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.

 

Mastic: see Asphalt Roof Cement.

 

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

 

Material Safety Data Sheets (MSDS): a written description of the chemicals in a product, and pertinent other 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 employer’s responsibility to communicate its contents to employees.

 

Mechanically-Fastened Membranes: generally used to describe membranes that have been attached at defined intervals to the substrate. Mechanical fastening may be performed with various fasteners and/or other mechanical devices, such as plates or battens.

 

Membrane: a flexible or semi-flexible material, which functions as the waterproofing component in a roofing or waterproofing assembly, and whose primary function is the exclusion of water.

 

Metal Flashing: accessory components fabricated from sheet metal and used to weatherproof terminating roof covering edges. Frequently used as through-wall flashing, cap flashing (coping), counterflashing, step-flashing, etc. (See Flashing.)

 

Mil: a unit of measure, one mil is equal to 0.001 inches or 25.400 microns, often used to indicate the thickness of a roofing membrane.

 

Mineral-Surfaced Roofing: roofing materials whose surface or top layer consists of mineral granules.

 

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

 

Miter: the joint produced by joining two diagonally cut pieces.

 

Modified Bitumen: (1) a bitumen modified through the inclusion of one or more polymers (e.g., atactic polypropylene, styrene butadiene styrene, etc.); (2) composite sheets consisting of a polymer modified bitumen often reinforced and sometimes surfaced with various types of mats, films, foils, and 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 (capitance, infrared, or nuclear) to detect the presence of moisture within a roof assembly. (See Non-Destructive Testing.)

 

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

 

Mopping: the application of hot bitumen, with a roofer’s hand mop or mechanical applicator, to the substrate or to the felts of a bituminous membrane.

Solid Mopping: a continuous mopping of a surface.

Spot Mopping: a mopping pattern in which hot bitumen is applied in roughly circular areas, leaving a grid of unmopped, perpendicular bands on the roof.

Sprinkle Mopping: a random mopping pattern in which heated bitumen beads are strewn onto the substrate with a brush or mop.

Strip Mopping: a mopping pattern in which hot bitumen is applied in parallel bands.

 

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