Building backyard play fort

The Coffee Shop
1

I am planning on building a backyar fort for the kids, does anyone have advice on the structure?

I am thinking 4" x 4" posts on cement deck blocks on a 6’ x 6’ footprint… 2" x 6" perimeter joists with 2 x 6 joist hung off steel hangers on 12". 1 x 6 flooring. This will be my base, and the base will be approximetly 5 feet off the ground. I will put angle braces from the perimeter joists to the posts the perimeter joists will be attached with 4" lag bolts.

Does this sound like a solid enough base?

2

I’d trade carriage bolts for the lag bolts. 12" OC sounds like overkill to me, i’d do 16"OC. how are you going to secure the 4x4s to the ground? I would do more than “place” the 4x4s on blocks (not sure what you mean by cement deck blocks though).

3

16"oc is plenty, tho 4x4’s sitting on blocks is kind of sketchy… dig down, set into concrete and sonic tubes will prove very secure :slight_smile:

4

Plan has been modified to a certain extent, one post is being traded for a tree. The structure will be sitting on the same footing used around here for decks.

http://www.google.ca/...amp;tx=66&ty=105

Will the 16" OC be good enough for the 1" planks?

2 x 3/8 lags will not be strong enough on each perimeter joist, which is also supported by a 45 degree bracing?

I want this structure to be easy to take down.

5

Initially, I was going to say that if the base was 5’ off the ground, and assuming a 6’ wall, no roof (fort), your centre of gravity with several kids in the fort is too high for a 6’ base, un-anchored. With the tree as one leg, you may be ok, provided that the tree is stout enough, but not sure…

Kids do dumb things, and rushing from side-to-side in the fort, throwing their weight around is not inconceivable; I’d be hesitant to build it without anchoring - dig down, poured cement bases. Set your bases below grade, so if/when you take it down, you can simply cover the bases with soil and grass.