| Term | Definition |
| Macadam | Refers to a pavement type generally consisting of large single size aggregate with a surface layer of smaller material with or without binder to lock the surface together. Can be either a bitumen based or water based Macadam Pavement. |
| Machine Direction | The direction parallel to the paper-bound edge of a sheet of gypsumboard. |
| Machine Room | Area where commercial and industrial refrigeration machinery, except the evaporators, is located. |
| Macro blind | 2" aluminum blind |
| Macrozones | Large zones of earthquake activity such as zones designated by the Uniform Building Code Map. |
| Madder | Coloring matter originally derived from the pulverized root of a plant cultivated in Europe and Asia Minor; now largely made synthetically. |
| Madras cotton | Brightly colored fabric, woven with a checked plaid or striped design. |
| Magneflex | 1" aluminum blind installed between two panes of glass, usually in a door. |
| Magnesium Silicate | White extender pigment which adds fluffiness to products in which it is used; provides very little opacity. |
| Magnet | A body having the capability of attracting iron and producing a magnetic field external to itself. |
| Magnetic | Having the properties of a magnet. |
| Magnetic Catch | A cabinet catch that uses a magnet to hold the door closed. |
| Magnetic Clutch | Device operated by magnetism to connect or disconnect a power drive. |
| Magnetic Compass | An instrument showing the direction of magnetic north and compass bearings. |
| Magnetic Core | Magnetic center of a magnetic field. |
| Magnetic Door Holder | A door holder using a magnet to hold it in an open position. |
| Magnetic Field | A region of variable force around magnets, magnetic materials, or current-carrying conductors. |
| Magnetic Gasket | Door-sealing material which keeps door tightly closed with small magnets inserted in gasket. |
| Magnetic Hammer | A special design hammer magnetically sensitized to hold a metal fastener during application. |
| Magnetic Pole | 1. Either of the two nonstationary areas in the north and south polar regions of the earth to which a magnetic compass needle will point 2. Either of the poles of a magnet. |
| Magnetic Starter | Automatic protective equipment using an electromagnet to operate; insures that a motor does not receive too high a current when starting up. |
| Magnetism | A field of force which causes a magnet to attract materials made of iron, nickel-cobalt or other ferrous material. |
| Magnetite | An aggregate used in heavyweight concrete, consisting primarily of ferrous metaferrite (Fe3O4); a black magnetic iron ore with a specific gravity of approximately 5.2 and a Mohs hardness of about 6. |
| Magnetron | A diode vacuum tube in which the flow of electrons is controlled by an externally applied magnetic field to generate power at microwave frequencies; the active element of a microwave oven. |
| Magnification Factor | An increase in lateral forces at a specific site for a specific factor or set of conditions. |
| Magnitude | A measure of earthquake size which describes the amount of energy released. |
| Mahogany Veneer | A thin layer of straight-grained medium density wood for an outer finish or decoration. |
| MAI | Member of the Appraisal Institute; a professional designation of a qualified real estate appraiser. |
| Mail Chute | An inclined or vertical channel through which mail travels from the exterior of a box or building to a container inside that box or building. |
| Main | The chief pipe, duct, or cable in any electrical, water, gas, sewer, vent or other utility system. |
| Main Breaker | 1. A switch in a main electrical service panel where the service wires attach. 2. The main electrical service protective device where the power enters a building. |
| Main Drain | See Main Outlet. |
| Main Outlet | Outlet fitting(s) at the bottom of a swimming pool, spa or hot tub through which passes water to the recirculating pump; also called Main Drain or Sump Pot. |
| Main Runners | The heaviest integral supporting members in a suspended ceiling; main runners are supported by hangers attached to the building structure and in turn support furring channels or rods to which lath is fastened. |
| Main Switch | See Service Disconnect. |
| Maintenance | The systematic upkeep of property or equipment. |
| Maintenance Equipment | Any of a variety of implements to maintain and clean areas or equipment. |
| Maintenance Painting | 1. Repair painting; any painting after the initial paint job. 2. All painting except that done solely for aesthetics. |
| Maisonette | 1. A small house. 2. An apartment on two floors. |
| Maisoning | The process of planning and carrying out the keying and master keying of a building; especially complex systems as in hotels and office buildings. |
| Majolica | 1. Earthenware with an opaque luster glaze and overglaze colored decorations. 2. Any decorated earthenware having an opaque glaze. |
| Make-Up Air | Fresh air brought into a building from outdoors through the ventilation system and that has not been previously circulated through the system. |
| Make-Up Water | Fresh water used to fill or refill a swimming pool. |
| Male | Any part, such as a bolt, designed to fit into another (female) part. External threads are male. |
| Male Thread | Outside threads on a pipe or fitting. |
| Maleic Resins | Resins based on reaction between maleic anhydride or maleic acid with glycerine and rosins. |
| Malice | A conscious desire to do harm. |
| Malicious Prosecution | Pursuing a lawsuit without probable cause. |
| Mall | 1. A sheltered walk or promenade. 2. A shopping area grouped around a common pedestrian way. |
| Malleable | Of metals, capable of being formed into new shapes by hammering and bending. |
| Malleable Iron | Iron that can be hammered or bent without breaking. |
| Malleable Strap | A metal fastening plate that can be hammered or bent without breaking. |
| Mallet | A hammer with a wooden head. |
| Malpractice | Negligent act or omission of a professional. |
| Malpractice Insurance | See Errors and Omissions Insurance. |
| Managerial Competence | An aptitude for management and fulfilling of all the responsibilities inherent in the managerial functions such as planning, control, cooperation, and communication. |
| Mandrel | 1. A tapered axle inserted into a hole in a piece of work to support it during machining. 2. A metal bar used as a core around which material may be cast, molded, forged, bent, or otherwise formed. 3. The shaft and bearings on which a tool is mounted, as |
| Mandrel Test | A physical bending test for adhesion and flexibility. |
| Manganese | 1. A greyish-white, hard and brittle, metallic chemical element that resembles iron but is not magnetic. 2. A mineral that is contained in the clay used for brickmaking. |
| Manhole | A hole through which a person may go to gain access to an underground or enclosed structure. |
| Manhole Base | The cast iron frame into which a manhole cover fits. |
| Manhole Cover | A heavy, round or square, steel or iron cover used to gain access to underground work through a manhole. |
| Manhole Removal | The act or process excavating an existing manhole and removing it. |
| Manhole, Communication | See Communication Manhole. |
| Manhole, Electric | See Electric Manhole. |
| Manhole, Watertight | See Watertight Manhole. |
| Manifold | A pipe fitting with several lateral outlets for connecting one pipe with others. |
| Manifold Gauge | Chamber device constructed to hold both compound and high-pressure gauges; valves control flow of fluids through it. |
| Manifold, Service | See Service Manifold. |
| Manila Paper | See Cream Paper. |
| Manila Resins | Alcohol soluble natural resin obtained by tapping Agathis alba trees. |
| Manometer | A pressure gauge for gases and liquids. |
| Manor | The house of a landed estate. |
| Mansard Roof | A type of hip roof which has four sloping sides, each of which becomes steeper partway down. |
| Mansion | A large imposing residence. |
| Mantel | 1. A projecting shelf above the fireplace opening. 2. The entire finish around a fireplace. |
| Mantle | The main bulk of the earth that lies between the crust and the central core. |
| Manual | 1. Done with the hands. 2. A book of instructions for operating a machine or performing some task. |
| Manual Frost Control | Manual control used to change operation of refrigerating system to produce defrosting conditions. |
| Manual Proportioning Control | In an asphalt batching plant, a control system in which proportions of the aggregate and asphalt fractions are controlled by means of gates or valves which are opened and closed by manual means; the system may or may not include power assist devices in th |
| Manufactory | A factory. |
| Manufacture | Making of articles as in a factory, especially on an industrial scale. |
| Manufactured Roof | A factory-finished roof system. |
| Manufactured Wall | A factory-finished wall system. |
| Manufactured wood | A wood product such as a truss, beam, gluelam, microlam or joist which is manufactured out of smaller wood pieces and glued or mechanically fastened to form a larger piece. Often used to create a stronger member which may use less wood. See also Oriented |
| Manufacturer's specifications | The written installation and/or maintenance instructions which are developed by the manufacturer of a product and which may have to be followed in order to maintain the product warrantee. |
| Manufacturer’s Bond | A surety company's guarantee that it will stand behind a manufacturer's liability to finance roofing membrane repairs occasioned by ordinary wear within a period generally limited to 5, 10, 15 or 20 years. |
