Architectural and Engineering Glossary

Water Theater

A terraced structure in which water flows from higher terraces to lower ones. 

Water Tower

A tower into which water is pumped to raise its level high enough above the level of a water distribution system so that the system will be supplied with adequate water pressure.

Water Valve

A device in a water distribution system to start or stop,regulate,or prevent the reversal of flow of water in a system.

Water Vapor Barrier

See vapor barrier.

Water Vapor Diffusion

 The process by which water vapor spreads or moves through permeable materials caused by differences in water vapor pressure.

Water Vapor Permeability

That property of a material which permits the passage of water vapor through it;the time rate of water vapor transmission through a unit area of flat material of unit thickness induced by a unit vapor pressure difference between two specific surfaces,under specified temperature and humidity conditions.

Water Vapor Retarder

See vapor barrier.

Water Vapor Transmission (WVT)

The rate of water vapor flow,under steady specified conditions,through a unit area of material between the two parallel surfaces (and normal to these surfaces).

Water Well

See well,4.

Water-base Paint

A paint capable of being thinned or diluted with water;for example,casein paint,latex paint,vinyl paint.

Water-cement Ratio

The ratio of the amount of water,exclusive only of that absorbed by the aggregates,to the amount of cement in a concrete or mortar mixture.

Water-checked Casement

A casement having grooves cut under the sill and meeting stile to prevent capillary movement of water.

Water-cooling Tower

A structure,usually on the roof of a building,over which water is circulated,so as to cool it evaporatively by contact with the air.

Water-gel Explosive

One of a wide variety of materials used for blasting;contains substantial proportions of water and a high proportion of ammonium nitrate,some of which is in solution in the water.

Water-hammer Arrester

A device installed in a piping system to absorb hydraulic shock waves and eliminate water hammer,1.


Said of a metal that has been quenched in water after being heated to a critical temperature.

Water-leaf Capital

Same as water leaf .

Water-level Control

A control used to maintain the water level in a boiler to reasonably close limits;use of the control makes it unnecessary to add large quantities of replacement water at any one time.

Water-reducing Admixture

1.An admixture which either (a) increases the slump of  freshly mixed concrete or mortar without increasing the water content or (b) maintains the slump with a reduced amount of water due to factors other than air entrainment.2.In concrete,an admixture which can produce a large reduction in water or flowability without an undue set retardation or entrainment of air.

Water-reducing Agent

A material which either increases workability of freshly mixed mortar or concrete without increasing its water content or maintains workability with a reduced amount of water.

Water-repellent Cement

 A hydraulic cement having a water repellent agent added during the process of manufacture.

Water-repellent Preservative

A water repellent,2 that provides moderate protection against the deterioration of wood.

Water-supply System

Of a building,the water-service pipe,the water distributing pipes,and the necessary connecting pipes,fittings,control valves,and all appurtenances in or adjacent to the building.


An obsolete term for watertable. 

Waterborne Preservative

A water soluble chemical used to treat wood for protection against decay and insects.


In a fire sprinkler system,an alarm which is actuated when the flow through the sprinkler system is in excess of a predeter-mined maximum value.


Inside a cistern,the highest water level to which the ball valve should be adjusted to shut off.


In the building trades,descriptive of any material or construction which is impervious to water.

Waterproof Paper

A water impervious paper;usually a synthetic resin has been added to the pulp or mixed with the sizing.

Waterproof Portland Cement

A portland cement interground with a water repellent material such a stearate (e.g.sodium or aluminum);reduces capillary water transmission under little or no pressure but does not completely stop water vapor transmission.


A material,usually a membrane or applied compound,used to make a surface impervious to water.


1.A dividing line between drainage areas.2 .A wash,1.3. A water table,1.4.An area from which a community or region receives its supply of water.

Watershed Dormer

Same as shed dormer.


A duct,spout,or the like,through which rainwater is discharged from a roof or gutter;for examples,see gargoyle and canale


1.Said of an enclosure or barrier that does not permit the passage of moisture.2.Said of a surface that is impermeable to water except when exposed to a hydrostatic pressure sufficient to produce structural discontinuity by rupture.


A complete system of pipelines,conduits,and so forth for distributing water from one or more reservoirs,purifying the water,and then pumping it through a distribution system for use by a community.


A unit of power;the power required to do work at the rate of 1 joule per second,which is equal to the power dissipated in an electric circuit in which a potential difference of 1 volt causes a current of 1 ampere to flow.


A unit of work equal to 3,600 joules;equivalent to the power of 1 watt operating for a period of 1 hour.

Watt-hour Meter

An electricity meter which measures and registers the active power in an electric circuit with respect to time.


A framework of interwoven rods,poles,or branches.


A primitive form of wall construction consisting of upright wood poles with branches interwoven between them (wattle) that are then covered with plaster mixed with clay and straw (daub);often used to fill the space between structural timbers of timber framed buildings in order to provide increased thermal insulation;also see jacal,2.

Wave Front

Of a sound wave,a continuous,imaginary surface which is the locus of points having the same phase at a given instant.

Wave Molding, Oundy Molding, Swelled Chamfer, Undulating Molding, Undy Molding

A molding decorated with a series of stylized representations of breaking waves.

Wave Scroll

Same as Vitruvian scroll.


For light waves or sound waves,the distance between two successive points of a periodic wave in the direction of propagation,in which the oscillation has the same phase;the distance the wave travels in one period.For light waves three common units of wavelength are:micrometer,nanometer, and angstrom.

Wavy Grain

A curly figure in wood grain,similar to fiddleback,but with more uniform ripples and waves.


A thermoplastic solid material obtained from vegetable,mineral,and animal matter;soluble in organic solvents;used in paste or liquid form as a protective coating or polish on wood and metal surfaces and as an additive in paints.


In a finished piece of marble intended for interior use,the filling of cavities with materials patterned and colored to match.


A street,alley,or other thoroughfare or easement permanently established for the passage of persons or vehicles.


Abbr.for “welded base.”