New rough opening for sliding patio door. Serious Remodeling:

Installing A New Sliding Door -
Framing The Rough Opening

In This Article:

The new rough opening is laid out, temporary bracing is installed, the studs are cut, the old window removed, then the siding is cut away. A new header and trimmer studs are installed.

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Skill Level: 4 (Advanced) Time Taken: 6 Hours

By , Editor


My first step in this job was to read the instructions for the sliding door and then locate the materials needed for the header and the new studs. The instructions required a rough opening of exactly 72" wide by 80" high, which left about 1/4" on the top and sides for adjustment.

That meant the header had to be 75" long (72" span plus 1.5" for each trimmer stud.)

I cut two 2 x 12's to 75", and a piece of 7/16" thick Oriented Strand Board (OSB) for a spacer, to make a beam that would be very close to 3.5" thick.

I used a framing nailer to assemble the header. Hand-driven nails would work just fine, too.


The finished header, ready for installation.


The location of the new sliding door.


Much of the thinking in this project involved laying out the cuts in the existing framing. The red marks indicate where the bottom and top edges of the header will meet the double-stud that will remain.

The other double-stud (actually a trimmer stud and a king stud) will have to be installed using new lumber. I laid out the locations and marked them clearly.


The wall had blocking between every stud, so one piece had to be cut to accept the new trimmer/king stud

The middle studs had to be cut where the top of the header would intersect them. I used a 4' level to lay out the cut lines.



This is a load bearing wall that I'm cutting into, and it needs to be supported until the header is installed.


Supporting weight of roof so wall can be modified.

Supporting a load bearing wall during construction is not difficult. A temporary stud is placed near each stud that gets cut.

The lower end must bear on something to spread the load to several floor joists. In this case a scrap of 2x6 was used. I used 2x6 boards for these temporary supports because that's all I had available. Normally, 2x4's would work, unless the roof was especially heavy.


In this project, there was no finished ceiling, so I placed the temporary stud under the tail of the rafter.

The other end was wedged into the board on the floor. These boards were not nailed (though nails couldn't hurt), they were only held in place by the friction of being wedged tightly. I used a 4 pound sledge to force the stud tight.

Notes: This building had no finished ceiling. If there was a ceiling, I would have nailed two of the temporary studs to a temporary top plate that pressed on the ceiling and held the roof in place. This assembly would have to be placed as close as possible to the wall being cut, one to two feet away may be adequate.

If the roof load was not adequately supported, the reciprocating saw blade will likely get pinched frequently while making cuts in supporting studs.


With the wall supported by three posts, I made the cuts in the old studs with the circular saw. Of course, it doesn't cut all the way through, but I'll finish it with the reciprocating saw.

The king stud (10' long) and trimmer (80" long, the rough opening height) were laid out and nailed together.

Note: Normally the bottom plate would be cut out after the opening is framed. But this building is unusual in that the bottom plate rests directly in the floor joists. Normally the plywood subfloor is installed and then the walls are raised, meaning that normally there is plywood under the bottom plate. In this case I left the bottom plate intact, which will create a slightly higher door sill than optimal, but the alternative is messing around with filler planks under the door and maybe having a structure that is not sturdy enough.

Normally the trimmer stud would be cut to 1.5" shorter than the rough opening height.


 The blocking was cut to accept the double-stud.

The new double stud was installed and toe-nailed to the bottom plate.


The new stud was toe-nailed to the blocking and at the top.

Next the old studs were cut the rest of the way, using a reciprocating saw.


This window had to be removed next. I cut whatever nails were visible inside.

The rest of the removal had to be done from the outside.


The wide casing is an integral part of this 1950's Andersen window.

Prying between the siding and the casing caused the unit to work free.

Even though this Andersen casement window was about half-a-century old, it was still in remarkably good condition, good enough to re-use.

With the window removed the next task was to remove the framing boards around the window.

A reciprocating saw is essential to this step. A long fine-tooth blade gets in between studs to cut the nails.


Some of the cuts are easy.

The old window opening was not even framed properly. They used a double 2x4 header and no trimmer studs.


The hard part was cutting the nails that held the sheathing to the studs. It meant getting in behind the stud, and that required a long blade, about 8".

When all the old studs were cut out I checked to make sure there were no nails that would get pinched behind the new header.


 Another view of the wall after removal of the studs.


The header installed easily, by myself, with no helpers.

I was lucky that it fit right the first time (or is that skill?) I installed a second door a few days later and the header was not nearly so cooperative.

The temporary supports were removed (after the header was nailed securely).


Once installed, I nailed the header all over the place; at least eight 3" nails at each end, plus toe-nails into the trimmer studs and king studs.

The cripple studs (the old full ones that got cut short) were toe-nailed into the header.


The reciprocating saw was used to cut through the sheathing and siding.

The last part of the opening that I cut was the very center of the top. This meant that the whole wall panel fell away cleanly without peeling away.

A much nicer view!


At this point the rough opening is framed but there is still more work to prepare for the slider door.

The siding has to be cut back from the opening to accept the nailing flange of the door frame.

Some replacement doors or windows would not require this step because they do not use a nailing flange to attach to the wall. Such units are screwed into the side of the opening. The unit about to be installed here was intended for new construction, and most new construction windows and patio doors have a nailing flange.

I made a line about 3-1/4" back from the edge, intending to fit a 1x4 board around the door frame.

Note the cross-section of this wall: studs, sheathing and cedar clap-board siding.


I screwed a 1x4 to the wall as a saw guide.

Without this board for the saw to ride on, the blade would cut into the sheathing as the siding zig-zagged up and down. The blade depth was set to just barely cut into the sheathing.


The wall after the cut was made.


The 1x4 was taken off and the short pieces of siding were removed. The siding pieces directly above and below the opening were also removed.

At this point the rough opening is complete. The methods here would work almost step-by-step for the installation of a conventional entry door in an existing wall. Installing a window is quite similar except for the framing of the sill beneath the opening.

But What About Vinyl Siding?

This project was made easy because the wood siding is easy to cut, and easy to patch. Doing the same project with a vinyl-sided wall is a little more difficult, but not beyond the means of the moderately experienced handyman. The problem lies in installing the J-channel. Normally J-channel is nailed on before the siding is installed. Adding J-channel later is tricky because it can't be nailed normally. What I've done is glue the J-channel to the wall with construction adhesive or (better) siliconized acrylic latex caulk. Then I fill in the gap between the J-channel and the window with a 1x4 board and caulk the gaps.

WARNING: If you are going to undertake a project this big, make sure you completely understand all the steps involved. Consult your local building department and check if permits are required. We encourage our readers to look at other competent sources for second opinions, because the work shown here may not be applicable to your home.

See The Sliding Door Installed


Tools Used:

  • Circular Saw
  • Reciprocating Saw
  • 4' Level
  • Hammer
  • Chalk Line, Square
  • Cordless Drill/Driver

Materials Used:

  • Lumber, 2x12x8'
  • 2x4x10'
  • 16d Nails
  • 12d Nails


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Copyright © 1999, 2005

Written August 13, 1999
Revised January 11, 2005