COSC 254

A level surface of concrete that lies directly on the ground. Used for roads, sidewalks, patios, runways, and basements or ground floors of buildings. Usually experiences little structural steps except a direct transmission of compression between in superimposed loads and the ground beneath.

Slab on grade

Reduce the passage of sound through the partition itself.

Sound attenuation blankets

Applied over galvanized metal lath, using accessories of galvanized steel, or in wet ares or exterior applications, of solid zinc, or plastic, which are less prone to corrosion.

Stucco

the finishing process is based on the use of __ that resembles a smooth, sticky plaster.

joint compound

Distribute the weight of the masons sufficiently that he or she can kneel on the surface of the concrete without making indentions.

knee boards

What size board is Type X board is produced by some manufactures. It is used to create 2-hour partitions with a single layer of gypsum board on each face and 4-hour partitions that include two layers on each face?

3/4 inch

Weather-Resistant, used for exterior soffits, carport ceiling, undersides of exterior applications.

Exterior gypsum soffit board

Correspond to the degrees of flatness and levelness required, and are produced using special finishing equipment and techniques.

F-numbers

Step performed immediately after striking off the concrete, usually performed by hand, using flat-surfaced tools, typically 4 to 10 feet in length called bull floats or darbies. These are drawn across the concrete to flatten the surface.

Floating

Can be used to eliminate the need for a separate vapor retarder in exterior wall assemblies. If the back of the board faces a dead airspace at least 3/4 inch thick, it can also act as a thermal radiant barrier.

Foil-backed gypsum board

Make very durable partitions, especially in areas with heavy wear, moisture problems, or strict sanitation requirements. Nonfading and virtually indestructible.

Glazed structural clay tiles

What helps protect the slab against cracking caused by concrete shrinkage during curing, temperature stresses, concentrated loads, frost heaving, or settlement of the ground beneath.

Grid of wire or bars (WWF or Rebar)

A prefabricate plaster sheet material that is manufactured in width of 4 feet and lengths of 8 to 14 feet.

Gypsum board

Which type of plaster has more sculptural potential that any other material due to its fine grain and even texture?

Gypsum plaster

What are some other names for gypsum board?

Gypsum wallboard, plasterboard, and drywall.

Formed by casting full-depth preformed joint materials, typically 3/8 to 3/4 inch width, into the slab, complete separating the slab from adjacent elements.

Isolation joints/expansion joints

Similar to dry-set mortar, but with additives that improve the cured mortar's freeze-thaw resistance, flexibility, and adhesion.

Latex/polymer modified portland cement mortar

Gypsum board is the __ of all interior finishing materials for walls and ceilings.

Least expensive

What level of finish consists of the minimum, just the boards, without taping, finishing, or accessories. It is usually used only for temporary construction or where finishing is postponed until a later date?

Level 0

Various proprietary synthetic polymer adhesives used for light-duty applications.

Organic adhesives

Control joints should be arranges in __ directions such that they create panels roughly in square proportion.

Perpendicular

Covered with pain, printed paper, or decorative plastic film during is manufacture. If handled carefully and installed with small nails, it requires no further finishing. Used in a number of demountable office partitioning systems.

Redecorated gypsum board.

Edge profile useful in pred-ecorated panels

Round and beveled

Used to make linear ornaments such as classic cornice moldings.

Running plaster ornament

Formed with "dimples" that hold the lath away form the surface of the wall a fraction of an inch to allow the stucco to key to the lath, is attached with nails or screws.

Self-furring metal lath

Cure rapidly by chemical reaction are used to minimize the waiting time between application. Used in some high production commercial work.

Setting compounds

Can completely nullify drying shrinkage, allowing the casting of large slabs on grade that are entirely free of contraction joints.

Shrinkage Compensating cements

Why are metal trim accessories required at exposed edges and external corners?

To protect the brittle board and present a neat edge

Edge profile that serve to join core board panels in concealed locations.

Tongue-and-groove

Propriety, fire-resistant alternative to Type X board. Often, a thinner board of Type __ may be submitted for a thick one of Type X.

Type C gypsum board

Required for most fire-rated assemblies. Core is reinforced with short glass fibers. When exposed to fire, the fibers hold the gypsum in place to continue to act as a barrier to fire rather than permitting it to erode or fall out.

Type X gypsum board

The least least expensive of the gypsum plaster systems and is competitive in price with gypsum board finishes in many regions.

Veneer plaster

Used in locations exposed to moderate amounts of moisture, with facings of water-repellant paper or glass matt and moisture-resistant core formulation is used.

Water-resistant gypsum backing board

Can a two-coat application of veneer paster be directly applied to surface of site cast concrete or concrete masonry wall?

