What's the best way to cut metal roofing to fit a valley? Tuolumne, Calif., builder John La Torre suggests using a circular saw equipped with a metal-cutting blade. He suggests setting the blade just deep enough to cut through the low parts, and he adds that you should cut slowly. La Torre also suggests an angle grinder fitted with a metal-cutting blade. His advice includes cutting tools that don't produce sparks or metal shavings (sheet-metal nibblers and sheet-metal shears). His go-to when electric tools aren't available? Two off-set aviation snips.
Check out La Torre's full response here: