Architectural and Engineering Glossary

N

Network

1.An aggregate of interconnected electric conductors consisting of high voltage feeders,step-down transformers,protective devices,mains,and services.2.In CPM terminology,the same as arrow diagram.

Neutral Axis

An imaginary line in a beam,shaft,or other member,subjected to bending,where there is no tension or compression and where no deformation takes place.

Neutral Surface, Neutral Plane

An imaginary surface within a beam,subjected to bending,where there is neither compression nor elongation.

Neutralizing

The treatment of concrete,cement,or plaster with solutions of weak acid salts to neutralize the lime before painting.

No Slump Concrete

Freshly mixed concrete with a slump of less than 1⁄4 inch (6 mm).

Node

1.In electric wiring,a junction point at which several distribution or wiring conductors come together.2.A panel point.

Nominal Dimension

1.In masonry,a dimension greater (by the thickness of a mortar joint) than the dimensions of the actual masonry unit;in the United States,not exceeding 1⁄2 inch (13 mm).2.In lumber,a dimension that may vary from the actual dimensions as provided for in the local building code.

Nominal Mix

The proportions of the constituents of a proposed concrete mixture.

Nominal Size

The dimensions of sawn lumber before it is dried or surfaced.Also see dressed size.

Nominal Strength

The strength of a structural member calculated in accordance with provisions and assumptions of the strength design method of the applicable code,before the application of any strength reduction factors.

Non Restrictive Specification

A building specification that does not restrict the purchase of a product to a specific manufacturer or to the purchase of a material from a specific supplier.

Non-air-entrained Concrete

Concrete in which neither an air-entraining admixture nor an air-entraining cement has been used.

Non-sag Sealant

A compound that exhibits little or no flow when applied in vertical or inverted joints.

Non-vision Glass

Same as obscure glass.

Nonagitating Unit

A container for carrying concrete from a central location,where it is mixed,to the job site;the unit does not agitate the concrete enroute to the work.

Nonautomatic Sprinkler System

A sprinkler system in which all pipes and sprinkler heads are maintained dry and which is supplied with water through a fire department siamese connection.

Noncohesive Soil

A soil such as gravel or sand in which the particles do not stick together,as opposed to a sticky clay or claylike silt.

Noncollusion Affidavit

A notarized statement by a bidder that he has prepared his bid without collusion of any kind.

Noncombustibility

That property of a material which enables it to withstand high temperature without ignition.

Nonconcordant Tendons Tendons,

in a statistically indeterminate structure,which are not coincident with the pressure line caused by the tendons.

Nonconcurrent Forces

Forces that do not have a common point of intersection.

Nonconcurrent Loads

Two or more elements of live or dead loads that,for design purposes,are considered not to act simultaneously.

Nonconforming

Said of any building or structure which does not comply with the requirements set forth in applicable code,rules,or regulations.

Nonconforming Work

Work that does not fulfill the requirements of the contract documents.

Noncoplanar Forces

Forces that do not lie in a single plane.

Nonprestressed Reinforcement

In prestressed concrete construction,reinforcing steel which is not subjected to prestressing or posttensioning.

Nonpublic Fixture

A plumbing fixture intended for the use of a family or an individual (for example,a W.C. in a residence or apartment or a private toilet in a hotel or motel room).

Nonrenewable Fuse

A fuse in an electric circuit which must be replaced after it has interrupted the circuit by melting.

Nonreturn Valve

A combination check valve and globe valve used at the discharge of a high pressure boiler.

Nonvitreous Tile

Ceramic tile having a degree of vitrification evidenced by a water absorption greater than 3%;an exception is nonvitreous floor and wall tile,which has a water absorption above 7% but less than 18%.

Nonvolatile

In a paint film,that portion which remains after the water,solvents,and diluents have evaporated.

Nook

An alcove opening off a room to provide additional or more intimate space,sometimes at a fireplace or adjoining a kitchen for dining.

Nook Shaft

A column or colonnette set in a square break,as at the angle of a building, or where the jamb of a doorway meets the external face of a wall.

Nook Window

A window in an inglenook. 

NOP

 Abbr.for “not otherwise provided for.” 

Noraghe

Same as nuraghe.

Normal Aggregate

A concrete aggregate of more or less usual weight,in contrast to aggregate using lightweight concrete.

North Side

The left side of an altar of a church,as one faces the altar.

Norway Spruce

See spruce.

Nose

See nosing.

Nose Key

Same as foxtail wedge.

Nosing Line,nose Line

The slope of a stair determined by a line connecting the lead edge or nosing of the stair treads.

Nosing Strip

In stair construction,a molding which has the same profile as the nosing on the stair treads.

Nosing,nose

The prominent,usually rounded,horizontal edge which extends beyond an upright face below;as the projection of a tread beyond a riser.

Notch Joist

A joist having one end notched to fit over a wood girder which supports it; the lower edge of the joist is supported by a ledger.

Notch Ornament

See notched molding.

Notched Lap

See notching.

Notched Molding,notch Ornament

An ornament produced by notching the edges of a band or fillet.

Notched Rafter

A rafter having a notch on the underside near its lower end;this enables it to be fitted over,and fastened to,a horizontal timber supporting the rafter.

Notching

Joining of timbers,usually meeting or crossing at right angles,by cutting a notch in one or both pieces.