When old decks get rickety, it's often due to failing fasteners, not the wood. Low-quality screws will corrode, discolor your deck, and eventually shorten your deck's life. Use stainless-steel (shown) or coated screws made specifically for pressure-treated wood. These screws will resist corrosion and extend your deck's lifespan. Warning: The popular electroplate-galvanized screws are not acceptable for decks.