How to Cut Metal Roofing

Cutting metal roofing is a bit tricky because if you are not careful and don’t use the right tools, you’ll end up hurting yourself. This article will show you several ways to cut metal roofing safely and correctly.

Since metal roofing is available in different sizes, they have to be cut to fit the roof where they will be installed. The most common tools carpenters use in cutting metal roofing are shears and tin snips. You can cut the metal roofing by hand with these tools into the desired length and width.

It is not easy to cut metal roofing. If you are not careful in cutting it, you can easily cut yourself. So, you need to wear protective gloves while cutting it. It is also possible to use a high-speed circular saw to cut it. However, that will create too much heat on the metal.

Read on to learn more about cutting metal roofing, the different ways you can do it, and some helpful tips to make the cutting safer.

How to Cut Metal Roofing

How to Cut Metal Roofing

Use Shears and Tin Snips

Metal roofing sheets are sold at different standard sizes. If you want to install them on your roof, you have to cut them into size to fit the roof correctly. Cutting metal roofing is not that easy. The usual tools carpenters use to cut them are shears and tin snips.

Use Circular Saw for Cutting Thicker Corrugated Metal Roofing

You can also use a circular saw. But that will involve high-speed cutting, which can produce too much heat. Circular saws can be used for cutting thicker corrugated metal roofing. This power tool will enable you to cut long and straight cuts on thick metal.

Do Not Use Power Tools for Thinner Metal Roofing

For thinner metal roofing, it is best not to use power tools. Tin snips and shears will be enough to cut the thin metal into the desired length and width. You can also use nibblers to cut round shapes on the metal.

Make Use of Jigsaw

It is also possible to use a jigsaw to cut metal roofing. But your work will be slow, especially if you cut corrugated sheets. You also need to apply oil on the metal being cut if you make a long cut. The oil will keep the jigsaw blade cool while cutting the metal.

Beginners Can Use Angle Grinder

If you have no other cutting tool except an angle grinder, you can certainly use it to cut metal roofing. It is an excellent alternative metal cutting tool, especially for a beginner. However, angle grinders are designed for cutting thicker and shorter metals.

Since metal roofing is thin and long, using an angle grinder to cut it will somewhat be like overpowering to the metal.

What to Do Before You Cut the Metal Roofing

Cutting metal should be approached carefully. Before learning how to cut metal roofing panels, you first need to learn about safety procedures. Observe the following procedures to avoid accidents while cutting metal roofing:

1. Lay the Metal Roofing on a Flat Surface

Put the metal roofing on a flat and stable surface with its underside. It could be a workbench where the sheets won’t easily move while cutting them. Use adjustable clamps to keep the sheets in place. The flatter side of the roofing must be on top to make it easier for you to cut across.

2. Mark the Spot Where You Will Start to Cut

Get a tape measure and measure along the sides of the roofing material. Mark the spot where you will start to cut and end the cut. Use a permanent marker to mark the spots.

Mark the spots precisely because gaps in your measurements will result in water leakage once the whole roofing is installed. It is a good practice to measure twice before cutting.

3. Use a Combination Square to Draw Straight Lines to Cut Over

To ensure you are making correct measurements, use a combination square for drawing straight lines that will guide you in cutting the metal sheets. Put the adjustable part of the combination square flush against one edge of the metal sheet.

Then stretch the ruler outward and across the sheet. And then use a permanent marker to connect the starting and ending points of the line. Ensure that your lines are straight and accurate as much as possible.

4. Wear Safety Gear

Before cutting the metal, be sure to wear the required safety gear. These include a pair of goggles, a pair of hand gloves, a dust mask, and so forth. If you are using a power tool, wear earplugs as well.

For additional protection, you should also wear long pants, a long-sleeved shirt, and safety shoes (if possible).

Cutting Metal Roofing with Shears and Tin Snips

how to cut metal roofing sheets

Tin snips are just like scissors, but they are for cutting metals, bigger and thicker than ordinary scissors. Since they are for cutting metals, you have to be very careful in using them. They can quickly cut parts of your body if you are not careful:

1. Use Snips for Short Metal Cuts

Snips are available in different types. The right snip that you need to use will depend on the kind of metal sheets you will cut:

Plain Snips

Use plain snips if you are cutting straight lines. This type of snip can be used for most metal roofing cuts.

Left-handed Snips

Use a left-handed snip with red handles to cut metal sheets counterclockwise. This is done to remove metal to your left. But use a right-handed snip that has green handles if you are cutting clockwise. This removes metal to your right.

Whatever type of snip you choose, the cutting process will be slow because you will do the cutting by hand, inch by inch.

2. Create a Pilot Hole

If you need to cut inside a sheet of metal, you need to create a pilot hole in the spot where you need to start the cut. This is where you can begin cutting whatever shape is required. Start by using a drill to drill a hole in that spot. The hole must be large enough to accommodate the snip or the jigsaw blade.

The size of the metal cutting drill should be at least 1/2 inch. Drill the hole right at the spot where you are starting the cut. Then trim your cut toward the guideline that you have drawn. You don’t need to drill a pilot hole if you want to cut from one end of the sheet to the other.

An alternate way is to punch a hole through the metal by hammering down a nail or a screwdriver to the metal sheet. Punch the hole on the spot that you want to cut.

3. Open the Snips and Line Up the Blade Along the Guideline

Cutting metal roofing is similar to cutting a piece of paper with a pair of scissors. Open the blades of the snips and line them up along the guideline that you have marked down. Then fit the blades snugly to the metal.

Start to cut the metal. While cutting the metal, ensure that it is pressed up against the jaws of the snips. Work carefully and slowly. Ensure that the blades of the snips are in line with the guideline and are cutting through the metal.

