Table of Contents
Introduction and the plans
This article explains how to construct a platform or deckA flat floored roofless area adjoining a house. Timber deck: An outside floor structure comprising of posts, bearers, joists and decking boards. around a tree, how to make steps up to it, a safety handrail up the steps and around the platform, and also how to add a slide and swing-set.
This tree house is really a tree platform – a platform built around a tree rather than the traditional type of tree house consisting of a small playhouseA small house for children to play in. built or placed in the tree’s branches.
The tree house was specifically designed for younger kids. Since built, it has had plenty of use from kids three years old and upwards and it’s amazing just how fast the kids seem to hone their climbing skills.
The stairs make it easy for younger kids to get up to the tree house and there is a good handrail around the entire platform.
If you are making a similar type of structure for older and more adventurous kids, then you could probably do away with the steps and incorporate a ladder instead.
Safety note: Young kids should not be left to play on such a structure unsupervised.
Below are the plans and lumberAny of the framing wood. amounts, followed by building instructions on other pages.
Keep in mind that this tree house was designed for a particular patch around a particular tree, and as patches and trees vary, you may also need to vary the plans to suit your tree and surroundings. Therefore, these plans and instructions are intended as a guide only.
The plans
Lumber stock sizes and total amounts
Excluding the swing-set
150×50 (2″x6″) stock for joists and stair treads. 26 meters (85 ft) required.
100×100 (4″4″) stock for posts and sides of slide. 14.5 meters (47 ft) required.
200×50 (2″x8″) stock for stair stringers. 3.6 meters (12 ft) required.
50×50 (2″x2″) stock for balusters. 70 meters (230 ft) required.
75×50 (2″x3″) stock for handrail. 12 meters (40 ft) required.
150×25 (1″x6″) stock for decking. 33.5 meters (110 ft) required.
Making the platform
Step 1: The boundary joists
NailA short nail with a large flat head used for securing roofing felt, plasterboard, sheet metal to wood etc. the boundary joists together around the tree.
Use 150mm x 50mm (2″x6″) lumber suitable for exterior use and fixTo secure with nails or screws. with 100mm (4″) galvanizedCovered with a protective coating of zinc. nails.
Refer to the plans for dimensionsAny of the three linear measurements, length, breadth and depth..
Step 2: Raise the boundary joists
Temporarily prop-up the boundary joists to the required height.
Use any available woodTimber, lumber. The hard fibrous lignified substance under the bark of trees for the props and fasten them to the boundary joists with clamps.
Further support with rope around the tree and joists to prevent sway.
Ensure that the boundary joists are level all the way around.
Step 3: The footingA base (in or on the ground) that will support the structure. holes
Dig footing holes directly below each corner.
Make the holes 300mm x 300mm (12″x12″) square and about 600mm (2ft) deep if the ground is medium firm.
Cut the posts to length so that they are flushBeing even with. with the top of the boundary joists and at least 75mm (3″) off the bottom of the hole.
Clamp the posts to the joists and ensure that they are plumbVertical; Upright..
Step 4: ConcreteA mixture of sand, gravel, water and cement which hardens to a stone like condition when dry. around the posts
Make a mix of concrete in a wheelbarrow at a ratio of 3 gravel, 2 sand and 1 cementA powdery type substance made from a mixture of earths materials such as limestone and shale, which is sintered (cause to become solid mass by heating without melting), ground, and mixed with small amounts of calcium sulphate and calcium carbonate. Cement is activated by water and when mixed with gravel and sand, forms concrete.. Add clean water and mix to a uniform consistency
Carefully shovel the concrete into each hole.
Fill to within 75mm (3″) of the top of the hole.
Step 5: Fix the posts to the boundary joists
When the concrete has cured, drill and boltA metal rod that has a head on one end and threads on the other and is used to fasten together lumber. The most common bolts used or referred to in projects within this website are coach/carriage bolts and hex bolts. the boundary joists to the posts.
Use two 12mm (1/2″) galvanized bolts at each corner.
You can then remove the temporary props.
Deck frame
Step 6: The intermediate joists
Place and fix the intermediate joists.
Space them so that the deck boards do not have to spanThe horizontal distance between supporting structures. more than 400mm (16″) at any point.
Refer to the plans for an example.
