse attachment bolts). Please see our Hardware page
for more information.
Q. "Do you need to have a tree to build a treehouse?"
No - it's possible to build platforms on posts, on top of which forts and playhouses can be placed. Nelson Treehouse and Supply has built a number of these, but we prefer working in trees. On the other hand, we often use poles to support long spans. These help stabilize the treehouse and take some of the burden off the tree.
There are a number of companies out there that deal only with post supported houses, and there are many plans available in books that are designed for this kind of accurately shaped and sized platform. Tree houses tend to have platforms whose shape is influenced more by the tree than the structure you want to build so they are more uniquely planned.
Q. "I'm worried about hurting the tree. Won't nails, bolts and screws damage or kill my tree?"
This is a very common concern from people who want to preserve the safety of their tree. You will find that in almost every case, correctly fitted attachments cause minimal damage to a tree.
Q. "Does anyone live full time in a tree house?"
Yes - see p122 of 'The Treehouse Book' and p3 of 'Home Tree Home' - Gus Gunther's house. Also, Corbin Dunn's
shows a very large house he built that is suitable for living in.
Q. "Does Nelson Treehouse and Supply build treehouses suitable for living in?"
Generally we don't do this for a number of reasons. First, a lot of people looking to do this are trying to create a more economical living space than building a ground based house. However, to fit a tree based structure with plumbing and the associated equipment is quite complex, requiring considerable support and design considerations. This extra load is what causes the overall cost to rise beyond the suggested budget.
Permits are usually required for structures with plumbing because they can be seen as a permanent living residence. There may also be concern about the structural safety of the house so an engineer may have to prepare a report on the plans.
We are currently in the design phase for a fully equipped treehouse that will be plumbed and have electricity. It gains extra support with the use of 'artificial trees' crafted from steel and concrete and molded to look like real wood.
Q. "Do you or any other company sell pre-fabricated treehouses?"
We only design and build treehouses on a project-by-project basis. Every tree house is different because of the size, shape and type of tree it is in. Pre-fabrication of treehouses would not be possible as each project is different. We are not aware of any other treehouse company that sells pre-fabricated treehouses either.
Q. "Lightning: I live in the Northeastern part of Pennsylvania and lightning is definitely a concern. What precautions should I try to incorporate into the treehouse (lightning rod and cable)? Common sense says get the heck out when there is lightning in the air. Any words of wisdom would be greatly appreciated!!!!!!!!!"
You sort of answered your own question: "Common sense says get the heck out when there is lightning in the air." Generally speaking lightning rods are not recommended as they attract the strike and then hopefully, if all goes as planned, successfully direct it to ground. This can be on the tree.
Nelson Treehouse and Supply has never installed a lightning rod in a tree. We did, however, uninstall one once in Michigan. It had been installed years before and clearly was a burden to the tree, mainly because of the wired and rewired cables.
To date, in over 150 tree structures, we have been notified of only one structure succumbing to lightning.
Q. "What is a possible 'Hole-in-the-Roof' solution for keeping rain out of a treehouse?"
We usually design our foundation/platform system attaching the structure to the tree to occur only at the main deck level (and/or below with knee braces or struts) to achieve substantial loading capacity there to sustain the complete live and dead loads of the tree house throughout its entire height.
However, in doing that we are then left with a big hole in the roof at the peak. We leave ample room so the tree can sway and grow. A quick, down & dirty way to secure that hole to rain intrusion is by installing a flexible skirt or shroud or gasket of some sort that fits like the boot of a stick shift in a car. A large truck tire inner tube or swimming pool liner material works well. We wrap the flexible material around the stem of the tree reasonably firmly (but not too tightly, so it is allowed to stretch) about 8 to 9 inches above the surface of the roof and then draping it down to the roof like a skirt and with enough bellow or loft (so the tree can move as much as it needs relative to the roof) and then attach it to the surface of the tree house roof with tacks, staples, screws or an adhesive or some combination thereof. As far as how you attach the shroud/gasket to the tree we suggest a bungee cord. To attach with a bungee cord create a chimney (or collar) with the shroud material around the tree stem and allow it to hug the tree. Use the bungee cord like a belt around the chimney/collar and then let the rest of the shroud drape down over the roof. Even though you are girdling the tree with the bungee cord the tree will overcome the strength of the bungee's elastic as it grows in girth. It is a good idea to check this connection every summer.
