Building Office Partition Walls

Building a partition wall is an easy way to divide a large space or redirect traffic through a large room. By definition, a partition wall is a non-load-bearing interior wall that is designed to support only the materials of the wall itself; it does not support the ceiling or floor above. A partition wall typically connects to the floor below and to the ceiling joists or floor joists that make up the ceiling above. Because the floor and ceiling are already in place, it's usually easiest to build the partition wall piece by piece, rather than building it on the floor and tipping it up into position, as is done with new home construction.

Building partition walls is a good solution for any business owner who owns their office space, or where a lease agreement allows for such build-out. Leasing tenants may need to negotiate agreements with owners in order to do such work. Small business owners may well be able to complete such work themselves, as the carpentry involved is fairly basic. Or, a standard framing carpenter can be hired to do the work, including finishing the walls.

Partition Wall Components

A partition wall typically has vertical studs connected to two horizontal plates—a top plate and bottom plate. The plates are fastened to the floor and ceiling. While the bottom plate can fasten to any part of a wood subfloor (the plywood or particleboard layer under the finish flooring), the top plate must be anchored into the ceiling or floor joists. This is easiest when the wall runs perpendicular (or at an angle) to the joists. If the wall is parallel to the joists, the top plate should be aligned under a joist, or you must install blocking between two joists and fasten the top plate to the blocking.

If the wall includes an opening, with or without a door, the wall will get a horizontal header spanning across the top of the opening, plus two studs at each side of the opening to support the header and define the sides of the opening.

Tools and Supplies You Will Need

Building partition walls yourself requires ordinary household carpentry tools and supplies readily available on home centers.

• 2 x 4 lumber
• Carpenter's pencil
• Miter saw, circular saw, or table saw
• Plumb bob/ chalk line
• Screw gun and utility screws
• Carpenter's level
• Prehung door (where necessary)
• Drywall and drywall finishing supplies
• Hammer and finish nails (or power nailer)
• Paint and painting supplies
• Trim moldings (as needed)

Cutting and Marking the Plates

Start the wall framing by cutting the top plate and bottom plate to the full length of the wall. Hold the plates together to mark the stud layout. Most walls have studs spaced 16 inches "on center" (measuring from the center of one stud to the center of the next). Partition walls also can be framed with studs at 24 inches on center if desired. Mark the stud locations on one side edge of both plates, including any openings.

Installing the Plates

Using a chalk line, mark on the floor where the bottom plate will be installed. Screw the bottom plate to the subfloor with wood screws. Use a straight 2 x 4 and a level to position the top plate directly above the bottom plate, or use a plumb bob to position the top plate. Install the top plate by screwing into the ceiling or floor joists (or blocking) above. Do not fasten the bottom plate where there will be openings for doors.

Installing the Studs

Due to ordinary house settling, it's unlikely that the bottom and top plates will be perfectly parallel, so you probably can't cut all of the studs to the same length. Instead, measure between the plates at each stud location and cut a stud to fit. Install the studs by toenailing—nailing or screwing at an angle—through each side edge of the stud and into the plate.

Framing Openings

Openings for doors typically are 1 inch wider and 1/2 inch taller than the actual dimensions of the door unit (the door and its frame, not the door itself). At each side of an opening, install a full-length king stud at the outside, followed by a shorter trimmer stud (or jack stud) on the inside of the opening. Install a horizontal header on top of the two trimmer studs, then install short cripple studs between the header and the top plate to continue the general stud layout of the wall.

After the last studs are installed, cut out the bottom plate inside any openings. The wall is then ready for drywall or other surface materials.

Finishing Walls

Once partition walls are framed, including the door openings, the next step is to hang, tape, and finish the drywall surfaces.

Drywall installation involves hanging sheets of 1/2-inch-thick drywall to the studs using drywall screws, then applying joint tape and finishing all joints and screw heads with taping compound (mud). Walls are generally painted as soon as the mudding and finishing are complete, although it can also be done after doors and trim are installed.

Installing Prehung Doors

Where partition walls are being installed to create individual rooms, you will probably want to install prehung interior doors. This is normally done immediately after the walls are painted.

Prehung doors are sold already framed within side jambs and top jamb, and with case moldings included. Installation is a simple matter of inserting the door within the framed openings, shimming it in place, attaching the jambs to the studs with finish nails, then nailing on the included case moldings. Staining or painting can be done either before or after before the doors are installed.

Installing Trim

The final step to building a partition wall is to install whatever trim moldings are needed. This may include the case moldings for doors, baseboard and shoe moldings, and sometimes crown moldings or other ornamental moldings.