The door opening on the right had been covered over by a previous owner. The other opening, covered with plastic, had been the entrance to this room.

However, these marks are NOT the lines where the studs will be cut.

Since we were installing a 32 inch door, I laid out the opening to be 34 inches wide. The height of the opening was 82 inches above the sub-floor.

After I marked the new end points of the original studs, I cut them with a circular saw, which can only cut about 2½" deep.

To complete the cuts, I used a reciprocating saw with the blade mounted upside down.

This step wasn't entirely necessary, I just felt like doing it this way.

Warning:

When cutting studs in a non-load-bearing partition, there is normally no need to support the structure above. If a stud is under any serious load, the reciprocating saw blade will be pinched as the cut is completed, and the saw will shake the operator instead of cutting the wood.

If there is any chance that a partition supports some load, the weight of the overhead structure needs to be supported by temporary bracing, and the loads need to be transferred all the way to the foundation, which may require additional bracing in rooms below.

For more information about supporting load-bearing walls, read this article about cutting a big opening.

Since this is a non-load-bearing interior wall, the header can be made from two 2x4's laying flat.

Got A Load?

A header in a load-bearing wall is usually made from a pair of 2-by boards standing on edge, with a plywood spacer to create the required overall thickness. Of course, the height of the header (i.e. 2x6, 2x8, 2x10 or 2x12) depends on many factors, such as length of the opening, floor loads overhead, roof loads, etc. Load-bearing headers are beyond the scope of this article... there are lots of books about framing carpentry that discuss this topic.

I placed the trimmer stud in position on the right-hand side... it's not fastened yet.

I pre-drilled the holes for these screws to prevent the wood from splitting too much.

But...old plaster often has sand in it, so drilling through plaster can ruin drill bits. I used a carbide-tipped masonry drill bit.

Then we secured the wall surface to the new studs with drywall screws. This must be done before cutting the opening, or else the plaster will crumble.

This wall consists of drywall over plaster with a layer of paneling added just to irritate us. We used 2" drywall screws to make sure they would reach into the framing.

There are carbide-coated blades for cutting plaster, but the one I have isn't long enough to cut from the back side using the stud as a guide. This blade got dull quickly and I had to throw it away when we were done.

The other alternative is cutting from the front side, but it's very difficult to keep the cut close to the studs. And cutting from the front side would create more sawdust, and we were trying to minimize dust in this project.

We carefully lowered the cut-off piece down to the floor, then broke up the plaster and drywall.

There are two doorways visible here... the doorway on the left will become the entrance to a hall closet. This doorway required some special attention because the old studs were leaning quite badly.

So we had to work with these cropped-off old studs (red arrow). We couldn't remove them all because the old lath is nailed to them.

In the top picture you can see a 3/4 inch thick spacer, and in this picture there is 1½" spacer (a block of 2x4) with another thin piece of plywood. This is so typical of old house remodeling.

Note how the old studs protrude beyond the face of the new studs.

The width of the wall between the two doorways is important, because if that narrow section of wall is too skinny, it will be difficult to install the trim around the doors.

As we were framing this, we knew that the door casings were going to be either 3½" or 4" wide, a bit wider than the standard 2¼" casing.

Don't ask about the color... I didn't choose it.

The casing on the left side of the door had to be ripped narrower, yet it doesn't stand out. If we hadn't left enough distance between the doorway and the partition, this casing could have looked really dumb.