This glossary contains many useful terms and definitions that will help you understand much of the work we do at ROOFCORP.

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Mansard: a decorative steep-sloped roof on the perimeter of a building.

Mansard roof: a steeper roof that terminates into a flat roof at its high point.

Masonry: construction, usually set in mortar, of natural building stone or manufactured units, such as brick, concrete block, adobe, glass block, tile, manufactured stone or gypsum block.

Mastic: a thick adhesive material used as a cementing agent for holding waterproofing membrane in place. (see Asphalt roof cement).

Mat: a thin layer of woven, non-woven, or knitted fiber that serves as reinforcement to a material or membrane.

Mat slab: a concrete slab designed with reinforcement to resist the uplift forces created by hydrostatic pressure.

Material safety data sheets (MSDS): a written description of the chemicals in a product and other pertinent data, including such things as safe handling and emergency procedures. In accordance with OSHA regulations, it is the manufacturer’s responsibility to produce an MSDS and the employers responsibility to communicate its contents to employees.

Mechanical damage: in SPF-based roofing, physical damage to a completed SPF-based roof system not caused by normal wear and tear.

Mechanically fastened membranes: generally used to describe membranes that have been attached at defined intervals to the substrate.

Membrane: a flexible or semi-flexible roof covering or waterproofing whose primary function is to exclude water.

Metal: any of various opaque, fusible, ductile and typically lustrous substances that are good conductors of electricity and heat.

Metallic waterproofing: consist of finely graded iron particles combined with an oxidizing catalyst. When mixed with water (or water, cement, and sand), the finely distributed particles expand, creating a waterproof layer that becomes a part of the surface to which it is applied.

Metal rain collar: a metal counterflashing used to wrap a penetration and prevent water infiltration though the top of the penetration base flashing.

Meter: unit of length measurement in the metric system; 1 meter is equal to 39.37 inches.

Metal roof panel: an interlocking metal sheet having a minimum installed weather exposure of 3 square feet (279000 mm2 or 0.28 m2) per sheet.

Metal roof shingle: an interlocking metal sheet having an installed weather exposure less than 3 square feet (279000 mm2 or 0.28 m2) per sheet.

Mil: a unit of measure, one mil is equal to 0.001 inches, or 25.4 micrometers (m), often used to indicate the thickness of a roofing membrane.

Mildew: a superficial growth produced on organic matter or living plants by fungi.

Millimeter: a unit of measure equal to one thousandth (0.001) of a meter, or 0.03937 inches.

Mineral fiber: insulation composed principally of fibers manufactured from rock, slag or glass, with or without binders.

Mineral granules: see Granules. Mineral stabilizer: a fine, water-insoluble inorganic material, used in a mixture with solid or semi-solid bituminous materials.

Mineral-surfaced roofing: roofing materials whose surface or top layer consists of a granule-surfaced sheet.

Mineral-surfaced sheet: a roofing sheet that is coated on one or both sides with asphalt and surfaced with mineral granules.

Miter joint: a joint between two members at an angle to each other; each member is cut at an angle equal to half the angle of the junction; usually the members are at right angles to each other.

Model (building) codes: a compilation of standards or codes established to provide uniformity in regulations pertaining to building construction.

Modified bitumen: (1) a bitumen modified by including one or more polymers (e.g., atactic polypropylene, styrene butadiene styrene, etc.); (2) composite sheets consisting of a polymer modified bitumen often reinforced with various types of mats or films and sometimes surfaced with films, foils or mineral granules.

Moisture contour map: a map used to graphically define the location of moisture within a roof assembly after a moisture scan has been performed.

Moisture relief vent: a venting device installed through the roofing membrane to relieve moisture vapor pressure from within the roofing system.

Moisture scan: the use of a mechanical device (capacitance, infrared, or nuclear) to detect the presence of moisture within a roof assembly. (see Non-destructive testing.)

Mole run: a meandering ridge in a roof membrane not associated with insulation or deck joints.

Monolithic: formed from or composed of a single material; seamless.

Monomer: a low-molecular-weight substance consisting of molecules capable of reacting with like or unlike molecules to form a polymer.

Mop-and-flop: an application procedure in which roofing elements (insulation boards, felt plies, cap sheets, etc.) are initially placed upside down adjacent to their ultimate locations; coated with adhesive or bitumen; and turned over and adhered to the substrate.

Mopping: the application of hot bitumen with a mop or mechanical applicator to the substrate or plies of a bitumi-nous membrane. There are four types of mopping.

• Solid mopping: a continuous coating.

• Spot mopping: bitumen is applied roughly in circular areas, leaving a grid of unmopped perpendicular areas.

• Sprinkle mopping: bitumen is shaken onto the substrate from a broom or mop in a random pattern.

• Strip mopping: bitumen is applied in parallel bands.

Mud cracking: surface cracking resembling a dried mud flat.

Mud slab: a layer of concrete, typically 2 inches (50 mm) to 6 inches (150 mm) thick, used as the substrate for membrane waterproofing.