Architectural and Engineering Glossary



A passage for ventilation between thermal insulation and roof boards.


Abbr.for “American Institute of Steel Construction.”


Abbr.for “American Iron and Steel Institute.”


In southern Spain,an ornament in brick walls,formed of patterns,a half brick deep,more or less complicated.


On drawings,abbr.for aluminum.


1.An alcove or small room opening off the atrium of an ancient Roman house.2.A small room on each side of a cella.


Fine-grained,translucent variety of very pure gypsum,generally white or delicately shaded.


A shaded public walk or promenade.

Alarm System

An electrical system that is installed in a building as a protective measure against fire or unauthorized entry.In the event that the system is activated,an alarm (such as an audible signal or flashing light) is turned on;see fire alarm system and burglar alarm system.

Alarm Valve

See wet alarm valve.


1.A piazza,corridor,or covered walk.2.The flank of a building.

Albani Stone

A pepper colored stone used in buildings in ancient Rome before the introduction of marble.


A white lime used for stucco;made by burning marble.


Same as aluminum bronze.


In ancient Roman architecture,a space on the surface of a wall covered with white plaster,located in a public place,on which public announcements and records,etc.were written.


A Moorish or Spanish fortress or castle. 


A metal product clad with an aluminum or aluminumalloy coating,usually as a protection against corrosion.


A small recessed space,opening directly into a larger room.


In ancient Roman architecture,a room used by bathers for anointing themselves.


A principal constituent of portland cement clinker;primarily tricalcium silicate,but includes small amounts of magnesium oxide,aluminum oxide,ferric oxide,and other oxides.


Same as live.


Any of the various chemically active bases such as the soluble salts of metals,e.g.the water-soluble salts of sodium and potassium which occur in constituents of concrete and mortar that may result in deleterious expansion. 

Alkali Reactivity

Of a concrete aggregate,its susceptibility to alkali aggregate reaction.

Alkali Resistance

1.The degree to which a paint resists reaction with alkaline materials such as lime,cement,plaster,soap,etc.a necessary property for paints in bathrooms,kitchens,laundries.2.The degree to which a porcelain enamel will resist attack by aqueous alkaline solutions.

Alkali Soil

A soil,with salts injurious to plant life,having a pH value of 8.5 or higher.

Alkali-silica Reaction

In portland cement,the reaction between the alkalies and particular siliceous rocks and/or minerals which are present in some aggregates;may result in abnormal expansion and cracking of concrete under service conditions.

Alkaline Soil

Soil containing soluble salts of magnesium,sodium,or the like,and having a pH value of between7.3 and 8.5.

Alkyd Paint

A paint using an alkyd resin as the vehicle for the pigment.

Alkyd Resin

One of a group of thermoplastic synthetic resins;used in bonding materials,in adhesives,and in paints and varnishes.


A broad walk,planted with trees on either side,usually at least twice as high as the width of the walk.


A part of a wall which is thinner than the rest,esp.the spandrel under a window.


A figurative representation in which the meaning is conveyed symbolically.

Allen Head

A screw having a hexagonally shaped recess in its head.

Allen Wrench

A wrench for Allen head screws;a steel bar,hexagonal in shape,which is bent to form a right angle.


1.A service way providing a secondary public means of access to abutting properties;a narrow passageway between or behind buildings,sometimes permitting traffic for only one lane of cars.2.A garden walk between rows of trees;an allée.

Allowable Pile Load

The allowable concentrically applied load which is permitted along the central axis of a pile.

Allowable Soil Pressure

See allowable bearing value.


See ambry.


The oxide of aluminum;an important constituent of the clays used in brick,tile,and refractories.

Aluminum Brass

Brass to which aluminum has been added to increase its corrosion resistance.

Aluminum Bronze

A copper-aluminum alloy,usually with 3 to 11% aluminum;may contain additional additives;has good corrosion resistance and may be cast or coldworked.

Aluminum Primer

An aluminum-based primer,1 that has excellent water resistant properties.

Anchor Beam

In a typical Dutch barn in colonial America,a massive horizontal timber that spans the barn from one gable end to the opposite end.

Anchor Block

A block of wood,replacing a brick in a wall to provide a nailing or fastening surface.

Anchor Bolt,foundation Bolt,hold Down Bolt

1.A steel bolt usually fixed in a building structure with its threaded portion projecting;used to secure frameworks,timbers,machinery bases,etc.2.See brick anchor.

Anchor Cable

A cable or line,one end of which is held in a fixed position.

Anchor Dart

See anchor.

Anchor Fastener

A mechanical  device (such as a bolt or spike) used to secure a timber or wood framework.

Anchor Iron

Same as beam anchor.

Anchor Line

Same as anchor cable.