How to properly cut metal panels

Mechanical Seam Metal RoofAs we all know, metal roofing can be one of the most durable systems available, lasting for decades. But you may not be aware of how crucial it is to properly cut the panels. This is a key part of high-quality metal roof installation.

Why is this such a big deal? If the galvanized zinc coating is damaged or scratched at all, the area will be prone to rusting. To prevent this, certain techniques must be used to cut them. The following steps are important to the process:

  • Before cutting the metal, place it on a perfectly flat work surface, with the underside facing up. Measure out the length that you’ll need to cut it, using a tape measure. Mark that spot with a permanent marker, place the combination square onto the mark where it needs to be cut and drag the combination square and permanent marker along the cut line.
  • Now it’s time to begin cutting. Remember that any blemishes on the surface of the metal will be vulnerable to rust, and this will cause the roof to be weaker than normal. To cut, use a power shear, nibblers or tin snips. Align the cutting blades with the cutting line that has been marked on the underside — but make sure it’s perfectly aligned. Even if it’s off by a tiny bit, it could cause a lot of damage to the panel.
  • The power shear or other type of cutting tool should be used slowly. This sounds simpler than it actually is, but with patience and a steady hand, you’ll get the hang of it.

metal roofing panel

Some people choose to use a saw when cutting metal panels. If you do so, you need to make sure there are no burrs left on the ends of the panels, because these rough edges will rust. Also, the filings that fly off the blade during the cutting process are hot, and they will therefore stick to the surface of the panels. These filings must be removed or you will end up with rust and pitting on the surface.

At right is a picture of a metal panel that was improperly cut and wasn’t brushed off correctly. Notice the rust issues that have resulted.

If you’d like to know more about how to precisely cut your metal panels, contact our team of friendly professionals today. We’re always here to help you!