Posted on February 2, 2010 with No Comments
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.
Posted on September 27, 2009 with No Comments
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 garnier limbs, 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
Posted on August 31, 2009 with 2 Comments
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
Posted on August 4, 2009 with 2 Comments
Question from Randy, Milford, DE:
“I just “finished” a treehouse for my kids and while looking around on the net, came across your site. After reading over it, I realized that I made a cardinal error and “pinned” one of the support beams to the tree. It is a large Oak and I have a 2 x 12 lag bolted to it with about three 6.5” x ½”. The front half of the treehouse platform is supported by two 2 x 12 beams bolted to two 4 x 6 posts. Obviously, the beam that is pinned to the tree will create problems in the future. Is there a “simple” solution that I could implement to save the tree from trauma and the house from falling down in the future? I can send photos if you would like.
Where are you located?”
First of all Randy, you are not alone. We regularly hear from people just like you who want to support their treehouse in a better way. There are multiple issues here that may be at play. It would help to see a close up photo or two of the area where the treehouse beam and tree connect, and it would help even more if you hire us or a local arborist to inspect it. Sometimes, we see things in person that are not noticed or describes over email/photos.
Options:
1) You can leave it alone and keep an eye on it. It might be okay for a while, and if the tree is growing around the beam, and doesn’t appear to be suffering too much, you may decide to let the tree deal with it. How valuable is your tree? $1000? $25,000? How much did your treehouse cost you to build?
2) You can hoist or jack the treehouse up, detach the beam from the lag bolts, and install a larger fastener such as a garnier limb underneath the beam, and then set the house back down on the larger fastener. This runs a risk, because you already made 3 holes close together, and now you’re adding another one only a few inches below. This is a good move if the wounds in the tree do not coalesce. You could also choose to raise or lower the whole treehouse to prevent the wounds from being so close together.
3) You could permanently suspend each side of the treehouse beam to points higher in the tree. Make sure you are comfortable with cabling and working at that height, and use cable that is rated for at least double the total dead and live load that will be on it. The advantage is that the new wounds will be far from the other ones. But it does mean working higher in the tree, and attaching loads higher in trees means more sway and possibly greater chances of storm damage depending on how high you go up.
4) Your backup plan, if the tree is suffering and #2 or #3 won’t work or the risks aren’t acceptable, is to add two more posts near the tree and a new beam. When you remove the old beam, if possible, don’t remove the lags that go into the tree unless they are loose in their holes. You may cut them flush to the outer bark if desired.
There may be other options or considerations that will come to mind if we can see the tree and treehouse, but we’re likely to choose one of the above.
Posted on July 7, 2009 with No Comments
Question from George, Glen Ridge, NJ:
“In your list of things not to do, you say not to “pin” a beam. What exactly does that mean?”
Well, “pinning” would mean any way of fastening a tree house beam directly against the bark of the trunk, such that the beam will not move independently from the trunk. This is typically done by buying the biggest lag bolts at the local hardware store (usually 1/2″), predrilling, and lagging right through the beam and into the tree. Some tree house builders in Japan used to pin two parallel beams to a tree by clamping them together with all-thread, washers, and nuts. They squeezed the tree so hard that it would actually hold some weight before slipping down. I still consider those beams pinned because they can’t move, and the tree must decide whether to push them away or grow around them - neither of which is good for the tree or the tree house.
Take a look at what is happening here to a tree house built by a “do it yourselfer” in Pennsylvania.
Unsafe method of attaching a tree house beam
This tree house was 3 years old at the time of the photo and one of the main beams has been pushed out over the head of the lag bolt about 7/8″ or more than half way off the 2×12. When will it fall down? Probably in another 3 years or so. Also note that these two yellow poplar trees are not looking very happy either, and it’s only been 3 years.
