All About Tree Houses

Portland, OR Treehouse Builder

treetop — Wed, 09 Mar 2011 23:35:21 +0000

Every once in a while we find a new product or service that is relevant to many of our visitors. Today I met Schuyler from Elevated Living in Portland Oregon. He is a treehouse builder with a design for a suspended single tree platform. He had some help from Charley Greenwood to design the treehouse attachment bolts he needed for his design, and he is willing to travel to install his treehouses, but is mostly focusing on installing them on the great trunks of douglas fir, redwood, and cedar in the Pacific Northwest.

His platforms use four treehouse attachment bolts near the top, and the suspension rods are hidden within the roof system and suspend the four corners of the structure. His preferred size to build is 12×12, which is quite a comfortable space. If anyone has experienced any treehouses by Elevated Design, please comment here and share your reviews.

Building a Treeless Treehouse

treetop — Thu, 17 Feb 2011 18:11:19 +0000

How to build Treeless Tree Houses on Poles

(5 questions from Jeff)

Question #1 – Poles Instead of Trees

I can’t seem to find hardly any information on building a treeless treehouse.I have five used utility poles, 15-17 foot tall that I thought would be good for the “foundation”. Are these strong enough for an “average” tree house?

Answer: So long as they are not decayed, they should be more than strong enough. You can tar the underground portion to make them last longer, and apply a water sealer to the above ground portion. Typically, poles or trees left in the round shape are stronger than a corresponding milled (rectangular) post. Nature knows best…

Question #2 – Setting Poles for a “Tree-less” Tree House

Do I put the poles in the ground or put in a concrete tube and mount the poles to that?
Answer: I would put them several feet into the ground if you don’t want to erect X bracing everywhere which is kind of ugly but functional. I would pour concrete in the hole at least below the frost line.

Question #3 – Floating Brackets on Post Treehouses

Can I bolt direct to poles or do I need to use moveable mounts still due to the wind factor?
Answer: You should bolt directly to the poles. So long as the project is 100% ground supported (no trees), then there is no need for floating brackets. All structures will move a little in the wind, but the idea is that if the structure is not rigid enough to resist moving when the wind blows, then it better allow for movement without damage.

Question #4 – Safety of Treehouses Built on Poles

Any safety factors or limitations?
Answer: So long as the posts don’t tip over and general wood fastening rules are followed, a treeless treehouse on posts is pretty safe. Beyond that, I better defer to your engineer.

Question #5 – Treeless Treehouse Resources

Any where else I can look for help and or examples of what I’m asking?

Answer: Why yes! There are a lot of resources and examples! Here are two videos that show very different types of treeless treehouses:

That first treehouse video was very simple and the poles were an A-Frame style (instead of trees). This next one is more along the lines of a traditional treehouse built on poles.

Notice the bracing in that treeless tree house between the posts. If you bury your posts deep enough, you may not need so much bracing, but that is a matter of checking building codes…

We have a few examples in our portfolio: Treehouse #7 and Treehouse #15

There are also some guides online (don’t hold us responsible for content on other sites:

There is also a website called www.treelesstreehouse.com that may have useful tips.

The Best Tree Houses in the World – Part 1

treetop — Mon, 15 Nov 2010 23:55:02 +0000

As the owner of a professional, US based tree house building company; I’ve seen and built hundreds of tree houses. So looking outside of the continental United States, I created a list of some of the best tree houses in the world.

A Tour of the Best Tree Houses in the World

Some of the most remarkable tree houses I have seen combine unique design, solid construction and creative artistry. It’s not always the biggest or most grandiose that qualifies a tree house as one of the best, it’s also the ability of the tree house builder to seamlessly incorporate the tree and the environment. To make it look like the tree house actually belongs in its host tree.

Blue Forest Sustainable Tree Houses

Based in East Sussex England, the team at Blue Forest created this amazing tree house in, where else, Sherwood Forest. Titled the “Center Parcs Tree Houses” this collection of three tree houses is truly an amazing work of craftsmanship, architecture beauty and design.

