TREE HOUSE 101
Jordan William Green
Have
you ever wanted to build a tree house? I will tell you how!
The first step is to pick a tree. A tree with a nearly level
branch is ideal, but others will do. If you chose to use two trees (as I did)
you will need to make sliding joints on the tree that moves more. If you do not
use the sliding joints, your wood will end up cracking and nails will break or
pull out because of the trees moving independently. (SEE PICTURE BELOW)
Do not use cottonwood birch, poplar, spruce, or other trees with
soft wood. I recommend ash trees because they are strong enough to hold up a
tree house, but you can nail into it easily, unlike oak. Pine trees (Norway
pine, white pine, etc.) move a great deal and you may have trouble with that,
but otherwise would work fine. If you use pine, you will need to leave an extra
large gap around the sliding tree. (SEE PARAGRAPH 4)
Once you have picked a tree you may find that you need
additional support. A 4x4 post works great for this. It should be slightly
shorter than the height of your beam (to allow for adjustments).
I recommend that you put one beam up first, than a joist
(temporarily nailed into the opposite tree) so that your beams are at the same
height. Put the second beam up to the bottom of the joist, clamp it to the
joist to hold it up temporarily, and then use 3-4” deck 
screws or longer nails to attach it.
Remember to pull the nails from the joist to the tree out. The best size wood
to use is a 2x10 for a beam supported at two points or a 2x6 for a beam
supported at many points, but 2x8s work fine. For the joists use 2x8s or 2x6s.
Pressure-treated lumber is the best for your tree house as it will not
rot. You can never make your tree house two strong!
To prevent the joists from sliding side to side, use scrap
lumber nailed on both to the beam sides of the joists. You can use sheet metal
to prevent the wood from wearing itself down. The joists should be placed at
about 24” on center, no more than that though.
Nail the other ends into the beam on the non sliding side by
nailing scrap 2x4s into the beam and then nailing the joists into them. For
added stability you can cut 2x4s to fit in-between the joists, but that is only
necessary for long spans and large overhangs.
For the ladder there are a couple of
options. Build stairs, build an actual ladder, use an old ladder, or use 2x4s
nailed into the tree. I recommend that you use the 2x4s nailed into the tree
method. There is something to be said about this old fashioned approach, but
you must attach the rungs securely to the tree. Even my rungs have fallen off
(luckily I didn’t fall, but you may not be so lucky!). Use long screws to
attach your rungs. If you use nails, use the longest nails you can find (within
reason), and use many of them. Your ladder will not be the best looking part of
the tree house because of the amount of nails and screws used to attach it. You can never make your tree house two
strong!
Your instinct may tell you the next step is the floor, but your
instinct is wrong. Putting the posts for the railing or walls before putting on
the floor is a lot easier. Putting a piece of plywood on top of the posts can
serve as a place to work from. If using a railing, cut your posts so that your
railing will be 3 feet above the floor. Bolts are recommended to use for
attaching the railing, but nails or screws will work. If you are building a
shelter with no walls (just a roof) attach the posts the same way. Cut them to
the desired length before attaching them. Keep in mind that it is a lot easier
to make a roof with only one slope than one with 2 or more.
Once you have your posts up, you can put the floor on. There are
endless possibilities for floors. You can use dimensional lumber (2x4s, 2x6s,
etc), decking, or plywood. If you use plywood, do not use pulpboard, OSB, or
other chipboards, as they fall apart when they get wet. I recommend ¾” plywood
if you use plywood. The best material to use is solid wood decking. Leave a gap
between the boards to allow water to flow through. Keep in mind that pressure
treated lumber will shrink when it dries out.
Now that you have the floor done, you are done with the hardest
part of building the tree house. Next is the railing or walls. Frame your walls
as you would for a house on the ground. 2x4s 16” on center. Put your siding
material on while you are on the ground. Get a bunch of your closest friend and
raise up the walls and nail them into place. Do the same for the roof. Once you
have it up in the tree attach it and you are done (you will never be done, but
this is the part where you go home and have a relaxing nights sleep).
For the railings, use 2x8 or 2x6 rails on top of the 4x4 posts
and be creative on how to fill in the space in-between. I used 2 2x4s running
parallel to the top rail.