The better method is to “perch“, or set the beam on top of a much larger fastener some inches away from the trunk so that the tree can grow without constriction or rubbing due to wind movement. Thank you for the question… -Dan Wright
Posted on June 24, 2009 with No Comments
Tree Top Builders, a custom tree house building company, volunteered at the Camp at Old Mill to build a tree house, zip line, and some cabling for a low elements challenge course.
The Camp at Old Mill, near Coatesville, PA, is a haven for Coatesville’s kids to retreat to year round. Tree Top Builders founder, Dan Wright, volunteered Tree Top’s services to build a professional quality tree house for the camp. The camp intends to use the tree house for camp outs and as a zip line launch platform. The challenge course will be for group building activities.
The main 12’x16’ tree house platform is on the bank of the Brandywine River and is 12 feet high in two hickory trees. The zip line launches off a 17 foot high launch pad and zips nearly 200’ to another tree. The challenge course includes a tire traverse, a wild woozy, and other low ropes elements for group activities.
Tree Top Builders regularly volunteers its services to non-profit organizations such as non-profit youth camps and the Make-A-Wish Foundation. Custom tree houses are exclusive projects, so part of the company’s vision is to put kids in tree houses that otherwise wouldn’t have access to one in their own yard.
Posted on June 20, 2009 with 1 Comment
We plan to use this category to answer all Tree House Questions that you have. Please leave a comment here with your question or email to treetopbuilders@verizon.net. We will then respond publically to all relevant tree house, tree platform, or tree house accessory questions. We are experts in attaching things to trees, and so we probably won’t answer questions about general construction or trees unless we can answer the question in a way that would be interesting to other readers looking for tree house building information.
For Quick answers to common questions, please check out this tree house questions page. Otherwise, ask away and we will respond for everyone to read…
Posted on June 13, 2009 with 4 Comments
Introduction to Zip Lines from Tree Houses
Zip lines are great fun, but they can also be dangerous. Make sure that they are built properly, along with the tree houses that serve as the zip line launching platforms. There is a lot of variety in zip lines, and this post will serve as an introduction to the many choices out there.
Are Harnesses & Helmets Necessary?
Life involves a lot of risks. Only you can decide which ones to accept for you, your kids, and your guests who will inevitably be using the zip lines and tree houses. That being said, some zip lines are less than 100 feet and the rider is never more than 7 feet off the ground. Most people on this style do not wear harnesses or helmets. But other zip lines are hundreds of feet long and start in tree houses that are 30′ high, where a fall could be fatal. We strongly recommend requiring harness and helmet use in such cases as a precaution.
What about Grade?
If the bottom tree is on significantly lower ground than the tree house, you have two choices: 1) raise the end cable, or 2) use a braking system. Raising the end cable to a higher point in the tree will slow the ride down and account for the grade difference. Braking systems are questionable because they can fail, especially when not properly installed and regularly inspected. In short, gravity stopping is safer, but using a brake allows the zip line to be faster.
How to get off the Zip Line
Zip lines are properly installed with a sagging cable to minimize tension when the zip line is loaded. As you jump from the tree house and proceed down the cable, you should install the zip line so that after you stop via gravity and/or braking system, you then coast back to a point that is not too high off the ground for an easy dismount. This typically stops about 60 to 80% of the way from the tree house to the bottom tree. Alternatively, in canopy tours, or zip lines that connect several tree houses, you will need a braking system that allows you to come to a stop at the far tree house without hitting the end tree at 30 mph or so, which really hurts you, although the tree will hardly notice it.
Be Careful…
Zip Lines and Tree Houses are potentially difficult and/or dangerous to install. Please make sure that you use proper safety equipment while working on ropes or ladders, and please do adequate research to determine the proper sizes of cable and get professional grade hardware so that you don’t have to worry, just have fun! Tree Top Builders is available to install zip lines and tree houses. We will also attempt to answer all zip line and tree house building questions posted to this blog as a service to built-it-yourselfers, so please ask away!
Posted on June 1, 2009 with 1 Comment
Top 7 Reasons People Build Tree Houses
1.Tree Houses are Escapes from the “Normal.”
