
Everyone loves a big shade-providing tree this time of year. But sometimes the big gnarly roots can take up a lot of space, get in the way and be a tripping hazard. When nothing can grow under a tree, a tree-deck is a good solution.
Before
That was exactly the situation we have at the river house. We have a big evergreen tree beside our dock. First, the root system was so big, it restricted the size of the dock platform we could build. Second, it was just plain in the way. Third, we wanted a flat surface to put down things such as the box to store the cushions, a flower pot, and maybe a cooler.

@Geraintthewelsh is the expert in these areas, and I am letting him take over with an explanation of how to build a tree deck.
Meet The Builder
Hi, I am Geraint, the one who does all of the execution of the design ideas around here. This is a basic description of how you build a tree deck.
Determine The Size
The first step is to determine the size of your deck. One thing to keep in mind is that boards come in standard stock of eight, ten, twelve foot etc. lengths. If you choose to build your deck at one of the pre-determined sizes, there will be less cuts. Our go to store is @homedepot.
Our tree deck at the river house is 8 x 8. This size is big enough to cover the roots in question, and but up against our existing dock platform.
Tree Deck Supplies
This is what you will need:
- four 2 x 6 x 8 or (your chosen length)
- seven 2 x 4 x 8 for support stringers (your chosen length)
- 18 deck boards 3/4 inch (if you are building a bigger tree deck, you will need more)
- standard 4×4 post – will need 10 inches for each corner
- bag of chipped stone 3/4 inch
- four patio stones 12×12
- 2 1/2 inch deck screws
- drill
- level
- shovel
- jig saw
- chop saw
Once you know the size of your deck, you can take the preparation steps.
Preparations
At each of the four corners of the tree deck, dig down about a foot and add chipped rock. On top of this, add a patio stone or deck support in each corner. This support is adequate for a simple platform. If you were going to build an actual deck you would need to dig down and put in footings.
Build The Frame
Now you can build your square by screwing the four 2 x 6s together into a square frame. Place it in its intended location.

Next, you will take the post that you bought and cut it into four 10 inch pieces. One of these is for each corner. Determine how far you would like the deck off the ground and screw the first corner it into place. Using the level, screw the posts in each of the three other corner, ensuring it is level. (You don’t want to leave very much space underneath the frame as you want to prevent critters from setting up home underneath.) I filled a little space that I had on one side with some extra wood, as the ground is uneven.
Build The Support Structure
The next step is to build the internal under structure. In my particular case, the roots were very high so I used 2 x 4s for the under structure. Instead of 16 inch centres which is standard, I put them on 12 inch centres for strength. For the 8 x 8 foot square tree deck you would need seven.

Add The Deck Boards
The last step is laying the 3/4 inch deck boards across the tree deck. It becomes a little bit tricky when you have to cut around the tree itself. I did this by calculating the outline of the tree with a pencil and a piece of board. To do this lay the deck board that is going to be cut on top of the last deck board you put down. Use a small piece of deck board to mark the outline of the tree. Do this with a pencil in increments making dots on the board. This is a similar process you would use when tiling.

The Finished Product
The new tree deck has made a big difference to our dock area. It looks much tidier and is functional.

If you are stumped by tree roots, consider building a deck around them.
Always
Leslie

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