The steps that follow show a sliding patio door. If you are replacing a patio door that operates smoothly, you may not need to alter the rough opening. However, if the old door was difficult to operate, check the rough opening carefully. After the rough opening is prepared, you’ll need about four hours to install the door. Make sure you’re comfortable measuring, sawing, fastening, and leveling. Project tip: A set of hinged patio doors installs much like a slider but also has some of the challenges of hanging a standard exterior door. Because two doors meet in the middle, any sagging or out-of-square condition will be multiplied. Provide extra strength for the hinges by removing one hinge screw and driving a 3-inch screw through the hole into the wall framing. When shimming and aligning the unit, pay special attention to the critical point where the two doors meet. The doors should fit snugly but not so tightly that they are difficult to operate. (On wood units there is often a special piece of molding called a T astragal on the vertical edge of one of the doors.) Project tip: Follow manufacturer’s instructions for sealing the opening. In this arrangement, pieces of building paper and self-stick flashing tape are cut to fit and installed in the correct order, so water has no chance of seeping behind and damaging the house’s sheathing.
