I am replacing a large 1980s rotted, not to new code, and termite ridden deck. At first I used Pt for everything because it is cheap. AFTER research in deck magazine, fine homebuilding, and Simpson strong tie, and noticing the rot in the old pt wood and not in the old redwood, I changed to cedar deck boards. Cedar has to be sealed on all 6 sides before installation immediately. It comes kiln dried and mine came with anchorseal on both ends. COMPOSITES Are know to warp and look cheap. Pt metal connectors (required) have to be either stainless steel (expensive) or galvanized with waterproof membrane joist tape (expensive) between the connector and the Pt wood. The new pt wood destroys galvanized metal. STUDY the idc chapter 507, decks from 2015 and 2018 before rebuilding your deck. Also watch the videos from finehomebuilding and Simpson strong tie. Buy a copy of Professional Deck Magazine. Btw, my old joists are 16" on center so I had to use 2X 6 not 5/4 deck boards. If you are installing new joists 12" on center you can use 5/4 but it still will not be as strong or long lasting as
2 x 6. MY estimated cost for cedar, metal hardware and deck screws is 12,000. including 2 sets of stairs and stair railing. The estimate from the deck company was 50, 000 to redo the entire1100 sq Ft deck with stairs and railings. Do it slow and do it according to the new prescriptive code and you will have a safe, beautiful, rot free deck for many years with maintenance and cleaning. good luck