How to Replace a Sliding Glass Door - DIY Home Improvement Guides - How to Repair and Remodel your Bathroom, Kitchen and more

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Home Improvement > Doors & Windows > How to Replace a Sliding Glass Door

Learn how to repair damaged door framing and install a new triple-paned door.

Fifty years of dry rot, weather damage and cold winds from the nearby lake have convinced homeowners to replace their old sliding glass doors with a tripled-paned glass model. They must remove the old door and damaged wood before reconstructing and resizing the doorway to accommodate the new door assembly.

Step by Step Instructions with Video

Step
1

Assess the Damage and Assemble Tools and Materials

Assess the apparent damage. Assemble tools and materials to remove the existing door and reconstruct the dry-rotted areas of the doorway. You will be using a power nail gun and a saw to cut pressure treated wood, so protect yourself with safety glasses and a face mask.

Step
2

Detach the Brackets Holding the Fixed Door Panel

Detach the fixed panel door by removing screws from two brackets at the top and bottom of the door. Use a power driver to loosen the screws.

Step
3

Lift the Stationary Panel from the Tracks

Slide the fixed door to the center and lift it from the track.

Step
4

Prepare to Remove the Sliding Panel

Pry off the retaining strip that holds the sliding door in place. Next, remove the interior door casing. Lift out the sliding portion of the old door and dispose of both panels properly.

Step
5

Remove the Nails Holding the Door Frame in Place

Pull out the nails that hold the door frame in place. Use a hammer and nail remover.

Step
6

Detach and Remove the Aluminum Threshold

Remove the threshold, first removing screws and then lifting the aluminum strip.

Step
7

Pull the Doorframe Away from the Doorway

Pull the doorframe away from the opening and set it aside for disposal.

Step
8

Pry Out All Loose and Rotted Wood

Tear out any dry rot or loose wood until you have exposed solid material. A small crowbar along with a hammer and wood chisel will assist in prying up the loose material.

Step
9

Coat Un-treated Lumber with Wood Preservative

Coat un-treated lumber with wood preservative and use treated lumber for the remaining construction to restore the house and door framing.

Step
10

Set a Pressure-treated Two-by-six in the Doorway Floor

Set a pressure-treated two-by-six in place as the floor to the doorway. As an extra precaution, coat the ends with wood preservative.

Step
11

Use a Nail Gun to Secure the Two-by-six

Nail it in place with a cordless nail gun.

Step
12

Confirm the Two-by-six Is Level

Check with a bar level to determine whether the two-by-six is level. In the project, it is not.

Step
13

Repeat the Process for a Second Two-by-six

Set a second pressure-treated two-by-six on top of the first one. Coat its ends with wood preservative, too.

Step
14

Insert Shims to Support the Second Two-by-six

Insert shims under the lower end of the second board. We stack two shims and turn them so their respective wood grains run in the opposite direction before we place them several inches from the end of the second two-by-six.

Step
15

Confirm the Second Two-by-Six Is Level

Check with the bar level to ensure that the second board is level.

Step
16

Insert Additional Shims to Support the Two-by-six

Insert a series of shims along the length of the board to support it. Do not move the two-by-six out of its level position as you add the shims.

Step
17

Trim the Protruding Ends of the Shims

Use a Japanese handsaw to saw off the protruding ends of the shims.

Step
18

Nail the Second Two-by-six in Place

Nail the second two-by-six in place with the nail gun, driving the nails through the shims at the same time.

Step
19

Cover the Two-by-Six Construction with Sheet Metal Flashing

Cover the face of the new two-by-six construction with sheet metal flashing and then fold it over the top surface, back towards the house.

Step
20

Secure the Flashing with Galvanized Roofing Nails

Use a hammer to secure it with galvanized roofing nails.

Step
21

Nail a One-by-six Spacer Across the Top of the Doorway

Nail a one-by-six treated lumber spacer across the top of the doorway to lessen the height of the opening. Replacement doors are typically smaller than older doors, so measure both your new door and the opening to determine how much you will need to retrofit.

Step
22

Add a One-by-six Spacer to the Side of the Doorway

Add a vertical one-by six along the edge of the doorway, because the new door is about 3/4-inch narrower than the original. Secure it with the nail gun as well.

Step
23

Bend Out the Nailing Flange

Bend out the nailing flange along the top and sides of the new sliding door assembly. You will nail the flange to the house in a later step to hold the door in place, but it also provides some weather sealing.

Step
24

Apply Caulking to the Nailing Flange

Apply a 3/8-inch bead of exterior-grade caulking to the side of the nailing flange that will go against the house. You will probably need to lean the tall door against the railing so that you can easily reach the top and sides. The caulk will provide a weather-tight seal along the flange and the framing.

Step
25

Apply Caulking One Inch from the Edge of the Flashing

Apply a 3/8-inch bead of exterior caulking to the flashing at the bottom of the doorway. Essentially, you will outline a long rectangle set in from the edges of the flashing about 1 inch.

Step
26

Position the Door and Tilt It Against the Door Frame

Position the base of the door along the flashing and slowly tip it upwards until it is fully upright and the flange meets the doorway framing. Be sure to center the sliding door assembly on the doorway opening.

Step
27

Nail Through the Top Center of the Nailing Flange

Hammer a single nail through the flange at the top center of the doorway to hold it in place while you make adjustments.

Step
28

Confirm the Sides of the Door are Vertical

Use a bar level to confirm the sides of the door assembly are perfectly vertical. If necessary, shim one side to level the door assembly. Use the same process as outlined earlier for the two-by-sixes that form the doorway floor.

Step
29

Secure the Door with Additional Nails

Hammer in the rest of the nails to secure the door assembly in its level orientation.

Step
30

Replace the Door Casings with Exterior-grade Lumber

Replace the door casings at the top and sides with exterior-grade lumber. Paint the trim, if desired.