A nondestructive retrofit fire sprinkler protection system including a
sprinkler fitting with a unique shape that inserts behind a wall surface
and that securely connects a sprinkler head emerging from a wall location
to preferably concealed sprinkler piping located in a room at a point
where the ceiling surface meets a wall surfaces. In addition, a room
coupler fitting is adapted to be inserted between wall structures to
connect sprinkler piping in adjacent rooms.