When cutting up small pieces for a project, an easier way to doublecheck for accuracy is to measure a number of the pieces at once. If you have four pieces which should be exactly 8 in. long, lay them end to end and measure. This multiplies small errors hard to detect on only one piece. For example, if the four pieces measure 32-1/8 in. instead of 32, then you know that each of the pieces is 1/32 in. too long.
A myth of metal roofing is that it is noisy. Metal roofs with solid sheathing and insulation control noise from rain, hail and bad weather just as well as any other roofing material.