Yes

In freshly placed concrete, water that rises to the top surface of the ocncrete as the solid cement and aggregate particles settle. Watery sheen on the surface of concrete.

bleed water

a nonslip surface, a stiff-bristled janitor's pushbroom may be drawn across the surface of the slab after troweling to produce a striated textureish

broom finish

What is the core of gypsum board formulated of?

calcined gypsum, starch, water, regenerated foam to reduce the density of the mixture, and various additives.

Invisible moisture barrier membrane over the slab surface.

curing compound

What are the most common compounds used to bond tile to the backer board?

dry-set mortar, latex/polymer modified portland cement mortar, and organic adhesive

Does gypsum plaster expand or shrink during hardening? What about Stucco?

gypsum plaster expands while stuck shrinks

Control joint spacing recommendations vary with the __ of the slab and the __ rate of concrete.

thickness, shrinkage

Must be done for a completely smooth, dense surface. Done immediately after the second floating, either by had, using a smooth, rectangular steel trowel, or with a rotary power trowel.

troweled.

What size board is largely used in double-layer wall finishes. Though less durable than panels, it may also sometimes be applied as a single-layer finish over ceiling joist or wall studs spaced no more than 16 inches apart?

3/8 inch

When stucco is applied in two cats directly to the surface of concrete or concrete masonry, what is the total thickness in inches?

3/8 to 1/2 inch

Gypsum board partition assemblies have been designed and taste with fire resistance rating of up to __ hours and sound transmission performance of up to at least STC __.

4, 69

What size board is made for manufacturing housing, where weight reduction to facilitate shipping is an important consideration?

5/16 inch

What size board is also limited to stud spacing of not more than 24 inches. It is used where addition fire resistance, stiffness, durability, or sound deadening is required?

5/8 inch

Then stuccos is applied in three coats over metal lath, what is the total thickness in inches?

7/8 inch

How long must tuck be kept moist for before it is allowed to dry in order to attain maximum hardness and strength through full hydration of its portland cement binder?

A week

Standard for most gypsum board product types.

ASTM C1396

What is the standard for veneer plaster?

ASTM C587

What is the standard for gypsum board finish levels? Who developed them?

ASTM C840 by Gypsum Association

Provides greater resistance to indentation and penetration and is installed where it is likely to so be subject to rough usage. It may be manufactured with heavier facing paper and bacon sheets, have its core reinforced with cellulose fiver, by faced with glass fiber mesh, or be backed with polycarbonate oil.

Abuse resistant or impact resistant gypsum board

Can be used as reinforcement for cast plaster ornament. These greatly increase its strength and toughness and allow it to be produced in thinner sections and larger pieces than unreinforced plaster.

Alkali-resistant glass

How are control joints made?

By either running a special trowel along a straightedge while the concrete is still plastic or by sawing partially through the concrete shortly after it begins to harden using a diamond or abrasive saw blade in a power circular saw.

How can nail popping be minimized?

By using fully dried framing lumber, ring shank nails that have extra gripping power in the wood, and the shortest nail that will do the job.

Layer of 1 1/2-inch-diamete crushed stone at least 4 inches deep that is compacted over the subsoil. Acts as a drainage layer to keep moisture away form the underside of the slab.

Capillary break

Made by pouring soupy plaster into molds. Hardens in a few minutes, allowing the mold to be stripped and reused.

Cast plaster

Sag-resistant, 1/2 inch thick, substantially lighter than, but just as resistant to sagging as 5/8 inch panels.

Ceiling gypsum board

Often added to wall for reason of appearance, durability, sanitation, or moisture resistance.

Ceramic tile facings

Stucco walls are therefore provided with __ at regular intervals to channel the shrinkage into predetermined lines rather than allowing it to occur randomly.

Control joints

Intentionally weekend sections created through the concrete slab where the tensile forces caused by the concrete dying shrinkage are relieved.

Control joints/contraction joints

A 1-inch thick panel that is used for shaft walls and solid gypsum board partitions. to facilitate handling, it is fabricated in sheets 24 inches wide.

Coreboard

Occurs when the top of the slab loses moisture more rapidly than the bottom,.

Curling (wrapping)

Under what conditions should the slab be cured and for how long?

Damp conditions for at least a week

Use concealed mechanical fasteners that can be disassembled and reassembled easily without damage to the panels.

Demountable partition systems

A mix of cement, fine sand, and water retention compounds that allow the thin mortar layer to cure properly.

Dry-set mortar

A mixture of marble dust, binder, and admixtures, furnished either as a dry power to be mixed with water or as a premixed paste.

