Door Fit is Poor
DEAR TIM: I have just had a new steel door installed which goes from my garage into my house. Everything looks fine, except the door does not fit properly on the upper left corner opposite the hinges. It appears that it should go in about a quarter of an inch. You can push it with your hand, in about a quarter of an inch. What is wrong and how can it be fixed? Bob Gile
DEAR BOB: The carpenter that hung the door has twisted the frame to fit both the rough framed and the finished drywall opening. In the perfect world, all wall surfaces and stud walls are in the same plane. This means if you stretched a string from any point on the wall to another point, there would be no high or lows spots whatsoever. But your wall is slightly twisted in our imperfect world.
If you want perfectly flat walls, you need to plan ahead when building. You can achieve this easily with steel studs that are almost always perfectly straight or use engineered lumber studs that look like super-thick pieces of plywood. Standard solid-wood studs can have crowns in them that cause all sorts of problems. A crown is a hump along the thin edge of a stud or any piece of dimensional lumber. A good analogy of the crown in lumber is the shape of almost every suspension bridge. The center of the bridge is always higher than the ends. The deck of the bridge is not flat but a gentle arch.
The carpenter who installed your door wanted the woodwork trim around the door to fit correctly so he forced the door jambs and frame to be flush with the adjacent wall surfaces. Doing this caused the door frame to twist while the flat door itself stays in the same plane.
You can fix it by enlarging both the mortise of the top and middle door hinge as well as tapping the frame out to meet the door ever so slightly. The hinge mortise needs to be enlarged so each hinge moves towards the center of the door jamb about 1/16th of an inch.
I would like to see the frame come out away from the wall only 1/8th inch where the door projects out from the frame. By making both of these adjustments, the door will once again be flush with the jamb at that upper corner. But realize that moving the hinge position in will cause the door edge to not be flush with the jamb once the door is closed. You have to decide which adjustment provides the desired result with the least amount of visual discomfort.