How to Put in a Sliding Glass Door

RON HAZELTON:
Well, today's trip is to Cooperstown, New York. I'm going to be visiting Bill and Barbara Harmon. This all-American mainstream is surrounded by miles and miles of wooded hillsides, though the real jewel of Cooperstown has to be nine-mile-long Otsego Lake. Barbara Harmon's deck looks right out on the lake. And while the views are stunning, the cold wind that comes off the water, seems to pass right through her old sliding glass door, almost like it wasn't even there.

You have a nice house here. Tell me a little bit about this. You guys been here a long time?
BARBARA HARMON:
We've been here about 25 years and the house has been here close to 50. Originally built by a shop teacher from the local school.
RON HAZELTON:
Really?
BARBARA HARMON:
Yeah. And it was a restaurant for a time.
RON HAZELTON:
Went from a house to a restaurant and back to a house again.
[BOTH SPEAK AT ONCE]

BARBARA HARMON:
And now it's our home, yeah.
RON HAZELTON:
Wow. Well, everything's held up pretty well, except for the door here. Looks like it's got some rot going on down here —
[BOTH SPEAK AT ONCE]
BARBARA HARMON:
It does need some work, doesn't it?
RON HAZELTON:
— so this looks — oh, yeah, it's time for a replacement. This is also —
[BOTH SPEAK AT ONCE]
BARBARA HARMON:
It sure —
RON HAZELTON:
— just one pane of glass.
BARBARA HARMON:
That's right and we're triple pane on the new one, so I'm real happy about that.
RON HAZELTON:
Oh, yeah, that's good. Okay, that will —
[BOTH SPEAK AT ONCE]
BARBARA HARMON:
It's good and warm.
RON HAZELTON:
— that will keep things nice and toasty here. And I imagine that's important 'cause you've got a lot of cold air blowing in off the lake here.
BARBARA HARMON:
Cold air, a lot of snow.
RON HAZELTON:
You dressed to work?
BARBARA HARMON:
I am.
RON HAZELTON:
Ready to go?
BARBARA HARMON:
Good and warm. I'm ready. Looking forward —
[BOTH SPEAK AT ONCE]
RON HAZELTON:
Okay, let's tear this old one out. Grab some tools and we'll get going here. Come on.

BARBARA HARMON:
Thanks.
RON HAZELTON:
This old door, like most, has both a sliding panel and a fixed panel. Our first step is to take out the fixed side by removing two brackets — one at the top, the other at the bottom.

With all the screws out, we slide the door to the center and get ready to lift it from the trash. Barbara's husband, Bill, a college professor, arrives just in time to lend a hand.

That way, if we break it, it's — you know, it's your door.
BILL HARMON:
It's my fault, huh?
RON HAZELTON:
Just lift the bottom right out.
BARBARA HARMON:
Okay.

RON HAZELTON:
That should drop from the top and let's just bring it over here. Maybe we can lay it up —lean it up against this railing here.

To remove the sliding door, we first pry off a retaining strip and then the interior door casing.

Okay, that's free. So Bill, I'll drop the top of this to you, is that all right? And I'll —do you want to take it all the way down and I'll, I'll take this end of it here.
BARBARA HARMON:
Get on another side with you.
RON HAZELTON:
Okay. I think you get to rest. You did all the hard work.
BARBARA HARMON:
Oh, good.
RON HAZELTON:
With the doors out, we can start on the doorframe. We begin by pulling out the nails that have been driven through the exterior trim. Then, we remove the threshold and pull the frame away.

Pull it out. There we go.
[BOTH SPEAK AT ONCE]
Out with the old. You pull it out — there we go, okay.

Now remember that dry rot we saw earlier? Well, there's even more down here beneath the old threshold. So we tear out everything that's rotten. Finally, when we've gotten down to solid material, we rebuild.

Untreated lumber gets a coat of wood preservative. The rest is already pressure-treated.