EXTRAS:
Bench:
To
build a bench use 17” 2x8s or 2x6s for the horizontal supports. Attach the
supports to the wall or railing that will be used as the backrest with nails or
screws. Use 4x4 posts for the vertical supports cut just shorter than the
height of the bench. I recommend that your bench be placed 17” to 20” off the
floor or decking. For the seat use a 2x10 and a 2x8. You will end up with a
3.5” overhang. Under this overhang place you can place a 2x8 or 2x6 (whichever
you used for your horizontal supports) to provide a more finished look. For the
seat back you can use a 2x10, or a couple of other boards, nailed to the wall
or railing.
Shelf:
To
build a simple shelf start with a 2x10 or 2x8 scrap, a 2x8 or 2x6 45 degree
triangle, and a 2x4 scrap. Nail the 2x4 to the triangle with the tops flush
against each other. Then nail the 2x10 or 2x8 on the other side of the triangle
for the shelf. Place on the tree or wall where desired and attach through the
2x4 with nails or screws. To add a hook pound a nail into the 2x4 at a slight
angle and leave it sticking out a little.
WHAT NOT TO DO:
Do
not build your tree house on public land unless you have permission as is talked
about here. This tree house was ordered to be
removed to the tune of £1057.50 ($1450
Do not connect your tree house to a
deck or your house. It may pull the deck off of your house or damage the
structural integrity of your house. The tree moves, but your house does not!
Although the deck may look inviting, with the first major wind storm, I have a
feeling that you will not be too happy.
Do not build excessively heavy items
in your tree house, such as a brick chimney. The authors of the book “The
Treehouse Book,” Peter and Judy Nelson, found out. Their tree house fell down
at
Do not strip the bark from a tree. The
bark is what provided nutrients to the top of the tree, and if you strip a full
circle, the tree above that point will die.
ABOUT MY TREE HOUSE:
I started trying to build a tree house
many years ago. Most of them were just plywood nailed to a tree branch. My
current tree house sits on the remnants of another attempt. I built that tree
house in a shelterbelt in the farmyard of my grandparents in
My current tree house uses the support
beam from the first tree house, but other than that it is all new. It is
located on between two ash trees. The tree house is still a work in progress.
Up to this point I have only used recycled and/or left over wood for
construction. I am using nails that I found in a barrel in an old building used
for storage of extra wood (except for attaching the stair rungs and beams). My
total cost for this project is 
$0.00 so far.
I used 2x4s for the decking, but ran out half way through. I plan on building a
shack on the far end of the deck with 2 bunks and a window.
It has been easy to use power tools at
this tree because the building in the background of the top picture has
electricity. If you don’t have electricity as close as I do, you can use a
generator or a power converter that plugs into a cigarette lighter. I may
eventually put lights in the tree house, but I will wait until the building is
up. If you do put electricity in your tree house, use waterproof fixtures and
GFCI outlets to protect against electrocution and fire. (Remember that the tree
provides no ground if there is a short.)
I used the sliding joints in my tree house and
I can already see the paint wearing off of the aluminum sheets I used to
prevent wear. On windy days (In 
ground you
don’t need the sliding joint, but the torque is much grater near the bottom of
the tree.
I plan on building a trap door for the
opening where the ladder comes up (LEFT) so that people (mainly my
younger cousins) don’t fall down the hole. If you have noticed the oil barrels
and scrap metal you know you would not want to fall on that. If you are going
to be doing work, such as roofing, where you are more likely to fall, I
recommend using a climbing harness tied off to a good sturdy branch with a
figure 8 knot.
The floor of my tree house
is about 9’ off the ground. It is 7’ by 6’ currently, but will be 7’ by 12’
when finished. I have named the tree house “Alta Vista” after the name my late
great grandfather used for the farm where I am building it. (And don’t you
think the name “High View” is appropriate for a tree house)?
This is the plan for the understory of my tree
house. The joists are not attached to the beam on the right. The short joist on
top is to support the end of the floorboards from touching the tree. I
recommend using something like this so that you don’t defeat the purpose of the
sliding joist. You also should have a backup plan. Chains work great. I chose
to use prepunched strapping because I had it readily available in the scrap
metal pile below the tree house. Other methods may work too. You can never
make your tree house too strong.
This is my master plan for the tree
house. So far I have completed the deck part, but not the house part. Most of
the materials for the house will have 
to be
purchased, as I have used almost all of the useful wood in the wood shed. The
door and window are in the wood shed, so I won’t have to buy them. For the roof
I plan on using metal sheeting (such as that on the building below my tree
house). Eventually I may insulate and heat the house.
IF YOU HAVE
ANY QUESTIONS OR COMMENTS PLEASE ADDRESS THEM TO:
Type “TREE
HOUSE” in the subject line.
MORE PICTURES
AND INFORMATION COMING SOON!