Architectural and Engineering Glossary



A Pratt truss.


In the lumber industry, abbr. for “nosed one edge.”


Abbr. for “National Association of Architectural Metal Manufacturers.”


The strike plate of a door lock.


A straight, small, rigid, slender shaft of metal, one end of which is usually pointed; the other end has a head that may be driven with a hammer; used as a fastener to join separate pieces of wood, to attach tiles to a wood sheathing on a roof, and so on. Nails were hand wrought until the invention of machines for their manufacture in the early 19th century. See cut nail, dog nail, hand wrought nail, wire nail, wrought nail.

Nail Claw

A tapered steel bar having a curved  end which is slotted; generally used to pull nails from materials, such as wood, into which they had been driven. Also called a claw bar, nail bar, nail puller, pinch bar, pry bar, ripping bar, wrecking bar.

Nail Gun

 A compressed-air device for driving nails.

Nail Plate

A metal plate which is placed over the two ends of pieces of wood that are to be joined (in the same plane); it is secured to each end by screws or nails driven into the wood through holes in the plate.

Nail Puller

Same as nail claw.

Nail Punch

Same as nail set.    

Nail Set

A short steel rod, usually tapered; used to drive a nail or brad below, or flush with, a wood surface.

Nail Shank

The main body of a nail; the shaft between the head of the nail at one end and the point of the nail at the other end.

Nailable Concrete

Concrete into which nails can be driven; usually made with a suitable light weight aggregate, with or  without the addition of sawdust.


1.An ornament, often highly deco- rated, resembling the head of a nail. 2.The enlarged top of a nail.

Nailhead Molding

A molding decorated with  a series of quadrangular pyramidal projections resembling the heads of nails.


In roofing, the process of fixing roofing materials to the substrate. In exposed  nailing, the nails are left exposed to the weather. In concealed nailing, the nails are protected by  the next sheet of roofing material.

Nailing Anchor

See wood stud anchor.

Nailing Block

 A wood brick.

Nailing Ground

A ground to which trim can be nailed.

Nailing Joist

A steel joist which has a nailing strip permanently attached to it.

Nailing Marker

A small mark cut into one member to position a nail for correct entry into a second wood member.

Nailing Strip

A wood strip, attached to a surface; used as a base for nailing or fastening another material

Naked Flooring

The timber or framework on which floor boarding is laid.

Naked Wall

A wall with lath in place, ready for plastering.


A unit of length used to express wavelengths of light in and near the visible spectrum; 1 nanometer equals 109 meter or 10 angstroms.Abbr.nm.


The relatively short fuzzy ends of fibers forming the surface of the carpet.


A distillate of petroleum or coal; generally has low solvency and high volatility; used as a solvent in paints and varnishes.


A drier used in paints; made with naphthenic acid and lead, cobalt, calcium, or manganese salt.

Napkin Pattern

Same as linenfold.

Naples Yellow, Antimony Yellow

A light yellow pigment; the true pigment is a basic antimonate of lead, but is imitated by mixtures.

Narrow Side

Of a door, the face of a door which contacts the doorframe stops.

Narrow-light Door

A door having a narrow rectangular fixed light, usually placed in a vertical position near the lock stile.

Narrow-ringed, Close-grained

close grown, fine grained, slow grown Descriptive of wood having narrow annual rings.


An enclosed porch or vestibule at the entrance to some early Christian churches.NAT On drawings, abbr. for “natural.”


1.A swimming pool. 2.A building containing a swimming pool.

National Building Code

See BOCA National Building Code and Uniform Building Code.

National Electrical Code

A nationally accepted guide to the safe installation of wiring and equipment; not intended as a design specification but rather for the practical safeguarding of persons and of buildings and their contents from hazards arising from the use of electricity for heat,light, power, and other purposes. Provides rules, recommended by the National Fire Protection Association, governing the installation of interior electric wiring.These rules, subject to revision every three years, a standard of the National Board of Fire Underwriters, have been incorporated in many municipal ordinances; city or state regulations take precedence where they differ from the rules of the Code.

National Electrical Manufacturers Association.

A trade association of electrical manufacturers setting standards of construction quality and dimensional uniformity.

National Electrical Safety Code (NESC)

Rules, prepared by the NESC and approved by ANSI,which govern: (a) methods of grounding;(b) installation and maintenance of electric supply stations and equipment,of overhead supply and communication lines,and of under ground and electric supply and communications lines;and (c) operation of electric supply and communication lines and equipment.

National Fire Protection Association

An organization devoted to all aspects of fire safety.

National Register Of Historic Places

A US government organization that maintains lists and files of documentation of buildings,structures,objects,districts,and sites of national,state,or local significance.Buildings on the Register may be marked with plaques that provide historical information about  them.Also called the National Register. Address:National Park Service,US Department of the Interior,P.O. Box 37127, Washington, DC 20013-7127.

National Style

A term sometimes used as a synonym for Greek Revival style during the height of its popularity,from about 1830 to 1850.

National Trust For Historic Preservation

A national,nonprofit private organization chartered by the US Congress to encourage public participation in the preservation of buildings,objects,and sites that have been significant in American history.Address:1785 Massachusetts Avenue,NW,Washington, DC 20036.


A basket weave,as a pattern carved or painted to imitate interlaced withes,2 of matting.natural asphalt Asphalt occurring in nature, produced from petroleum by natural evaporation or distillation;usually not suitable for paving purposes until refined and softened to proper consistency by combining with flux oil.

Natural Bed

Of a stone, a plane parallel to its natural strata.

Natural Cement

A product obtained by finely pulverizing calcined argillaceous limestone which has been burnt at a temperature no higher than necessary to drive off carbon dioxide.

Natural Circulation

The circulation of air or water due to differences in density rather than to the actions of a pump or blower.

Natural Clay Tile

A ceramic tile made from clays that produce a dense body, having a distinctive, slightly textured appearance.

Natural Cleft Finish

The finish of metamor phic rock (such as slate or quartzite) resulting from cleaving it along its bedding plane.

Natural Convection

The convection resulting from the flow of air caused by temperature differences in an enclosed space, as opposed to the flow of air caused by a fan.Also known as free convection.