Is there any reason you should not cut metal roofing with a saw rather that snips?

We have a lot of roofing to cut to fit and have been advised against cutting it with a circular saw with a metal cutting blade. Instead we were told to use nippers as sawing it makes it rust. We have done this in the past and have never had a problem, however this is for an equestrian facility that will have high visiblity with the outside public and we want to put our best foot forward. Any suggestions as buying a high-quality set of powered nippers is expensive versus buying metal cutting blades.

Public Comments

1. I have cut both ways and also used a pneumatic snip shearer. I found the fastest way was a circular saw with an abrasive blade or a wood cutting blade on backwards. As for the rusting, have a small can of metal paint close at hand and just brush, roll or spray the end. This will decrease the chances of rust. I have had rust equally appear on the different cutting methods. Obviously wear good eye and face protection when using the saw. A good thick pair of leather gloves will also save some nasty cuts. Cuts from metal take longer to heal. Good luck!
2. depending on the blade you use, but my experiences with insulating and lagging duct work, usually with an .040 embossed alum. either flat stock or boxed ribb is that when we cut it with a saw it leaves a little bit of a jagged edge. Snips will be a cleaner cut. With our box ribb material we have no choice but to use a saw, and to clean up the edge we'll file the burr off to clean it up.