National Bureau of Standards.
NCMA. National Concrete Masonry Asociation.
NEAT CEMENT. A pure cement undiluted by sand.
NFPA. National Fire Protection Association
NICKED BIT FINISH. A stone surface with parallel raised projections of various sizes and spacing, formed by an irregularly notched planar blade.
NIDGING (or NIGGING). A method of dressing stone, usually hard, by hand, using a pick or pointed hammer to furrow the entire surface.
NOMINAL DIMENSION. A commercial dimension greater than an actual masonry dimension usually by the thickness of a mortar joint.
NONCOMBUSTIBLE. A material which, in the form in which it is used, is either one of the following; 1. Material of which no part will ignite and burn when subjected to fire. Any material conforming to Standard No. 4-1 UBC. shall be considered noncombustible. 2. Material having a structural base of noncombustible material with a surfacing material not over 1/B inch thick which has a flame-spread rating of 50 or less. "Noncombustible" does not apply to surface finish materials. Material required to be noncombustible for reduced clearances to flues, heating appliances or other sources of high temperature shall refer to noncombustible material.
NONCORRODING. Applies to metals resistant to harmful oxidation or other corrosive actions because of its chemical composition (e.g., stainless steel, bronze, or copper).
NONSTAINING MORTAR. A mortar with low free-alkali content to avoid efflorescence to staining of adjacent stones by migration of soluble materials.



A concrete masonry unit that is not rectangular. Usually used as a corner block to maintain the masonry pattern on the exposed face of a single-wythe wall whose thickness is less than half the length of the unit.
ONYX. A banded, varicolored form of quartz.
Rock consisting mainly of calcite and made up largely or in considerable part of oolites or granular particles that may be tiny fossils or fossil fragments having oolitic coatings.
OPEN SLATING. Pattern for installing slate shingles, with spaces between adjacent slates in a course, providing ventilation if hung on open battens and reducing the amount of slate required. Spaces are covered by higher and lower courses. Also called space slating.
ORNAMENTAL FACING. Masonry design as to produce a decorative effect.
OVERHAND WORK. Laying brick from inside a wall.




Residue from terrazzo grindings.
Material such as brick, block, or stone that is stacked on wooden platforms to permit mechanized handling.
PANEL. Panelized masonry, see prefabricated masonry.
PANEL WALL. A non-loadbearing exterior masonry wall having bearing support at each story.
PARAPET WALL. That part of any wall entirely above the roof line. (UBC)
PARGETING (PARGING). The process of applying a coat of cement mortar to masonry.
PARQUETRY. A flat pattern assembled of closely fitted pieces, usually geometrical. Many patterns consist of two or more colors or materials.
PASSIVE SOLAR SYSTEM. A solar system in which the building structure itself collects and stores directly the sun's energy and distributes the resulting heat by natural means.
PARTITION. An interior wall one story or less in height.
PATCH. Compound used to fill natural voids or to replace chips and broken corners or edges in brick or in fabricated pieces of cut stone. Applied in plastic form. Mixed or selected to match the base material in color and texture.
PAVER. 1. A paving stone, brick, or quarry tile. 2. A paving stone more than six inches square.
PAVING STONE. A block or chunk of stone shaped or selected by shape for surfacing a yard or traffic surface.
PCA. Portland Cement Assocation.
1.Wall built of pebbles in mortar. 2. Wall faced with pebbles embedded, at random or in pattern, in a mortar coating on the exposed surface.
PEDIMENT. The triangular face of a gable, if separated by an entablature or molding from the lower wall and treated as a decorative unit. By extension, a triangular surface used ornamentally over doors or windows.
PERPEND STONE. A variety of bond stone that extends completely through a masonry wall and is exposed on both wall faces. A through stone.
PERPEYN WALL. Wall built in the interior of a building and at a right angle to an enclosing wall, forming divisions like stalls, as in church buildings.
PHENOCRYST. A course crystal in the fine-grained matrix of the igneous rock called porphyry.
PERMEABILITY. Property of allowing passage of fluids.
PICKED FINISH. A stone surface covered with small pits produced by a pick or chisel pint striking the face perpendicularly.
PICK AND DIP. A method of laying brick whereby the bricklayer simultaneously picks up a brick with one hand and, with the other hand, enough mortar on a trowel to lay the brick. Sometimes called the Eastern or New England method.
PIER. An isolated column of masonry.
PIERCED WALL. A masonry wall in which an ornamental pierced effect is achieved by alternating rectangular or shaped blocks with open spaces.
PILASTER. A wall portion projecting from either or both wall faces and serving as a vertical column and/or beam.
PITCHED STONE. Rough-faced stone that has had each edge of the exposed face pitched. It is cut at a very low bevel, nearly in the plane of the face, in a straight line to form a defined arris at each mortar joint.
Tracery designs, usually simple and geometrical, cut through a thin slab of stone.
PLINTH. 1. A square or rectangular base for a column, pilaster, or door framing. 2. A monumental base, many of which are ornamented with moldings, base reliefs, or inscriptions, to support a statue or memorial. 3. The base courses of a building collectively, if so treated as to give the appearance of a plattorm.
PLUCKED FINISH. Surface on stone produced by setting a planer blade so deep that it removes stone by spalling rather than by shaving.
PLUMB BOB. A shaped metal weight that is suspended from the lower end of a line to determine the vertical.
PLUMB RULE. A narrow board with parallel edges having a straight line drawn through the middle and a string attached at the upper end of the line for determining a vertical plane. Modern masons call their levels a plumb rule.
POINTING. Troweling mortar into a joint after masonry units are laid. See also tuckpointing.
POSITION. (of brick) Indicates final position in the wall.
PREFABRICATED MASONRY. Masonry construction fabricated in a location other than its final inservice location in the structure. Also known as preassembled, and panelized masonry.
PRESSURE-RELIEVING JOINT. An open joint left at stated horizontal intervals to allow for expansion and contraction, commonly below horizontal supporting elements. Such joints are sealed with flexible caulking to prevent moisture penetration. (Expansion joint.)
PRISM. A small masonry assemblage made with masonry units and mortar. Primarily used to predict the strength of full scale masonry members. ASTM E447.
PROJECTION. A stone, brick, or block that has intentionally been set forward, at one end or throughout, of the general wall surface to appear more rugged, rustic, or to create a pattern.

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