Metal roof provides increased wind resistance when compared to other roofing materials. This is because metal roofing systems use interlocking panels. The disadvantages of metal roofs include the noise created from rain hitting the roof, and, in snowy areas, the tendency of snow to easily fall off the roof and onto pedestrians or property. Originally, metal roofs were made of corrugated galvanized steel: a wrought iron–steel sheet was coated with zinc and then roll-formed into corrugated sheets. Another approach is to blend zinc, aluminum, and silicon-coated steel. These products are sold under various trade names like "Zincalume" or "Galvalume". The surface may
What Time Is It? (song) Efron) and Gabriella Montez (Vanessa Hudgens) is also visible. When the clock has ten seconds to go before the bell, the class commenced chanting "summer!" getting louder until the bell rings, after which the song is performed. The music video contains clips directly from the movie, and was released on July 31, 2007 on the iTunes Store. The music video was also released on the Disney Channel. The song peaked at number 1 on the "Billboard" Hot Single Sales chart for 28 weeks, which became the highest selling single of the year-end chart in 2007. What Time Is It? (song)