I live in Florida and currently have a deck support by ten 9" round, 10' high pilings. The outer ledge boards are double 2x10x10 bolted to the piling which are notched to accommodate the double 2x10s.
The current deck is only 5.5' wide. The pilings are spaced 9 feet apart with one piling on each side of the deck every 9 feet to support it. I only want to extend the deck 30".
Instead of tearing the whole deck off and redoing the supports to cantilever it which can only be 24", I thought I could use 2x10s for a knee brace on each side of the piling and run 14" galvanized bolts through it. Then I would run a 2x10 parallel to the house on top of the knee brace on the outside and use lag screws to attach it to the knee brace. Then use 2x8x30" long with galvanized joist hangers to attach to the existing double 2x10 which is resting in a slotted space on the piling and bolted to it And the 2x10 bolted on top the knee brace.
____________________________
| <-- hanger |/|
old | new |/|
joist | joist |/|
________|_________________|/|
| |/|/| / /
| |/|/| / /
| |/|/| <-- beam / / <-- knee brace
| |/|/| / /
| |_|_| / /
| |
| | <-- piling
| |
| |
Do you think this would work or do you have any other ideas?
To answer some of your questions. The pilings are pressure treated wood telephone poles. They are 9" round. I have attached a side view of the knee brace I'm considering using,