pinning in
Isaac Kremer/ September 9, 2018/ / 0 comments
The closure of open joints in rubble work or rough walling by small wedges or spalls of stone fitted into the interstices and bedded solidly in mortar, especially to avoid hollow spaces in the interior of a wall; but it is customary, in specifying for the face work of such a wall, that there shall be a few spalled joints. (Sturgis, 1900)