Outdoor bleachers or we call it Grandstand also are commonly used for outdoor events. Spectators wanted to sit comfortably while watching their favorite event likes sports or shows.I prefer outdoor bleachers with roofing because you get protection from the heat of the sun or from the pouring rain. Outdoor bleachers are usually made from wood, concrete, stell and sluminum materials that can withstand weathering conditions.The seating usually inclineds downwardas opposed to straight to make sure everyone from back sees everything that the front seaters are seeing.