Measuring Jamb Width

A properly sized door jamb seamlessly integrates with the surrounding wall, covering its full thickness for a clean, finished look. To determine the correct jamb width, start by measuring the total wall thickness, which includes both the wall stud and the sheetrock.

Interior Jamb Widths

“Flat” jambs with adjustable stops are available for interior doors in the following widths, to match the following wall stud and sheetrock thicknesses:

Flat Jamb With Adjustable Stop

STUD, SHEETROCK THICKNESS	JAMB WIDTH
2×4 Stud, 1/2” Sheetrock	4-5/8” Wide
2×4 Stud, 5/8” Sheetrock	4-7/8” Wide
2×6 Stud, 1/2” Sheetrock	6-5/8” Wide
2×6 Stud, 5/8” Sheetrock	6-7/8” Wide

A “kerf” is a slot cut on the edge of the jamb, used to wrap the drywall corner bead (rounded drywall corners) into the jamb. Kerfed flat jambs create a “caseless” opening, where drywall connects directly to the door frame – eliminating the need for case mouldings and achieving a clean, modern look. Kerfed (both sides) flat jambs for interior doors are available in the following widths, to match the following wall stud and sheetrock thickness.

Krefed (Both Sides) Flat Jamb with Adjustable Stop

STUD, SHEETROCK THICKNESS	JAMB WIDTH
2×4 Stud, 1/2” Sheetrock	3-1/2” Wide
2×4 Stud, 5/8” Sheetrock	3-1/2” Wide
2×6 Stud, 1/2” Sheetrock	5-1/2” Wide
2×6 Stud, 5/8” Sheetrock	5-1/2” Wide

Kerfed (one side) flat jambs for interior doors are available in the following widths, to match the following wall stud and sheetrock thicknesses:

KERFED (ONE SIDE) FLAT JAMB WITH ADJUSTABLE STOP

STUD, SHEETROCK THICKNESS	JAMB WIDTH
2×4 Stud, 1/2” Sheetrock	4-1/16” Wide
2×4 Stud, 5/8” Sheetrock	4-3/16” Wide
2×6 Stud, 1/2” Sheetrock	6-1/16” Wide
2×6 Stud, 5/8” Sheetrock	6-3/16” Wide

Exterior Jamb Widths

“Rabbeted” jams are required for exterior doors, providing enhanced durability and a secure fit. Unlike flat jambs, rabbeted jambs included a non-adjustable stop cut into solid wood. Rabbited jambs are available in the following widths, to match the following wall stud and sheetrock thicknesses:

Rabbeted Jamb

STUD, SHEETROCK THICKNESS	JAMB WIDTH
2×4 Stud, 1/2” Sheetrock	4-5/8” Wide
2×4 Stud, 5/8” Sheetrock	4-7/8” Wide
2×6 Stud, 1/2” Sheetrock	6-5/8” Wide
2×6 Stud, 5/8” Sheetrock	6-7/8” Wide

Kerfed (one side) rabbeted jambs for exterior doors are available in the following widths, to match the following stud and sheetrock thicknesses:

KERFED (ONE SIDE) RABBETED JAMB

STUD, SHEETROCK THICKNESS	JAMB WIDTH
2×4 Stud, 1/2” Sheetrock	4-1/16” Wide
2×4 Stud, 5/8” Sheetrock	4-3/16” Wide
2×6 Stud, 1/2” Sheetrock	6-1/16” Wide
2×6 Stud, 5/8” Sheetrock	6-3/16” Wide