Just bought a new tub which I'm installing into a bathroom with framing that I already knew was oversized (60-3/4), but I figured I should be able to shim the studs to get everything to line up. I find, however, that the brand new tub I bought has a flange that isn't square. At its shortest point, on one end, it's 59-1/2. At the opposite end, it's just shy of 60. As this is my first time doing a bathroom, I don't know if this is common and to be expected, and usually not an issue because the opening is usually square, or something screwy that should be returned. Comments? It's a steel tub with porcelain. With the way this tub is, and the non-square nature of the studs, it's going to be next to impossible to get the backerboard to extend out far enough so the tile isn't hitting the flange.