| Manufacturers Standardization Society of the Valve Fittings Industry, Inc (MSS) | 127 Park Street, NE, Vienna, Virginia 22180, (703) 281-6613 |
| Map | A two-dimensional representation of a part of the earth's surface. |
| Maple Flooring Manufacturers Association (MFMA) | 60 Revere Drive #500, Northbrook, Illinois 60062, (708) 480-9080. |
| Mar | To disfigure, spoil, or impair the perfection of a surface or object. |
| Marble | Limestone that is more or less crystallized by metamorphism, that ranges from granular to compact in texture, that is capable of taking a high polish, and that is used in architecture and sculpture. |
| Marble Chips | Graded aggregate of maximum hardness made from crushed marble to be thrown or blown onto a soft plaster bedding coat to produce marblecrete. |
| Marble Flooring | A floor system using marble as its finish material. |
| Marble Mosaic Tile | Tile made of small marble pieces that vary slightly in size, usually about one-half inch square. |
| Marble Paver | A type of igneous stone that is harder and more durable than regular bricks, used for driveways and patios for use with or without mortar. |
| Marble Tiles | Marble cut into tile sizes 12 inches square or less, usually 1/2 inch to 3/4 inch thick; available in several types of finishes, such as polished, honed, or split faced. |
| Marble, Imported | See Imported Marble. |
| Marblecrete | A marble chip embedded finish for plaster. |
| Marbleizing | See Faux Marble. |
| Marblite | Plaster lining of marble granules with white cement to finish concrete pools. |
| Marezzo | An imitation marble produced with Keene's cement to which color pigments have been added. |
| Marine Plywood | Plywood panels manufactured with the same glueline requirements as other exterior-type panels but with more restrictive veneer quality requirements. |
| Marine Varnish | Varnishes especially designed to resist long immersion in salt or fresh water and exposure to marine atmosphere. |
| Mark1 | 8 gauge aluminum high quality miniblind with special headrail, made by Levolor. |
| Marked Crossing | A crosswalk or other identified path intended for pedestrian use in crossing a vehicular way. |
| Market Area | The geographic area from which a real estate development expects to derive its customer base. |
| Market Data Approach | A real estate appraisal method by which the subject property is compared with other properties that have recently been sold or leased. |
| Market Study | A forecast of future demand in a particular market area for the type of real estate project proposed for development on a specific site. |
| Market Value | The price of something on the open market where the buyer and seller are both knowledgeable, and under no pressure to complete the transaction. |
| Marketable Title | Title to land that is unencumbered by any lien that would affect its value or marketability |
| Marketing Management | Development of a marketing concept by a contractor, including such factors as advertising, copy for phone directory, letterhead for stationery, logo, and business cards. |
| Marl | A calcareous clay, containing approximately 30 to 65 percent calcium carbonate (CaCO3), found normally in extinct fresh water basins, swamps, or bottoms of shallow lakes. |
| Marquee | 1.A canopy over an entrance. 2. A large tent set up for outdoor receptions. |
| Marquetry | Decorative work in which elaborate patterns are formed by the insertion of pieces of material, such as wood, shell, or ivory, into a wood veneer that is then applied to a surface, such as a piece of furniture. |
| Marquisette | A thin, open-mesh fabric, often of artificial fibers. |
| Marsh | An area of soft, wet, or periodically submerged land, generally treeless and usually characterized by grasses and other low vegetation. |
| Masking | 1. The presence of a background noise increased to a level to which a sound signal must be raised in order to be heard or distinguished. 2. When painting, protecting areas not to be painted. 3. Application of protective materials used in plastering machin |
| Masking Power | The ability of a fired glaze to mask visually the body on which it is applied. |
| Masking Tape | Adhesive coated paper tape used to mask or protect parts of surface not to be finished. |
| Mason | 1. A skilled worker who builds by use of brick or stone set in mortar. 2. See Stonemason. 3. See Brickmason. |
| Mason's Hammer | A tool used by masons and tilesetters to score and cut brick, block, stone, or tile. |
| Masonite | Trademark. Fiberboard building panels made from steam-exploded wood fiber and binders. |
| Masonry | Stone, brick, concrete, hollow-tile, concrete block, gypsum block, or other similar building units or materials or a combination of the same, bonded together with mortar to form a wall, pier, buttress, or similar mass. |
| Masonry Accessory | Any of various components necessary for masonry construction. |
| Masonry Anchor | A fastening device or mechanism used in a masonry wall. |
| Masonry Base | The lowest course of masonry in a pier, foundation, wall or footing. |
| Masonry Bonded Hollow Wall | A hollow wall built of masonry units in which the inner and outer wythes of the walls are bonded together with masonry units, such as in the all-rolok and rolok- bak walls. |
| Masonry Brick | Bricks that are shaped and molded in various sizes and shapes. |
| Masonry Cement | Portland cement with dry admixtures designed to increase the workability of mortar. |
| Masonry Chimney | A vertical noncombustible structure with a flue or flues to remove smoke and other gases constructed of shaped or molded masonry units. |
| Masonry Cleaning | 1. The final removal of excess grout and concrete and mortar stains, from an exterior surface of a masonry structure. 2. In older structures, the cleaning of the surface by any of several means but commonly steam, chemical, and in some rare instances sand |
| Masonry Control Joint | A sawed, tooled, or formed groove in a masonry joint to regulate the location of cracking resulting from the dimensional change of different parts of the structure. |
| Masonry Facing Panel | A masonry structure having a decorative exterior surface. |
| Masonry Flashing | A thin, continuous sheet of metal, plastic, rubber or waterproof paper used to prevent the passage of water through a joint in a wall, roof, or at a chimney; the material used and the process of making watertight the roof intersections and other exposed p |
| Masonry Floor | Shaped or molded masonry units such as, stone, brick, tile or concrete units used for finished floor coverings. |
| Masonry Furring | Metal or wooden strips attached to any masonry surface on which wall boards or sheathing may be conventionally attached. |
| Masonry Grout | A mixture of cementitious materials and aggregates and water used to fill the hollow spaces of masonry units and cavities. |
| Masonry Insulation | Any type of insulation for hollow masonry units. |
| Masonry Lintel | Masonry member placed within masonry wall or partition to support loads over an opening. |
| Masonry Manhole | A masonry vertical access shaft from the surface to the underground utility. |
| Masonry Painting | The act or process of applying paint to seal or color a masonry surface. |
| Masonry Paver | Shaped or molded units, composed of stone, ceramic brick or tile, concrete, or cast-in place concrete used for driveways and patios. |
| Masonry Plaque | A commemorative or identifying inscribed tablet made of shaped or molded units, composed of stone, brick, tile, or concrete. |
| Masonry Plaster | A plaster surface on masonry usually made from a cement-based mixture, commonly called stucco on newer buildings, but may be some other material on older historic structures. |
| Masonry Reinforcing | Lateral steel rods, wire, or mesh placed between courses of masonry units. |
| Masonry Research | See Masonry Institute of America. |
| Masonry Restoration | The act or process of the repair of a masonry structure. |
| Masonry Sandblast | The act or process of abrading or cutting masonry structure surfaces using sand ejected from a nozzle at high speed by compressed air; an effective form of cleaning masonry, but used sparingly because of its inclination to remove the outer (usually glazed |
| Masonry Society, The (TMS) | 3775 Iris Avenue, #6, Boulder, Colorado 80301-2043, (303) 939-9700. |
| Masonry Tie | A reinforcing strip, bar, or wire used to link courses of masonry together or to bond them with a wood or concrete backup wall. |
| Masonry Unit | Any brick, tile, stone, or block used in masonry construction. |
| Masonry Veneer | A nonstructural tier or layer of brick or stone attached to a structural masonry or wood framed wall. |
| Masonry Vent | Opening in a masonry structure to provide natural ventilation. |
| Masonry Wall | A wall constructed of brick, stone, or concrete block. |
| Masonry Waterproofing | Any of a variety of materials applied to masonry structures to resist or prevent the passage of water. |
| Masonry, Gypsum | See Gypsum Masonry. |
| Mass | 1. Quantity of matter held together so as to form one body. 2. A body of matter of indefinite shape. 3. The quantity of a body that is its measure of inertia. |
| Mass Concrete | 1. Concrete without reinforcing; also called plain concrete. 2. Any large volume of concrete cast in place intended to resist applied loads by virtue of mass; generally a monolithic structure incorporating a low cement factor with a high proportion of lar |