Treehouse Company

Also based in England and relatively new on the scene, The Treehouse Company is located near Northamptonshire and builds some of the finest tree houses we’ve seen. While not a grandiose in scale as some of the other “Best Tree Houses”, the Treehouse Company offers clean lines, solid construction, regard for the environment and enjoyable, practical tree houses.

Treehotel

One of my favorites!

Based in Sweeden, Treehotel boasts some of the best tree house designs we’ve ever come across. Treehotel is a collection of 7 of the most amazing and unique tree house designs. Ever more exciting, the Treehotel really is a hotel and any of these amazing tree houses can be reserved for a night’s stay.

Look at this amazing tree house titled the Mirror Cube. The walls of the tree house are covered with a mirror like film, camouflaging the tree house among the surrounding trees.

Tree House Hotel Costa Rica

Another tree house hotel, this one is based in Costa Rica. Consisting of 5 private tree houses, the Tree House Hotel has an amazing collection of arboreal architecture in the middle of the Costa Rican jungle. Not only do you stay in one of the world’s best tree houses, you gaze out over jungle views that are truly remarkable. Visit their website to see pictures of the wildlife seen from the tree houses.

Tree Houses of Hawaii

Although listed on the Tree Houses of Hawaii website, the Sanya Nanshan Treehouse Resort and Beach Club is based in China. Yet another tree house hotel, the Big Beach in the Sky Treehouse is an impressive display of architecture and design. I imagine the view over the South China Sea is spectacular. This tree house also has a suspension bridge leading down to the dunes. Certainly a worthy accessory for one of the best tree houses in the world.

Five of the Best Tree Houses I’ve Seen

I hope you enjoyed this display of tree house architecture. At Tree Top Builders, we’re happy to see that the art, science and craftsmanship of tree house construction are alive and well throughout the world. We’ll keep adding to our best tree houses of the world list so stay posted!

Can’t get enough? Here are some other websites and resources showing their picks for the best tree houses in the world.

WebUrbanist’s Best Tree Houses

The Daily Green’s Top Tree House Choices

MatadorNetwork’s Coolest Tree Houses

Treehouse Safety for kids

treetop — Wed, 29 Sep 2010 22:27:56 +0000

Treehouse building has exploded here in America. Tree houses usually top most kids’ wish lists, although few ever have their own. The popularity, however, calls the topic of safety into examination. Professional treehouse companies like Tree Top Builders are very concerned that one single lawsuit could create extra regulations for back yard kids tree houses and zip lines. Just this week, a boy in the UK died in a rope swing connected to his treehouse. Over there, where the culture is less litigious, it was concluded an unavoidable accident. In America, however, that event would likely have led to suing the rope manufacturer, the treehouse builder, and perhaps the township too, along with giving lawmakers reason to ban tree houses or increase safety regulations. So I’m writing this to hopefully avoid some common safety hazards that are often part of do-it-yourself tree houses. Without any further ado, here are 5 safe treehouse building practices to keep in mind:

1. Keep the height reasonable – If a child climbs on top of the safety railings or out the window, how high will he be off the ground? What height makes spinal or head injury unlikely? Assuming a reasonably soft landing surface, probably somewhere around 6-12 feet is reasonable. If you are more protective with your kids, then keep the treehouse on the lower end of the range.

2. Avoid Rope Ladders and Climbing Ropes – In my experience, while these are quintessential treehouse accessories, they are where most of the falls occur on a project. If you have to have a rope ladder, please anchor the bottom, make the ascent less than 10 feet (preferably 6-8), and put a thick pile of wood chips or other soft mulch surface below. The video says 9 inches, and that would be okay right under a high fall area, but more than 4 inches of mulch can overheat tree roots, so only do it in a limited area and never right against the trunk of the tree.

3. Build Railings to Code – In most places, no part of the railing should have any holes equal to or greater than 4″. The top rail should be 36″, and if the treehouse is very high, you may consider following residential code for balconies at 42″.

