Main Frame

An assemblage of rafters and columns that support the secondary framing members and transfer loads directly to the foundation.

Main Wind Force Resisting System

A structural assembly which provides for the overall stability of the building and receives wind loads from more than one surface. Examples include shear walls, diaphragms, rigid frames, and space structures.

Manufacturer

A party who designs and fabricates a Metal Building System.

Manufacturer’s Engineer

An engineer employed by a manufacturer who is in responsible charge of the structural design of a Metal Building System fabricated by the manufacturer. The manufacturer’s engineer is typically not the Engineer of Record.

Masonry

Anything constructed of materials such as bricks, concrete blocks, ceramic blocks, and concrete.

Mastic

See “Sealant”.

Mean Roof Height

Average height of roof above ground.

Metal Building System

A complete integrated set of mutually dependent components and assemblies that form a building including primary and secondary framing, covering and accessories, and are manufactured to permit inspection on site prior to assembly or erection.

Mezzanine

An intermediate level between floor and ceiling occupying a partial area of the floor space.

Mill Duty Crane

Cranes with service classification E and F as defined by CMAA.

Moment

The tendency of a force to cause rotation about a point or axis.

Moment Connection

A connection designed to transfer moment as well as axial and shear forces between connecting members.

Moment of Inertia

A physical property of a member, which helps define strength and deflection characteristics.

Monolithic Construction

A method of placing concrete grade beam and floor slab together to form the building foundation without forming and placing each separately.

Monorail Crane

A crane that travels on a single runway beam, usually a “S” or “W” beam.

Multi-Gable Building

Buildings consisting of more than one gable across the width of the building.

Multi-Span Building

Buildings consisting of more than one span across the width of the building. Multiple gable buildings and single gable buildings with interior columns are examples.

Multiple Girder Crane

A crane which has two or more girders for supporting the lifted load