To many, the appeal of tree houses is that you don’t see them every day. True tree houses, that is, structures supported by trees or built closely around them, are less common than pools, boats, play sets, gazebos, or fancy flower beds. Many who build tree houses are simply seeking something different from what everyone else has.
2. Nicely Finished Tree Houses Expand the Borders of the Home.
Some tree houses are connected to a ground house by a bridge or stairway from a deck. But even if it’s a short walk down a wooded path, tree houses practically extend the use of the home. As guest rooms, tree houses are unmatched in novelty. As a result, as bed & breakfast units, they generate higher than average rental rates. Well built tree houses can have all modern comforts of ground houses and some tree houses are even built as permanent homes.
3. Tree Houses are Iconic Imaginative Places.
You don’t have to look far into kids culture to find tree houses. Cartoon and book characters have disproportionately more tree houses than the average real kids who want to be like them. Tree Houses are homes for Ewoks, and Elves if your imagination takes you into the world of fiction.
4. Tree Houses get the Kids out of the House
Most tree houses are kids tree houses, and many parents build aerial retreats to get the kids outside in the fresh air rather than in front of the computer or television. Active play is good for kids of all ages. Tree houses, with their climbing features, swings, zip lines, and places to play and hide definetely fall into the category of “active play.”
5. Playsets are not as cool as Tree Houses.
Playsets may call themselves “tree houses,” but they have a completely different function and appearance. Playsets are typically only 4-6 feet high, have notoriously small square footage (to make them cheaper) and kids grow out of the plastic slides and small features by age 9 if not earlier. Tree Houses, on the other hand, can be built to appeal to the whole family.
6.Tree Houses make Fantastic Gifts or Special Rewards.
Many Tree Houses are birthday or holiday gifts. Sometimes grandparents build tree houses to make their yards more fun for the grandkids. The most popular time to build tree houses is the beginning of summer, which is where graduation events coincide with outdoor weather.
7.We all Innately Want to Build Tree Houses!
The desire to build tree houses comes from our instinct to create our own space. As small children, we love to hide under blankets. Next, we are moving furniture around to make walls. Before long, we are grabbing hammers and nails to start building tree houses. Why fight nature? Come on, you know you want to!
Now it’s your turn: Not that the above aren’t sufficient, but what other reasons can you all think of for building tree houses?
Posted on June 1, 2009 with No Comments
Top 10 Tree House Building Mistakes
1. Choosing a tree without consulting an expert
Building a tree house starts with a foundation analysis. What species is the tree? Where is the tree in its natural life cycle? Is the tree healthy - free of defects, decay, disease? You may not need a professional tree house builder or arborist to look at the tree if you know the basics or research your tree online. But first consider the level of investment you are making in the tree house before bypassing this step to save a few hundred bucks. How much time and money will you spend on the tree house? What is the intrinsic value of your tree? Every ground house starts with the footer inspection and then concrete, and every tree house starts with the tree’s structural grounding, core integrity, and health.
2. Neglecting to have even a reasonably basic tree house plan
It can be fun to build your tree house one board at a time. It certainly gets you started sooner. But this causes a few common mistakes. When there are multiple branches or trunks, your eye-balling methods may deceive you. You may find that in order to pass a main tree house beam where you thought you could, you have to cut a major branch (bad idea). Secondly, most people have trouble sighting level, especially when the grade is sloped. Note that a tree house platform constructed perfectly level will not necessarily be parallel with the ground. This matters because you may find that what you thought was a 10-11′ span may actually be 13′, which would require a stiffer beam and more support. So it’s back to the lumber store to return the 12′ joists and get some 16’s, and now you need 2×10s instead of 2×8s, increasing the weight, cost, and difficulty of the tree house unexpectedly. Even if you can sight level and your beams and spans work out, you may still end up trying to improvise extra tree house attachment points on the fly, which may lead to less than optimal decisions for the tree house and/or the tree. Our advice: climb the tree, take measurements, temporarily mark each beam, draw the tree house platform on paper, and do whatever else it takes to reduce the surprises once you start building.