Drying-type joint

Control joints extend at least __ the depth of the slab.

1/4

What size board is used as gypsum backing board in certain sound control applications. Boards of this thickness may also be used for tight-radius bend?

1/4 inch

What size board is made as scoreboard, for use in shaft wall construction?

1 inch

3 stresses that cause cracking originate from what?

1. Shrinkage as the concrete cures 2. Thermal expansion and contraction 3. Differential movement between the slab and abutting building elements.

What size board is the most commonly used thickness. It may be applied to studs and joists spaced up to 24 inches?

1/2 inch

For normal concrete slabs 4 to 8 inches thick, what should recommended range of joint spacing?

11 feet 6 inches to 17 feet 6 inches with thinner slabs requiring closer joint spacing than thicker ones

What level of finish requires only that joins be covered with tape set in joint compound. Its primary use is in areas of the building that are not open to view, such as above ceilings, in attics, and in service corridors. Also the minimum finish level for fire-resistance-rated gypsum board assemblies, in which application may also be referred to as fire taping?

Level 1

Level of finish that adds to level 1 finish a coat of joint compound over the accessories and fasteners. After joint tape is set in compound, these joints are also immediately wiped with a join knife a second time to add a thin coat of compound over the tape. Appropriate in garages, warehouses, and storage areas, and for boards used as a backer for ceramic tile.

Level 2

Finish level that adds a full second coat of compound over tape, accessories, and fasteners after the first coat has dried. It is intended for surfaces that will be texted or cover with heavy wall coverings.

Level 3

Finish level that is designed for surfaces to be finished with flat paints light textures, or thin wall covering. It adds a third distinct coat of joint compound over takes seams, fasteners, and accessories.

Level 4

Finish level that adds a very thin skim coat of join compound over the entire surface of the board. The skim coat has no measurable thickness, because its purpose is only to fill pores and low spots in the wall to produce a very smooth surface. it is recommended for surfaces that will receive gloss or semigloss pains and for surfaces that will be lit in such a was as to cast shadow that can highlight even sigh imperfections.

Level 5

If no sheathing is used, the wall is laced tightly with strands of __ a few inches apart and paperbacked metal lath is attached, after which stucco is applied to encase the building in a thing layer of what amounts to reinforced concrete.

Line wire

For interior floor slabs on grade, what is laid over the cursed stone to further protect the slab from moisture in the ground?

Moisture Barrier (vapor retarder)

Combines moisture-resistant cores with chemically treated cores with chemical teated paper or glass-matt facings that are not conducive to mold growth. Alternatively, panels may be manufactured with strengthen cores that eliminate the need for facing materials of any kind.

Mold-resistant gypsum board

Do screws or nails have higher tendency to pop?

Nails

Permits sheets to be joined with a flush, invisible seam by means of subsequent joint finishing operation.

Tapered edge

Whats the most common edge profile of gypsum board?

Tapered edge

What determines the number of coats of plaster required to cover a wall?

The degree of unevenness of the masonry surface.

Why can wood studs be troublesome with gypsum?

They usually shrink somewhat after the board is installed causing the nails to loosen slightly and "pop" through the finished surface of the board.

Application in which tile is applied to a base of portland cement mortar.

Thicket or mortar bed application

Most frequently made fiver-reinforced lightweight cement or glass-matt-faced water-resistant gypsum board.

Tile backing boards/backer boards

added in showers, steam rooms, and other wet locations to prevent water from seeping through the tile and into the wall behind.

Tile waterproofing membrane

Why is a thin, tangled filament matting inserted directly behind the plaster and lath in exterior applications where stucco is exposed to wind-driven rain?

To create a drainage space and lessen the risk of water penetration further into the wall assembly.

Why is gypsum board usually installed with the long dimension of the board horizontal?

To minimize the length of joints that must be finished and to create the stiffest wall possible.

Why should plaster be dampened thoroughly in advance of plastering?

To prevent premature dehydration of the plaster.

Used wherever the unique properties of other special board types are not required.

regular gypsum board

Performed where a concrete slab must meet narrow floor flatness limits. Performed with a rectangular flat-bottomed straightedge, sought 10 feet in length, which is drawn across the concrete slab surface to remove minor undulations produced during floating or troweling.

restraightening

Sometimes sprinkled over the surface of a slab between screeding and floating operations, which reacts with the concrete to form a very hard, durable surface for heavy wear applications (warehouses)

shake on hardeners

The first operation in finishing the slab is to __ or __ the concrete by drawing a stiff plank of wood or metal across the top edges of the formwork to achieve a level concrete surface.

strike off, screed

Name of a floor where there is close control over the flatness desireds

superflat floor