| Mass Curing | Adiabatic curing, using sealed containers. |
| Mass Law | In acoustics, the law relating to the transmission loss of walls, which states that in a part of a frequency range, the magnitude of the loss is controlled entirely by the mass per unit area of the panel; also, that the transmission loss increases 1 decib |
| Master | A fully qualified, proficient, skilled, and experienced builder, plumber, electrician, plasterer, painter, or other construction trade worker. |
| Master Key | A key that will open several locks, each keyed separately. |
| Masterformat | The copyrighted title of a uniform indexing system for construction specifications, as created by the Construction Specifications Institute and Construction Specifications Canada, commonly called the CSI format or numbering system. |
| Masterkeying | An arrangement of door lock cylinders having individual key changes which permits them all to be operated by a single key called the master key. |
| Mastic | 1. High viscosity solvent-based adhesive. 2. A pasty material used as a cement, as for setting tile, or a protective coating, as for thermal insulation or waterproofing. 3. Organic tile adhesive. 4. A viscous, dough-like, adhesive substance; can be any of |
| Mastic Asphalt | A mixture of bitumen and fines that can be used for waterproofing in building and industrial applications. |
| Mastic Grout | A chemical mixture of organic and inorganic ingredients forming a one part grouting composition that is used directly from the manufacturer; it is more flexible and stain resistant than cement grout. |
| Mat | 1. A large footing or foundation slab used to support an entire structure. 2. A grid of reinforcing bars. |
| Mat Formwork | The temporary support for a concrete mat during the pouring or placing of concrete. |
| Mat Foundation | A concrete slab used as a building or equipment foundation. |
| Mat Glaze | A colorless or colored ceramic glaze having low gloss. |
| Mat Reinforcing | The placing of metal or steel bars in freshly poured concrete mat to strengthen it. |
| Mat, Concrete | See concrete Mat. |
| Mat, Floor | See Floor Mat. |
| Matched Lumber | Lumber that is edge-dressed and shaped to make a close tongue-and-groove joint. |
| Matching | Machining boards to form tongue and groove joints. |
| Matchstick shades | A roman styled shade made of woolen sticks/dowels. Made by many manufacturers including Levolor and DelMar. |
| Material | 1. The matter from which things are made. 2. The physical things needed for construction. 3. Important, essential, and relevant. |
| Material Handling | The act or process of transporting materials on or to a jobsite. |
| Materialman | An individual or organization who supplies construction materials to a project. |
| Materials Used | This includes the cost of all materials used on the job; usually the largest single expense item on income and expense statement. |
| Materiel | The materials, equipment, and supplies used in a business or on a project. |
| Matrix | In concrete, the material that fills the spaces between the fine and course aggregates; the cement paste. |
| Matter | A physical substance in general that has mass and occupies space; occurs in the state or form of solid, liquid, or gas. |
| Mattock | A hand implement used for digging and grubbing, with features of a pick and an adze. |
| Maturing Range | The time-temperature range within which a ceramic body, glaze, or other composition may be fired to yield specified properties. |
| Maturity Date | The date on which an obligation becomes due. |
| Maul | 1. A heavy hammer for driving wedges. 2. A tool like a sledge hammer with one wedge-shaped end, used to split wood. |
| Maulstick | A light stick with a padded leather ball at one end, held by a painter in one hand to support the other hand. |
| Mausoleum | A large and grand tomb. |
| Maximum | (Pl. maxima) The highest possible or attainable amount. |
| Maximum Capable Earthquake | The maximum level of earthquake ground shaking which may ever be expected at the building site within the known geological framework; this intensity may be taken as the level of earthquake ground motion that has a 10 percent probability of being exceeded |
| Maximum Density | The maximum density that could be achieved in a sample of asphalt if it were possible to compact it so as to exclude all air voids between coated aggregate particles (also know as void-free density) |
| Maximum Size Aggregate | Aggregate whose largest particle size is present in sufficient quantity to affect the physical properties of concrete; generally designated by the sieve size on which the maximum amount permitted to be retained is 5 to 10 percent by weight. |
| MB | Megabyte. 1,024,000 bytes. |
| MBH | Thousands of British Thermal Units; for example, 82 MBH = 82,000 BTU. |
| MBMA | Metal Building Manufacturers Association. |
| MC | 1. Medicine Cabinet. 2. Medium-Curing Asphalt. |
| MCM | Thousand circular mils, designating wire size. |
| MCS | Multiple Chemical Sensitivity; a condition in which a person is considered to be sensitive to a number of chemicals at very low concentrations. |
| MDF | Medium-Density Fiberboard. |
| ME | Mechanical Engineer. |
| Mean | 1. The middle term in a progression of values. 2. Average. |
| Mean Effective Pressure (MEP) | Average pressure on a surface when a changing pressure condition exists. |
| Mean Radiant Temperature | The weighted average of all radiating surface temperatures within one line of sight. |
| Meat Case | A refrigerated unit for the storage and preservation of meat. |
| Mechanical | 1. Of or relating to machinery or tools. 2. Relating to, governed by, or in accordance the principles of mechanics. 3. Anything in the plumbing, heating, air-conditioning, or fire sprinkler trades. |
| Mechanical Adhesion | Adhesion between surfaces in which the adhesive holds the parts together by interlocking action. |
| Mechanical Application | Application of plaster mortar by mechanical means, generally pumping and spraying; distinguished from hand application with a trowel. |
| Mechanical Bond | 1. The physical keying of one plaster coat to another or to the plaster base. 2. Tying masonry units together with metal ties or reinforcing steel or keys. |
| Mechanical Cycle | Cycle which is a repetitive series of mechanical events. |
| Mechanical Engineer | An engineer who designs plumbing, air conditioning, and other environmental systems for buildings. |
| Mechanical Skimmer | See Surface Skimmer. |
| Mechanical Trowel | A power machine used to smooth and compact plaster finish coats; capable of producing an extremely smooth, dense surface; consists of revolving metal or rubber blades; also called a Power Trowel. |
| Mechanics lien | A lien on real property, created by statue in many years, in favor of persons supplying labor or materials for a building or structure, for the value of labor or materials supplied by them. In some jurisdictions, a mechanics lien also exists for the value |
| Median | 1. The middle value in a series of values. 2. A straight line in a triangle connecting a vertex with the midpoint of the opposite side. |
| Median Strip | A space between two opposing lanes of traffic, as in a divided highway. |
| Mediation | An alternative dispute resolution method by which a mediator assists and urges the parties to find a mutually acceptable resolution to their differences; unlike an arbitrator, a mediator cannot impose a solution or secession on the parties. |
| Medical Equipment | Apparatus or devices used in medical applications. |
| Medical Gases | In a hospital, the gases that are piped throughout the building for bedside and laboratory use, such as oxygen and nitrous oxide |
| Medical Incinerator | A device in which medical wastes are burned. |
| Medical Sterilizer | An apparatus that utilizes high heat or chemicals to sterilize medical equipment. |
| Medical Surveillance | 1. A periodic comprehensive review of a worker's health status. 2. The required elements of an acceptable medical surveillance program for various conditions that are listed in the Occupational Safety and Health Administration standards. |
| Medical Utensil Washer | A mechanical washing device which sterilizes, by high heat, medical utensils for use in surgeries and other health care needs. |
| Medical Waste | Waste materials created by hospitals or other medical settings. |
| Medicine Cabinet | A cabinet, usually found in the bathroom, where articles such as toiletries and home medicines are kept. |
| Medieval Cities | Irregular street patterns; fortified cities were first internally subdivided to the maximum utilization of the land; often internal part of the city acted as a second fortress. |
| Medium Density Fiberboard | A panel product manufactured from lignocellulosic fibers combined with a synthetic resin or other suitable binder; the panels are manufactured to a density of 31 pcf (0.50 specific gravity) to 55 pcf (0.88 specific gravity) by the application of heat and |
| Medium Duty Tile | Tile suitable for pedestrian traffic such as entryways in multiple dwellings and lobbies. |
| Medium Valve | A color midway between a dark color and a light color. |
| Medium-Curing (MC) Asphalt | Cutback asphalt composed of asphalt cement and a kerosene-type diluent of medium volatility. |
| Meeting Rail | See Checkrail. |
| Meeting Room | A room for holding meetings; a conference room. |
| Megahertz | One million hertz, a unit of radio frequency. |
| Megalopolis | 1. A large city. 2. An urban complex consisting of a metropolis and its environs. |
| Megawatt | 1,000,000 watts. |
