Completing the Deck

We got in another day working on the deck today.  We have now completed all the decking. Just as a safety precaution I have added one 4"x6" post from the ground to the deck. I have attached the post to the deck beam with a 10" lag bolt.  If you look in the picture below you can barely see the post immediately to the right of the ladder at the base. You can also clearly see the post in the picture immediately after that.  The deck is very level.  There is just a little sway, but I believe it to be the entire tree moving and not just a branch.  I might cable the oak tree over to the pine tree to try to minimize this swaying at some later time.  Next step is to install the railing.

Further Construction Progress on the Deck substructure and Decking Material

Partially Completed Decking

Over the last two days we completed the substructure of the deck for the treehouse.  We laid about half the decking material so far as you can see in the image above.  I figure about three more hours to finish installing the decking. The joists for the platform are 2x6s pressure treated lumber  hung on galvanized joist hangers each about 4 feet in length between the main beams of the superstructure on 18 inch centers.  The decking is western red cedar 1x8 fencing material. 

I am now working on the design for the railing and the stairway.  I have decided to put in one 4x6 post holding up the main branch, just so that there is more stability and there won't be so much movement when the weight shifts on the deck and the wind is blowing.

For the stairway I am going to hang a platform 7 feet below the deck from the rafters of the treehouse and then put in a stairway from the deck of the water tank cover to the platform.  Then, from there, there will be another stairway going up to the tree house deck (i.e., two rises each of about 7 feet). Don't forget that the deck on the water tanks is about 4 ft. above the ground already. So, the deck is 18 feet above the ground where the water tanks are located. The deck is about 23 feet above the ground level at the base of the tree.

 View from the deck

Starting the Treehouse -- Constructing the Deck

I have selected an oak tree appropriate for the treehouse.  I am a little concerned with the height that the deck will be at from the base of the tree. The tree is about 2 feet in diameter at the base.  The deck will be about 24 feet above the ground.  I have gone up into the tree and cleared out some smaller branches so that I can work unencumbered installing the deck for the treehouse.

I was fortunate to get my hands on some discarded 6"x6", 50 year old redwood beams. They are about 22 feet long.  My first approach was to design a "K" shaped beam structure and then box the "K" in with 2x6's, but once having raised the beams into the tree I have changed the structure to a square boxed in "H" structure.  Below are the pictures I have taken of the first three beams that I have put in place:

I installed the 14 foot cross beam first and used lag bolts  1/2"x10" and 14" to bolt the ends onto the two respective branches.  I had to install a shim under one end to get the beam level. The holes drilled into the beams are considerably larger than the lag bolt.

Next I installed the other two 11 foot beams, resting them near one end on the cross beam and on the other end to a substantial upright branch and to the trunk of the tree, respectively.

I will install one more beam between the last two beams and then cap each end of the deck with 2x8's.

First Thoughts

This time I am going to start documenting one of my projects before I start. I promise to take pictures both before, during, and after.  I will include information that I think will be helpful to others should they decide to take on a project of this type.

It all started when I built the deck onto the house.  Then the Oak trees in front of the deck were blocking the view.  So, I spent the last week trimming the trees so that I can see the view from the deck.  I have promised my grandson that I would build him a treehouse.  We had chosen one particular tree, but now that I have spent so much time in the oak trees, I know that the view from one particular oak tree will be much more interesting, so I have consulted with him and he is cool with moving our fantasy treehouse to a new tree.  

I have purchase a book which appears to be a good starting point for working on this project. It is:
Treehouses  & Playhouses You Can Build by David & Jeanie Stiles, Gibbs Smith, Salt Lake City, 2006. You can order this book from the publisher if you cannot find it, at 800 835 4993.