Is it normal for my form boards to look this wavy before a pour?

Wet concrete is heavy and it only pushes outward, so that bow is going to get significantly worse once the truck starts pouring if you don't fix it now. A 2x4 has almost zero structural integrity against the lateral pressure of a four-inch slab over a long span. If it's already bulging two inches dry, you're looking at a complete blowout or a permanent wave in the finished edge that'll look amateur from a mile away. You don't have to pull the stakes to fix this. The trick is to use a **kickers and deadmen** setup. Drive a fresh stake about three feet back from the form, then take a scrap piece of 2x4 and wedge it between that stake and the bulging section. Use a sledgehammer to tap the kicker until the string line shows the form is perfectly straight. You aren't going to snap the original stakes; they'll just pivot in the dirt as you force the board back into alignment. Once it's straight, screw through the kicker into the form so it can't shift. Since this guy was the 'budget' option, check the spacing on the existing stakes too. For a standard patio, you really want a stake every 24 to 32 inches. If he's got four-foot gaps between stakes, that's why it's warping. Add more support now becasue trying to kick a form back into place while it's full of wet mud is a nightmare you don't want to deal with. Honestly, I'd stay out of the drama with your buddy. If you want to help, just show him how to brace it and let him handle the 'pro' he hired. If the guy hasn't even put down rebar or finished the subgrade yet, he might just be in the rough-in stage, but you never take a chance on a visible bulge. Once that concrete sets, that banana shape is a permanent monument to saving a few bucks.

Man, classic case of you get what you pay for. If the forms look like a banana, I'd bet my truck the subgrade’s trash too. Did the guy even pack the dirt or throw down any gravel? I've seen these 'deals' turn into a cracked mess in two winters 'cause they skipped the prep work.

Honestly, I wouldn't touch his tools. If you fix it and it still cracks later, it's your fault in his eyes. I'd just grab a beer, sit back, and watch the show. It's gonna be a bumpy ride when that mixer shows up.

Seen this movie a hundred times. Back when we were doing the interstate ramps in '78, we wouldn't even look at a 2x4 for a form unless it was clear grain, but these days you’re lucky if the lumber isn't twisting right off the truck. If that guy left it like a banana, I’d bet he didn’t even bother with form oil. He’ll be prying those boards off with a crowbar and taking chunks of the finish with it. Tell your buddy to check for a 'turn-down' edge. If it's just a flat slab on grade with no thickened edge, that thing's gonna walk away the first time the ground freezes.