| Megohm | A unit of measure for electrical resistance. One megohm is equal to a million ohms. |
| Megohmmeter | Instrument for measuring extremely high resistances, in the millions of ohms range. |
| MEK | Methyl Ethyl Ketone. |
| Melt | To change a solid into a liquid by the application of heat; or the liquid resulting from such action. |
| Melting Point | Temperature at atmospheric pressure at which a substance will melt. |
| Melting Rate | In welding, the weight or length of electrode melted in a unit of time; also called Burnoff Rate. |
| Member | A single piece in a structure, complete in itself. |
| Membrane | 1. A sheet material that is impervious to water or water vapor. 2. A flexible or semi-flexible roof covering or waterproofing whose primary function is the exclusion of water. |
| Membrane Fireproofing | A lath and plaster membrane having among its functions that of providing a barrier to fire and intense heat. |
| Membrane Roof | A roof structure with a covering of a sheet material that is impervious to water or water vapor; commonly a single sheet of material. |
| Membrane Waterproofing | A membrane, usually made of built-up roofing or sheet material, to provide a positive waterproof floor over the substrate, which is to receive a tile installation using a wire reinforced mortar bed. |
| Membrane, Neoprene | See Neoprene Membrane. |
| Meniscus | The upper curved surface of a liquid in a tube, concave when the liquid wets the tube, convex when it does not. |
| MEP | Mean Effective Pressure. |
| Mercalli Scale | System used to determine the location of the epicenter of an earthquake on the basis of defining zones of intensity by observations of damage by persons experiencing the earthquake. |
| Mercoid Bulb | Electrical circuit switch which uses a small quantity of mercury in a sealed glass tube to make or break electrical contact with terminals within the tube. |
| Mercury | A silvery-white heavy liquid metallic element used in barometers, thermometers, amalgams, and electrical switches; the only metal that is liquid at ordinary room temperature; chemical symbol Hg. |
| Mercury Fixture | A light fixture that has an electric discharge lamp that produces a blue-white light by creating an arc in mercury vapor enclosed in a tube or globe. |
| Mercury Switch | An electrical switch that has mercury enclosed in a vial to make a silent contact. |
| Meridian Lines | Part of a governmental land surveying grid system covering the country, with base lines running east and west and meridians running north and south; townships are located with reference to a specific base line and meridian; for example, T3N, R12W, MDBM is |
| Mesh | The square opening of a sieve. |
| Mesh Tape | See Joint Reinforcing Mesh. |
| Mesh Tie | A wire used to hold sheets of mesh together so they will not move or spread apart when concrete is poured over the mesh. |
| Mesh Wire | A series of longitudinal and transverse wires arranged at right angles to each other in sheets or rolls, used to reinforce mortar and concrete; welded-wire fabric. |
| Mesh, Reinforcement | See Welded Wire Fanbric. |
| Mesh, Slab | See Slab Mesh. |
| Message Tube | A cylindrical tube typically installed in the walls of a building or structure, operated by the suction of air, to transport messages placed in containers. |
| Met | Term applied to the heat release from a human at rest. It equals 18.4 Btu/sq. ft./hr. or 50 kcal/m2/hr. |
| Metal | 1. Any of various fusible, ductile and typically lustrous chemical elements that can conduct heat and electricity. 2. Any alloy. |
| Metal Anchor | A bolt or fastener made of metal. |
| Metal Beam Anchor | Formed steel component used to anchor one end of a beam to another beam, girder, or column and prevent displacement of the beam under lateral or uplift loads. |
| Metal Bridging | Diagonal or longitudinal metal members used to keep horizontal wood members properly spaced, in lateral position, vertically plumb, and to distribute load. |
| Metal Building | A building or structure constructed of a structural steel frame covered by metal roof and wall panels; commonly prefabricated in a factory and assembled at the site. |
| Metal Building Manufacturers Association (MBMA) | 1300 Sumner Avenue, Cleveland, Ohio 44115, (216) 241-7333. |
| Metal Chimney | Vertical metal structure with one or more flues to carry smoke and other gases or combustion into atmosphere. |
| Metal Clad Cable | Electrical conduit made of a flexible steel jacket wrapped around insulated wires. |
| Metal Clad Door | A flush wooden door covered in sheet metal. |
| Metal Clip Angle | Short length of metal angle used to attach two components. |
| Metal Cripple Stud | Less than full height metal stud, such as under or above an opening. |
| Metal Decking | Light-gauge, corrugated sheets used in the construction of roofs or floors. |
| Metal Door Buck Anchor | Formed steel component used to anchor door bucks or jambs to concrete or masonry construction. |
| Metal Ductwork | The light sheet metal material out of which the ducts of an HVAC system are manufactured. METAL ELECTRODE. A filler or non-filler metal electrode used in arc welding consisting of a metal wire with or without a covering or coating. |
| Metal Fabrication | The building, construction or manufacture of metal structures or metal devices. |
| Metal Floor Track | Horizontal channel shaped steel member located at bottom of framed wall to receive metal studs. |
| Metal Framing | The construction of a building or structure by using steel; the construction of frame houses and partitions by using light gauge metal studs and members. |
| Metal Framing Anchor | Fabricated metal devices used to transfer structural loads from a wooden structural member to another or other material member or supporting structure. |
| Metal Furring | A length of metal channel attached to a masonry or concrete wall to permit the attachment of finish materials to the wall. |
| Metal Girder Anchor | Formed steel component used to anchor end of girder to another girder, beam, or column and prevent displacement of girder under lateral or uplift loads. |
| Metal Grating | Metal screening made from sets of parallel bars placed at right angles to each other to allow water to drain through, while protecting persons and vehicles from the drain opening. |
| Metal Halide Lamp | A lamp that uses an electric-discharge to produce light from a metal vapor such as sodium or mercury. |
| Metal Joist | Horizontal cold formed metal framing member of floor, ceiling or flat roof to transmit loads to bearing points; often refers to a Bar Joist. |
| Metal Joist Anchor | Formed steel component used to anchor end of joists and to wall plate or beam and prevent displacement of joist under lateral or uplift loads. |
| Metal Joist Bridging | Diagonal or longitudinal metal members used to keep metal joists properly spaced, in lateral position, vertically plumb, and to distribute load. |
| Metal Joist Hanger | Formed steel component used to support end of load bearing joists and transmit loads to another joist or beam. |
| Metal lath | Sheets of metal that are slit to form openings within the lath. Used as a plaster base for walls and ceilings and as reinforcing over other forms of plaster base. |
| Metal Lath Steel Framing Division of National Association of Architectural Metal Manufacturers, (MLA) | 11 South LaSalle #1400, Chicago, Illinois 60603, (312) 201-0101. |
| Metal Lintel | A horizontal metal member spanning and carrying the load above an opening. |
| Metal Louver | A framed opening in a wall or door with fixed or movable flaps, manufactured from metal. |
| Metal Pan Stair | A stair assembly constructed to hold precast or cast-in place concrete, masonry, or stone in sheet metal pans at the treads and landings. |
| Metal Primer | First coating applied in finishing metal. |
| Metal Quarry Tile Rack | Racks that are available in many patterns and made to order for special patterns, used to maintain uniform joint widths between quarry tiles. |
| Metal Rafter | Horizontal cold formed metal framing member for floor, ceiling or roof to transmit loads to bearing points. |
| Metal Railing | A guard or open fence with rails and posts made of metal. |
| Metal Railing Bracket | Metal wall bracket to support a railing. |
| Metal Roof Removal | The act or process of tearing off and carrying away an old metal roof. |
| Metal Shear Plate | Metal plates used to transfer shear loads between timber members. |
| Metal Shingle | 1. A roof covering unit manufactured from metal and applied in an overlapping pattern. 2. Metal material used as an exterior wall finish over sheathing. |
| Metal Sleeper Clip | Metal clip used to secure wood sleepers to a concrete floor. |
| Metal Stair | A single or series of metal steps with framework connected at landings. |
| Metal Stair Pan | A stair assembly constructed to hold precast or cast-in place concrete masonry or stone in metal sheet pans at the treads. |
| Metal Stud | Vertical formed steel channel within a framed wall. |
| Metal Stud Bracing | Element used to prevent buckling or rotation of metal studs. |
| Metal Stud Bracing, Horizontal | Horizontal element used to provide stiffness and to prevent buckling or rotation of metal studs. |
| Metal Tie Strap | Formed steel component used to tie one wood framing member to another. |
| Metal Timber Connector | Fabricated metal devices used to transfer structural loads from a timber member to another timber or other material member or supporting structure. |
| Metal Toilet Partition | A prefinished, manufactured dividing wall in a toilet room. |
