Architectural and Engineering Glossary

D
Davit

A movable crane, 1 that projects over the side of a building.

Day

One division in a window, as in a large church window.

Day Gate

In a bank, an interior grille door to a safe deposit vault; used when the main vault door is open.

Daylight Factor

The ratio of the illumination at a point on a given plane to the illumination on a horizontal plane from the whole of an unobstructed sky of assumed or known luminance distribution; a measure of the daylight illumination at that point.

Daylight Glass

A bluish glass, often colored with cobalt, used with incandescent lamps to produce the effect of daylight by absorbing excess radiation in the red part of the light spectrum.

Daylight Lamp

1.Any type of lamp which produces light whose spectral distribution approximates that of a specified daylight condition. 2.See incandescent daylight lamp.

Daylight Saturation Level

Said of the condition where the illumination provided by daylight equals or exceeds the illumination provided by artificial lighting.

Daylight Width, Sight Size, Sight Width

The width of a glazed opening which admits light.

Daylighting

Lighting of the interior of a building by natural means; for example, by windows or skylights.

DB

Abbr.for decibel.

DB. Clg.

Abbr. for “double headed ceiling.”

DB(A)

A unit of sound level;a reading taken on the A scale of a sound level meter.

DBL

On drawings,abbr.for “double.”

DBT

Abbr.for dry bulb temperature.

Dc, D-c, D.c., DC

Abbr. for “direct current.”

DD

On drawings,abbr. for Dutch door.

De-bonding

In pretensioned construction,a procedure used to prevent specific tendons from becoming bonded to the concrete for a specified distance from the ends of the flexural members. 

Deactivation

The reduction or removal of the corrosive qualities of water,usually by passing the water through a deactivator while hot. 

Deactivator

A tank containing iron filings which removes active oxygen and other corrosive elements from water that passes through it.

Dead

Descriptive of electric wiring which is not connected to a source of voltage.

Dead Bolt

A type of door lock;the bolt,which is square in cross section,is operated by the doorkey or a turn piece.
 

Dead Door

Same as blank door.

Dead End

1.A length of pipe leading from a soil,waste,or vent pipe,building drain,or building sewer,which is terminated by a plug,cap,or other closed fitting;there is no circulation in this length of pipe,and no waste from a plumbing fixture is fed into it. 2.The point of fastening in a running rope system where the other end is fastened to a rope drum.3.In concrete work,the end opposite that to which a load is applied.4.A portion of a corridor in which the travel to an exit is in one direction only.
 

Dead Flue

A flue that has been bricked up or otherwise sealed off.

Dead Knot

A knot that has lost its fibrous connection with the surrounding wood; it can easily loosen and fall out or be knocked out.

Dead Leaf

Same as standing leaf.

Dead Leg

Same as dead end.

Dead Level

Said of a roof surface having a declination of less than 2%.

Dead Load

1.The weight of a structure itself,including the weight of fixtures or equipment permanently attached to it.Compare with live load.2.The load imposed on a pipe located in a trench and covered by infill;depends on the depth and width of the trench,and the density and character of the infill material.

Dead Man Anchor

Same as guy anchor.

Dead Parking

Long term,unattended storage of a vehicle.

Dead Room

A room characterized by an unusually large amount of sound absorption.

Dead Sand

Sand that may be used as an underneath course for a finished layer of loose stones or gravel.

Dead Shore

An upright piece of heavy timber used as a prop or support for a dead load during structural alterations to a building,esp.one of two supports for a needle.

Dead Wall

A wall whose entire surface is unbroken by a door,window,or any other opening;a blank wall.

Dead Weight

See dead load.

Dead Window

Same as blank window.

Dead-air Space

Unventilated air space within a structure,as in a shaft,ceiling,or hollow wall. 

Dead-burnt Gypsum

See anhydrous calcium sulfate.

Dead-end Anchorage

Anchorage at the end of a tendon which is opposite the jacking end.

Dead-front

Descriptive of a piece of electric equipment so constructed that there are no parts which can be touched from the front of the assembly that are at a voltage different from that of the earth.

Dead-piled

Descriptive of lumber or panels stacked without spacers.

Dead-soft Temper

The temper of sheet copper used for roofing.

Deadening

The use of damping material.

Deadlatch

Same as night latch.

Deadlight

See fixed light.

Deadlock

1.A lock equipped with a dead bolt only.2.A lock in which a bolt is moved by means of a key or thumb turn,and is positively stopped in its projected position.

Deadman

A buried concrete block,log,plate,or the like,which serves as an anchorage,e.g.,as an anchor for a tie to a retaining wall;depends on its own weight and passive pressure from the soil to hold it in place.

Deadwood

1.Dead tree limbs or branches.2.Wood from dead trees.
 

Deal

1.(US) Pine or fir lumber cut to a specified size, usually at least 3 in. (76 mm) thick and 9 in. (229 mm) wide. 2.(Brit.) Square-sawn softwood lumber, 17⁄8  in. (47.6 mm) to 4 in. (101.6 mm) thick and 9 in. (228.6 mm) to under 11 in. (279.4 mm) wide.