How to Build a Door Frame

Door Framing Construction

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Project Overview
  • Working Time: 1 hr
  • Total Time: 1 - 2 hrs
  • Yield: Door frame, rough opening 82-inch by 34-inch
  • Skill Level: Intermediate
  • Estimated Cost: $30 to $60

At the heart of every good door installation is a sturdy and accurately built door frame. If the door frame is flimsy or if it is not true, everything built on top of it will not work properly. The door may scrape or not fit properly. On the other hand, if you do frame the door well, the door jambs and trim will look professional and the door itself will swing free and close tightly.

The good thing is a door frame isn't expensive or difficult to build, not does it use special, expensive materials. A door frame is composed only of two materials: two-by-fours and nails. So, creating a well-built door frame is less about materials and more about technique. As long as you measure precisely, cut the two-by-fours correctly, and nail them well, the door casing and trim will follow perfectly. Besides those few materials, your only tools are a hammer, saw, level, and measuring tape.

Main Elements of a Door Frame

A door frame is internal; you never see a door frame except when building it. All of the visible components are the door casing, trim, and the door itself: built upon the door frame but not the door frame itself. Think of a door frame like a four-sided picture frame: top, bottom, and two sides.

Top of the Door

  • Header: The header is a horizontal two-by-four that runs the width of the door frame. It is the topmost part of the door frame. The top of the door's exposed casing will attach to the header.
  • Short Support Studs: Short vertical studs just a few inches long run between the header and the top plate.

Top Plate

The top plate is a doubled-up series of two-by-fours that run continuously around the perimeter of a room or the home. The top plate is already part of the house and is not part of the door frame construction.

Sides of the Door

  • King Stud: The king stud is a vertical two-by-four that runs from the top of the sole plate to the top plate. The top of the king stud touches the bottom of the top plate.
  • Jack Stud: The jack stud is a vertical two-by-four that runs from the sole plate to the header. The top of the jack stud touches the bottom of the header and supports the header.

Bottom of the Door

A horizontal two-by-four bottom (or sole) plate rests on top of the home's subfloor. The building elements that form the sides of the door—the king stud and the jack stud—rest on the bottom plate. The sole/bottom plate might already be in place or you may need to add it.


If a door frame is supposed to be four-sided, why isn't there a bottom side? Is it flush or do you walk over this bottom side? The door's bottom or sole plate is initially built as a continuation of the wall system's bottom plate. After the jack stud is nailed into place, the section of the plate between the two jack studs is cut out and discarded.

What You'll Need

Equipment / Tools

  • Electric miter saw
  • Framing hammer
  • Tape measure
  • Pencil
  • Bubble level or laser level


  • 6 two-by-fours
  • 1 box 12d nails


  1. Size the Door Opening

    Generally a door's rough opening will be 2 inches wider and 2 to 2-1/2 inches taller than the actual door size. This accounts for 3/4 inch jambs and bottom threshold. For a pre-hung 36-inch wide by 80-inch tall door with threshold, the finished rough opening would be 38 inches wide by 82 inches tall. It is best to know the actual door and manufacturers rough opening recommendations before starting.


    Building a door frame is one project where you really need high-quality two-by-fours. Look for premium kiln-dried two-by-fours that are not wet and which are perfectly straight and true.

  2. Add the Bottom or Sole Plate

    If you are cutting a door into an existing wall, there will already be a bottom plate. Otherwise, nail a continuous two-by-four across the width of the doorway. The two-by-four will extend across the doorway for now but later will be cut away.


    For a doorway with a rough opening of 34 inches, cut the bottom plate to 40 inches.

  3. Add the King Studs

    Cut the king studs so that they extend from the top of the sole/bottom plate to the underside of the top plate. This measurement will vary by ceiling height.

    Tape the bubble level to each of the king studs as you place them. Or shoot a plumb line from the laser level.

    Nail the king studs so that they are 38-1/2 inches apart, on-center. Toenail the king studs into place.

  4. Add the Jack Studs

    Cut two of the two-by-fours each to 80-1/2 inches. Nail the jack studs to the insides of the king studs—that is, on the inward-facing part of the door. Drive the nails directly into the king studs rather than toenailing the jack studs.

  5. Cut and Add the Header

    Cut the header to 37 inches long. Standing on a ladder, place the header on top of the jack studs. Nail the header into place by driving nails through the header and into the ends of the jack studs.


    This single two-by-four header method is only suitable for interior non-load-bearing walls. Exterior and interior load-bearing walls will require at a minimum two two-by-fours placed on edge with 1/2 inch plywood sandwiched between them. Depending on the width of the doorway and local codes, you may be required to install a different type of structural member such as laminated veneer lumber LVL wood.

  6. Add Support Studs Over the Header

    Measure the distance between the top of the header and the underside of the top place. Cut off two pieces of two-by-four to that length. Toenail these support boards into the top place. The bottom sections of the support boards can be secured by driving nails upward through the header.

  7. Cut the Sole Plate

    Use the hand saw to cut away the section of sole/bottom plate that extends across the doorway. If the flooring is subfloor, it is safe to cut directly down to the subfloor since minor cosmetic damage is not a concern, though still be careful toward the end of the cut to avoid damaging the subfloor. If the flooring is a decorative floor covering, place tape on the cutting area to avoid damage. Slow down your cutting toward the end to avoid biting into the flooring.


    Another way to avoid damage to decorative flooring is to cut the sole/bottom plates to size ahead of installation.

  8. Finishing the Door Frame

    Check the door frame to make sure that no nails are protruding and that the studs are smooth. Nail down any protruding nails. The door frame is now ready for either a prehung door or for the construction of a door casing from scratch.

When to Call a Professional

A carpenter can help with building door frames for exterior or load-bearing walls. Double-wide door frames for French doors or sliding doors need specific framing due to the lengthened spans.