I built this tree house during the glorious summer heatwave of 2003.

I used 4″x3″ timber for the legs and base. Prior to construction, I had soaked the ends of the wood in preserver for several days. The post holes were dug just slightly bigger than the posts – probably about 6″ diameter. I poured pea shingle in each hole to rest the posts on. This ensures good drainage and prevents the bottom of the posts getting waterlogged. I used PostCrete to fill the remainder of the holes around each post.

I reinforced each corner with a 4×2″ brace fixed with 8″ coach screws, to stop the structure from racking

Then I installed 4×2 floor joists, leaving a larger gap on the first one to allow for the floor hatch

I laid the floor using 2 sheets of 8×4 of ¾” exterior grade plywood. Using CLS timber I created the studwork for the side walls. (I’ve only just learned that CLS = Canadian Lumber Standard – I always wondered!). I held it square with temporary battens

I made 6 identical roof trusses from cls, strengthened at the apex with a ¾” plywood plate.

Then I installed studwork at the gable end wall

Then I created a window frame

At the front of the tree house the floor extends out and overhangs the front by about 4 feet. This is made from the side rails which are 12ft long and run from back to front. I supported the overhang with longer 4×2 braces, bolted on as before. One of the 12ft lengths was twisted at the end so I had to shape all joining pieces to allow for this.

I fitted 4×2 joists for the balcony part.

On the front gable end wall I installed noggins to act as door frame and window frame. I added diagonal bracing to prevent racking.

Prior to cladding the walls I stapled-on building paper to act as a water barrier in case driving rain blew water up under the cladding.

Then it was time for the shiplap cladding. Each end of the cladding was soaked in wood preserver.

I used decking as a floor for the balcony

Then it was time for the roof, using Onduline corrugated sheets

Next I papered and cladded the gable end wall

And the same for the front gable end

Time for paint

Finishing the roof over the balcony was awkward because I had to overhang the edge. I laid a ladder flat on the balcony and got two family members to stand on it to weigh it down while I walked out on the ‘gang plank’ to work on the roof!

I fitted a door

Influenced by the houses I had seen in Bavaria on holiday that year, I designed the balcony balustrade in a similar style

Fifteen years later, 2018, it’s still standing

although threatened to be engulfed by nature!


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