a jamb-like member, usually surfaced four sides, which increases or extends the width of the exterior door frame jamb; sub-jambs imply a larger width than “jamb liners”; can also be used with window units; extension jamb.
a jamb-like member, usually surfaced four sides, which increases or extends the width of the exterior door frame jamb; sub-jambs imply a larger width than “jamb liners”; can also be used with window units; extension jamb.