Architectural and Engineering Glossary



On drawings,abbr. for head.

D-crack, D-line Crack

1.In concrete surfaces,one of many fine,closely spaced cracks;often in random patterns.2.In highway slabs,one of the fine cracks parallel to the edges,joints,and larger cracks or cutting diagonally across the corners.


Abbr. for “dressed and center matched.”


 In the lumber industry, abbr. for “dressed and headed.”


In the lumber industry, abbr. for “dressed and matched.”


Abbr. for “dressed and matched beaded.”    


Abbr.for “dressed and standard matched.”


Abbr. for “dressed one side.”


Abbr. for “dressed two sides.”


Abbr. for “dressed two sides and center matched.”


Abbr. for “dressed two sides and matched.”


Abbr. for “dressed two sides and standard matched.”


Abbr. for “dressed on four sides.”


A soft brush used to apply varnishes.

Dabbing, Daubing

Dressing a stone surface with a special pointed tool to produce a pitted appearance.


On drawings, abbr. for double-acting door.


1.The middle portion of a pedestal between the base (or the plinth) and  the  surbase (or the cornice, cap, or entablement); also called die.2.The middle part (sometimes all parts) of a protective, ornamental paneling applied to the lower walls of a room above  the
baseboard.3.A rectangular groove cut across the full width of a piece of wood to receive the

Dado Cap

A chair rail or cornice at the top of a dado.

Dado Head

 A power driven rotary cutter, usually consisting of two identical circular saws with a chipper between them; used in woodworking for cutting flat bottomed grooves.

Dado Rail

A chair rail.


A small decorated tracery motif in the form of a distorted cusped lancet, with the foot pointed; a pointed oval shaped opening in the tracery.


In Buddhist architecture, a monumental structure containing relics of Buddha or of some Buddhist saint.


A raised platform reserved for the seating of speakers or  dignitaries.


In Persian and Indian architecture, a veranda, or sometimes a more stately reception hall, more or less open to the weather, with a roof carried on columns, or the like.


A slab or large tile of stone, baked clay, etc., esp. a tile of which the surface is incised or otherwise ornamented, such as the medieval sepulchral slabs set in the pavement and walls of churches.

Dammar, Damar, Dammer, Gum Dammar

A naturally occurring resin; useful in paints and varnishes because of its light color.

Damp Course, Damp Check, Dampproof Course

In masonry, an impervious horizontal layer of material (as tile,  dense  limestone, metal, etc.) to prevent the capillary entrance of moisture from the ground or a lower course, but used also below copings, above roof level in chimneys, and elsewhere to stop downward seepage.

Damp-proof Membrane

See membrane waterproofing.


1.A device used to vary the volume of air passing through an air outlet, inlet, or duct; it does not significantly affect the shape of the delivery pattern. 2.A pivoted cast iron plate at fireplace throat, i.e., between fireplace and  smoke chamber, to regulate draft. 3.Same as fireplace damper.


The dissipation of energy with time, e.g.,the dissipation of energy in a mechanical system whose free oscillations decrease with time, resulting in a decrease in its amplitude of vibration.

Damping Material

A viscous material applied to a vibrating surface, such as a metal panel, to reduce the noise which it radiates.


1.A treatment of concrete or mortar to retard the passage or absorption of water,or water vapor,either by applying a suitablecoating to exposed surfaces or by using a suitable admixture.2.A damp course.3.Applying a water impervious material to a surface,such as a wall,to prevent the penetration of moisture.


Colloquial term for stairs.

Danish Knot

Same as Runic knot.

Dao, Paldao

A variegated colored wood from the Philippines and New Guinea, having shades of gray, green, yellow, brown, and pink with dark streaks; moderately hard, heavy; used for cabinets, plywood, and interior finish.


A notch in a timber for receiving another timber or into which the head of a pile is fitted. 

Dapped Beam

Said of a beam (or girder) having a notch to receive another notched beam.


1.In Indian and Persian architecture,a gateway.2.In Oriental architecture,a dwelling.

Darby, Derby Slicker

1.A float tool used in plastering, either wood or metal, about 4 in. (10 cm) wide and about 42 in. (approx. 1 m) long, with two handles; used to float or level the plaster base coat prior to application of the finish coat, or to level the plaster finish coat before floating or troweling. 2.A hand manipulated straightedge usually 3 to 8 ft (1 to 2.5 m) long, used in the early stage leveling operations of concrete finishing to supplement floating.

Dash-bond Coat

A thick slurry of portland cement, sand, and water dashed on surfaces with a paddle or brush to provide a base for a subsequent plaster coat.

Dashed Finish

An exterior wall finish, obtained by throwing small pebbles against a smooth mixture of cement while it is still wet. Also see rock dash.

Date Of Agreement

The date stated on the face of the agreement.If no date is stated,it may be the date on which the agreement is actually signed,if this is recorded, or it may be the dateestablished by the award;also referred to as thecontract date.

Date Of Commencement Of The Work

The date established in a notice to proceed or, in the absence of such notice, the date of the agreement or such other date as may be established therein or by the parties thereto.

Date Of Substantial Completion

The date certified by the architect when the work,1or a designated portion thereof is sufficiently complete, in accordance with the contract documents,so the owner may occupy the work or designated portion thereof for the use for which it is intended.

Date Stone

A stone,imbedded in the walls of many old buildings,carved with the date of completion of the structure.


A level surface or point to which other levels are related; a reference in measuring elevations.

Datum Dimension

A dimension that exactly locates a reference point,reference line, or reference plane.

Datum Line

Same as reference line.


1.A material such as clay, mortar, mud, or plaster (often mixed with straw), used as infilling between logs,as a coating over walls, or as plaster in wattle and daub.2.To coat roughly with plaster or mud.


1.See dabbing.2.A rough coating of plaster given to a wall by throwing plaster against it.