4. Attach the treehouse properly to the trees – While tree houses don’t usually fall down unexpectedly, these accidents can cause great injury or even death if occupied when they fall. The tree attachment method is a critical aspect the safety of the overall structure and must be done in a way that is more than strong enough as well as a way that allows the trees to remain healthy.

5. Have the structure reviewed for safety by a carpenter, arborist, or both! – If you need help, please get it! While this is kind of a plug for our safety & treehouse consulting services, if you are not in our area, you can always find a good local arborist and carpenter and have them review either your plans, your completed treehouse, or both, looking for anything that these professionals would consider not safe.

Yes, there may be a lot more to keep in mind regarding treehouse safety, but this is a start. Nothing is more important with tree houses than keeping kids of all ages safe while enjoying them!

-Dan Wright

Treehouse Bolt Selection for Hemlock

treetop — Fri, 09 Jul 2010 12:07:58 +0000

Treehouse design & bolt questions from Merritt in Washington:

1. TABs for western hemlock? — Yes, they will work in hemlocks. Here on the east coast, the Hemlocks (Tsuga Canadensis) are under attack from a tiny woolly adelgid. I don’t believe that’s a problem with the western Hemlocks (Tsuga heterophylla) that you are probably working in. We have successfully used Treehouse Attachment Bolts in Eastern Hemlock trees.

2. Is it really a good idea to perch a cross beam on TAB/bracket assemblies or would it be better to hang the beam from a properly designed TAB/hanger assembly? My tree house will be built in four trees with 8’ and 10’ cross beams at opposing ends. Two 16’ longitudinal (6×12 No.1 DF) beams supporting the deck and house floor will float on top of the cross beams. The point of greatest concentrated load will need to support 3000# total design load. I am concerned that the cross beams will be subject to rollover if perched rather than hung. — Rollover can be an issue, but you can address that by connecting the beams to the crossing joists with brackets or angled pieces of wood. Or you can suspend them in hangers if you prefer, but we never use that method unless the tree is leaning outward.

3. How does one go about estimating the anticipated lateral movement at each attachment point? The smallest of my four trees is a western hemlock with a 13” D at the planned location of attachment which is 12’ above grade. I expect that allowing for 4” of movement will be plenty but don’t really know. The other three trees are a much larger hemlock and two larger Douglas-fir. — You can build a simple temporary ground supported structure next to or around the tree. Then go out there during a thunderstorm and measure how far the trunk actually moves at that height. Or you could develop a safer measuring process… My guess is that it won’t move more than 1″ at 12′. The way to allow movement is with floating treehouse brackets.

4. I realize that TAB producers are reluctant to provide design values and understand the numerous variables that can affect the actual capacity of each individual installation. Nonetheless designers and builders need a standardized reference value on which to base their assumptions. E.g. Values for Z_ll and Z _l_ and withdrawal in dry lumber of a given specific gravity as is provided for lag screws in the NDS would at least give a basis for design. Without that it’s a total WAG and that’s not a good situation for safety nor for potential loss of investment. — The primary reason why these numbers aren’t available is that there aren’t enough sales of these parts to warrant investing in testing that would cost over $25,000. If you have $25,000 or so to invest in such a venture, or know someone else who does, then please let me know. But as far as helping you out, most professional treehouse builders will review your plans and suggest hardware for $100-250, and that way you can make use of our experience and judgement, in liu of numbers, although I agree that the numbers would be more satisfying.

Best Wishes,

-Dan Wright

Redwood Treehouse Question

treetop — Thu, 06 May 2010 02:14:30 +0000

Question from Pete:

“I would like to build my daughter a small treehouse. Are redwoods suitable trees for building treehouses in? As you know they are quite fast growing. would a single tree or multiple trees be preferable? not too many branches all trunk. What fasteners would you recommend? I am a contractor and am going to build the treehouse myself. Thank you for any insight you may have.”

