What is a Masonry Opening (Mo) ?
Definition of Masonry Opening (Mo) in Construction The rough opening required in a masonry wall, which will allow the proper installation of a window or door unit. The masonry opening will be calculated to allow the necessary additional room for the adjustment and correct installation of the window or the door. Normally a shim space is allowed, both vertically and horizontally, to allow the installation of tapered shims to correctly position the window or door unit. The masonry opening sizes are important to coordinate the proper coursing of the masonry construction. Masonry units are standard sizes and the mortar joints remain standard also. With these known dimensions, the coursing of the masonry construction must be figured to allow the proper positioning of window and door openings. The proper masonry openings is vitally important to the proper coordination of the construction project as well as the coordination between the ordering of the windows and doors. Replacement windows and doors also require the identification of the proper masonry opening. Replacement windows and doors will be custom built to allow installation within existing openings in an existing structure. The MO is important and the proper coordination of these dimensions is paramount in the successful ordering and installation of new and replacement window and doors.