Plaster Flashcards
A composition of gypsum or lime, water, sand and sometimes hair or other fiber, applied in a pasty form to the surfaces of walls or ceiling in a plastic state and allowed to harden and dry.
Plaster

A basecoat plaster made of calcined gypsum mixed with sand, water, and various additives to control its setting and working qualities.
Gypsum Plaster

Gypsum heated to drive off most of its chemically combined water.
Calcine gypsum

Calcined gypsum in white, powdery form, containing no additives to control the set, used as a base for gypsum plaster, as an additive in lime plaster, and as a material for making ornamental casts.
Plaster of Paris
A soft mineral, hydrated calcium sulfate, used as a retarder in portland cement and in the making of gypsum plaster.
Gypsum
A finely granular form of pure gypsum, often white and translucent, used for ornamental objects and work.
Alabaster

A mixture of lime, sand and sometimes a fiber, used as a basecoat plaster.
Lime plaster

The addition of portland cement to lime plaster to improve its strength and durability.
Cement Temper
Plaster work applied in three successive coats, a scratch coat followed by a brown coat and a finish coat.
Three-coat plaster
Plasterwork applied in two coats, a basecoat followed by a finish coat.
Two-coat plaster
The final coat of plaster, serving either as a finished surface or as a base for decoration.
Finish Coat
A thin levelling or finish coat of plaster.
Skim Coat
A roughly finished, levelling coat of plaster, either the second coat in three-coat plaster or the base coat in two-coat plaster applied over gypsum lath or masonry.
Brown Coat, Floating coat
Any plaster coat applied before the finish coat.
Basecoat
The first coat in three-coat plaster, which is scratched to provide better bond for the second brown coat.
Scratch coat
A basecoat of neat gypsum plaster.
Hardwall
A gypsum basecoat plaster having no admixture except hair or other fiber, used for on-the-job mixing with aggregates.
Neat Plaster
A mill-mixed gypsum basecoat plaster containing coarse cellulose fibers for greater bulk, strength, and fire resistance, used neat or mixed with sand to obtain a basecoat of superior hardness.
Wood-fibered plaster
A gypsum basecoat plaster containing a small amount of lime and chemical additives to improve the bond of succeeding coats to dense, nonporous surfaces.
Bond plaster
A gypsum basecoat plaster containing perlite as an aggregate to reduce its weight and increase its thermal and fire resistance.
Gypsum-perlite plaster
A gypsum basecoat plaster containing vermiculite as an aggregate to reduce its weight and increase its thermal and fire resistance.
Gypsum-vermiculite plaster
Plaster that is formulated and dry-mixed by the manufacturer, requiring only the addition ofwater at the job site.
Ready-mixed plaster
A finish coat in plastering, consisting of lime putty to which gauging plaster is added to control the setting time and counteract shrinkage.
Gauged Plaster
A specially ground gypsum plaster for mixing with lime putty, formulated to provide either a quick-set or a slow-set for finish coat of plaster.
Gauging Plaster
A finish coat of lime putty and Keene’s cement or gauging plaster, troweled to a smooth, dense finish.
Hard Finish
Quicklime slaked with sufficient water to form a thick paste.
Lime putty, plasterer’s putty
Trademark for a brand of white anhydrous gypsum plaster that produces an exceptionally strong, dense, crack-resistant finish.
Keene’s cement
Havign all water of crystallization removed.
Anhydrous
A finish coat of lime putty and white gauging plaster, troweled to a smooth, dense finish.
White Coat
A ready-mixed gypsum plaster applied as a very thin, one- or two-coat finish over a veneer base.
Veneer plaster, thin-coat plaster
A low-density plaster containing vermuculite or other porous material to enhance its ability to absorb sound.
Acoustical Plaster
A coarse plaster composed of portland or masonry cement, sand and hyrated lime, mixed with water and applied in a plastic state to form a hard covering for exterior walls.
Stucco

Stucco made with masonry ement or with portland cement mixed with less than 50% by volume of lime.
Portland cement Stucco
Portland cement stucco to which lime is added in an amount greater than 50% by volume to improve the plasticity of the mix.
Portland Cement-lime stucco
A stucco used in ancient times, made from powdered marble and lime mortar and often polished.
Albarium

The first coat of plaster on a masonry wall.
Rendering Coat, Rough Coat
A wet, rich mix of portland cement and sand thrown onto a smooth brick or concrete surface and allowed to harden to provide a key for a first coat of plaster.
Spatter Dash
A grooving or roughness applied to a surface to improve its bond with another surface.
Key
A finish coat of plaster made with white marble dust to receive a fresco.
Intonaco

Plasterwork imitating granite or marble.
Scagliola
A textured finish coat of plaster containing sand, leveled and smoothed with a float.
Sand-float finish

A fine-textured stucco finish produced by smoothing with a carpet or rubber-faced float.
Float Finish

A stucco finish produced by dragging a serrated tool across the stucco surface before it sets.
Combed Finish, Dragged Finish

A stucco finish produced by trowelling the high spots of a dashed stucco surface before it sets.
Dash-troweled Finish

A stucco finish produced by troweling the high spots of a stippled stucco surface before it sets.
Stipple-troweled finish

A plaster used in ornamental work, consisting of finely ground gypsum and hydrated lime.
Molding Plaster
A sheet-metal template cut to the desired profile, backed with wood and pushed along between temporary grounds or rules to form a plaster molding along the angle between a wall and ceiling.
Running Mold, Horsed Mold
The wooden support for the sheet-metal template of a running mold.
Horse
Fine ornamental plasterwork, esp exterior plasterwork bearing designs in low relief.
Pargetting, Parget