| Metal Toothed Ring | Metal rings with toothed edge to embed in wood to resist shear. |
| Metal Track | Horizontal channel-shaped steel member located at top or bottom to receive metal studs. |
| Metal Trim | See Casing and Bead, 4. |
| Metal-Clad Cable | A fabricated assembly of insulated conductors in a flexible metallic enclosure. |
| Metal-Electrode-Arc Welding | An arc-welding process wherein metal electrodes are used. |
| Metallic Color Tile | Tile that has been coated with metal flakes to reflect light. |
| Metallic Grout | Grout that has been coated with metal flakes that reflect light. |
| Metallic Soap | A compound of metal and organic acid; used as driers, fungicides, suspending agents, and flatting agents. |
| Metallize | 1. To coat, treat or combine with a metal. 2. Coat with a thin layer of metal. |
| Metallurgy | The science concerned with the production, purification, and properties of metals and their application. |
| Meter | 1. An instrument for measuring consumption of gas, electrical current, or water. 2. A metric unit that equals 100 centimeters or 1000 millimeters and is equivalent to 39.37 inches. |
| Meter Center | The room or area where meters for measuring the usage of water, electricity and/or gas are located. |
| Meter Center, Indoor | See Indoor Meter Center. |
| Meter Socket | A receptacle with electric contacts in which an electric meter is plugged. |
| Meter Stop | A valve used on a water main between the street and a water meter; it permits installation or removal of the meter. |
| Meter, Electric | See Electric Meter. |
| Meter, Gas | A mechanical measuring and recording device of the volume of gas passing a given point. |
| Meter, Water | See Water Meter. |
| Metering | The mechanical process of measuring the usage of water, electricity or gas. |
| Metes and Bounds | A type of legal description of land where each segment of the boundary line is described by length and bearing. |
| Methane | A colorless, odorless, highly inflammable gaseous hydrocarbon, sometimes known as marsh gas or firedamp, produced by decomposition of organic matter in marshes and mines or the carbonization of coal, used as a fuel and raw material in chemical synthesis |
| Method of Joints | Mathematical procedure for determining the forces in the members of a truss or frame. |
| Methods of Sections | Mathematical procedure for determining the forces in the members of a truss or frame. |
| Methyl Acetate | An inflammable fragrant liquid used as a lacquer solvent. |
| Methyl Alcohol | Poisonous alcohol obtained by destructive distillation of wood. |
| Methyl Ethyl Ketone (MEK) | A flammable liquid cleaning solvent. |
| Methyl Formate | Low pressure refrigerant. |
| Methyl Isobutyl Ketone (MIBK) | A strong flammable organic solvent. |
| Metopes | See Tryglyphs and Metopes. |
| Metric System | A standard measuring system based on the meter, decimally subdivided into centimeters and millimeters. |
| Mexican Paver Tile | Handmade terra cotta-like tile, used mainly for floors; they vary in color, texture and appearance, from tile to tile and within each tile; available in squares up to 12 inches, hexagon, octagon, elongated hexagon, fleur de lis and other shapes; coated wi |
| Mezzanine | A low-ceilinged story between two main stories of a building; an intermediate story that projects in the form of a balcony. |
| MFMA | Maple Flooring Manufacturers Association. |
| Mho | The practical unit of electrical conductance equal to the reciprocal of the ohm. |
| MI | Malleable Iron. |
| MI Cable | Mineral insulated sheathed cable. |
| MIA | 1. Marble Institute of America, 33505 State Street, Farmington, MI 48335, (810) 476-5558. 2. Masonry Institute of America, formerly Masonry Research. |
| MIBK | Methyl Isobutyl Ketone. |
| Mica | Any of a group of silicate minerals with a layered structure. |
| Mica Pigment | Extender pigment made from silicates of aluminum and potassium which are split into very thin plates or sheets; used as reinforcing pigment since it tends to reduce checking and cracking. |
| Micro | One millionth part of unit specified. |
| Micro blind | 1/2" aluminum blind |
| Microbiologicals | Agents derived from or that are living organisms (for example, viruses, bacteria, fungi, and mammal and bird antigens) that can be inhaled and can cause many types of health effects including allergic reactions, respiratory disorders, hypersensitivity dis |
| Microfarad | Unit of condenser electrical capacity equal to 1/1,000,000 farad. |
| Microlam | A manufactured structural wood beam. It is constructed of pressure and adhesive bonded wood strands of wood. They have a higher strength rating than solid sawn lumber. Normally comes in l ½" thickness' and 9 ½", 11 ½" and 14" widths. |
| Microliter | One millionth of a liter. |
| Micrometer | 1. A gauge for accurately measuring small distances or thicknesses. 2. A unit of length equal to one millionth of a meter; also called a Micron. |
| Micron | A micrometer, one millionth of a meter. |
| Micron Gauge | Instrument for measuring vacuums very close to a perfect vacuum. |
| Microphone | An instrument that turns sound waves into electric current for the purposes of transmitting or recording music or voice. |
| Microregionalization | Breaking up of macrozones into much smaller zones of specific earthquake intensity and activity. |
| Microscope | An optical device found in a laboratory which has a surface for placing materials to be examined, and a lens which magnifies those materials. |
| Microscopic soil particles | Clay and silt; particles that cannot be observed by the unaided human eye. |
| Microvolt | One millionth of a volt. |
| Microwatt | One millionth of a watt. |
| Microwave Oven | An oven in which food is cooked by the heat produced as a result of short electromagnetic wave penetration of the food; the active element is the magnetron. |
| Middle Strip | The zone of a two-way concrete slab that lies midway between columns. |
| Midget Trowel | A small hand trowel used for pointing and small confined areas. |
| Mil | A unit of length or thickness equal to 1/1000th of an inch. |
| Milar (mylar) | Plastic, transparent copies of a blueprint. |
| Mild Steel | Steel containing less than three-tenths of one percent carbon, not used as structural steel because of its low strength. |
| Mildew | 1. A discoloration caused by fungi. 2. A parasitic fungus growth occurring in insufficiently vented and damp surface areas. |
| Mildewcide | Substance poisonous to mildew; prevents or retards growth of mildew. |
| Mile | A measure of distance equal to 5280 feet. |
| Milieu | Environment or setting. |
| Military Crest | A ridge that interrupts the view between a valley and a hilltop. |
| Mill | 1. A building used for grinding, machining, manufacturing, or woodworking. 2. A machine for grinding or crushing. |
| Mill Scale | The oxide layer formed during the hot rolling of metals, such as that formed on hot-rolled reinforcing bars. |
| Mill White | White paint used to augment illumination on interior wall surface of industrial plants, office and school buildings; the vehicle is usually of the varnish type. |
| Mill-Mixed Plaster | See Gypsum Ready Mixed Plaster. |
| Milli | Combining form denoting one thousandth (1/1,000); for example, millivolt means one thousandth of a volt. |
| Milliammeter | An instrument that measures very small amounts of electrical current. |
| Milliampere | One thousandth of an ampere. |
| Millibar | One thousandth of a bar, the metric unit of atmospheric pressure equivalent to 100 pascals. |
| Millimeter | A metric unit of distance measurement equal to 1/10 of a centimeter or 1/1000 of a meter. |
| Millimicron | 1. A unit of length equal to one thousandth of a micrometer. 2. A nanometer. |
| Millisecond | One thousandth of a second. |
| Millwork | Generally, all wood materials manufactured in millwork plants and planing mills, including such items as inside and outside doors, window and door frames, blinds, mantels, panel work, stairways, moldings and interior trim, but not including flooring, ceil |
| Milori Blue | An iron blue pigment. |
| Mineral Aggregate | Aggregate consisting essentially of inorganic nonmetallic materials. |
| Mineral Black | A natural black pigment based on graphite. |
| Mineral Dust | The portion of the fine aggregate passing the 0.075mm (No. 200) sieve. |
| Mineral Fiber Felt | A building felt with mineral wool as its principle component. |
| Mineral Fiber Tile | A pre-formed ceiling tile that is composed of mineral fiber and a binder; has good thermal properties and acoustics. |
| Mineral Filler | A finely divided mineral product at least 70 percent of which will pass a 0.075mm (No. 200) sieve; pulverized limestone is the most commonly manufactured filler, although other stone dust, hydrated lime, portland cement, and certain natural deposits of fi |
| Mineral Granules | Opaque, natural or synthetically colored aggregate commonly used to surface cap sheets, granule-surfaced sheets, and roofing shingles. |
| Mineral Insulated Cable | An electric cable insulated with a mineral sheathing. |
| Mineral Oil | An oil obtained from mineral sources as opposed to vegetable; usually petroleum or one of its distillate products. |
| Mineral Spirits | A clear distillate of petroleum, a solvent for asphaltic coatings. |
| Mineral Surfaced | Factory made roofing cap sheet or shingles covered with mineral granules. |
| Mineral Surfaced Roofings | Built-up roofing materials whose top ply consists of a granule-surfaced sheet; this is an asphalt saturated felt that is coated on one or both sides and is surfaced on the weather exposed side with mineral granules. |
