Tree Fort Deck & Railing

It’s becoming somewhat recognizable…

After finishing the frame, I worked on putting down the deck. I had to search a couple of home centers, but was able to find some premium pressure treated boards that would work. It’s actually fairly nice looking 5/4 stock with a smooth radius on the long edges. The platform is 8′ in length, so i was able to buy 8′ lengths and nail the majority of them without any cuts. The only cuts I did have to make were around the opening for the trunk of the tree. I tried to maintain a opening of about 2″ to allow for growth of the tree.

The decking went down fairly quickly…I was able to finish in one evening. After that, on the next evening, I started working on the posts that support the railings and the roof. The construction is simple, just a half lap at the bottom of the post that fits flush with the outside of the rim joists and the deck flooring. I test fit each post and checked for plumb. I had to make some adjustments removing some material with a chisel where needed to get the post to sit plumb. Then I nailed the post into the rim joist with 16d galvanized.

The posts went up quickly (in a couple evenings) [much faster than my blog posts!]. Then I moved onto attaching the top and bottom rails of the railing. It’s a tree house, so I ditched my idea of half lap or M & T joinery, and went with butt joints. As a result, I flew through this stage of the project. I simply used some clamps to hold the boards (2 x 4) in place while I nailed 16d through them into the posts. I checked for level and did the same at the other end of the board. I didn’t make any cuts until the board was attached to the posts. I simply flush cut the boards to the posts with a hand saw…a hand tool trick that saves time and give you great accuracy.

I made my way all the way around the platform attaching both bottom and top rails. I cut away the bottom rail where the opening would be. I made sure to leave the top rail in place to act as a safety stop to prevent someone from accidentally falling out. Then using a scrap block of 2 x 4, I installed the middle rail, which actually supports the majority of the boards that make up the railing. I placed the scrap block below the upper rail and butted the middle rail against it while I nailed the middle rail in place. I had the top rail already level and square, which allowed me to use the spacer (scrap block).

Next I was back off to the store to buy some more wood to complete the railing. I went with the same 5/4 premium material that I used for the deck flooring. Once I had the lumber I needed, I made some more spacer blocks based off of the Sketchup drawing. I needed to make one spacer for the distance from post to the first board, and another spacer for the distance between each board. Of course, I double checked the distance between posts to make sure I was still matching up to the drawing. I was off on one section, so I had to do some math on the fly and make the necessary adjustments.

This part of the railing was the most time consuming…mostly because of the cuts I had to make. The other reason being that mother nature keep fighting me with rain. Perhaps she was not happy with me driving lag bolts into her tree.

Anyways, I kept toiling away until I made my way around the platform. I did make one change to the design of the railing on the fly. On the front and back (the 6′ dimension), I attached the middle board to not only the bottom and middle rail, but the top rail as well.

I did this for a couple of reasons. First there is a six-foot span between posts on the front and back, which didn’t support the top rail as expected…it just had too much movement for my liking. The second reason, which was a benefit of the first, was it added a little touch to the design.

Next up is the ladder and a late addition to the design…

– JR