The process of giving a wall a rough finish by throwing plaster against it.
Daubing

An exterior wall finish produced by throwing and pressing small pebbles into unset stucco.
Pebble Dash

An exterior wall finish composed of a stucco mixed with fine pebbles and dashed against a wall.
Roughcast, spatter dash

Any of a number of suitable surfaces for receiving plasterwork, such as gypsum lath, metal lath, wood lath, masonry or brickwork.
Lath

A thin, narrow strip of wood used with other strips to form latticework, a backing for plaster or stucco, or a support for slates or other roofing material.
Wood Lath

The attching of wood strips or metal channels to a wall or other surface, so as to provide as even base for lath or a finish material, or to provide an air space between a wall and a finish material.
Furring
The adhesion of plaster to its base produced by mechanical or chemical means.
Plaster Bond
The physical keying of a plaster coat to a plaster base or with another plaster coat roughened by scoring.
Mechanical Bond
A chemical substance applied to a suitable substrate to improves its bond with a succeeding layer.
Bonding Agent
The absorption of water from a finish coat of plaster by the basecoat or gypsum lath, resulting in a better bond.
Suction
A strip of wood or a metal bead used at an opening as a uide for plastering to a given thickness and as a stop for the plaster work.
Ground
A strip of wood, plaster or metal applied to a surface to be plastered to serve as a guide for making a strue surface and plastering to a given thickness.
Screed
A preformed metal screed for separating a plastered surface from another material along the base of a wall.
Base Screed
A perforated metal screed for venting a concealed space behind a plastered surface.
Vented Screed

A preformed metal screed applied over jointsin a gypsum lath to control cracking.
Expansion Screed
A preformed metal strip installed to relieve shrinkage, temperature or structural stresses within a large plastered or stuccoed area.
Control Joint
A preformed metal strip having two expanded or perforated flanges and variously shaped projecting noses, used as a ground and to strengthen and protect an external angle in plasterwork or a gypsum board surface.
Corner Bead, Angle Bead
A corner bead having a rounded angle.
Bullnose corner bead
A flexible corner bead for forming and reinforcing the curved portion of an arched opening.
Arch corner Bead
A preformed metal strip having an expanded or perforated flange and variously shaped ends, used as a ground and to strengthen and reinforce the edges of plasterwork or a gypsum board surface.
Casing Bead

A plaster base fabricated of expanded metal or of wire fabric, painted or galvanized for corrosion resistance.
Metal lath

Metah lath fabricated by slitting and expanding a sheet of steel alloy to form a stiff network with diamond-shaped openings.
Expanded-metal lath

An expanded-metal lath having v-shaped ribs to provide greater stiffness and permit wider spacing of the supporting framing members.
Rib lath

A rib lath used over steel joists as formwork for concrete slabs, or as lathing in a solid plaster partitions.
Self-centering lath
Expanded-metal, welded-wire or woven-wire lath that is dimpled to space itself from the supporting surface, creating a space for the keying of plaster or stucco.
Self-furring lath

Welded- or woven-wire fabric, usually with a paper backing, used as a base for plaster or stucco.
Wire Lath

Expanded-metal or wire lath having a backing of perforated or building paper, used as a base for plaster or stucco.
Paper-backed lath

A strip of expanded-metal lath bent to form a 90d angle, used at an internal corner to prevent cracks in plastering.
Corner Lath, Corner reinforcement

A narrow strip of expanded-metal lath for reinforcing joints in gypsum lath or junctures between different types of plaster bases.
Strip Lath

Coarse cotton, fiberglass, or metal mesh, used for bridging and reinforcing a joint or as a base for plastering or painting.
Scrim

Gypsum board having a nair=entrained core faced with absorbent paper, used as a base for plaster.
Gypsum Lath, Rock lath

Gypsum lath punched with small holes to provide a mechanical key for plaster.
Perforated Gypsum Lath

Gypsum lath having an aluminum foil backing that serves as a vapor retarder and reflective thermal insulator.
Insulating gypsum lath
Gypsum lath having a special paper facing for receiving veneer plaster.
Veneer Base
Any of various sheet materials used in covering a wall or ceiling as a substitute for plaster or panelling.
Wallboard
A sheet material having a gypsum core faced with paper on each side, used for covering walls or as lath.
Gypsum board, drywall, plasterboard
Trademark for a brand of gypsum board.
Sheetrock

Types of Gypsum Board joint profile
Square Edge
Tapered Edge
Beveled Edge
Rounded Edge
Tongue and Groove
A gypsum board having a core containing additives for increased fire resistance.
Type-X Gypsum Board
An inexpensive gypsum board used as the base layer in a multilayer assembly for increased rigidity, sound insulation and fire resistance.
Backing Board
A gypsum board 1-in (25.4)mm thick, used as a base in solid gypsum-board partitions and for lining shafts.
Coreboard
A gypsum board having a decorative vinyl or printed paper surface.
Prefinished Gypsum Board
A pasty compound for embedding joint type, filling indentations and finishing the joints in a gypsum-board surface.
Joint Compound
A strip of paper, paper-faced cotton, or plastic mesh used with joint compound to cover the joints between sheets of gypsum board.
Joint Tape
Gypsum board having an aluminum foil backing that serves as a vapor retarder and as a reflective thermal insulator when the foil faces a 3/4” minimum air space.
Foil-backed gypsum board

A gypsum board having a fire-resistant core and faced with a water-repellent paper, used as exterior sheathing.
Gypsum Sheathing