You can, with a little bit of patience and the right tools, install your own patio door. The DIY option makes the benefits of a new patio door available to many consumers who might not be ready to invest in the expense of a professional installation. In many instances, the price of removal and installation by a contractor can be a greater expense than the door itself.
There are as many specific methods to install patio doors as there are patio door manufacturers. This is especially true in sliding units that come with a broken down frame. The sheer weight of a full-sized wooden door with insulated glass can be overwhelming, so most sliding patio door units are shipped completely disassembled. This makes it easier to handle. The key to a successful installation is to follow the enclosed directions to the letter, paying careful attention to the order in which things are done.
Perhaps the most overlooked step in the process of installing a patio door is the preparation of the opening. Obviously, the fun part of doing your own home improvement projects is installing your new product, stepping back, and taking pride in a job well done. Unfortunately, that eagerness can be the DIY-er's worst enemy, especially when it comes to patio doors. While excitement is to be commended, the best advice is to slow down and make sure the opening is correct before trying to put the new unit in.
Prep the Opening
The first step is probably the simplest task to perform in the history of construction and remodeling. It is also the one most frequently ignored and the one most likely to cause very large headaches, sleepless nights, marital discord, and general misery. Measure the new door that you have sitting proudly in your garage before you remove the old one. Many people have made emergency trips to their local lumber yard to buy plywood because they needed to board up an opening for the night, or for a few days. If your door was a specially ordered one, you might have to board up for a few weeks while a new one comes in. Even if the salesman at the home improvement store promised you that it would fit, measure first.
The second step in preparing the opening is to make sure all the remnants of the previous door are gone. Again, this may seem like an elementary step, but it is one that can cause time-wasting problems down the road. Make sure there are no nail heads or bent screws leftover that will impede your effort to set the new door into place. Make sure all of the old shims are removed and that the floor where the sill is to be set into place is clean, dry, swept, and ready to accept whatever silicone sealant is recommended by the manufacturer of the door that you are installing.
The third step is to check the structural integrity of the opening itself. Make sure that the jack studs - the ones on each side of the opening - are level and immobile. If the previous door was subject to years of heavy traffic, it is possible that those studs may have started to work loose and that you are able to twist them slightly by hand. If this is the case, then your new door will be loose in the opening before you even start. These loose studs can generally be tightened up with a well placed 12 gauge nail or a drywall screw in the toe of the stud. The header needs to be checked as well. The header is the beam that runs across the full length of the door. This is what keeps your door from bearing the weight of the roof on an exterior wall. While you have the wall opened up, it is a good idea to check this piece and make sure that there are no major cracks or splits that will affect the header's ability to do its job.
Install the New Door
Once you are confident that the opening is the right size, is free from obstructions, and is structurally sound, it's time to open the box. For broken down units, it is advisable to get all of the pieces of the frame laid out in the order that they will be installed. This order can be determined by referring to the manufacturer's instructions.
If the unit is pre-hung, then it is ready to slide into place. Run several heavy beads of construction adhesive on the floor directly under where the sill of the door will sit. Gently set the door into place and, level in hand, begin sliding shims into place in order to ensure a tight fit within the rough opening. Fill all open gaps with fiberglass insulation to increase the energy efficiency of your new door.
Once the door frame is properly square and level, begin securing the door to the rough opening frame with screws through the frame at the point where the shims have been inserted. The manufacturer's instructions should include a detailed diagram of exactly where the shims and screws should be located. Actually, most frames already have predrilled holes so that you will know exactly where the screws are to go. This is especially true of vinyl units.
Once the frame is properly installed, it is time to set the door panels into place. The placement of the stops that hold the stationary panel in place will be clearly marked on the instructions. In most cases, you will want to wait until you have also set the active panel into place before tightening these stops. You may need a little wiggle room as you set the other panel into place. Once both panels are properly set, you can go back and tighten all the stops and install the hardware.
Interior and exterior trim options will obviously need to be customized to match what is already installed in or on the house. Many manufacturers will provide the ability to special order trim pieces for the outside that match the finish of the door. Most popular molding and vinyl trim styles for the interior are available at any large home improvement retailer.