How to Frame a Door Jamb

Framing door jambs is a simple project.

Doors are framed in two three sided rectangular arches. The outside arch is a part of the wall and consists of two pairs of vertical studs, two studs on each side and a horizontal header. The jamb, or interior frame fits within this and is made up of two vertical members known as jambs and a horizontal cross member known as a jamb header. The jamb will be spaced off of the wall frame with shims so that is is level and square and the door hangs inside of this.

Things You'll Need

• Door jamb kit
• Hammer
• Nails
• Tape measure
• Level
• Shims

Instructions

1. Buy a prefab jamb kit. These come with side pieces cut to size and door stop already attached. It will save time and is generally cheaper than buying the individual pieces. Cut the top, horizontal member to length ¾ inch wider than your door to allow for the notches in the side jamb and ¼ inch clearance between jamb and door.

2. Glue and nail the jamb header into place in the notches on each side jamb. This will create a three sided rectangle. Stand this rectangle frame up into the wall opening and center it between the vertical inside studs, known as jack studs.

3. Wedge shims between the top of the jamb header and the bottom of the wall frame header. Tap them in snugly with a hammer, careful not to cause the header to bow downward. Drive one nail up through the jamb header and the shims into the wall frame header directly above the jamb.

4. Level the side jambs. Position a level along the front edge of the hinge side jamb. Wedge shims behind this jamb at the top corner, do not nail, yet. Use the hammer to gently adjust the jamb in or out so that the bubble in your level is centered in the indicator. Add shims in the bottom corner, between the jamb and the jack stud. Nail one through the jamb and shims into the jack stud.

5. Repeat the leveling process with the remaining jamb. Before nailing it into position, measure between the jambs just under the header, then again at the bottom of the frame. If the two measurements do not line up, adjust the jamb in or out slightly, by removing or adding shims behind it, to make the measurements equal. Nail through the jamb and shims into the jack stud at the bottom and top of each side jamb.

6. Add shims and nails behind the middle of each jamb and above both corners of the jamb header to completely secure the jamb frame into the wall.

References

• Trim Carpentry Techniques: Craig Savage, Taunton Press, 1989
• Home Tips: How to Install Door Jambs