Hi Pete,

It sounds like you have done your research on your redwood trees and are asking the right questions to build your treehouse. I know of a lot of treehouses build in Coastal Redwood Trees (Sequoia sempervirens). The two issues to keep in mind with redwood trees are that they grow fast and the wood is soft. These are two reasons to use larger treehouse attachment bolts when building in redwood trees. The larger bolts give you 1) more bearing surface on the tree’s wood, and 2) they space your beams out away from the trunk so that the tree has more room to grow.

The bark of a coastal redwood tree can be several inches thick and it is non-bearing. This means that your load from the treehouse beam is going to be perched out some distance from the bearing surface, and there is significant leverage the further away you place the load. So, unless the treehouse is tiny, I would back up the treehouse attachment bolt with a suspension cable , and then you’re all set. Here is an example of a treehouse bolt that would do the job, and a suspension plate that fits on the end to cable up to reduce leverage. You can connect the suspension plate to a large lag bolt with some cable. This type of a system costs something to buy all the parts, but it will allow your redwood trees the greatest future growth opportunities and still provide more than adequate support for most normal sized treehouses.

Best wishes with your treehouse,

-Dan Wright

Is My Treehouse Plan Safe?

treetop — Sun, 02 May 2010 15:41:03 +0000

Question from Greg, Bellevue, WA:

“Building a treehouse for the kids; but now that my wife has researched a little is freaked out that what I’m doing isn’t safe so I’ll ask for advice on the basic support structure.

Three cedars approx. 50-70 ft tall, 14″-18″ dia. at 12′ off the ground where the main beams are in a triangle roughly 12’x8’x7’. The beams are 4×6 and are attached w/8″ FastenMaster Timberlok screws directly against the trunk (3 staggered at each point approx 2″ apart, and in hindsight from what I’ve read I realize this is not ideal; question ‘do I change it now?’), these screws have a rated sheer factor of 3K lbs and pullout factor of 1,500 lbs ea. with only 2″ of thread embedded. I used these because they are about 3/16″ in dia. rather than drill 1 large hole (and I had them in the shop). The beams were placed on the outside of the trees w/the floor joists attached to 3/4″ ply overlapping the beams, but not attached to them to allow movement effectively making a floating lid over the beams. The main question is, at 12′ off the ground on trees this size are those Timberloks substantial enough (I don’t know the sheer factor of a single 3/4″ or 1” bolt and also in hindsight 1 penetration is better than 3; again ‘do I change it now?’) or do I need to rethink this before going further. We’ve had some good wind and it seems to move just fine, I’ve been in the construction trade for 20 yrs, but I’ve never put 1,500 lbs of structure/people/snow/whatever in a tree before and I was making it up as I went….

I attached a sketch to help clarify“

Plan sent in by Greg to ask if treehouse attachments are safe

Hi Greg,

I’ll tell you what I think would be safe for your treehouse, and then you can decide whether to act on it or not (and what you’re going to tell your wife in reality).

1) The shear rating on a fastener is meaningless unless the load is applied in shear. Due to the softness of a tree’s outer tissues, there is probably some leverage and bending going on which reduces the safety factor. I think that Timberloks are completely insufficient for what you are doing and you’re asking for a disaster… Even though it has held up so far, I have no confidence that it will remain that way over time and as you add weight (2 separate issues). I would recommend larger fasteners, no doubt. An example might be a treehouse bolt such as a 3″x9″ TAB or 6″x9″ TAB. These have the advantage of being backed up or extended if necessary as the tree grows or as you decide to add the 2nd & 3rd stories to your fort. In this case, I would say yes, change it now. (with the right tools, you can temporarily suspend each corner while you change fasteners, so as not to lower what you’ve already built to the ground).

2) I would recommend using a larger beam on a 12′ span. Something more like a 4×10 / 4×12. If there is any doubt about sizing of beams to ensure safety, then please consult a local engineer or your town’s building department for the best advice. I’ve seen treehouses built with undersized beams and you will likely experience higher than normal deflection (bounciness) and it will sag in the middle over time. The 4×6 probably won’t fall down, but why not make it feel safe and remain flat over time? This is one that I may or may not change now, that’s up to you and your building department.

