Cutting corrugated roofing

timbatrader · Sep 28, 2019

I have heard but are unable to confirm abrasive wheel is not recommended the small sparks that come off wield to the surface and are not able to be brushed off which then promotes corrosion nibbler is the way to go If it was me I'd go for the more expensive single length option less hassle quicker put up and will last longer the lap joints are always the first place to fail

Jstpssng · Sep 28, 2019

oosik said:
I turned the four sheets over and cut them all at once from the bottom side. If there were going to be any "raggie stuff" I wanted it to be on the bottom. It turned out good. If you do end up using some kind of blade in your worm drive - use eye protection and a FULL face shield. And a work jacket. I picked tiny, tiny chunks of AL out of my hide for a day or so. A little festered red spot would show up - pick at it with a sharp pointed knife. Dig out a tiny chunk of AL.

Big mistake on my part - I only wore a short sleeve T-shirt. I DID wear safety glasses and a full face shield.

Also earplugs are a good idea. I never thought of doing them all at once, I always do manage to find the hardest way to accomplish anything.

dstig1 · Sep 28, 2019

timbatrader said:
I have heard but are unable to confirm abrasive wheel is not recommended the small sparks that come off wield to the surface and are not able to be brushed off which then promotes corrosion nibbler is the way to go If it was me I'd go for the more expensive single length option less hassle quicker put up and will last longer the lap joints are always the first place to fail

Bingo. Metal roofing manufacturer told me the same, directly from the horses mouth. Only use shears to cut, no saw blades or abrasives as the chips/dust will cause rust to start quickly as they imbed in the surface of the panels. They said that would void warranty, which isn't an issue here as it sounds like these are not new, but still seems like sound advice. ...Unless you just don't care, in which case a circular saw would easily be the fastest and straightest way to go....

sodamo · Sep 28, 2019

Good points, Rolf.
When we built the house we used structural metal roofing panels, finished metal panel each side, R20 foam in between. Had to cut 2 panels each roof (5) on both sides due to thickness. These were for width, splitting each panel into useable sections, 1/3 & 2/3 width as I recall. Longest panels were 30ft. Basically freehand, following chalkline as I had no way to fix a guide. Interior, flat side was easier than ribbed exterior. But, boy, what a mess. Noisy as **** using the worm saw with a metal blade and wax lube.

atsah · Sep 28, 2019

Circular saw with the blade reversed cuts it well.. It makes a racket that's for sure..

WranglerX · Sep 28, 2019

Skill saw with fine tooth carbide tipped blade, and cut from back side....and GOGGLES UNDER FACE SHIELD and cover up really well..... Sounds extreme but the saw will spread the shards everywhere, its like beach sand gets in every crack or crevice.....Its no fun going to ophthalmologist to get metal shard removed for eyeball....

If you need saw guide lightly clamp a length of 2x4 on each side of panels and use bolts or threaded rods to secure....

Dale

LS Tractor Owner · Sep 28, 2019

I was able to get 7 1/4" metal cutting circular saw blades at Home Depot a couple of months ago. I cut 4 sheets of galvalume U- panel at a time. Really clean cut. I think they were 28 or 30 carbide teeth. They are used in the normal rotation, the teeth are almost "flat" at almost 90 degrees to the blade. They weren't expensive at all, around $10 or $11 each. I bought 2 of them thinking they would wear out quickly, but lasted for cutting the whole roof (about 30 panels). It's still very noisy and a lot of chips.

I would do a search for "metal cutting blades at Home Depot " ... That's how I found them. They were in stock at my local store.

Alan W. · Sep 28, 2019

I had some white used roofing that I placed on coop. I cut it with a Lennox metal max blade. This us a diamond abrasive blade that cuts with a lot less sparks than a cutoff wheel. I have had no rust spots and until lately it has been wet.

mapper · Sep 29, 2019

Electric sheet metal shear works well, a bit slower than a circular saw but much less mess. Just long curls about a quarter inch wide, gloves are a must, they are sharp. Got mine from Grizzly, $80 for electric (don't recall paying anywhere near that), they also have pneumatic for $45.