4. Squeeze the Handles When Cutting the Metal

When cutting with tin snips, press the jaws of the snips down and as hard as you can on the metal, and then open the blades wide again. Repeat this exercise until you reach the end of the cut. Ensure that you can cut as much metal as you can with each stroke. This will ensure a smooth overall cut.

Remember that tin snips can leave jagged edges. So, be careful in handling the metal. Snips are also the best cutting tool if you are cutting shorter lengths of metal across the width of the metal sheet.

5. For Quicker Straight Cuts, Use Power Shears

If you want to do quicker and straighter cuts, use power shears. They are similar to snips, but they need electricity or compressed air to run. Shears are the best for cutting 2 feet lengths in metals. If you only have a short time to cut several metals sheets, shears are what you need.

They are easier to use because you only need to position the blade onto the cutting line, press the unit’s trigger, and control the blade as it cuts through the metal. While shears can produce clean cuts, you still need to use them cautiously. Don’t rush the blades when cutting because they can get stuck sometimes.

Again, how to cut metal roofing? To fit your roof, you have to cut the metal sheets. For this purpose, get your tin snips or shears, or you can also use a circular saw or a nibbler. A circular saw will get the job done faster, while you can make rounded cuts with a nibbler.

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Cutting Metal Roofing with an Angle Grinder

You can also use an angle grinder to cut metal roofing. Cutting metal with an angle grinder usually follows this procedure:

1. Use Continuous Diamond Wheel

Remove the controlling nut of the angle grinder and slip a continuous diamond wheel in it and re-attach and tighten the nut. Use the spindle to lock the wheel in place. Turn it to the right until it can’t go any further. A diamond wheel will be ideal for corrugated metal sheets.

2. Place the Part to be Cut Over the Edge of the Work Surface

Put your work material on top of the work surface. Position the part that you want to cut over its edge. If the metal is thin, place a heavy object over the sheet to avoid moving while cutting it. You can also stack several sheets of thin roofing material so you can cut them at the same time.

3. Tighten the Grinder Blade

Check the disc of the angle grinder and make sure it is tight. Lock it in place using the spindle lock button. Use a wrench to tighten the nut in the middle before releasing the spindle lock. Then place your hands on the handles of the grinder.

4. Wear Protective Gear

Be sure you wear your hand gloves and goggles before running the angle grinder. When you cut the metal roofing, the cut edges will be sharp. As you cut the metal, there will be small sparks that will fly around, so you need to wear protective gear.

5. Hold the Angle-Grinder at 45° and Start Cutting

Flip the angle grinder’s safety off and turn it on. Wait until it attains its full power, and then press the disc against the spot where you want to start cutting. Be sure that the blade is at a 45° angle towards the metal. Don’t put any pressure on the disc.

The friction produced from the grinder will move it slightly forward. Just make the movement as steady as possible until you reach the end of the cut. Cutting with an angle grinder gives you more control. It will enable you to cut straight lines and curved lines.

Cutting Metal Roofing with Circular Saw

how to cut metal roofing with tin snips

You can also use a circular saw to cut across metal sheets. Here is the usual method of cutting roofing material using a circular saw:

1. Wear Protective Gear

Don’t even begin to use a circular saw to cut metal sheeting without any protective gear. Wear at least a pair of goggles and a pair of hand gloves. A face mask is also recommended because fumes from cutting metals are harmful to your lungs.

2. Put the Metal over the Work Surface

Put the metal roofing on top of the work surface. Ensure that nothing will block the circular saw blade as it cuts through the metal.

3. Attach Metal Cutting Blade on the Circular Saw

Remove the controlling nut at the center of the circular saw and slip a metal cutting blade on it. Replace the controlling nut and tighten it. Make sure that the blade is secured in its place. Then engage the blade protective cover (if there is one).

4. Brace the Work Material with Your Free Hand

Control the movement of the metal roofing by bracing it with your free hand. Then press the base plate of the circular saw against a stable edge where you want to begin the cut. Hold the roofing material at least two feet away from the circular saw. Then turn on the circular saw and carefully make your starting cut into the metal.

5. Guide the Circular Saw Slowly

Slowly guide the circular saw blade as it cuts its way into the surface of the roofing material. This machine will do most of the work as it pulls forward from the traction of the teeth of the circular blade. All you have to do is to steady the machine as it cuts through the surface of the metal.

Don’t move the circular saw at an angle. Be sure to hold it steady at an upright angle. If you sense a kickback from the saw, immediately release the trigger and let the machine rest for a while before starting it again.

How to Estimate the Number of Metal Roofing Required

Use a Measuring Tape

If you think of installing roofing material on your roof, you need to know the number of metal sheets your roof will need. You need to measure the roof where the metal roofing will be installed to get this number. Use a measuring tape to measure the length and the width of the roof, plus the additional allowances needed on all the roof edges.

Choose the Roofing Material’s Size

Now, choose the size of the roofing material you will buy. You will require the length and width dimensions of the roofing materials to calculate the total quantity that will fit the roof and its additional allowances.

Add Allowance

You can do this by dividing the estimated roof area by the area of one sheet of the roofing material. The number you will get is the quantity of roofing material you need to buy. Add some allowances in case some of the roofing materials are destroyed while they are being installed.

Conclusion: How to Cut Metal Roofing

Since they are available in different standard sizes, you have to cut metal roofing to fit the size of the roof where you need to install them. The usual way carpenters cut metal roofing is by using shears or tin snips. They cut metal roofing into the desired length and width by hand.

When cutting roofing material made of metal, you need to be very careful. Always wear the required protective gear, such as a pair of goggles and working gloves. You are cutting pieces of metal which can be dangerous if not handled properly.

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