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Frequently Asked Questions
We are often asked questions about safe and correct treehousing. We have kept record of all of these questions over the years and present them to you here as a resource as you consider how to design and build your own treehouse. We have included the most commonly asked questions as well as a few of our favorites that we thought were vital or amusing information. Enjoy!
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| Q. |
"What are the "dos and don'ts" about protecting the tree?" |
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| A. |
Do:
- Use single, large bolts or GLs 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.
Don't:
- 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.
- 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.
- Position bolts that penetrate the tree vertically closer than 12 inches.
- Cut away excessive amounts of bark or wood to provide a flat surface (like to ensure a beam is bolted on vertically).
- Use more nails or screws than you need to temporarily position supports.
- 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.
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| Q. |
Permitting: What are the permitting requirements/building codes for constructing tree houses? |
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| A. |
This varies widely according to your location. You will have to contact your local planning department to find out your specific restrictions. As a guideline, the following factors can cause difficulty:
- If any part of your tree house extends above a height of 25 feet from ground level (more of a UK issue).
- If the tree house upsets a neighbor, either by extending into their property, or by causing a 'visual disturbance'. You may already be restricted from building anything at all within a certain distance of property boundaries (like 5-15 feet).
- If you intend to use your tree house as commercial accommodation.
- If you have any plumbing/water supplies fitted. Electricity tends to be less of a problem, especially if you just use a 'temporary' extension lead as a supply.
- If there are any significant seismic restrictions or considerations (like in California).
- If your area (county, province) has specific language in their building code regarding tree houses.
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| Q. |
Many TreeHouse Workshop examples I've seen use metal brackets. Can these be ordered? |
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| A. |
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 Garnier Limbs (GLs). See our catalog of specialized
hardware here. They have their own page where you can find out more here. |
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| Q. |
GL support system: What exactly is the GL tree support array comprised of? And, typically, what does it cost?
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| A. |
The GL tree anchor support array (aka: "GL suspender set-up system") is a designed hardware system that involves several parts.
The cost of the whole GL Suspender is referenced below and can be ordered through THW here.
- 1-1/4"/ 34" diameter GL bolt (machine shop made), $270.00 each
- 1-1/4" diameter "teardrop" shaped nut (machine shop made), $48 each
- Dynamic uplift arrestor (machine shop made), $70.00 each
- Static uplift arrestor (machine shop made), $50 each
- UHMW plastic pad (high tech stuff), $12.00 each
- (2) 1/2" x 4" galvanized lag bolts, $3 each
- (2) 1/2" shackles, $14 each
- 3/4" x 9" turnbuckle, $47.50 each
- 4' to 10' thimbled eye-to-eye swedged cable (3/8" wire) sling, $43 to $47.50
- 1" x 10" galvanized lag bolt, $43
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| Q. |
"Do you need to have a tree to build a treehouse?"
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| A. |
No - it's possible to build platforms on posts, on top of which forts and playhouses can be placed. TreeHouse Workshop 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. See the question about plans.
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| Q. |
"I'm worried about hurting the tree. Won't nails, bolts and screws damage or kill my tree?"
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| A. |
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. A lot of work in this area has been carried out by Michael Garnier of Out 'n' About Treesort.
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| Q. |
"Does anyone live full time in a tree house?"
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| A. |
Yes - see p122 of 'The Treehouse Book' and p3 of 'Home Tree Home' - Gus Gunther's house. Also, Corbin Dunn's web site shows a
very large house he built that is suitable for living in. See the links page. |
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| Q. |
"Does TreeHouse Workshop build Treehouses suitable for living in?"
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| A. |
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.
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| Q. |
"Do you have any plans for a tree house/playhouse?"
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| A. |
Sorry, at present we only make plans to order. This is because every tree house is different to every other, primarily based around the size, shape and type of tree it is in.
Although technically not tree houses, forts built on poles set in the ground can have a set plan. You may find plans for these types of structures in tree house or playhouse books. There are none on this site because our tree houses are built entirely supported by the tree, or with only partial support from the ground. In this case the plans are unique to the individual structure.
There are many publications available that will give you ideas of structures to build as playhouses. These can be easily adapted into tree houses by the construction of a suitable platform in the tree. After you have built this, the rest of the structure is exactly the same as building on the ground.
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| Q. |
"Do you or any other company sell pre-fabricated treehouses?"
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| A. |
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.
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| Q. |
"How much does a treehouse cost?"
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| A. |
Each treehouse project is unique and requires different materials and amounts of labor to craft it. We would be happy to consult you on
your own building plans, or design and build the treehouse of your dreams for you. Please see our Services page here for
more information on our rates. |
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| 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!!!!!!!!!
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| A. |
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.
TreeHouse Workshop 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 100 tree structures, we have been notified of only one structure succumbing to lightning.
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| Q. |
"What is a possible 'Hole-in-the-Roof' solution for keeping rain out of a treehouse?"
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| A. |
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 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.
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| Q. |
"Are there articles or published data regarding significant treehouse engineering practices?"
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| A. |
You might be interested to see if you can get your hands on an article printed in Vol. LXIX, No. 4, July-August 2000 issue of "Building Standards" magazine (ISSN 0270-1197) which is a publication put out by The International Conference of Building Officials, 5360 Workman Mill Road, Whittier, CA 90601-2298. Telephone 562/699-8031, fax 699-4253. Website: www.icbo.org. The
article I'm referring to is on pages 20-23 and is entitled "Habitable Treehouses: Not as Simple as Swiss
Family Robinson" by David A. Bassett, P.E., C.B.O. and Charles S. Greenwood, P.E.. THW employs the
services of Charles Greenwood, PE quite often. Also, I suggest checking
out www.treehouseengineering.com> |
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| 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?"
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| A. |
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.
See GL Support System question above. It will give you an overview of the basic limb support system (all components) we recommend using. The heart of the basic limb system is the primary hardware device we typically use, called the GL, 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.
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