Step 7: BlockBlocking. A pieces of wood that runs between other members (studs, joists, rafters) to provide support, add strength and/or act as a solid support between panel joins. around the tree
Block around the tree branches.
Use any available off-cuts of wood.
The purpose of this step is to give the deck boards a support to attach to close up to the branches.
Step 8: Platform extension
Add any (only if needed) additional platform extensions.
The purpose of this particular platform jut-out is to off-set the angle of the slide in order to keep it a safe distance from the fence.
Any such jut-out extensions should have a galvanized metal strapShort lengths of metal strap 25×1 (1/16×1) used to fix members together to resist uplift. fixed to the top of the joists/blockings to prevent possible downward tilt. See picture.
Step 9: The stair landing
Make the stair landing.
CantileverA structural member which has a free end projecting beyond its supporting wall or column; length of span overhanging the support. Any structural part of a building that projects beyond its support and overhang. the landing from under the platform joists.
Run the landing joists 1500mm (5ft) under the platform joists.
Secure the landing joists to the platform boundary joistOne of a series of parallel members used to support the floor. Part of the framing that provides the structure for a floor. with galvanized twist strap or similar. (See the picture as well as the plans for further detail.)
Laying the deck boards
Step 10: The deck boards
Start laying the deck boards.
Begin by nailing the first deck boardA piece of sawn, or dressed lumber of greater width than thickness. Usually 19mm (3/4") to 38mm (1 1/2") thick and 75mm (3") or more wide. flush with the front joist and then continue with the rest.
Cut around any branches.
Step 11: More deck boards
Continue laying the deck boards until finished.
TrimThe finish materials in a building, such as narrow boards applied around openings (window trim, door trim) and vertical corner battens. off any excess.
Do the same on the landing.
Attaching the slide
Step 12: Attach the slide
Attach the slide.
Most slides that you purchase will come with full installation instructions.
For information about slides and where to purchase them click here.
Making the steps
Step 13: Make the step pattern
Make a template that you will use to mark out the tread positions on the stair stringers.
Take a piece of cardboard 300mm (12″) square or larger (alternatively you can use any type of board or thin wood).
Cut out a triangular piece from the cardboard as shown in the diagram.
Step 14: Mark the steps on the stringers
Lay out the two stringers 200×50 (2×8) flat on a couple of work stools.
Hold the cardboard template with its longest edge flush to one edge of the stringer, approx 300mm (12″) in from one end, and pencil mark around the template. Repeat this action five times on each stringer.
Ensure that one stringer mirrors the other.
Step 15: Mark the treads
To continue marking out for the treads, use a piece of lumber about 600mm (24″) long and the same thickness as the treads, which is approximately 46mm (1 1/2″). This piece of lumber is to be used only for marking and can then be discarded.
Hold this piece of lumber flush on one of the tread pencil lines marked on the stringer.
Mark each side of the 46mm (1 1/2″) thick lumber across the full width of the stringers, as shown in the picture.
Repeat this action to all tread lines, on both stringers
Step 16: Cut the stringers to length
Cut the stringers to length.
Lay them in place to check for length.
Make any necessary adjustments.
Sometimes the bottoms of one or both of the stringers may need to be trimmed if the ground is uneven.
Step 17: NotchA U-shaped cutout in a member to house another member. A notch has two sides and can be anywhere along the member except the ends (unlike a rebate that is an L-shaped cut-out with one side and is always at an end or side of a member). the stringers
Lay the two stringers back on the work stools.
Notch (check out, rebateAn L-shaped cutout with one side, that is always at an end or side of a member, unlike a notch that is a U-shaped cutout.) the stringers to house the treads.
SetHow much the teeth are angled out on a circular saw blade. the blade depth on a circular saw to approximately 12mm (1/2″) and make repeated cuts along and between the tread markings on the stringers.
There is another article on how to make exterior steps here
The steps
Step 18: Tread housing
Tap and knock over the remaining uncut bits between the tread lines with a hammer.
Then clean out the grooves with a sharp chisel. The more saw cuts that were made, the easier the chiseling.
Step 19: Fix the treads
Insert the front treads into the rebated grooves.
Remember, each tread is made up of two pieces of 150mm x 50mm (2″x6″) stock.
