How to Replace a Sliding Glass Door
For older homes, it may be necessary to replace existing sliding glass doors due to age, disrepair, or energy efficiency. For ambitious, do-it-yourself homeowners, replacing the doors themselves can be a great way to save money. There are four main steps in the process of replacing a sliding glass door: (1) selecting a replacement door, (2) removing the existing door, doorframe and threshold, (3) installing the new door, and (4) sealing the new sliding glass door. These instructions guide you through the replacement process using a vinyl sliding glass door as an example.
Note: Replacing a sliding glass door will require at least two people to remove the existing door and install the new door.
Equipment and Tools
You will need the following equipment and tools to replace your sliding glass door:
- Tape measure
- Level or other straight edge
- Pry bar
- No. 8 wood screws (3-inch)
- Phillips head screwdriver
- Flat head screwdriver
- Razor blade
- Reciprocating saw
- Circular saw
- Miter saw
- Safety goggles
- Rubber mallet
- Expanding foam sealant for windows and doors
- Silicone window and door caulk (weatherproof)
Warning: Follow the manuals' safety precautions when operating power tools and saws. Failure to do so could result in bodily injury. Always wear safety goggles, work gloves, and proper footwear to prevent eye injury.
Selecting a Replacement Door
After deciding to replace your sliding glass door, you will want to determine the material of the replacement doors. You will also need to determine the level of energy efficiency you want that corresponds to your budget. Before purchasing a replacement door, be sure to measure the existing sliding glass door, doorframe, and threshold.
Types of sliding glass doors. Typically, sliding glass doors are constructed of aluminum, wood, vinyl, fiberglass, or foam core. To choose which material is right for your home, consult a sliding glass door retail specialist or manufacturer. These instructions use a vinyl sliding glass door as the example.
Determining energy efficiency. Not only will energy-efficient sliding glass doors help with your utility bills and reduce your carbon footprint, you can also receive a tax credit. The National Fenestration Rating Council (NFRC) rates each product based on the energy performance of the product. New products will have an NFRC rating label that includes ratings for energy performance characteristics to help you determine which product to buy.
For a sliding glass door to be considered energy-efficient, it must have a high-performance glaze. Most sliding glass doors are double paned with a low-emissivity (low-e) coating that qualifies as energy efficient.
Fenestration products (windows, doors, and skylights) are rated based on their solar heat gain coefficient (SHGC) and U-factor. The SHGC is the ratio of the solar heat gain entering a space through the fenestration product to the incident solar radiation, measuring how well the product blocks heat from the sun. The SHGC is expressed as a value between 0 and 1. The lower the SHGC, the less solar heat is entering a space.
The U-factor measures how well a product prevents heat from escaping a space. U-factor ratings generally fall between 0.20 and 1.20. The lower the U-factor level, the greater the insulating value of the window. The following table summarizes the criteria for energy-efficiency based on glazing level and NRFC ratings.
Energy Efficiency Criteria by Glazing Level
1/4 or 1/2 Lite
3/4 or Full Lite
Removing the Existing Doorframe and Threshold
Remove all door treatments (curtains or blinds) from around the existing sliding glass door before replacing the door. You may want to put a tarp on the surrounding floor or on surrounding furniture to minimize any debris being tracked through your home.
Preparing the existing sliding glass doorframe and threshold. Using your razor blade, score drywall and cut the weather stripping around your existing sliding glass doorframe and threshold. Scoring will give a clean breaking point to help prevent damage to surrounding drywall you want to maintain.
Preparing the new sliding glass doorframe and threshold. Most new sliding glass doors will come with a thin plastic strip (mounting strip) around all edges of the frame. If you are replacing an existing sliding glass door and the trim cannot be removed, remove the mounting strip. To remove the mounting strips, use your razor blade to score along the bottom edge and bend forward and backward using pliers until you are able to snap completely off.
