This is all flat casing with 5 1/2" head casing and 4 1/4" side casing. The head is typically biscuit jointed to the side casings, glued and screwed to help control any seasonal movement.
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The trim in this house consists of 4 1/2" side casings, 5 1/2" head casings on doors, windows and cased openings and 7 1/4" baseboard with a bead.
Hope that helps!
Window Trim - Jamb: 1x3, Head: 5/4x4, Sill Base: 1x3, Window sill 1x6
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