Cutting Metal Roofing

[SeanD]

I was able to get away with using a jigsaw to make a few cuts in my metal roofing for the stack and around the cupola. It wasn't pretty, but it was very easy and they will all be covered up with flashing, etc. I'm going to need to make a cut along the gable end and it will be visible, so I want it pretty straight.

Will I get a better looking cut from a steel cutting blade in my circular saw? The metal flaps all over the place and the line I'm aiming for becomes a blur. The vibration even knocks my clamps off. Any tips?

Thanks,
Sean

[kcompo]

4 1/2'' hand grider with thin metal blade works good for metal roofing.

[gator330]

Sawsall with a metal blade cuts like butter follow a line nice finished look. by the way nice sugar house!!!

[LEROY MILLER]

a circular saw with metal blade works really good for tin you can get a nice strait cut.

[Haynes Forest Products]

Try screwing a board to the part your cutting off. As stated discs cut nice and sometimes holding the Sawzal at a angle to the cut instead of stright up and down can help with the joy ride the saw likes to take.

[twobears1224]

a metal cutting blade in your skilsaw cut from the backside and set the blade so it,s cutting at the 1/3 point on the blade..adjust as it wears.

delbert

[BryanEx]

4 1/2'' hand grider with thin metal blade works good for metal roofing.

I went this route too. A metal cutting disc (not grinding - it's much thinner) and used a straight strip of plywood as a straight edge to rip four factory painted 7 1/2' panels to fit a shed roof line. I was really pleased with the finished cut and it didn't take long at all.

Whichever route you choose remember the safety glasses, ear protection, and don't do it anywhere near your wood pile. ;)

[Smitty]

Sean,
thin cut off wheels (.035) on the hand grinder works great, but tends to
throw heavy sparks:mad: :mad: (be careful). If no other option, a regular wood blade
for a circular saw, put on backwards, cuts tin great, really great, but put on your safety
glasses, it tends to throw big pieces of stuff:o , minimal sparks.:cool:


hope this helps
Al Smith

[gmcooper]

Ok, we install lots of metal roofing with our construction business. We work with one manufacturer frequently and they send us a fair amount of work on high end and difficult roofing projects.

USE electric shears to cut metal roofing! Kett brand shears are not much money and work well. A nibbler will work as well.

DO not use skill saw or grinder wheels. This is straight from the manufacturer! It's usually in the warrenty section. Using a high speed blade or disc heats up the metal as it grinds thru making the cut. The metal heats up and expands as well as heating the painted surface. This will cause the metal to rust at an accelerated rate and it voids most if not all company warrantees. Secondary issue is all the hot sparks when using a skill saw or grinder with cutting disc is sparks landing on finished surface and damaging the finish which will also cause rusting at an accelerated rate.

[3rdgen.maple]

nibbler nibbler nibbler. But all other options will work. Just cover up the painted with tape or wood. Don't want it all scratched up and earplugs are a must.

[Squaredeal]

x2 on the regular skil saw blade in backwards. Works best if you use a steel, non carbide blade. I have installed many roofs over the years using this trick. Don't forget the gloves and eve protection AND ear protection -it's a screamer.

[WESTVIRGINIAMAPLER]

Utility knife works good too if you score it along the edge of something like a 2x4 a few times, it will usually break off pretty easily after you bend it and a saw blade backwards works pretty good too as stated in previous post.

[SeanD]

Thanks for all the quick responses. All of these methods are easy enough to try. For future readers, the eye and ear safety is definitely a must. I didn't get a lot of sparks with the jigsaw, but bits of metal did shoot off in my direction more than a few times and it is LOUD especially inside the shack.

Thanks again,
Sean

[Dave Y]

If you are cutting a metal roof a good pair of right handed tin snips work very well. I have cut plenty with that tool or get a nibbler they are not that expensive. They also can be rented.

[Flat47]

I saw a demo of Diablo brand circular saw blades. It was pretty impressive. They had one circular with a fiber cutting disk in it, and another circular saw with a Diablo metal cutting specific blade in it. They used each to cut some 1"x1" angle steel. The fiber blade threw sparks all over the place and heated the angle steel until it was glowing red. The other blade cut through it with nearly any sparks, gave a nice clean cut (no rough edge), and you could grab the metal with out being burned right after cutting it. I think those Diablo blades are really expensive, though. And, no - I have no ties to them.

