Is this much oil canning normal for a brand new metal roof?

That's classic oil canning, and honestly, using wide flat pans without any striations or ribs on a south-facing wall is a recipe for exactly this. Metal expands and contracts like crazy when the sun hits it, and that thermal energy has to go somewhere. If the panels are locked down too tight or restricted by the fasteners, they can't slide vertically, so they buckle outward to compensate.

You need to check if the crew used a fixed fastening pattern where they shoud have allowed for movement. If those clips are cranked down or if the screws are driven too hard into the substrate, the panel is trapped. Also, if your deck or strapping isn't perfectly level, 24-gauge will telegraph every single hump and dip in the wall behind it. White siding makes the panels look sharp in the shade, but those afternoon shadows in the ripples are what make it look like a total mess during the walkthrough. This isn't something that's going to settle down or go away after a few seasons. It is pure physics. In fact, it might look diffrent every hour depending on the temperature. You’re in a tough spot right now becuase once the panels are snapped or seamed, there isn't a quick fix. You can try loosening the perimeter flashing or the termination points to see if it relieves some tension, but usually, the stress is built into the length of the pan itself. Next time, you really have to push the client toward **striations** or pencil ribs. They break up the flat surface tension and do a much better job of hiding the inevitable expansion. And if they absolutely insist on the flat look, you have to warn them in writing about oil canning before the first panel goes up. For now, you might have to pull a few of the worst sections and check the clip spacing to see if that buys you any flatness, but don't expect it to fix itself.

I'm curious about the clips mentioned. If I'm doing a smaller shed or a garage, is there a specific sound or feel I shold look for to know if I've over-tightened the fasteners? I'd hate to get to the end of a long day and realize I've accidentally locked the whole thing down.

Also, since dark colors absorb more heat, woud a black or dark bronze panel be a total nightmare for oil canning compared to the white ones mentioned here? I was hoping to go with a dark matte finish, but now I'm worried the sun will just turn it into a wavy mess by noon.

Dark colors are definitely a bigger headache. If you think white shows waves, black or bronze in that direct sun will look ten times worse because the heat absorption is so much higher. It's basially a radiator on the wall.

Regarding the fastener 'feel,' you should be able to grab the rib and physically slide the panel up and down a tiny bit. If it’s locked solid and won't budge, you’re going to have ripples by lunch. I always check a few panels mid-day; if they're stuck tight against the clips, we back the screws off untill the metal can breathe.

I've seen guys try to fix this by shimming the substrate before the panels go on, but if your wall isn't dead flat, 24-gauge is going to telegraph every single imperfection. Sometimes it’s just a slightly bowed stud or even thick overlaps on the house wrap that cause that first kink. Once the panel has a reason to buckle, the sun just does the rest. If you're stuck with those flat pans now, check your trim pieces at the top and bottom. Sometimes the perimeter flashings are pinned too tight and they don't let the panel breathe, which makes the oil canning look way worse than it actualy is.

I’ve seen some guys run a bead of structural sealant or a thin backer rod down the center of the substrate before the panel goes on. It creates a tiny 'crown' that forces the metal to bow outward consistently rather than letting it flutter or oil can randomly. Another thing to look at is how the panels were handled. If the crew 'rolled' them over thier edges while carrying them instead of keeping them flat, they could have introduced a permanent twist. Once that metal is stressed during the carry, the afternoon sun just highlights the damage. If they're alredy seamed, you're likely stuck with the look.