3) Allowing movement is a good idea, so you’re on the right track. I would recommend using a floating bracket on the fasteners, which allows a low friction interface between the beams and the attachment bolts. This is the system that I would use if I was building it for you.

4) Lastly, I see you have 3 beams up there. Chances are, I bet you only need 2 of them. You may need to adjust which side of each tree the two beams are attached to, but for a normal joist layout, it will be just as safe with 2 beams as with three. That is cheaper to buy hardware for and better for your trees since you’re only making 4 attachments instead of 6.

Best Wishes building a safe treehouse, and please reply here and let us know how it goes.

-Dan Wright

Winter Tree House Building

treetop — Tue, 02 Feb 2010 19:38:26 +0000

Most people, when building tree houses, never consider winter construction because they want to be inside when it’s cold outside. But there are a few good reasons to build during the winter. Building tree houses during winter may reduce construction induced stress on the host trees. Here’s 3 reasons why:

Building tree houses in winter is good for the trees and fun for us too!

1. If you need to wound a tree for building a tree house or general pruning, the dormant winter season is the best time of year to do it. The scent from tree wounds can attract insects that spread oak wilt or Dutch elm disease. We’re also concerned here in Pennsylvania about the spread of the Emerald Ash Borer. But insect and fungal activity is at a minimum during the winter so the transmission risk is very low.

2. Building in winter, just previous to the growth season, will also permit the tree to direct its spring vigor toward responding to the attachment point injury and the weight and wind sail forces from the new tree house. The tree will grow reactive tissue around the attachment points which helps the tree compartmentalize or “wall off” the wound. This extra growth, over time, is beneficial for the strength of the tree house and resists spread of decay in the tree. Trees also grow more and thicker structural roots on an as needed basis, so they will grow more roots to respond to the added wind sail effect created by tree house walls and the overall weight of the structure. These factors immediately shock the tree, but it will likely regain balance over a couple growing seasons. A tree house built at the end of winter, just previous to the onset of the spring growing season, will have the full benefit of that year’s reactive growth to help the tree adjust to the new wounds and loading.

3. Soil disturbance, one of the most serious tree threats during tree house construction, is much reduced during winter when the ground is frozen. Foot prints and vehicle tires can seriously reduce the ongoing health & vigor of trees when they compact the soil. Trees need air spaces between soil particles to aid in absorbing nutrients. But frozen soil becomes rigid, protecting those tiny air spaces from compaction.

Winter can be a great time for building tree houses. It may not be when most humans would think of tackling an outdoor project, but when we consider the arboreal benefits, perhaps more of us will wear an extra layer and build our tree houses over the dormant winter season.

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Whether to attach a Yurt Treehouse to Trees or Use Posts

treetop — Sun, 27 Sep 2009 18:43:18 +0000

Question From Peter:

“I’m thinking of using 4-5 trees as supports for a 12′ yurt platform. The platform would be only 1-2 feet up from the ground and placed on 2 (very) roughly parallel beams attached to 4 trees (each between 2 trees), with possibly a diagonal beam additionally attached to one of those trees and extending to a fifth tree (for center support).

trees, measurements, and treehouse platform layout

The distance between edge of platform and bark of tree would range from about 6 inches to 5 ft. (if there’s a center beam) or 3 ft. (if there’s not). I’m attaching a site diagram, for your reference. I believe the trees I would be using are pines. Their trunks are between 1 and 1.5 feet in diameter at 1 ft. above the ground, and they are very tall. It looks like their foliage is in the top third.

My questions are these: (3)

1. Would there be movement to worry about that close to the ground? If so, should I use fewer trees and partially support the platform from the ground?

2. Should I support the platform from the ground, regardless of how many trees I use?

3. While I am aware of hardware options, my preference is to use slings and/or lashings to attach the beams to the trees, with a layer underneath the straps to protect the bark. I would take down the yurt and platform on a yearly basis in order to adjust the straps, but otherwise, they would stay up year-round. When I’m gone from the site, I would remove the beams from the trees. Would this work? I’m aware there have been efforts to build treehouses without hardware, but can’t seem to find info about this on the web.”