Removing the existing sliding glass door panels and screen door. Sliding glass doors have two panels: one that is movable (the sliding door) and one that is stationary. If your existing door has a screen door as well, remove it first by lifting the door up and off the bottom track and then out towards you to remove the screen door from the tracks.
Before removing the stationary door panel, check for any screws holding the door panel in place. If there are screws holding the panel in place, use your drill to remove the screws. Use a pry bar move the side of the panel door from against the wall so you can grip both sides of the panel. Lift the door panel up and off the bottom track and then out towards you to remove the door panel from the tracks.
To remove the sliding door panel, lift the door up and off the bottom track and then out towards you to remove the door panel from the top track.
Removing the existing doorframe and threshold. To remove the existing doorframe and threshold, first remove any screws or nails holding the frame to studs of the wall. Once the screws or nails are removed, use your pry bar to pry the doorframe and threshold from the door opening.
If you are unable to pry the doorframe out, use a reciprocating saw to cut through the center of the top part of the doorframe. Carefully, start from the cut part of the doorframe to collapse the existing frame and threshold inward using pliers.
Preparing the door opening for the new sliding glass door. Measure the opening of the doorway and new sliding glass door to determine if the new doorframe will be thicker than the removed doorframe. If the new sliding glass door is thicker than the existing doorway opening:
- Measure the width necessary in the doorway opening and mark the walls and flooring that needs to be removed.
- Score drywall along the marked line around the doorway opening.
Note: You may need to score two or three times to score deep enough to cleanly break the drywall.
- Break off the drywall you wish to remove by placing the edge of the pry bar underneath the exposed edge of the drywall. At the same time, apply pressure to the drywall you want to maintain to prevent cracking.
- Remove the drywall and any debris in the path of the new sliding glass doorframe.
- Remove any flooring in the path of the new sliding glass doorframe using a circular saw for hardwood or laminate flooring, a razor blade for carpet, or a wet tile saw with a diamond blade for ceramic tile.
Warning: Always wear proper safety gear when operating power tools and saws to prevent injury.
- Remove any remaining dust or debris from around the doorway opening.
Installing the New Sliding Glass Door
Before installing the new sliding glass door, remove the sliding door panel from the doorframe until after the doorframe has been installed. The stationary panel should remain intact.
Installing the new doorframe. Situate new doorframe so that the track for the sliding door panel is facing the interior of the home and the track for the screen door and stationary door panel is facing the exterior. To install the doorframe into the doorway opening:
- Lift the doorframe into place and use a rubber mallet to tap the doorframe into the doorway opening.
- Using shims to level the doorframe if needed, insert a No. 8 wood screw (3-inch) into each corner of the doorframe.
- Insert a No. 8 wood screw (3-inch) into the center of each vertical side of the doorframe.
Inserting the sliding door panel. Insert the sliding door panel by lifting the door panel up and into the top track. Push the door panel up and away from you to place the bottom of the door onto the bottom track. After any necessary wheel adjustment, the door panel should then be able to slide horizontally.
Inserting the screen door. Insert the screen door the same way as the sliding door panel by lifting the screen door up and into the top track. Push the screen door up and away from you to place the bottom of the door onto the bottom track. The screen door should then be able to slide horizontally.
Installing door handles and locks. Install door handles and locks using the instructions that came with the new sliding glass door.
Sealing the New Sliding Glass Door
To prevent any damage due to weather and to prevent hot and cold air from entering or exiting your home, seal around the doorframe using expanding foam caulking and weatherproof silicone caulking. Apply the expanding foam caulking in any large gaps around the interior and exterior of the doorframe. Allow the expanding foam to cure before removing any excess.
Note: Refer to instructions on the expanding foam caulking container for curing times.
Apply weatherproof silicone caulking around the edges of the exterior of the doorframe to completely seal the edges of the doorframe.
Once all caulking has cured, you can install decorative molding and window treatments around the sliding glass door.