The answer to 'how to maintain deck' is to regularly clean, inspect, and seal the deck to protect it from weathering and wear. Start by sweeping the deck to remove any dirt, leaves, or debris. Then, use a deck cleaner and a stiff-bristle brush to scrub the surface, paying close attention to any cracks or gaps. Rinse the deck thoroughly with a garden hose. Once it's clean, allow the deck to fully dry before applying a high-quality deck sealant or stain. This will help protect the wood from moisture, sun damage, and fading. Repeat this cleaning and sealing process every 1-2 years, or as needed based on the condition of your deck.
It's also important to inspect the deck regularly for any loose boards, protruding nails, or other structural issues. Address any problems promptly to prevent further damage. If you're not comfortable performing major repairs or replacements, it's best to hire a professional deck maintenance service.