Thousands shipped since 1992 - 800.793.8555

Call: +1 800-793-8555
Intl: +1 719-268-1325
Email:[email protected]



Dado – A rectangular groove across the width of a board or plank. In interior decoration, a special type of wall treatment.
Damper – Valve for controlling airflow. When ordering registers, make sure each supply outlet has a damper so the air flow can be adjusted and turned off. Dampers maybe either manually or automatically operated. Automatic dampers are required for exhaust air ducts.
Dampproofing – A process used on concrete, masonry or stone surfaces to repel water, the main purpose of which is to prevent the coated surface from absorbing rain water while still permitting moisture vapor to escape from the structure. (Moisture vapor readily penetrates coatings of this type.) “Dampproofing” generally applies to surfaces above grade; “waterproofing” generally applies to surfaces below grade.
Darby – A flat tool used to smooth concrete flatwork immediately after screeding. See Bullfloating
Dead Load – The constant, design-weight (of the roof) and any permanent fixtures attached above or below.
Decay – Disintegration of wood or other substance through the action of fungi,
Deck – An elevated platform. “Deck” is also commonly used to refer to the above-ground floors in multi-level parking garage.
Deck Paint – An enamel with a high degree of resistance to mechanical wear, designed for use on such surfaces as porch floors.
Deflect – To bend or deform under weight.
Deflection – The amount of bending movement of any part of a structural member perpendicular to the axis of the member under an applied load.
Density – The mass of substance in a unit volume. When expressed in the metric system, it is numerically equal to the specific gravity of the same substance.
Design Pressure – Specified pressure a product is designed to withstand.
Dew Point – Temperature at which vapor condenses from the atmosphere and forms water.
Dimension Lumber – Yard lumber from 2 inches to, but not including, 5 inches thick and 2 or more inches wide. Includes joists, rafters, studs, plank, and small timbers.
Direct Nailing – To nail perpendicular to the initial surface or to the junction of the pieces joined. Also termed face nailing.
Distortion – Alteration of viewed images caused by variations in glass flatness or inhomogeneous portions within the glass. An inherent characteristic of heat-treated glass.
Dolly Varden Siding – Beveled wood siding which is rabbeted on the bottom edge.
Doorjamb (interior) – The surrounding case into which and out of which a door closes and opens. It consists of two upright pieces, called side jambs, and a horizontal head jamb.
Dormer – An opening in a sloping roof, the framing of which projects out to form a vertical wall suitable for windows or other openings.
Double-Glazing – In general, any use of two lights of glass, separated by an air space, within an opening, to improve insulation against heat transfer and/or sound transmission. In insulating glass units the air between the glass sheets is thoroughly dried and the space is sealed, eliminating possible condensation and providing superior insulating properties.
Double Plate – when two layers of 2 x 4’s are placed on top of studs in framing a wall.
Double Strength – In float glass, approximately 1/8″ (3 mm.) thick.
Double Tree – Refers usually to a precast roof deck panel poured with two fins in its underside to impart flexural rigidity.
Downspout – The metal pipe used to drain water from a roof.
Drawing Outline – A top view drawing of a building or roof showing only the perimeter drawn to scale.
Drawing Detail – A top view drawing of a building or roof showing the roof perimeter and indicating the projections and roof mounted equipment, drawn to scale.
Dressed and Matched (Tongued & Grooved) – Boards or planks machined in such a matter that there is a groove on one edge and a corresponding tongue on the other.
Dressed Size Lumber – The dimension of lumber after shrinking from green dimension and after machining to size or pattern.
Drier Paint – Usually oil-soluble soaps of such metals as lead manganese, or cobalt, which, in small proportions, hasten the oxidation and hardening (drying) of the drying oils in paints.
Drip – (a) A member of a cornice or other horizontal exterior finish course that has a projection beyond the other parts for throwing off water. (b) A groove in the under. side of a sill or drip cap to cause water to drop off on the outer edge instead of drawing back and running down the face of the building.
Drip Cap – A molding placed on the exterior top side of a door or window frame to cause water to drip beyond the outside of the frame.
Drip Edge – A device designed to prevent water from running back or under an overhang.
Drippage – Bitumen material that drips through roof deck joints, or over the edge of a roof deck.
“Dropping” a Stringer – In carpentry, means cutting short on the bottom of a stairs, to allow for thickness of the first tread.
Drop Siding – Usually ¾ inch thick and 6 and 8 inches wide with tongued-and-grooved or shiplap edges. Often used as siding without sheathing in secondary buildings.
Dry Glazing – Also called compression glazing, a term used to describe various means of sealing monolithic and insulating glass in the supporting framing system with synthetic rubber and other elastomeric gasket materials.
Dry-In – To make a building waterproof.
Dry Seal – Accomplishment of weather seal between glass and sash by use of strips or gaskets of Neoprene, EPDM, silicone or other flexible material. A dry seal may not be completely watertight.
Dry Sheet – A ply mechanically attached to wood or gypsum decks to prevent asphalt or pitch from penetrating the deck and leaking into the building below.
Drywall – Sheetrock (gypsum board) that covers the framing and taping, coating, and finishing to make the interior walls and ceilings of a building. Drywall is also used as a verb to refer to installation process.
Dry-Wall Construction – A type of construction in which the interior wall finish is applied in a dry condition, generally in the form of sheet materials or wood paneling as contrasted to plaster.
Drywall Hammer – A special hammer used for nailing up gypsum board. It is also known as an ax or hatchet. Edges should be smooth and the corners rounded off. The head has a convex round & checkered head.
Drywall Nail – Nails used for hanging regular drywall that is to be taped and finished later must have adequate holding power and a head design that does not cut the face paper. They must also be of the proper depth to provide exactly 1 inch penetration into the framing member. Nails commonly used are chemically-etched and are designed with a cupped head.
Duct – A cylindrical or rectangular “tube” used to move air either from exhaust or intake, and for distributing warm air from the heating plant to rooms, or air from a conditioning device or as cold air returns. The installation is referred to as “duct work”.
Dumbwaiter – An elevator with a maximum footage of not more than 9 sq. ft. floor area; not more than 4″ headroom and a maximum capacity of 500 lbs. used for carrying materials only.
Durometer – The measurement of hardness of a material. A gauge to measure the hardness of an elastomeric material.