wall someone or something off
to separate or segregate someone or something by building a wall. She sat right across from me at her desk, listening to every phone call I made. Finally, the manager walled her off so we now can carry on our business in privacy. They walled off the south door to the building.
wall something off (from someone or something)
to deny access to an area by building a wall as a barrier. The manager was told to wall the incinerator area off from the machinery area. Please wall off the incinerator area.