Creating an Opening in a Wall for Doors or Windows
One of the scariest phrases that a man can hear from his wife is, “I wish we had a window right here.” Well, maybe it’s not the scariest thing, but sometimes can appear overwhelming at first. Once you get all of the information about how your house was put together, most of the work can be done in an afternoon.
The first step to determiining the level of difficulty of your project is whether your wall is load-bearing or non-load-bearing. It’s always best to assume that it is load-bearing so you don’t destroy a section of your house and void your home owner’s insurance. The best way to differentiate between load and non-load walls is by their orientation. Most homes have joists running from the front of the house to the back. If there is a basement, this is easy to see. There will be a beam fairly close to the centerline of the house where the joists overlap and rest on the beam. The beam will be held up by Lally columns and the ends will be set into the concrete or block wall, or on a pier sticking out from the wall. The load-bearing walls are directly above this beam as well. The second floor will be similar, but the walls may not necessarily line up with the walls from the first floor. If you have an attic, you will see the ceiling joists overlap and rest on this wall which is usually a hallway wall. Bearing walls are not always stacked one on top of another. Another situation that can occur is that a column or post may be concealed inside the wall.
The investigation gets more complicated if your second floor has a smaller footprint than the first floor. Certain sections of the first floor walls will be carrying loads from the second floor, while others are not. Just because a wall is perpendicular to the floor joists, doesn’t make it a bearing wall.
Assume all exterior walls are structural, load-bearing walls unless you have a very large house with steel beams carrying the load of the exterior. This is not typical in an average home. Usually the front and back exterior walls of the home are load-bearing since they are parallel to the center beam of the house. The load of the roof is transferred to these walls all the way down to the foundation. The exception is if you have a hip roof; the sloped end sections will transfer a small load to the side walls. However, if you saw the home under construction, you would see that the details for the side walls are the same as the front and back with full headers over the windows. If the house has been remodeled, a former outside wall could now be an inside wall. Examine the foundation to find these “hidden” outside walls.
If you are considering opening up a large section or removing a wall entirely, you should consult with a structural engineer to come out at determine what walls are load-bearing. The few hundred dollars will be money well spent.
Your wall will most often be 2 x 4 framing with the studs on 16 inch centers. The finish can be drywall, plaster over drywall--or plaster and lathe in older homes. Some older homes will have thicker studs and may be spaced further apart. Once you have determined whether or not the wall is load-bearing, you need to see what’s inside the wall.
The item most often found inside a wall will be electrical wiring. Even if the receptacle or switch is not inside the area you are going to work on, the wires usually are run around the perimeter of the room. They may go through the floor joists under openings, but that’s what you’re trying to create, so there is a good chance a wire is there. Plumbing drain lines and vents may also be inside the wall, but not in exterior walls. If they are, you either live in the South, or you have another problem which is the subject for another article. Plumbing lines are usually found on walls that have plumbing fixtures next to them, but from the second floor, water and drain lines can be very far from their point of origin. A well-designed house will have the plumbing concentrated in a few areas of the home.
If the house is older, there may be old abandoned electrical wires, gas lines, or piping. Be aware of the location of HVAC ductwork also. Most returns are not ducted inside the wall, but utilize the wall cavity formed by the studs and drywall to create the “duct”.
Creating an Opening in a Non-Load-Bearing Wall
3" Deck Screws
2" Drywall Screws
Measure the window or door that you will be installing. If you are just creating a trimmed opening, determine the width and height.
For windows, check with the installation instructions to see what the rough opening should be. You usually add an inch to the width and an inch to the height of the unit. For doors, remember to add the thickness of the jambs, (2 times ¾ inch, or 1 ½ inches) to the width of the door, plus one half to three-quarters of an inch to the rough opening. A 32-inch door would have a rough opening of about 34 inches. Determine the height of the opening; if there is a new floor being installed or a transition strip, account for the new thickness. Most interior doors are 6 feet 8 inches, or 82 inches for the rough opening which includes the top jamb and some space for adjustment. Draw the opening on the wall with a measuring tape and level.
