When installing a new door in an old wall, it's rare for that wall to be perfectly plumb, level, and square. In this article, remodeling contractor Mike Sloggatt provides a detailed account of the steps he took to install new French patio doors in Fine Homebuilding's Project House. He begins by discussing the three options for installing a door in an out-of-plumb wall. The first is to hang it to match the wall. This is a viable method if the distance the wall is out of plumb is 3/8 in. or less over 8 ft.; otherwise, the door may develop phantom swing, which is when the door swings open or shut on its own. The second option is to hang the door plumb, which will work if the door is within 1/4 in. of plumb but will present problems for trim and siding if it's greater than that. The third option is to hang the door almost plumb--essentially a combination of the first two options. This is the method Sloggatt chose for the doors at the Project House. First, he prepped the opening, which involved checking it for plumb, level, and square and then using a sledgehammer to bring the wall closer to plumb. Second, he installed the pan after applying flexible flashing, then set the door in place. The final steps were positioning the door, checking the diagonals, fastening the door, strengthening the hinges, and installing the hardware. Sloggatt recommends two tools for installing doors, both of which he used on this project: an 8-in. suction cup for help in lifting doors, and a Pump Wedge, which holds a door in place with an adjustable amount of friction.