Last updated on April 27, 2022 4:37 am by the writer.
If you need to know how to cut metal roofs like corrugated roofing or plain sheet metal, first learn the different top sheet metal cutting tools so that you can pick the best tool for cutting metal roofing.
It also helps to order panels of corrugated roofing the right size so there is less cutting to do, however, you still need a metal cutting tool to cut the angles, curves, and lengths that couldn’t be made to order.
Make sure you have the right roofing material for durability considering the wind and rust protection. If you are close to the ocean you need more protection. Read on to find out what cuts metal roofing the best.
1. Cutting metal roofing with a nibbler
A nibbler with its metal blade is the best tool for cutting metal roofing. A nibbler tool, unlike electric metal shares, can be more easily moved around to cut around corners quickly and easily without jamming the metal cutting blade.
An electric nibbler is what a professional roofer would use, it punches its way through the metal in a fast and tidy way to leave a clean-cut.
Nibblers work great because they cut a decent amount of metal out with each punch so that the blade doesn’t jamb as shears and tin-snips would.
- Smooth and consistent cutting process from the starting point to the good results.
- Excellent for cutting around corners, or corrugated metal sheets on an angle as the cutter has to go up and down over each corrugate, the nibbler is good at this. Whereas shears or tin snips would be slow and messy.
- The cut is clean and tidy and generally without sharp edges, that other tools can leave.
- For cutting straight unseen edges, electric shears could be faster.
- Most costly tool option for cutting metal roofing.
- It leaves metal fragments behind.
2. Use electric shears to cut sheet metal roofing
Power shears are a cheaper tool that can quickly cut sheets of corrugated iron in straight lines with little effort and its metal cutting blade.
- Cheaper than a nibbler to cut corrugated metal roofing.
- Can cut straight lines fast than using tin snips by hand.
- Perfect for quickly cutting metal roofing, that is hidden under a ridge or flashing.
- Faster than a nibbler for straight cuts.
- It cannot cut around corners or cut angles well.
- Joust like tin snips they cannot cut along the same direction as the corrugate, only cross-cutting the metal sheet.
- The tool has less working life than a nibbler.
- Hard to use for anything but a straight cut.
- The sheet is ideally laid down on the ground when cutting.
3. Cut sheet metal with tin snips
The cheapest way to cut a thin metal panel is with a pair of aviation snips. First, use a pair of straight cuts, or left or right-handed pair, for cutting both straight, and around corners.
The best tin snips are good for cutting any edge of corrugated iron that is going to be seen, as they are easy to control when cutting. They make the easiest way to cut galvanized, stainless steel, and plastic flashings.
Although there are faster tools for bigger jobs like using an impact driver or drill attachment electric shears or a nibbler drill attachment.
You can generally get away with only 2 pairs, as most of the time you only need to cut around a corner from one side left or right.
You can turn a pair of corner cuts upside down to make a cut in the other direction if you want.
It is however sometimes better value just to get a set of three so you have a replacement pair as well.
When using tin snips to cut thick metal, or if you are using low-quality metal snips, they might fail with the two blades starting to separate causing the snips to not cut as effectively.
Metal corrugated roofing can come in different gauges, most gauges can be cut with aviation snips easily, but slowly.
And for this reason, there are other tools for cutting metal roofing such as metal shears or an electric nibbler as the best option.
There are 3 types of aviation snips.
- Straight cut
- Right hand
- Left hand
- It is easy to follow the cutting line for clean controlled specialty cuts, or short cuts.
- Reasonably easy to cut a big sheet up as long as both sides are biggish.
- The best tool to tidy up seen metal roofing areas, for example, you cut the seen visible roof edge quickly with a nibbler, while you cut first with the nibbler half an inch longer than needed. After the roofing has been installed you later trim the last bit of corrugated metal roofing in a tidy way with a good pair of aviation snips.
- It is a good option to cut big sheets of metal roofing so that the off-cut is big enough to hold and twist out-of-the-way to let the snips keep cutting.
- If you are cutting more than .75 Inches off, it is difficult to cut corrugated iron with aviation snips. Unless the of cut is big enough, to hold onto and bend out of the way.
- Very slow to cut corrugated metal roofing.
- You can’t cut along the sheet, the only effective cutting is cross-cutting the corrugated iron.
- Thicker metal is hard to cut.
4. Dont cut sheet metal with an angle grinder
Metal roofing is thin enough for much safer and faster tools to do the job.
Grinders with a metal blade can leave behind sparks that can burn the paint finish, and also leave a dangerous sharp cut edge.
But changing blades all the time isn’t a problem with shears or a nibbler.
- If you use a diamond wheel instead of a metal cutting blade cut-off disk, the blade won’t wear out and will still cut. It is also safer to use a diamond blade as it won’t crack or explode if it catches.
- If you are cutting thick corrugate, like hole or cut, out of a steel shipping container, then an angle grinder is the best choice – use a steel cut-off blade.
