Re: Deck gate
pretty simple actually, you need to put another post in at the house. get yourself another 4x4 x 48" and notch out the decking so it slides down along the ledger and the outside joist. fasten it with screws through the outside joist then install blocking between joists to lock the post in place plumb.
from there get some 2x4 pt and fence boards to make your gate, make the gate frame about 1/2" narrower than the distance between posts so it swings freely without hitting the posts. from there its just a latch
fire up the saw and make some dust