Canopy Replacement Roof Cover 10 x 20 Foot Top Tan Costco Heavy Duty Shelter New. 50 Elastic Ball Straps. Roof cover is sized to fit certain canopy frames 10 ft x 20 ft. 781893 / 496840 / 405094 / 122175. May be found on the sewn-in label on your current roof cover. Dimensions: 20′ L x 10′ W x 5.6′ H. The canopy used with this roof cover should not be used during heavy wind, ice, or snow conditions. The accumulation of snow and ice on the canopy roof may pose a safety concern. Under severe weather conditions, disassemble your canopy and store indoors. The canopy used with this roof cover is meant for vehicle, boat and other storage use. It should not be utilized as shelter for people gathering. This fabric meets the flammability requirements of CPAI-84. The fabric may burn if left in continuous contact with any flame source. The application of any foreign substance to the canopy fabric may render the flame-resistant properties ineffective.