- Thicker metal like a shipping container is easy to cut.
- Steel-cut of blades can wear out fast.
- Leaves a dangerously sharp edge that should be taken of with a file.
- Sparks can burn and damage the paint finish.
- So not recommended metal roof cutting tools.
- It is essential to wear safety glasses.
5. Dont cut roofing metal with a circular saw
A circular saw is mentioned many times on the internet for cutting metal roofing even though it is possible with a metal cutting blade it is messy dangerous and not professional.
Circular saws are for cutting wood or thicker aluminum only. Circular saws produce sparks on the saw blade that can burn the paint and cause corrosion on your roofing material later, a circular saw will also leave a sharp jagged cut that that would make it easy to cut your hand, and lastly, thin metal sheets are prone to causing dangerous kickback when using a circular saw.
Remember you read Bangingtoolbox to get advice from real tradespeople.
Tip: Make sure to order roofing the right size
Before you know how to cut roofing; order and let your supplier know what lengths are actually wanted. Basically, order the sheets at the length that you need them. This will eliminate wastage and reduce the amount of cutting that you would need to do.
Sometimes you are going to have to cut corrugated roofing yourself if you are recycling roofing material. Or if you have a roof angle that a factory won’t cut for you. Or when working around roof penetrations.
Get the right roofing thickness and gauge
Corrugated roofing comes in different gauges, the thinnest gauge is easier to cut with aviation snips, but if someone walks on your roof it can dent easily.
Corrugated roofing that has a thicker gauge isn’t that much more expensive, and worth it in my opinion. But requires a nibbler to cut, the thicker gauge.
With a stronger thicker gauge roofing iron you don’t have to worry so much about your getting dents if someone walks on the roof for maintenance.
A nibbler will easily cut all gauges of roofing but like I said above tin snips really struggle on thicker gauges compared to a nibbler.
Make sure that your tools are compatible with the thickness of your roofing material, nibbler tools pack plenty of grunt for thicker metals.
Expected rust protection for different roofing types
Roofing types by Materials
Galvanized steel roofing.
A galvanized steel roof has a zinc coating layer of protection only, the cut edges, therefore, are not protected around the sea.
These roofs will quickly rust from the cut join-up.
This is especially true around the sea. Known as the “sea spray” area.
Zincalume and galvalume roofing.
Zincalume and galvalume roofing are much the same except licensed in different country’s.
They are a mix of aluminum and zinc throughout rather than just a zinc coating. This gives cut edges some protection against rusting.
A Galvalume roof is available corrugated, with many design types.
It lasts a long time while being cheaper than getting a zinc or copper roof installed. Although as mentioned above, it can expand and shrink a lot with heat.
A zinc roof costs more but has a very good life in areas close to the sea this means your roof can last a lot longer. A zinc roof is generally installed with a series of trays and a cap.
A copper roof is the most expensive material to build a roof out of. Copper is extremely long-lasting even around the sea. It also looks very nice.
Although a copper roof will turn green after it ages for a few years, it is also bad for the marine environment, when the water run-off ends up in the sea via stormwater pipes.
Dos and don’t for cutting metal roofing
- Do cut multiple sheets at the same time to save time but don’t overload your tool.
- Do have different tools for the job, like a nibbler for most cutting, shears for only straight-line cutting, and aviation snips to trim pieces for making fine adjustments.
- Use an old tape measure on corrugated metal to protect your new one.
- When taking roof measurements allow for sheet overlap.
- Do make use of a roofing combination square for defining your marks.
- Be careful all the panels are strapped down at the end of the day so that there isn’t a chance of them blowing away and causing damage or injury.
- Don’t use a circular saw or an angle grinder for cutting metal roofing that will produce sparks and leave a dangerous cut edge.
- Don’t forget to order a ridge cap that is longer for folding down each side of the ridge.
- Always wear the correct PPE (Personal protective gear) Such as gloves, safety goggles, and hearing protection before operating your chosen metal cutting blade.
- Make your cuts on the ground, in a safe and clear area with the safest tool available.
- Set up scaffolding and fall protection handrails before getting on the roof.
- Have multiple people lift and handle each metal sheet for installation.
- Don’t use a tool that will leave sharp jagged cut edges on metal sheeting that can easily hurt you or others when handling and lifting into place.
- Use adjustable clamps to hold small sheets when cutting or to hold sheets in the correct spot before screwing them into place.
- Wear long pants to protect your legs from cuts, you could even wear long sleeves to protect your wrists and arms.
Now that you have the knowledge of the best way to cut metal for your new roof or renovation it is time to get to work!
As discussed fast straight cuts are done on corrugated metal with electric metal shears as they are affordable and work well. For cutting angles, straight lines, and curves you can use a nibbler tool.
And for tidying up your cuts make sure to have 2 pairs of aviation snips as the best tool to trim metal when making touch-ups.
Most roofers know the best way to cut metal roofing and thicker metal is to take advantage, of a high quality nibbler tool .
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