A third way to detect if a change has been made to a brick wall is if a different material was used to infill an opening. If framing or another masonry material such as cinderblock was used to infill the opening, then an architectural historian can identify where a major change has been made to the wall. At Montpelier a ca. 1812 arched doorway that had been framed in and plastered over was quickly identified by both the cracks in the plaster that covered the doorway and the lath that was used to secure the plaster.