3. Using too small or the wrong fasteners
Don’t assume that the biggest lag bolt on the shelf at your local big box home improvement retailer is suitable for holding up your tree house. Even a kids tree house with walls, windows, and a roof, will probably use a couple thousand pounds of materials. And then you need to allow for the tree house to also support live loads to cover as many people as can fit up there. It always pays to use the right fastener. Use screws or carraige bolts for places where the tree house will primarily be subject to pullout or tension forces. Use nails where shear forces are primary. Be careful to use approved fasteners for treated lumber. Beware that most of these mistakes will not cause tree house failure in the short term, so you might not necessarily know you made a mistake right away.
4. Using too many fasteners
Never place tree house fasteners too close together in the tree. Remember that trees don’t heal, they seal, or compartmentalize around each wound. If wounds are too close together, the tree may treat them as one wound, which will cause the wood between the fasteners to decay. This will almost certainly cause the tree house to fail. A better approach: Use one, large tree house fastener, instead of multiple smaller ones. I know it’s tempting to use the smaller ones because that’s what you can buy on the shelf, but don’t be lazy with tree house safety.
5. Pinning a beam to a tree
When a tree house beam is pinned to the tree, one of two bad things WILL happen: 1) the beam will restrict growth on that side of the tree, causing it to suffer, or 2) the tree will continue to grow, pushing the beam outward and right off the bolts it was secured with! Eventually, it will fall off and the tree house will fall down. It is advisable to “perch” the beam on a super strong professional tree house fastener like an artificial limb, rather than pinning a beam to the tree.
6. Inadequate stabilization of the platform
The tree house platform should be stable because any movement will wear parts loose over time and become more dangerous. We usually see problems with knee braces not being installed tightly to reduce movement. If the tree house fasteners themselves are moving, you have a big problem because the tree will never seal that wound properly. You will likely see liquid coming from the spot, the wound will remain open, the tree will suffer, and the fastener will get looser and looser and probably fall out.
7. Girdling the tree with rope, cable, or 2×4s
Don’t wrap anything around the tree to support the tree house. You can completely kill the limb or trunk if you do. Even if the tree survives, it will certainly suffer. We see this a lot on zip lines, and when cables or chains are used for tree house supports. We have also seen many people nail short 2×4s into the trunk to space the chains or cables 1.5″ away from the branch or trunk. That will lessen girdling, but it breaks rules #4 and #5. Get the right tree house fasteners to keep your tree happy.
8. Not leaving room for the tree to grow - boxing around
The tree house should only touch the tree where necessary. This means when you frame your beams, joists, rafters, etc., that they all need to allow the tree sufficient room to grow over time and sway in the breeze without rubbing the tree house. If you don’t do this, you risk girdling the tree and reducing the life of your tree house. If you later decide to extend the life of the tree house, your maintenance will be harder, so plan for growth. Ask an expert how fast your tree will grow.
9. Nailing ladder rungs onto the tree trunk
You may have seen a picture of 2×4 ladder rungs each nailed into a tree for tree house access. That is not nice to the tree. As a general rule, no part of the tree house should touch the tree unless it has too. There are many other ways to build a ladder or access the tree house. These types of ladders are repeat offenders for breaking rule #4.
10. Not bothering to preserve natural wood surfaces
Wood, whether pressure treated, cedar, or even bald-cypress has a clock. The sun, rain and snow will cause them to decay and the tree house will look older faster, and need replacement sooner. Commercially produced lumber does not last as long as the old growth forests. Profit drives companies to grow timbers faster, so they don’t build their natural resistance to decay and pests. If your tree house is built with reclaimed lumber, this might not apply, however, treatment will extend the life and beauty of any wood. At a minimum, protect your tree house by applying a clear sealant on the exterior floors, stairs, and railings every 1-3 years.
Questions? Contact Tree Top Builders for more information on safely building tree houses.