| Mineral Wool | Any of various lightweight fibrous materials used in heat and sound insulation. |
| Mineral Wool Insulation | Insulation manufactured from a lightweight vitreous fibrous material. |
| Mini blind | 1" aluminum blind |
| Minimal | Very minute or slight. |
| Minimall | A small regional shopping center. |
| Minimum | (Pl. minima) The least possible or attainable amount. |
| Miniscule | Very small. |
| Minor Changes in the Work | Changes ordered by the architect that are within the intent of the contract documents and do not involve a change in the contract sum or the contract time. |
| Minus Pressure | See Negative Pressure, 2. |
| Minute | 1. A unit of measurement of angles, equal to 1/60 of a degree. 2. A unit of time, equal to 1/60 of an hour 3. Extremely small or tiny. |
| Mirror | Polished surface that forms images by reflection of light rays, usually fabricated of glass with silver coating on reverse side. |
| Mirror Frame | Shop fabricated or field applied perimeter trim to contain mirror and protect and conceal edges of glass, usually constructed of metal or wood. |
| Mirror, Plate | Plate Mirror. |
| Miscellaneous ACM | Interior asbestos-containing building material on structural components, structural members or fixtures, such as floor and ceiling tiles; does not include surfacing material or thermal system insulation. |
| Miscellaneous Taxes Payable | Estimated taxes incurred during an accounting period and owed to local and State agencies. |
| Miscibility | Capability of being mixed or made homogeneous. |
| Misconduct | Wrongful conduct. |
| Misses | In painting, holidays; skips; voids. |
| Mist-Coat | Thin tack coat; thin adhesive coat. |
| Mistake | A legal doctrine under which formation of a contract may be prevented if a party entered into the contract under a material mistake of fact. |
| Miter | The junction of two pieces of carpet, wood, or other material at an angle; usually 45°, to form a right angle, but may be any combination of angles. |
| Miter Box | A device for guiding a handsaw in the correct angle for making a miter joint in wood, plastic, or metal. |
| Miter joint | The joint of two pieces at an angle that bisects the joining angle. For example, the miter joint at the side and head casing at a door opening is made at a 45° angle. |
| Miter Saw | A fine toothed saw, usually with a stiffened back, for cutting miters. |
| Mix | The act or process of mixing; also mixture of materials, such as mortar or concrete. |
| Mix Design | Devising the proportioning of water, portland cement, fine and coarse aggregates, and admixtures in a concrete mix. |
| Mixer | A machine used for blending the constituents of concrete, grout, mortar, cement paste, or other mixtures. |
| Mixer Efficiency | In concrete making, the adequacy of a mixer in rendering a homogeneous product within a stated period; homogeneity is determinable by testing for relative differences in physical properties of samples extracted from different portions of a freshly mixed b |
| Mixer, Colloidal | A mixer designed to produce colloidal grout. |
| Mixer, Horizontal Shaft | See Horizontal Shaft Mixer. |
| Mixer, Kitchen | A kitchen utensil which blends or combines food ingredients. |
| Mixer, Non-Tilting | A horizontally rotating drum mixer that charges, mixes, and discharges without tilting. |
| Mixer, Pan | See Mixer, Vertical Shaft. |
| Mixer, Plant | An operating installation of equipment including batchers and mixers as required for batching or for batching and mixing concrete materials; also called mixing plant when equipment is included. |
| Mixer, Tilting | A rotating drum mixer that discharges by tilting the drum about a fixed or movable horizontal axis at right angles to the drum axis; the drum axis may be horizontal or inclined while charging and mixing. |
| Mixer, Vertical Shaft | A cylindrical or annular mixing compartment having an essentially level floor and containing one or more vertical rotating shafts to which blades or paddles are attached; the mixing compartment may be stationary or rotate about a vertical axis. |
| Mixing Chamber | That part of a gas-welding or oxygen-cutting torch wherein the gases are mixed prior to combustion. |
| Mixing Cycle | The time taken for a complete cycle in a batch mixer. |
| Mixing Faucet | Separate faucets having a common spout providing control of the water temperature. |
| Mixing Speed | Rotation rate of a mixer drum or of the paddles in an open-top, pan, or trough mixer, when mixing a batch; expressed in revolutions per minute, or in peripheral feet per minute of a point on the circumference at maximum diameter. |
| Mixing Time | The period during which the constituents of a batch of concrete are mixed by a mixer; for a stationary mixer, time is given in minutes from the completion of mixer charging until the beginning of discharge. |
| Mixing Valve | A valve that permits mixing of liquids or a liquid and a gas. |
| Mixing Water | The water in freshly mixed sand-cement grout, mortar, or concrete, exclusive of any previously absorbed by the aggregate. |
| Mixing, Open-Top | A truck-mounted mixer consisting of a trough or a segment of a cylindrical mixing compartment within which paddles or blades rotate about the horizontal axis of the trough. |
| Mixture | The assembled, blended, co-mingled ingredients of mortar, concrete, or the like; or the proportions for their assembly. |
| MLA | Metal Lath Steel Framing Division of National Association of Architectural Metal Manufacturers. |
| Mnemonic | 1. Tending to assist memory. 2. Markings on fabricated parts to assist in assembling or installing in the right place. |
| Mobility | The degree to which a material flows. |
| Mobilization | 1. The act of putting into movement or circulation. 2. The assembly and movement of equipment to a jobsite. |
| Modacrylics | Modified acrylics; see Acrylics. |
| Modal Analysis | Determination of earthquake design forces based upon the theoretical response of a structure in its several modes of vibration to excitation. |
| Mode | 1. A manner of style or fashion. 2. A way of doing something. 3. The most frequent value in a set of data. 4. The slope of the vibration curve |
| Model | The original from which a mould or copy is made. |
| Modem | A device that connects a computer to the telephone system. |
| Modification | An agreed change to the terms of a contract. |
| Modified Bitumen | Bituminous membranes modified with styrene butadiene or atactic polypropylene to improve flexibility, elasticity, cohesive strength, resistance to flow and toughness. |
| Modified Mercalli | Modification of the original Mercalli Scale to represent construction materials and methods in the United States compared to the European construction methods and materials of the original Mercalli Scale. |
| Modular | Of or consisting of modules. |
| Modular Dimensional Standards | Dimensional standards approved by the American Standards Association for all building material and equipment, based upon a common unit of measure of four inches, known as the module; this module is used as a basis for the grid which is essential for dimen |
| Modular Masonry Unit | One whose nominal dimensions are based on the four inch module. |
| Modular Ratio | The ratio of modulus of elasticity of steel (Es) to that of concrete (Ec) usually denoted by the symbol n. |
| Modulating | Type of device or control which tends to adjust by increments (minute changes) rather than by either full on or full off operation. |
| Modulating Refrigeration System | Refrigerating system of variable capacity. |
| Module | A standardized part or independent unit used in construction. |
| Modulus of Deformation | A concept of modulus of elasticity expressed as a function of two time variables; strain in loaded concrete as a function of the age at which the load is initially applied and of the length of time the load is sustained. |
| Modulus of Elasticity | The ratio of the unit stress in a material to the corresponding unit strain; the ratio of normal stress to corresponding strain for tensile or compressive stresses below the proportional limit of the material; referred to as elastic modulus of elasticity, |
| Modulus of Rigidity | The ratio of unit shearing stress to the corresponding unit shearing strain; referred to as shear modulus and modulus of elasticity in shear; denoted by the symbol G. |
| Modulus of Rupture | A measure of the ultimate load-carrying capacity of a beam and sometimes referred to as rupture modulus, or rupture strength; it is calculated for apparent tensile stress in the extreme fiber of a transverse test specimen under the load which produces rup |
| Modulus of Subgrade Reaction | Ratio of load per unit area of horizontal surface (of a mass of soil) to corresponding settlement of the surface. |
| Mogul Base | A screw-in style base for an incandescent lamp of generally 300 watts or more. |
| Moir | Sometimes called watered silk. It is finished with a process that gives the fabric a wavy effect. Used for light upholstery, walling and cushions. |
| Moist Air Curing | Curing with moist air at atmospheric pressure and a temperature of about 70° F. |
| Moist Cure | See Cure, 4. |
| Moist Room | A room in which the atmosphere is maintained at a selected temperature (usually 23.0° C ±1.7° C or 73.4° F ±3.0° F) and a relative humidity of at least 98 percent, for the purpose of curing and storing cementitious test specimens; the facilities must be s |
| Moisture | Finely divided particles of water; vapor. |
