The best thing to put under outdoor furniture on a deck to prevent scratches is a dedicated protective pad or cup designed for furniture feet. These are typically made from durable, weather-resistant materials like felt, rubber, or plastic and attach directly to the bottom of chair and table legs. They lift the furniture slightly, distributing weight and creating a smooth barrier that glides instead of scrapes.
For broader coverage or under heavy items like grills, consider using a flat patio furniture mat or a roll-out deck protector. These large, interlocking tiles or mats made from PVC, polypropylene, or recycled composites provide a solid, scratch-proof surface. They also protect against spills and UV damage. Avoid using rugs without a proper non-slip pad, as they can trap moisture and lead to mildew on the deck boards.
The key is choosing a solution that is breathable to allow moisture evaporation, stable to prevent tripping, and tough enough to withstand the elements. This simple step preserves your deck's finish, prevents costly repairs, and maintains the beauty of your outdoor living space for years to come.