Remove one side of the drywall or plaster using a utility knife, keyhole saw, or reciprocating saw. USE CAUTION WHEN USING POWER TOOLS! If you have to cut through plaster and lathe, it is best to use a circular saw fitted with a carbide tipped blade set to the depth of the wall finish.
With one side cut, carefully remove the drywall or plaster. Make sure that there are no mechanical, electrical, or plumbing components present. If there are you will need to move them or hire a contractor to reroute them for you.
With the reciprocating saw, cut the nails or screws off between the wallboard and studs. Transfer the corners of the opening to the other side by drilling a small hole through the wall with a drill. Connect the holes on the other side with a pencil and level. Cut away the wallboard.
One side of the opening will need the wallboard removed up to the ceiling to allow for the framing to be installed and nailed into the top plate. Once the opening is framed, the wall will need to be repaired above the opening of the door or window. The standard framing for a door will require two studs cut to fit between the top and bottom plates--king studs--and two studs that are cut shorter to support the head of the opening, or trimmers. The head can be made out of two 2 x 4 studs cut to fit between the king studs, which is the rough opening for the window or door, that are nailed together and then nailed to the top of the trimmer. Above the head are small studs spaced on 16 inch centers from the original wall studs.
2 x 4 Header
If your wall has older framing members that are not the same width as 2 x 4 studs, then you will need to pack them out with pieces of plywood, or rip down 2 x 6 studs to the proper width.
The king studs and trimmers are “toe-nailed” into the top and sill plates. Toe-nailing is accomplished by hammering the nails on an angle from the edge of the stud into the plate. You will have to patch the wall to cover the new framing. It will look better to cut back the wall to the nearest stud and work from there.
The framing process is the same except for the addition of a structural header. Instead of using 2 x 4 studs you will need to use 2 x 10 or 2 x 12 boards installed on the short edge.
2 x 12 Header
The ceiling will need to be braced on both sides with a temporary wall. If you are working on an exterior wall, then you will need only one temporary wall set back about 2 feet from the existing wall, a wall made with 2 x 6 or 2 x 8 studs and similar top and bottom plates about 2 feet past each edge of the opening. The studs should be cut about 1/2 longer and pounded into place with a sledge hammer to make sure the temporary wall takes the weight off of the bearing wall.
After removing the drywall or plaster, test-cut one stud. If the saw blade binds when you are three-quarters of the way thru, stop immediately. The bracing wall is not taking the weight off of the bearing wall. Make sure that the temporary wall is not leaning and that the temporary studs are tight.
It may be necessary to hire a carpenter to do the work for you on very large openings, but any opening the size of a door or single-width window should not pose any problems.
Houses built before 1930 were often framed in a style called “Balloon-Framing.”
Balloon-framed houses require temporary support headers called whalers when making alterations that affect more than one stud in a load-bearing wall.
For instance, say you plan on making an opening for an archway or window on a ground floor exterior wall. The whaler would be anchored to the wall studs above the planned rough opening, and extend at least 20-inches beyond each side of the opening. It would be supported with wall studs and bracing that would run adjacent to the rough opening.
1. Mark the area for the rough opening; remove wall surfaces around the rough opening, from floor to ceiling.
2. Using a 2X8 long enough to extend beyond the planned opening, center the whaler against the wall studs, flush with the ceiling. Tack in place using 2-inch wallboard (flattop) screws.
3. Cut two lengths of 2X4 to fit snuggly between the bottom of the whaler and the floor.
4. Slide the 2X4s into position at the ends of the whaler; carefully tap until the 2X4 and whaler surfaces are flush and the 2X4s vertically straight. Attach using nailing plates and 3-inch nails.
5. Use a drill with a 3/16-inch bit to drill two holes through the whaler and into each stud it spans; secure the whaler using 3/8 X 4-inch lag screws with a washer.
6. Using a hammer, carefully tap tapered shims into place between the bottom of each temporary 2X4 support and the floor.
Some framing is more difficult to deal with than others, whether your home is balloon framed, has had additions or alterations in the past, or the door or window you are installing is very large. Have the contractor assess the wall before suggesting the best placement and type of temporary support for your project needs.