Q. "Are there articles or published data regarding significant treehouse engineering practices?"
Q. "I'm considering using knee braces to support the treehouse I'm building in a single tree. Do you sell simple knee brace attachments?"
There is no "catch-all/one-size-fits-all" single tree knee brace per se. A typical (entire) knee brace is composed of (in its simplest form) a piece of timber (4x6, 4x8, etc.) oriented in a diagonal position with an attachment system of some kind at the top (the structure end) and some sort of attachment system at the bottom (the tree end). Depending on height and observed dynamic tree motion the hardware connection systems top and bottom could be static or designed to flex with the relative motion of the tree.
The heart of the basic limb system is the primary hardware device we typically use, called the TAB, and it can be used in a single tree treehouse support strategy.
Single tree treehouses, typically, are more of a challenge to design and plan for: symmetrical vs. asymmetrical; the trunk (or limbs) of the tree coming through the house or the entire structure being non-breached and cantilevered off to one side. Umbrella style knee brace support systems are commonly used in conjunction with GL support systems in single tree treehouses that involve having a structure that encircles the entire trunk of the tree. The size, shape, diameter, height at which you build and a few other factors contribute to the overall approach in a single tree treehouse build. We would be happy to consult with you on this combination system.
Q. "I have some trees that I think will work for a treehouse. How do I create a Tree Layout Plan?"
In order to design a treehouse effectively on paper, you will need
to make a drawing showing all of the tree trunks and branches in the location of your treehouse, whether you are using them for support or not. We call this drawing a "Tree Layout Plan". This crucial drawing shows the diameters of the tree trunks and branches, and also the distances between them.
To draw the tree trunks and branches accurately, you need to take accurate measurements. The trees often do not sit on perfectly level ground, so be sure that your measurements are level in relation to each other, and not with the ground. For complex tree layouts, you will want to use a string level or a water level to make sure your measurements are at the same height. For simpler tree layouts you might only need your eye.
A simple way to begin this drawing is to make a rough sketch of the trees you plan to use on a sheet of paper before you begin the measurement process. Do not worry about scale at this point - that will come in later. Label all of your trees 1, 2, 3, etc. Now, starting at Tree 1, measure the distance from "bark to bark" along straight lines between the center of Tree 1 and all of the other trees, measuring the diameters of all trees as you go, taking care to note all of your measurements on the sketch.
By the end of the process, you should have a sketch showing the diameters of all of your trees and the distances between each and every one of them. See our sample tree layout plan below for an example of what this sketch might look like. Take care to ensure that all of your measurements are taken at the proposed floor level.
Using the information from the sketch, you can create a scaled Tree Layout Plan accurately showing the tree sizes and the distances between the trunks and branches. We recommend making this drawing on graph paper, for simplicity and clarity. A carefully created Tree Layout Plan is essential for designing a treehouse from scratch and also for consulting with the design staff at Nelson Treehouse and Supply.
Q. "What is the best way to paint or polyurethane a tree house? Can I spray polyurethane to seal it?"
Polyurethane is generally used for interior finishes. We use penetrating oil products to protect the exterior of our treehouses. Penofin Blue can be sprayed, however we prefer brushing or rolling, which encourages the product to soak into the grain of the wood. Also, these products are rather expensive and sprayers can be wasteful. Verde cannot be sprayed, but is extremely environmentally friendly, and odorless. Latex paint is also fine for exterior finishing, but we prefer to showcase the natural beauty of the wood rather than cover it.