FiberBuilt Umbrellas 9 ft. diameter Patio Umbrella has (8) flexible fiberglass ribs, molded nylon joints, hubs and end tips for strength that improves the performance of the umbrella during adverse weather conditions. Our innovative fiberglass support rib construction ensures strength, resilience and durability. We have developed a full line of contract quality umbrellas that hold up to the harshest weather conditions - intense sunlight, high winds, salt air and driving rain - and will not decay or lose their shape. Our flexible fiberglass ribs absorb wind gusts without breaking and last four to five times longer than traditional steel or wood ribbed umbrellas. For its inherent strength and longevity, the standard canopies of most of our umbrellas and cabanas are made of marine grade fabric.