Temperature Of A Steel Roof In The Sun

The iron isn t going to melt.
Temperature of a steel roof in the sun. Third many metal roofs especially the shingle shake and tile look ones have an integral airspace between the metal and the roof deck. Still the shine of bright white on a roof is imposing and can take away from the overall aesthetic of the house. If it s on the sun facing side in las vegas you may find it gets hot enough to cause burns. If people can touch it easily the temperature is a concern.
Imho i would still hedge my bets a little and suggest 180 degrees f. A more obtainable maximum temperature for a properly designed solar collector is 150 degrees f. Different sources report different temperatures. Second metal roofs lose any gained heat very quickly to the sky when the sun sets or goes behind a cloud or even when a slight breeze blows.
Degrees fahrenheit on a sunny 90 degree day. White is the most reflective color and white metal roofing can actually lower the ambient temperature in the home by reflecting more of the sun s rays into the environment. Tom i think metal roofs wouldn t show as big a temperature difference because they reflect a lot of the solar radiation. White shingles keep vented attics more than 15 degrees cooler than black shingles and a reflective metal roof would do more than that.
A definitive answer is not possible. If it s out of reach don t worry about it. As a reasonable first approximation for a maximum design temperature for solar heating of steel used in typical construction.