Hold them in place with little nails angled through the bottom edge of the treads into the stringer.
Step 20: Fix the stringers to the treads
Place the other stringer on top of the treads mirroring the bottom stringer.
Nail through the stringer into the treads using 100mm (4″) or 90mm (3 1/2″) galvanized nails: 3 nails per tread per side.
Step 21: Add the back treads
Fit the back treads in place.
Tap them along the tread groves until they are about 10mm (3/8″) from the front treads.
Nail through the stringer into the treads using 100mm (4″) or 90mm (3 1/2″) galvanized nails: 3 nails per tread per side.
Step 22: Place the stairs
Fix the steps in place. Nail the top of the stringers to the landing.
Temporarily pack with blocks of wood under the bottom tread until treads are level.
Dig a hole 250x250x250 (10″x10″x10″) under each stringer and fill with concrete. Place a galvanized wire or bracket into the wet concrete against the two stringers.
When the concrete has cured, place a piece of damp course membrane under the stringer and on top of the concrete pad. This prevents moisture from the concrete pad leaching into the lumber.
Making the handrail
Step 23: Mark for the handrail uprights
Cut the handrail pieces to size and lay them in place on top of the tree house deck.
Work out where the balusters go and mark the positions on both the handrail and the boundary joist.
Ensure that the gap between balusters is not more than 100mm (4″).
Step 24: Fix the balusters to the handrail
Lay the handrail on a flat work surface.
Nail the top of the balusters to the handrail on the marks.
Use three 75mm (3″) galvanized nails at each meeting. Nail one through the faceThe widest side of a piece of wood. of the baluster into the handrail and angle nailToenail. A nail driven at an angle to the member. the other two through the sides of the balusters into the handrail.
Pre-drill the holes in the balusters first.
Step 25: Fix the balusters to the joists
Pick the handrail portion up and temporarily clamp it in position to the boundary joist.
Nail the bottom of the balusters to the boundary joist on the marks.
Use three 75mm (3″) galvanized nails at each meeting. Nail one through the face of the baluster into the joist and angle nail the other two through the sides of the balusters into the joist.
Pre-drill the holes in the balusters.
Step 26: Posts for the slide entry
Position two posts, one each side of the slide.
Dig the postsee PILE into the ground about 500mm (20″).
No concrete is necessary, just ram and compact the soil around the post.
Cut the tops of the posts to the required height and add a headerA beam placed perpendicular to wall studs above doors, windows or other openings, to carry the weight of structural loads. Also called lintel..
Step 27: The stair handrail
Use 150×50 (2″x6″) stock for the stair handrail.
That is so the balusters can be fixed to the handrail about 62mm (2-1/2″) from the top, leaving enough free space for hands to be able to slide along the handrail without fingers catching the tops of the balusters.
Make the height of the handrail 1000mm (44″) off the deck around the platform but a little lower up the outer side of the stairs.
Making the swing-set
Step 28: position the tree end of the beamA supporting member.
Sit one end of the swing-set beam in between two solid branches.
Tie securely with rope.
We used a 125mm x 125mm (5″x5″) beam that was 3300mm (11ft) long. The height of the beam off the ground was 2500mm (100″).
Step 29: Prop the other end of the beam
Prop the other end off the ground 100mm (4″) above level.
This is to allow enough room to position and concrete the posts (A-frame) into the ground.
Step 30: Make and place the ‘A’ frame for the beam
Make up the A-frame which supports the end of the beam.
Work out the overall height of the A-frame (including the part that goes into the ground) and also work out the top angle cuts then make the fame up on the ground.
Fix a temporary braceTo make rigid. to the two posts to hold the shape.
When the A-frame is made, determine the position of the footing holes and dig them.
Then stand the A-frame upright in the holes. Use whatever braces and props are necessary to hold the A-frame in the right position and plumb (upright).
Make a mix of concrete in a wheelbarrow at a ratio of 3 gravel, 2 sand and 1 cement. Add clean water and mix to a uniform consistency and carefully shovel the concrete into each hole.
Fill to within 75mm (3″) from the top of the hole.
Step 31: Fix the beam
When the concrete has cured, lower the beam onto the A-frame and fix with galvanized nails, nail straps and nail plates.
Finally, hang your choice of swing(s) from the beam.
Leave a Reply