Honestly, the best way to protect outdoor furniture from cigarette burns is to combine smart material choices with a few small habits. If you're choosing urban outdoor furniture for a cafe patio, roof deck, or shared seating area, look for heat-tolerant surfaces such as powder-coated aluminum, stainless steel, stone, concrete, glass, and ceramic tile. I'd avoid thin plastic, resin wicker, untreated wood, and loose fabric cushions unless they can be removed easily. A metal or glass tabletop is far more forgiving than a plastic one, and a stone-topped side table gives smokers a safe place to rest a cigarette.
Make the right behavior easy. Put sturdy ashtrays within arm's reach of every seating cluster—not one hidden by the door. Choose deep, weighted ashtrays so they don't tip in the wind, and empty them often. If people tend to balance drinks and cigarettes on chair arms, add small metal trays or cup holders. For sofas and benches, use removable, washable cushions and bring them in when the patio is closed. Outdoor furniture covers are useful overnight and during off-hours, but make sure the furniture is cool and dry before covering it.
Protective layers help, too. A fitted cover on a table, a heat-resistant runner, or a small glass or metal tray can catch ash and give cigarettes a safe edge. Avoid loose tablecloths that can flap into a lit cigarette; if you use one, weight it down. Outdoor rugs won't protect upholstery, but they do make dropped ash easier to clean up.
If a burn does happen, act quickly: brush off ash, don't rub it in, and clean the surface according to the manufacturer's instructions. On fabric, trim loose charred fibers rather than pulling them. And honestly, polite signage helps—a simple "Please use ashtrays" sign and a designated smoking corner reduce accidents more than people expect. The goal isn't to make outdoor furniture fireproof; it's to keep lit cigarettes away from the materials that scar.