The top side of each sheet has ridges that stick up and are tricky to cut across cleanly. Always turn sheets so the ridges are upside down, valleys instead of mountains.
You could look up a metal roofing calculator online to help you figure out how many sheets you need. Then, fit the sheets together according to your roof measurements. For example, if you have a 21 ft × 10 ft (6. 4 m × 3. 0 m) roof, you have 210 sq ft (20 m2) space to cover. Divide it by an 18 sq ft (1. 7 m2) sheet to get an estimate of 12 sheets.
Focus on getting the marks precisely where you need to cut the sheet. Any gaps in the roof cause a big leakage problem, so measure twice.
Precision is very important when working with metal roofing. Any mistake you make could cause the metal to rust after you cut it. Make sure your line is as precise as possible!
Circular saws produce the most noise and debris of any tool you can use to cut the metal. If you’re using one, double-check that the roofing is sized correctly and that you have safety gear like a good pair of earplugs and a dust mask.
Select yellow or plain tin snips to cut straight lines. This type is useful for most cuts you need to make when working with metal roofing. Choose left-handed snips with red handles for cutting counterclockwise, removing metal to your left. Pick right-handed snips with green handles for cutting clockwise and removing metal to your right.
You won’t need a pilot hole if you’re cutting end to end across a sheet. Another way to do this is by hammering a nail or a screwdriver through the metal. Always make the hole on the part you plan on removing in order to avoid any lasting damage to the sheeting.
Work slowly, making sure you keep the scissors on the line and latched onto the metal.
Tin snips leave jagged edges, so handle the metal carefully. Wear a strong pair of gloves to protect yourself. The snips work best when cutting shorter lengths, such as across the width of a single sheet.
Shears cut similarly to scissors but are electric. All you have to do is hold the shears where you need to cut, press the trigger, and control the blade as it moves along the metal. Although quality shears slice more smoothly than a hot knife through steak, you still have to be careful with them. Sometimes they get stuck, forcing you to approach the cut from the opposite angle. As long as you don’t rush or force the shears, you won’t have much trouble.
Saw blades wear out over time, so replacing old blades gets a little costly if you cut a lot of metal. Saw blades get hot and can damage the roofing if you’re not cautious. They also create more dust and metal fragments that pose a risk to anyone without the proper safety gear. If you’re looking for an alternative to a circular saw, try an angle grinder. It’s more like a handheld version of a circular saw and works about as well on roofing. It is more mobile, but it requires more hand control.
Always check the blade’s label to ensure it’s right for your project. Look for blades meant to cut sheet metal or metal roofing. Carbide-tooth blades are costlier but last longer, so choose one if you plan on getting plenty of use out of your saw.
Unlike with tin snips, you don’t get a second chance to adjust, so keep a close eye on the blade. Move slowly, keeping your hands firmly placed on the saw’s guard at all times.
If the saw stops working, don’t force it forward. Turn it off and take it to the other side of the guideline. Complete the cut from that angle to create a secure but whole panel for your roof.
Nibblers are specialty tools, so they aren’t great for straight cuts. Fortunately, you have your saw for that. Use a nibbler instead for tasks like cutting a hole for a vent pipe.