Thanks for the questions, Peter, and I’ll tell you what I think.

1. If I were you, I would place several buckets upside down around a sample tree in the stand where you will build the treehouse yurts. Then place small boards on top of the buckets so that they run tangentially to the tree around it and are only about a half inch from the bark. Then go out there on a windy day and watch/measure how much the trees move at 1 foot high. They will certainly move, but I don’t believe they will move enough to affect your decision of what type of treehouse attachment to use. The principal is that the lower to the ground you are, the less the trees will move. However, what little movement they make becomes more difficult to stop due to leverage. Even if you theoretically could stop that movement, you might not want to because it will interfere with reactive root growth which strengthens the tree. Typically, I would use a floating bracket for attaching the treehouse to traditional fasteners like treehouse attachment bolts (TABs), but this is leading into your other questions.

2. If tree friendly construction is your primary goal, then you should consider using 100% ground support instead of attaching to the trees or using removable slings. The holes will damage some small roots, but with careful digging, this damage will be far less than penetrating fasteners. Either way, don’t forget that foot traffic around the treehouse during and after construction is often a much greater threat than using penetrating fasteners. I’ll also mention that you are diverting rainwater that would otherwise fall under the treehouse yurts and affecting where needles will build up over the years, but these issues are not as important as the above.

3. Some Japanese treehouse builders in the late 1990s did not want to penetrate the bark with fasteners, so they used large clamps. I understand that this practice has been found to do less short term damage, but more long term damage to the trees. Plus, it’s hard to get the clamps tight enough not to slide down the tree under the dead load alone… If you are committed enough to sling and resling the trees every year, then it might work out for you that way. Several arboretums in the Philadelphia area have held treehouse building events in the past few years and all of them had rules about not penetrating the trees. In my opinion, some of the non-penetrating methods were more damaging to trees than our normal practice of penetrating. If you go this route, please spend the extra money to get larger, wider, tree saving slings. These will have a greater bearing surface on the bark and will be less likely to cause grooves under the sling. They will also have higher load ratings so they will last longer when left out in the rain & UV. The primary concern, in my mind is that you are making regular work for yourself this way that may not get done enough, or that the slings may do surface damage to the bark a little bit at a time, especially while being taken down and reset, regardless of how careful you are about it.

Please leave a comment here after you consider all of your research and decide what to do. We’d also like to see a picture of your finished treehouse yurts! Thanks, and happy treehouse building, -Dan Wright

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Interesting Materials for Tree Houses

treetop — Mon, 31 Aug 2009 21:42:13 +0000

Question from Bill, Gloversville, NY
“Where can I find materials for my tree house? What do you suggest for roofing and siding?…”

Well, Bill, part of the fun in building tree houses is using some materials that you find yourself in your local area. Many simple kids tree houses use materials right off the shelf, such as pressure treated wood, T 1-11 siding, and a corrugated or asphalt shingle roof. These materials keep the cost of the tree houses down where more people can afford them. But, since you are building your tree house yourself and presumably not paying for any labor, then I’ll assume you have more time & money to track down some interesting materials.

Here are a few products for you to consider as a starting point for choosing roofing & siding materials.

T1-11 is strong, affordable, and takes stain well. It is much easier to stain before installing the sheets, and looks pretty decent if you put trim on the corners, rakes, & fasciae

this clear roofing is usually for greenhouses, but was chosen here so the red leaves would always be visible. Other corrugated roofing materials come in different colors, or sheet metal is yet another option.

This Adirondack siding is rough sawn, which is less expensive and has a rustic uneven look. It also looks great with a cedar shake roof, as shown. The windows are made by Pella, but you can get reused windows, custom designed pieces, or just staple screen over openings if you want to keep it simple.

Don’t forget to use your imagination with materials for tree houses. Find locally available materials, recycled materials, or home-made materials. If any of you readers come up with unique designs or materials for your tree houses, then please send me pictures. I may even feature your tree house in my next tree house book! Happy treehouse building and materials selecting! -Dan

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