Custom Cut Metal Roofing Panels Sourcing: 8 Questions I Ask Before Every Order

I handle material purchasing for a 40-person commercial roofing contractor. Which means I'm the person who gets the shop drawings secondhand, turns them into a quote request, and then explains to a project manager why the panels that arrived are the panels we ordered—but not the panels he pictured.

We put through somewhere around 70 material orders last year. Maybe 65, I'd have to pull the report. Roughly a third involved custom cut panels, and every one of those had at least one moment where somebody on our side said "wait, that's not what I thought we were buying."

So here's the list of questions I actually ask now. Not the ones on the supplier's FAQ page—the ones I had to learn the hard way, in roughly the order I learned them.

1. What actually counts as a "custom cut" panel?

Depends who you ask, and that's the problem.

For one supplier, custom cut means they pull a standard coil and cut it to the length you asked for. For another, it means they run a full panel layout from your drawings, including hips, valleys and the trim package. Length-only cutting is fast and cheap. Layout work takes engineering time and usually carries a setup charge.

If your quote request says "custom cut panels, per plans," you'll get two numbers that aren't measuring the same thing—and one of them will look wrong. Now I write the cut list myself, in inches, and I state the tolerance I'll accept. Most shops hold ±1/4" on cut length. Some quote ±1/2" and don't mention it. On a 20-foot panel, that gap shows up at the ridge.

2. How is a metal roofing panel price actually built?

What moves metal roofing panels prices is a short list. Coil price, gauge, coating, width, cut charge, and freight. Everything else is arithmetic layered on top of those six.

Coil price tracks the steel market and moves month to month, which is why nearly every quote we receive carries a 15- to 30-day validity window. If you're comparing a March quote to a June quote, you aren't comparing suppliers. You're comparing steel markets.

Gauge and coating are where specs go fuzzy. "24 gauge, galvalume" isn't a complete specification. ASTM A792 covers zinc-aluminum coated steel, but the coating weight designation (AZ50 versus AZ55) and the yield strength both affect the number, and neither is usually volunteered. Ask for both in writing.

3. Why do two quotes for the same spec come back 30% apart?

It's tempting to think that identical specifications should produce identical prices, and that the gap is either a mistake or a markup. That's usually not what's happening.

In my experience the gap is almost always one of four things. Freight basis, first—ex-works versus delivered to the job site is a double-digit percentage swing and it isn't always labeled. Then scope: trim, rake, ridge and fasteners are line items at some suppliers and bundled at others. Then coil source, domestic mill versus imported, which changes price and lead time and which you won't learn unless you ask directly. And finally gauge tolerance—sheet steel is allowed a thickness under-run, so a supplier running near the low end of tolerance is quoting a lighter sheet metal roofing panel at the same nominal gauge.

None of that is dishonest. All of it makes the totals non-comparable.

4. What do I need to send with a quote request?

Same list every time now. Ten minutes of work, and it saves a week of back-and-forth:

• Panel profile, plus the profile manufacturer's name if it's a proprietary standing seam
• Substrate: ASTM A653 galvanized or A792 zinc-aluminum, with coating weight
• Gauge, and whether that's nominal or minimum thickness
• Paint system and color, with a reference number
• Cut list in inches, with quantities per length
• Trim and flashing schedule
• Delivery address, and whether it's a job site or a warehouse
• The date you need it in hand, not the date you need it installed

That last one causes the most trouble. If I write "need by the 14th" and the crew mobilizes on the 14th, I've built in zero float for a delivery that involves a flatbed and a forklift.

5. Is custom cutting really more expensive than standard panels?

People assume custom costs more because custom work is harder. Sometimes it is. But the bigger driver is usually the offcut.

A coil is a fixed width. If your panel width nests cleanly into that coil, you pay for the steel you use. If it doesn't, you pay for the steel you use plus the strip you threw away. A 16-inch panel run out of a 36-inch coil leaves 4 inches of scrap on every pass, and that scrap is in your price whether or not it appears on the invoice. The arithmetic doesn't care whether you're buying corrugated metal roofing panels or standing seam—the width does.

So the causation runs the opposite way from what I first assumed. Custom doesn't cost more because it's custom. Inefficient nesting costs more, and inefficient nesting is just what most custom jobs happen to have. The practical move: ask what coil width they're running and how your panel nests into it. The suppliers who answer that in one sentence are usually the ones doing their own cutting.

6. What's the cost that never shows up in the quote?

The base panel price is roughly two-thirds of what we actually spend, on a good job. The rest lives in freight (and whether there's a lift gate or you need equipment on site), crating, and the trim and flashing package—which runs higher per lineal foot than the panels themselves do.

It also lives in waste. Field-cut panels need 5–10% overage. Factory-cut panels need 2–3% if the cut list was right, and 15% if it wasn't. And it lives in timing: panels that show up two weeks early sit on a job site and get walked on. Cheap until somebody has to reorder four pieces at rush pricing.

(Should mention: the $300 crate charge we argued about for a week is the reason zero panels arrived bent. I've stopped arguing about crates.)

7. Should I just take the lowest bid?

The numbers said go with the cheaper supplier. Fourteen percent less on paper, similar specs, references that checked out. My gut said something was off—their quote came back in two hours and I'd asked six questions. They answered two.

I went with them anyway, because I couldn't justify 14% to my operations manager with a feeling. Then the freight invoice arrived separately, the trim wasn't inside the original number, and the lengths had been cut to a cumulative total instead of per panel. We spent more than the higher quote would have cost, and I spent three weeks explaining it.

What I do now: I don't compare totals. I compare line items. Freight quoted, trim broken out, tolerance in writing. In that order. A supplier who won't break those out isn't giving you a quote—they're giving you an estimate wearing a quote's clothes.

8. What do I check before the first order with a new supplier?

Four things, in this order.

1. Can they invoice properly? Sounds trivial. In 2022 we used a small shop that issued handwritten receipts with no PO reference. Finance rejected the expense report and I ate $2,400 out of the department budget. Now I ask for a sample invoice before I send a PO.
2. Do they cut in-house or broker it? If they broker, the tolerance and lead time you were quoted belong to somebody else, and every change order runs through two companies.
3. What's the damage and shortage policy, in writing? "We'll take care of it" means nothing when a bundle arrives crimped and the crew is standing on a roof waiting.
4. Will they tell you what they don't do?

That last one is the tell. A supplier who says "we don't run curved panels" or "we don't stock that coating in this region" is being straight with you. One who says yes to everything is going to subcontract half of it, and your schedule will reflect that whether or not the quote did.

Full disclosure on where we landed: we moved our custom-cut panel orders to a sourcing partner instead of quoting each job direct. Not because the panels got cheaper—they didn't. Because the quoting process stopped eating a day of my week, and I got somebody else to argue about crates.