Mansard roof -  A type of roof containing two sloping planes of different pitch on each of four sides. The lower plane has a much steeper pitch than the upper, often approaching vertical. Contains no gables.

Masonry primer - An asphalt-based primer used to prepare masonry surfaces for bonding with other asphalt products.

Mastic -   See asphalt plastic roofing cement.

Mineral stabilizers -  Finely ground limestone, slate, traprock or other inert materials added to asphalt coatings for durability and increased resistance to fire and weathering.

Mineral-surfaced roofing -  Asphalt shingles and roll roofing that are covered with granules.

MANSARD ROOF - A roof which rises by inclined planes from all four sides of a building. The sloping roofs on all four sides have two pitches, the lower pitch usually very steep and the upper pitch less steep.

MASON'S HAMMER or BRICKLAYER'S HAMMER – Tool shaped like a chisel to trim brick or stone.

MASTIC – Heavy-consistency compound that may remain adhesive and pliable with age. Is typically a waterproof compound applied to exterior walls and roof surfaces.

MAXIMUM OCCUPANCY LOAD - The maximum number of people permitted in a room and is measured per foot for each width of exit door. The maximum is 50 per foot of exit.

MELT POINT - The temperature at which the solid asphalt becomes a liquid.

MEMBRANE - A generic term relating to a variety of sheet goods used for certain built-up roofing repairs and application.

METAL EDGE - Brake metal or metal extrusions which are secured at the perimeter of the roof to form a weathertight seal.

MIGRATION – Spreading or creeping of a constituent of a compound onto/into adjacent surfaces. See bleeding.

MIL THICKNESS - Measurement used to determine thickness of a coating. 1 mil = .001 inch (1/1000).

MINERAL SPIRITS - A by-product of petroleum, clear in color, a solvent for asphaltic coatings.

MOCK UP TESTING – Controlled air, water and structural performance testing of existing or new glazing systems.

MODULUS – Stress at a given strain. Also tensile strength at a given elongation.

MOLDING – Finish wood such as door and window trim.

MONITOR, SAW-TOOTH - A type of monitor characterized by sharp angled pitches and vertical sections, usually arranged in rows much like teeth of a saw.

MONITOR - A large structure rising above the surrounding roof planes, designed to give light and/or ventilation to the building interior.

MOPPING – In roofing, a layer of hot bitumen mopped between plies of roofing felt. Full mopping is the application of bitumen by mopping in such a manner that the surface being mopped is entirely coated with a reasonably uniform coating. Spot Mopping is the procedure of applying hot bitumen in a random fashion of small daubs, as compared to full mopping. Sprinkle mopping is a special application of installing insulation to the decks. It is done by dipping a roof mop into hot bitumen and sprinkling the material onto the deck. Strip Mopping is the application of bitumen in parallel bands.

MORTAR TYPES - Type M is suitable for general use and is recommended specifically for masonry below grade and in contact with earth, such as foundations, retaining walls and walks. Type M is the strongest type. Type S is suitable for general use and is recommended where high resistance to lateral forces is required. Type N is suitable for general use in exposed masonry above grade and is recommended specifically for exterior walls subject to severe exposures. Type 0 is recommended for load-bearing walls of solid units where the compressive stresses do not exceed 100 lbs. per square inch and the masonry wall not be subjected to freezing and thawing in the presence of excessive moisture.

MUD CRACKS - Cracks developing from the normal shrinkage of an emulsion coating when applied too heavily.

MULLION – A horizontal or vertical member that supports and holds such items as panels, glass, sash, or sections of a curtain wall.

MUNTINS – Horizontal or vertical bars that divide the sash frame into smaller lites of glass. Muntins are smaller in dimensions and weight than mullions.

MANSARD ROOF - A roof which rises by inclined planes from all four sides of a building. The sloping

roofs on all four sides have two pitches, the lower pitch usually very steep and the upper pitch less steep.

MASTIC - A heavy trowel applied bitumen used for flashings or patch work which remains

elastic and pliable.

MELT POINT - The temperature at which the solid asphalt becomes a liquid.

MEMBRANE - A generic term relating to a variety of sheet goods used for certain built-up roofing repairs and application. Also used to describe the combination of felts and moppings of bitumen forming a single flexible unit and waterproofing system of a BUR.

METAL EDGE - Brake metal or metal extrusions which are secured at the perimeter of BURM to form a weathertight seal.

MIL THICKNESS - Measurement used to determine thickness of a coating. 1 mil = .001 inch (1/1000).

MINERAL SPIRITS - A by-product of petroleum, clear in color, a solvent for asphaltic coatings.

MINERAL SURFACED - A heavy roofing felt that has very small granules embedded across its surface.

MODIFIED BITUMEN - Bitumen modified by special processing, generally with the addition of SBS type

rubber or atactic polypylenes (APP). Some are non-reinforced, while others are reinforced with polyester, polyvinyl acetate, fiberglass, polypropylene or aluminum foil.

MONITOR, SAW-TOOTH - A type of monitor characterized by sharp angled pitches and vertical sections,

usually arranged in rows much like teeth of a saw.

MONITOR - A large structure rising above the surrounding roof planes, designed to give light and/or ventilation to the building interior.

MOPPING - A layer of hot bitumen mopped between plies of roofing felt.

MOPPING, FULL - The application of bitumen by mopping in such a manner that the surface being mopped is entirely coated with a reasonably uniform coating.

MOPPING, SPOT - The procedure of applying hot bitumen in a random fashion of small daubs, as compared to full mopping.

MOPPING, SPRINKLE - A special application of installing insulation to the decks. It is done by dipping a

roof mop into hot bitumen and sprinkling the material onto the deck.

MOPPING, STRIP - The application of bitumen in parallel bands.

MUD CRACKS - Cracks developing from the normal shrinkage of an emulsion coating when applied too heavily.