| Moisture Barrier | A membrane used to prevent the migration of liquid water through a floor or wall. |
| Moisture Content | 1. The amount of water in a substance; in wood, it is usually expressed as a percentage of the weight of the ovendry wood. |
| Moisture Content of Wood | The amount of water contained in the wood, usually expressed as a percentage of the weight of ovendry wood. |
| Moisture Expansion | An increase in dimension or bulk volume of a ceramic article caused by reaction with water or water vapor; this reaction may occur in time at atmospheric temperature and pressure, but is expedited by exposure of the article to water or water vapor at elev |
| Moisture Indicator | Instrument used to measure moisture content of a refrigerant. |
| Moisture Meter | An instrument that measures electrical resistance in a material and equates it to the amount of ambient moisture content; often used by painters to judge the suitability of plaster, masonry, or other surface for the application of paint. |
| Moisture Movement | The movement of moisture through a porous medium; the effects of such movement on efflorescence and volume change in hardened cement paste, mortar, concrete, or rock. |
| Moisture Protection | The act or process of retarding the seepage of moisture. |
| Moisture Vapor Transmission (MVT) | Moisture vapor transmission rate through a membrane. |
| Moisture, Absorbed | See Absorbed Moisture. |
| Mold | A divider containing a cavity into which neat cement, mortar, or concrete test specimens are cast; a form used in the fabrication of precast mortar or concrete units (e.g., masonry units); also spelled mould. |
| Mold Oil | A mineral oil that is applied to the interior surface of a clean mold, before casting concrete or mortar therein, to facilitate removal of the mold after the concrete or mortar has hardened. |
| Mold, Casting | See Casting Mold. |
| Mold, Running | See Running Mold. |
| Molded Plywood | Plywood made to some desired shape other than perfectly flat; often this shaping is done at the time the layers are glued together; two ways of molding plywood are by applying fluid pressure and with curved forms. |
| Molding | A strip of wood, metal or plastic trim, used to conceal joints or provide decoration; also spelled moulding. |
| Molding Plaster | A fast-setting gypsum plaster used for the manufacture of cast ornaments. |
| Molding, Base | See Base Molding. |
| Molding, Bed | See Bed Molding. |
| Molding, Lip | See Lip Molding. |
| Molding, Picture | See Picture Molding. |
| Molding, Rake | See Rake Molding. |
| Mole Run | A meandering ridge in a roof membrane not associated with insulation or deck joints. |
| Molecule | The smallest fundamental unit of a chemical compound that can take part in a chemical reaction; a group of atoms that are linked together. |
| Molliers Diagram | Graph of refrigerant pressure, heat, and temperature properties. |
| Molybdenum | A metallic element that resembles chromium and tungsten in many properties, used in strengthening and hardening steel. |
| Moment | A measure of the tendency to produce rotational motion, equal to the result of multiplying a the magnitude of a force) by its perpendicular distance from a particular axis or point; Bending Moment. |
| Moment Connection | A connection between two structural members that is resistant to rotation between the members, as differentiated from a pin connection, which allows rotation. |
| Moment Diagram | A graphical method of representing the value of the bending moment at any point along a beam. |
| Moment Distribution | A method of structural analysis for continuous beams and rigid frames whereby successive converging corrections are made to an assumed set of moments until the desired precision is obtained; also known as the Hardy Cross method. |
| Moment of Inertia | The summation of the products obtained by multiplying each individual unit of area by the square of its distance to an axis. |
| Moment Resisting Frame | A structural frame composed of rigid joints in which the members and joints resist both vertical and horizontal forces. |
| Moment, Negative | See Negative Moment. |
| Moment, Positive | See Positive Moment |
| Momentum | 1. The quantity of motion of a moving body, measured as a product of its mass and velocity. The impetus gained by movement. |
| Monaco 1" miniblind | 6 gauge aluminum miniblind made by Levolor |
| Monastery | A house for persons under religious vows. |
| Monel Metal | An alloy of nickel with copper, aluminum, and iron that is resistant to corrosive liquids. |
| Monitor | A structure raised above the general roof level to provide vertical windows for light and air. |
| Monitor Cabinet | A cabinet whose doors have louvered panels to allow for ventilation, light, or finish design. |
| Monkey Wrench | An adjustable wrench. |
| Mono Pitch Truss | A truss which would develop a shed type roof. |
| Monochlorodifluoromethane | Popular low temperature refrigerant, Freon 12 or R-22, with a boiling point of –41° F. at atmospheric pressure; cylinder color code is green. |
| Monochromatic | Having or consisting of one color or hue. |
| Monochromatic Harmony | Color harmony formed by using shades and tints of a single color. |
| Monochrome Decoration | A single color decoration. |
| Monocoque | A type of construction in which the outer skin carries all or a major part of the stresses. |
| Monocottura | A single-fired tile manufactured by a process which allows the simultaneous firing of the clay with the glaze producing a finished tile with a single firing. |
| Monolith | A body of plain or reinforced concrete cast or erected as a single integral mass or structure. |
| Monolithic Concrete | Concrete cast with no joints other than construction joints or as one piece; generally, the term is used on larger structures. |
| Monolithic Construction | Constructed as one piece. |
| Monolithic Tank | One-piece shell structure. |
| Monolithic Terrazzo | The application of a 5/8 inch (15 mm) terrazzo topping directly to a specially prepared concrete substrata, eliminating an underbed. |
| Monolithic Topping | On concrete flatwork; a higher quality, more serviceable topping course placed promptly after the base course has lost all slump and bleeding water. |
| Monomer | 1. A chemical compound that can undergo polymerization. 2. An organic liquid, of relatively low molecular weight, that creates a solid polymer by reacting with itself or other compounds of low molecular weight or both. |
| Monomolecular | Composed of single molecules; substances that are one molecule thick. |
| Monomolecular Film | Films that are one molecule thick; used over bleeding water at the surface of freshly placed concrete or mortar as a curing agent, as it is a means of reducing the rate of evaporation. |
| Monopost | Adjustable metal column used to support a beam or bearing point. Normally 11 gauge or Schedule 40 metal, and determined by the structural engineer. |
| Month-to Month Tenancy | A lease of real property, written or oral, that provides for rent to be paid monthly, for no stated term, and would require 30 days notice by either party to terminate. |
| Montmorillonite | See Montmorillonoid. |
| Montmorillonoid | A group of clay minerals, including montmorillonite, characterized by a sheet-like internal molecular structure; consisting of extremely finely-divided hydrous aluminum or magnesium silicates that swell on wetting, and shrink on drying. |
| Monumental | 1. Of or relating to a monument. 2. Extremely great; massive; outstanding. |
| Mop and Flop | An application procedure in which roofing elements, such as insulation boards, felt plies, and cap sheets, are initially placed upside down adjacent to their ultimate locations, are coated with adhesive, and are then turned over and applied to the substra |
| Mop Basin | A floor set service sink; also called a Mop Receptor. |
| Mop Receptor | See Mop Basin. |
| Mop Sink | A deep well plumbing fixture with a faucet and a drain used for collecting and dispensing water for mopping and other janitorial purposes. |
| Mopping | 1. A layer of hot pitch or asphalt between plies of roofing felt. 2. Swabbing, as with roofing asphalt. |
| Moratorium | A legally authorized or prohibited suspension of contractual obligations, such as debt repayment. |
| Moresque | Multicolored yarn made by twisting together two or more strands of different shades or colors. |
| Morphology | The study of the forms of things. |
| Mortar | 1. A mixture of cement, sand and water; when used in masonry construction, the mixture may contain masonry cement, or standard portland cement with lime or other admixtures which may produce greater degrees of plasticity and/or durability. 2. A plaster mi |
| Mortar | A mixture of cement (or lime) with sand and water used in masonry work. |
| Mortar Board | A square shaped board, about 3 feet square, that is used to receive the mortar on a scaffold, for the use of the mason; also called Mud Board. |
| Mortar Bond | The adhesion of mortar to masonry units. |
| Mortar Box | The box used to mix mortar. |
| Mortar Hoe | The mortar hoe is used for hand-mixing mortar, usually with a perforated blade and a handle about 66 inches in length. |
| Mortar Mix | The amount of each material specified, portland cement, fine aggregate, admixture, and water. |
| Mortar Mixer | A mechanical device for the mixing of mortar; most are driven by gasoline combustion engines; electrically driven mixers are used when small batches of mortar are needed. |