Update: I googled them...$50 for an 8" "Steel Demon" blade...

[kinalfarm]

i always use the regular blade in backwards trick but a waffer blade is cheap and efective for cutting metal roofing too. they also make a blade called a metal devil that works well but they are pricy.

[wcproctor]

Go To Harbor Freight in Worcester and for 29.99 you can get a air shears they work the best. Where in Hopk. are you I would like come by to see your set up. Im in town all the time.

[johnallin]

I'm going to need to make a cut along the gable end and it will be visible, so I want it pretty straight.

Sean, If you have not already cut your roof panels, we measured and then used a pair of straight cuts on the gable end roof panels (watch out - it will give you popeye arms!) and then capped it with a piece of angle to finish off the cut and cap the rake board.

That's a awesome looking sugar house, by the way and I really like the windows up in the gables.

[SeanD]

Thanks. Full sheets got me to within 9" of the gable end, but then I ran out of time. So the big cut will have to wait until next weekend. My circular saw has a rip fence, so I might try that first.

wcproctor, I'll send you a PM.

Sean

[slammer3364]

I also used the saw blade backwards but why not just let it run out longer

[mapleack]

On a non cutting note, if your roofing is a particular color, not just galvanized. Go buy a spray can of clear Rustoleum and spray the exposed cut edges when you are done. No rust and no off color paint on your roof.

[PerryW]

Can you flip the sheet around so the ragged edge is NOT on the outside edge? I just use a skill saw with a cheap metal blade, though tin-snips would probably work since you don't have to cut over the ridges since you are making a vertical cut.

On a related note, I say someone predrill holes on the roofing sheets to make them easier to install. They just stacked all the sheets and got them all lined up. Then they measured and drilled holes for the screws drilling through all the sheets at once. Certainly made installing the screws easier.

[SeanD]

That's a great idea on the predrilling! I've got about a half dozen scratches I have to go back and hit with the touch-up paint from where the screw didn't bite and jerked out from under the drill, crashing the drill into the roofing. Grrrrrr!

I thought of doing the flip and leaving the factory cut edge facing out, but I need to do the math on the pattern of how the ribs overlap to get the right overhang on the gable end. If I flip it, the rib spacing will determine the overhang. Maybe I'll get lucky. I'll have to check.

Thanks,
Sean

[KenWP]

We used to do metal siding and the screws all had to be perfect or we had to replace a sheet. We had a gizmo that we used to put against the sheets and hit with a hammer and it indented a mark for all the screws. Then they all looked the same and no marks. Also if you have a center punch and mark the holes as you go along works also.

[johnallin]

Sean, If your roofing is like mine "Metal Sales Co" one edge has a small ledge built-in to help prevent water from climbing over the top, the other edge is slightly bigger to capture it and provide a good tight fit. Otherwise the two will not lay down properly - learned it the hard way...

You may or may not have the same panel but it's worth looking at.

[3rdgen.maple]

The metal trim peices that go on the edges of the roof will cover it up anyways unless you plan on not using them. I think if you are worried about how it looks putting them on is the way to go and it also seals the edges so the weather does not get under the metal roofing. Did the sales guy not order them with the roofing? First thing they asked me.

[vtsnowedin]

26 replies on how to cut a piece of tin?
How about using the best tool you have available be it a nibbler made a-purpose or a double bitted axe against a sheet set over a log? I like the 4 1/2 inch dimond blades in an angle grinder or a 7 1/4 inch diamond blade from TS but the skillsaw blade on backwards certainly works. Paint your rough edges or not it will take twenty years for it to rust away and the grand kids will have to deal with it. :)

[Dave Y]

27! That's what I like about this site. Everything gets over analyzed. Keep It Simple! Go tap some trees!

[johnallin]

28.....the edge trim is the answer. Use any 1x1 angle to cap the edge of the roof panel and rake trim.