It's been said that if a metal roof is perfectly installed, there is no need for sealants. Perhaps therein lies some truth, but perfection is elusive, especially under field conditions. All roofs will leak at some point, but metal roofs are particularly challenging. Metal has a high coefficient of expansion, so it moves more extensively with temperature swings. To complicate matters further, metal roofs feature flashings and other details that also move along different directions. Further…