All right, here comes our first 2 x 6. Good. You put some preservative on the end, the cut ends of that.
BILL HARMON:
Going to tap this in place.
RON HAZELTON:
Feel the power, Barbara, feel the power.
BARBARA HARMON:
Oh, I do, I do.
RON HAZELTON:
Okay, so that's, that's it. I'd say we're out about a half an inch over the whole run here. So let's take this board right here, this is our last 2 x 6.
BARBARA HARMON:
Yay.
RON HAZELTON:
Drop that in place, okay. Now on your end, Barbara, I'm going to take two shims and I'm going to run them in opposite directions like this. Just go ahead and slip those right under the end, about right here. Just lift the board up a little bit and push both of those in there — all the way, all the way back. There you go.

Now let me just check this. Oh —
BARBARA HARMON:
How could you be more perfect than that.
RON HAZELTON:
Okay. So now what we have to do is put a series of shims along here, every 12 inches or so, to support this all the way across.

We insert the rest of our shims, check for level, saw off the protruding ends and nail the final 2 x 6 into place. To protect our new framing from water damage, we're going to cover it with thin sheet metal called flashing.

We first cover the face of the new framing, then fold the flashing over the top. It's secured with galvanized roofing nails.

All right. Now this is just going to be a spacer. We have to make our upper opening here just a little bit lower. Okay. Barbara, are you ready? Actually, maybe a little close —further away from my finger.
BARBARA HARMON:
[LAUGHS] You don't want me to hit your finger.
RON HAZELTON:
Well, I — not that I don't trust you.
BARBARA HARMON:
[LAUGHS] Oh, I see.
RON HAZELTON:
Ah, that's better.

Replacement doors such as the one we're installing, are typically a bit smaller than the original. In this case, our new door is about 3/4 of an inch narrower than the old one, so we add a board to the side of the opening to make it slightly narrower.

Now this is called a nailing flange. Just —what I'm going to ask you guys to do is to bend this out. This is going to do a couple of things. This is how we're going to attach the door to the house and make some adjustments. It also provides a weather seal between the doorframe and the framing of the house.

So why don't you guys step in here. Just grab a hold of that.

We bend out the flange along the sides and top of the doorframe, then lean the door assembly against the deck railing for the next step.

We are ready to caulk. Your guns.
BILL HARMON:
Yessir.
RON HAZELTON:
Bill, Barbara. Bill, your job is to put a, a 3/8ths inch bead of caulk right down the center of this flange right here, okay?
BILL HARMON:
Okay.

RON HAZELTON:
Barbara, yours is to put a 3/8th inch bead along — sort of form like a, a rectangle about an inch or so in from the outside edge, all the way around this, especially on the end right here.
BARBARA HARMON:
Okay.
RON HAZELTON:
Okay, guys?
BARBARA HARMON:
Thank you.
RON HAZELTON:
Go for it.

The caulk will provide a weather-tight seal between the flange and the framing, the sill and the threshold. It's also great for other things.

I always say, you've got to put a little fun into home improvement.
BARBARA HARMON:
That's right.
RON HAZELTON:
This sentiment will remain Bill and Barbara's little secret — something they'll perhaps recall each time they step inside.

Now pick it up very slowly, very slowly. There we go. I want to step inside because I want to be sure we're centered. Hold it right there.
BILL HARMON:
Hold it.
RON HAZELTON:
Good, good. Looking great, guys.

I hammer a single nail through the flange to hold the doorframe in place, while we use a level to make sure the sides are perfectly vertical or plumb. Then the three of us hammer in the rest of the nails. Finally, we replace the door casings just as the chill of a brisk fall evening, rolls in off the lake.

