Aluminum is corrosion-resistant, withstands heavy rainfall, and requires little maintenance. If you want something more affordable, plastic won’t rust or weaken in humidity. You might need to clean it with soap and water once in a while, but the maintenance is minimal. If you’re determined to buy wood, cedar naturally adjusts to humidity levels, resists bugs and rot, and doesn’t require as much maintenance as some other woods. It’s also hard enough to resist scratches and dents.