Raised Decking advice for a newbie

[AndyDOHD]

HI,
New here and seeking advice.
Iam building a raised deck to put a "tree house" on. It is 2 metres off the ground at one end and 1/2 metre at the other. I have already placed a numbe of vertical supports and placed a periimeter of "joists" (14cm x 4cm x 350cm) in place. I have attached the perimeter joists to the upright posts using a M8 x 125mm coach screw and 1cm by 10cm coach screw.

I am about to add a number of floor supporting joists and wondered which type of coach screw should be used? I have bought Long coach screws (1cm by 20cm) and wondered whether these would be appropriate to join the joists to the perimeter joists at 90 degrees?

I also have M8 x 125mm 5/16" x 5") coach screws.

I have had a bit of difficulty tightening the coach screws and managed to "knacker" the socket (from a socket set) in the process despite predrilling the holes for the screws. Any advise would be gratefully appreciated.

 

[Belboz]

As I said in your original post - Does this meet with the PD rules??

B

 

[AndyDOHD]

I am building a "tree house" beside one of our old apple trees in our orchard. It's not actually in a garden as such, the land is sloping significantly this accounts for the heights. It wouldn't be overlooking anyone.