Well, there we go. You have got a door.
BARBARA HARMON:
We do, a beautiful door.
RON HAZELTON:
Yeah, three panes of glass. That cold air can come right in off that lake, hit that glass and bounce right back again. You're going to be cozy.
BARBARA HARMON:
And we'll be toasty warm.
RON HAZELTON:
You certainly will.
BARBARA HARMON:
We had quite a job. I was a little concerned when I saw that rotted wood down there but you've done a nice job, good work.
RON HAZELTON:
Hey, it was teamwork. Come on, it was teamwork.
[BOTH SPEAK AT ONCE]
BARBARA HARMON:
It was teamwork. All that hard preparation made for a well-framed and nice looking door.
RON HAZELTON:
What do you say we team up and have some dinner.
BARBARA HARMON:
I'd love to.
RON HAZELTON:
Well, that lake wind may be blowing outside, but we've certainly eliminated the wind chill factor in here. A toast to new friends, a cozy home and a job well done.

Replace a Single-paned Sliding Glass Door and the Surrounding Dry-rotted Wood and Install an Updated Triple-paned Insulating Door

Replace a sliding glass door and repair the accompanying dry rot that age and weather have fostered on the threshold. After we stop the dry rot, our DIY installation stops the heat loss with a good quality sliding glass door that is triple-paned, energy-efficient, and attractive. Slightly smaller than the original, the door requires resizing the opening with treated lumber.

removing the top bracket from the stationary door

Step 1

Remove the Fixed Portion of the Old Sliding Glass Door

Loosen the screws in the brackets at the top and bottom of the fixed sliding glass door. Move the door to the center of the track and lift it out.

Step 2

Pry off the Retaining Strip and Door Casings

Pry off the wooden retaining strip from the top of the door opening. Remove the interior door casing/molding. A putty knife and small pry bar can help to remove these components without damage so they can be reused.

removing nails with a nail puller and hammer

Step 3

Extract Nails from the Exterior Trim and Remove the Threshold

Use a nail puller and hammer to extract nails holding the exterior door trim to the house. Remove the threshold and pull the entire door frame away from the opening. Ensure no nails protrude and dispose of the trim properly.

prying up dry-rotted wood exposed under the old threshold

Step 4

Remove All Dry-rotted Material from the Doorway and Threshold

Remove all the crumbling dry-rotted wood around the doorway opening, particularly under the old threshold. Use a crowbar to pry up the disintegrating material until solid wood is revealed as a foundation for repairs.

leveling the new threshold with shims and a bar level

Step 5

Rebuild Threshold Framing with Treated Lumber and Level with Shims

Rebuild the threshold framing with two pressure-treated two-by-six planks secured with a pneumatic nail gun after coating both cut ends (and any untreated lumber) with wood preservative. Use a bar level and shim the planks as necessary to level.

folding the flashing back over the threshold framing

Step 6

Cover the New Threshold Framing with Sheet-metal Flashing

Cover the front and top of the new threshold framing with sheet-metal flashing. Cover the vertical exterior face of the framing first and then fold the flashing back over the top or horizontal face. Secure flashing with galvanized roofing nails.

nailing up treated-lumber spacers to resize the doorway

Step 7

Secure Treated-lumber Spacers to Accommodate the Smaller Sliding Glass Door

Secure treated lumber planks along the top and both sides of the doorway as spacers, if necessary, to fit the new door. Modern sliding glass doors are usually slightly smaller than the older models and may require fitting of the doorway.

caulking the rectangular perimeter of the threshold flashing

Step 8

Caulk the Door's Nailing Flange and the Sheet-metal Threshold Flashing

Bend out the door's nailing flange along its top and sides. Run a 3/8-inch bead of caulk down the center of the nailing flange on the interior side and another bead tracing the perimeter of the rectangular flashing strip.

centering the bottom of the door and tipping it into place

Step 9

Position the New Door and Ensure It Is Plumb

Center the bottom of the new sliding glass door in the opening and tip it up into place. Hammer a single nail through the flange to hold it temporarily ensure the door is plumb. Hammer in the rest of the nails.

Step 10

Reattach the Exterior and Interior Door Casings

Reattach the original door casings to complete the seal/appearance of the replacement sliding glass door. If you had to resize the doorway opening, you may need to cut new casings for the exterior and/or interior perimeters.