| Mortar Pumping Machine | The mortar pumping machine is used with the mortar mixer; mixed mortar is poured into the hopper, and a pneumatic gun forces the mortar through a hose; the mortar can be delivered through the hose to masons and tilesetters working high above street level; |
| Mortgage | A lien against real estate that secures payment of a debt. |
| Mortgage broker | A broker who represents numerous lenders and helps consumers find affordable mortgages; the broker charges a fee only if the consumer finds a loan. |
| Mortgage company | A company that borrows money from a bank, lends it to consumers to buy homes, then sells the loans to investors. |
| Mortgage deed | Legal document establishing a loan on property. |
| Mortgage loan | A contract in which the borrower's property is pledged as collateral. It is repaid in installments. The mortgagor (buyer) promises to repay principal and interest, keep the home insured, pay all taxes and keep the property in good condition. |
| Mortgage Origination Fee | A charge for work involved in preparing and servicing a mortgage application (usually one percent of the loan amount). |
| Mortgagee | The lender who makes the mortgage loan. |
| Mortgagor | The borrower under a mortgage. |
| Mortise | A slot cut into a board, plank, or timber, usually edgewise, to receive the tenon (or tongue) of another board, plank, or timber to form a joint. |
| Mortise Lockset | A lockset assembly with the mechanism installed in a mortised pocket within the door and frame. |
| Mortise-and-Tenon | A joint in which a tongue-like protrusion (tenon) on the end of one piece is tightly fitted into a rectangular slot (mortise) in the side of the other piece. |
| Mortuary | A building in which human remains are kept until cremation or burial. |
| Mosaic | 1. Tile with small inlaid pieces of porcelain or natural clay materials to form decorative patterns. 2. Small tile or bits of tile, stone, or glass used to form a surface design or an intricate pattern. |
| Moss, Peat | See Peat Moss. |
| Motel | A roadside hotel providing lodging and automobile parking. |
| Motion | Application to a judge or arbitrator for an order or ruling. |
| Motor | 1. A machine, electrical or internal combustion, supplying motive power for a vehicle or some other device. 2. Rotating machine that transforms fluid or electric energy into a mechanical motion. |
| Motor Burnout | Condition in which the insulation of an electric motor has deteriorated by overheating. |
| Motor Control | Device to start or stop a motor or hermetic motor compressor at certain temperature or pressure conditions. |
| Motor Control Switches | Any type of switching device which is used in a motor. |
| Motor Grader | A self-propelled machine for earth grading. |
| Motor Starter | High-capacity electric switches usually operated by electromagnets. |
| Motor Stator | Stationary part of an electric motor. |
| Motor, Capacitor | See Capacitor Motor. |
| Motor, Four Pole | See Four Pole Motor. |
| Motor, Two-Pole | See Two-Pole Motor. |
| Motor-Generator Set | A portable gasoline motor combined with an electrical generator. |
| Mottling | Speckling; a non-uniform paint color. |
| Mould | See Mold |
| Moulding | See Molding. |
| Mounted Tile | Tile assembled into units or sheets by suitable material to facilitate handling and installation; tile may be face-mounted, back-mounted or edge-mounted; face-mounted tile assemblies may have paper or other suitable material applied to the face of each ti |
| Movable Louver | An element for ventilation with equally spaced slats of wood or metal that can be opened or closed. |
| Movable Partition | A dividing wall that can be moved and arranged to form different walled spaces. |
| Moving, Shrub | See Shrub Moving. |
| Moving, Tree | See Tree Moving. |
| MPT | Male pipe thread. |
| MSDS | Material Safety Data Sheet. |
| MSHA | Mine Safety and Health Administration. |
| MSS | Manufacturers Standardization Society of the Valve Fittings Industry, Inc. |
| MSS Point | Minimum Stable Signal Point; the best superheat setting which will provide constant, or little change in temperature, at the thermostatic expansion valve temperature sensing element while the system is running. |
| Muck | 1. Mud rich in humus. 2. Finely blasted rock, particularly from underground. |
| Mud | 1. A slang term for mortar. 2. A slang term for gypsumboard joint compound products. 3. Any soil containing enough water to make it soft. 4. In rotary drilling, a mixture of water with fine drill cuttings and added material which is pumped through the dri |
| Mud Board | See Mortar Board. |
| Mud Cracks | The cracks that develop in an emulsion coating that has been applied too thickly. |
| Mud Jacking | Raising a sunken concrete slab by pumping a slurry under the slab through a hole in the slab. |
| Mud Pan | A hand-held container for holding a small quantity of gypsumboard joint compound products; usually the size of a bread pan. |
| Mudsill | Bottom horizontal member of an exterior wall frame which rests on top a foundation, sometimes called sill plate. Also sole plate, bottom member of interior wall frame. |
| Muffler, Compressor | Sound absorber chamber in refrigeration system; used to reduce sound of gas pulsations. |
| Mulch | A mixture, as of leaves and compost, that covers or is mixed with the earth, often to help enrich the soil; bark, crushed stone or other material used to cover planting beds, retain moisture, reduce weeds, and improve appearance. |
| Mullion | A vertical or horizontal bar between adjacent window or door units; the member between the openings of a window frame to accommodate two or more windows. |
| Mullion Heater | Electrical heating element mounted in a door or window mullion; used to keep mullion from sweating or frosting. |
| Mullite | A rare mineral of theoretical composition, a relatively stable phase in ceramics produced by the high temperature reaction of alumina and silica or by the thermal decomposition of alumina-silica minerals such as kyanite, sillimanite, andalusite, and vario |
| Mullite, Porcelain | See Porcelain Mullite. |
| Multi-Color Spraying | Spraying a surface with two or more different colors at one time from one gun. The multiple colors exist separately within the material and when sprayed create an interlacing color network with each color retaining its individuality. |
| Multi-Family Dwelling | A dwelling that will accommodate two or more families. |
| Multi-Layer | Two or more layers of gypsum board used in an assembly. |
| Multi-Level | A carpeting texture or design created by different heights of tufts, either cut or uncut loop. |
| Multi-Outlet Assembly | A type of surface or flush electrical raceway designed to hold conductors and attachment plug receptacles, assembled in the field or at the factory. |
| Multi-Unit Wall | A wall composed of two or more wythes of masonry. |
| Multi-Zone Air Handling System | A system providing conditioned air similar to a single-zone system; the temperature and flow of the air supplying each zone is controlled separately; a constant supply of air is supplied to the various zones. |
| Multiple Chemical Sensitivity | A condition in which a person is considered to be sensitive to a number of chemicals at very low concentrations. |
| Multiple Listing | A cooperative sales tool among brokers whereby they share their listings and, in the event of a sale, the listing broker and the selling broker share the commission. |
| Multiple Stage Compressor | See Compressor, Multiple Stage. |
| Multiple System | Refrigerating mechanism in which several evaporators are connected to one condensing unit. |
| Multiport Valve | 1. Filter control valve changing direction of water flow. 2. A valve for various pool filter operations, which combines in one unit the function of two or more single direct flow valves. |
| Muntin | 1. A small vertical or horizontal bar between small lights of glass in a sash. 2. The vertical member between two panels of the same piece of panel work. |
| Muntz Metal | An alloy of copper and zinc that contains 60 percent of copper, can be rolled hot, and is used for sheathing and bolts. |
| Mural | 1. A painting executed directly on a wall or ceiling. 2. Of a wall. 3. Tile installed in a precise area of a wall or floor to provide a decorative design or picture. 4. Glass or marble mosaic tile (tesserae) made to form a picture or design. 5. Ceramic ti |
| Muriatic Acid | Dilute hydrochloric acid (30% HCL), commercial grade, commonly used for cleaning mortar and grout stains from masonry surfaces. |
| Murphy Bed | A bed that may be folded or swung into a closet. |
| Murphy's Law | An observation that anything that can go wrong will go wrong. |
| Museum | A building used for storing and exhibiting objects of historical, scientific, or cultural interest. |
| Mushroom | The unacceptable occurrence when the top of a caisson concrete pier spreads out and hardens to become wider than the foundation wall thickness. |
| Mushroom Capital | A flaring conical head on a concrete column. |
| muslin | Lightweight gauze made from cotton. Sheer and crisp, it can be patterned with floral motifs. It is inexpensive but tends to shrink and crease. |
| muslin lawn | A crisper and more finely woven version of cheesecloth. It makes excellent translucent curtains. |
| Mutual Assent | An objective manifestation by parties that they intend to be bound by a contract. |
| Mutuality | The concept that a contract, to be enforceable at all, must be enforceable by both parties. |
| MW | Moderate Weather; see Grade MW Brick. |
| Mylar | Plastic sheeting used as a drafting medium by drafters. |