449 Questions
Which material is the most popular wall covering used in residential and commercial construction today?
Gypsum drywall
What percentage of homes being built in the United States and Canada use drywall for interior wall and ceiling coverings?
Around 90%
Where was the oldest preserved use of gypsum discovered?
Egypt
What was the material used to produce the first sheet of drywall?
Plaster of paris
Where can large gypsum deposits be found?
United States
What mineral rock is the forerunner of the present-day gypsum board made from?
Gypsum
What is the main advantage of using drywall over plaster?
Faster installation
How many coats of sanded gypsum plaster were applied to the walls of the pyramids in Cheops?
3
Which mineral is composed of calcium sulfate chemically combined with water of crystallization?
Gypsum
What percentage of the weight of gypsum rock is made up of combined water?
20%
What is the process called when gypsum is heated at 250° to 300°F to drive off the dry water?
Calcining
What does the gypsum become after the heating process is completed?
Plaster of Paris
What is the core of drywall panels made of?
Gypsum, wood, flour, starch, soap, and water
What property of gypsum makes it fire resistant?
Combined water
At what temperature is gypsum heated during the calcining process?
300°F
What is the chemical formula of gypsum?
CaSO4·2H2O
What is the fineness of the ground gypsum after it is crushed and ground?
Fine
Which material is used to sandwich the gypsum mixture in the gypsum board production process?
Specially treated paper
What is added to the core materials of drywall panels to provide fire resistance?
Fiberglass
What type of paper is used for both the front and back of water-resistant panels?
Special mildew and water-resistant paper
What type of edges do gypsum panels have when taping and finishing are to be applied?
Tapered edges
What type of edges do gypsum panels have when they are to be covered by a decorative covering with no finish applied to the joint?
Beveled edges
What type of edges do gypsum panels have when used as backing for ceiling tile or as sheathing for a wall?
Tongue and groove edges
What is the purpose of the tongue and groove edges in gypsum panels used as backing for ceiling tile or as sheathing for a wall?
To form a tight seal between the panel edges
What treatment is not required for the joints of gypsum panels with tongue and groove edges?
Sealing
What is the main advantage of using gypsum panels with beveled edges for decorative coverings with no finish applied to the joint?
The beveled edges join together to form a V-point
Which type of partition system uses panels with square edges?
Demountable partition systems
What is the main advantage of using gypsum drywall as a wall covering?
Versatility in size and type
What happens to the outer layer of gypsum in drywall when exposed to high temperatures?
It calcines and releases water as steam
Which material provides better sound damping than gypsum drywall?
Brick
What is the process called when gypsum is heated to drive off the dry water?
Calcining
What property of gypsum makes it a good insulator during a fire?
Low thermal conductivity
What is the density of gypsum compared to lighter wall materials?
Higher
What effect does the release of water as steam have on drywall during a fire?
It cools down the drywall
What is the purpose of using demountable partition systems?
To allow for easy reconfiguration
Which wall material is lighter than gypsum drywall?
Plywood
Which thickness of drywall provides an increased fire code rating and greater sound insulation?
16mm (5/8")
Which thickness of drywall offers more resistance to sag?
16mm (5/8")
In which type of construction should 16mm (5/8") thickness drywall be used?
Single-ply construction
What is the fire rating provided by Ultracode Core panels with double-layer construction?
4-hour fire rating
What is the width of coreboard panels?
61cm (24")
In which type of partition system are coreboard panels used?
Solid drywall partitions
What is the main advantage of using Ultracode Core panel systems?
Reduced labor material costs
Which thickness of drywall is used to increase the fire resistance rating in multi-ply installations?
13mm (1/2")
Which thickness of drywall is more rigid than 13mm (1/2") drywall?
16mm (5/8")
What is the fire rating provided by Ultracode Core panels with single-layer construction?
2-hour fire rating
Which material became the most popular wall covering material in nearly every community in North America after World War 2?
Drywall
What is the standard thickness of drywall panels?
5/8"
What is the recommended thickness of drywall panels for covering existing walls and ceilings without removing the original paneling or plaster?
6mm (1/4")
Which thickness of drywall panels is relatively lightweight and commonly used in mobile homes to keep weight to a minimum?
8mm (5/16")
What thickness of drywall panels is recommended for single-ply wall and ceiling construction in stationary buildings?
13mm (1/2")
What is the purpose of using 10mm (3/8") thick drywall panels in multi-layer installations?
To increase noise insulation
Which thickness of drywall panels is suitable for covering existing wall and ceiling surfaces?
10mm (3/8")
What is the width of drywall panels?
122 cm (48")
What were the first drywall panels sold as?
Lath backing for plaster
Which type of drywall panel is used for exterior applications?
Backing board
What is the width of standard drywall panels?
1.2m (4')
What is the color of the liner paper on the back of standard drywall panels?
Gray
What is the purpose of the tapered edge on standard drywall panels?
To make it easier to tape and fill the joint
What is the recommended thickness of standard drywall panels?
13mm (1/2")
What is the length of standard drywall panels commonly used?
2.4m (8')
What is the main advantage of using standard drywall panels over other types of drywall panels?
Wide variety of finishes
What are some special requirements that may necessitate the use of special drywall panels?
Increased fire resistance, water resistance, exterior applications
What is the purpose of the facing paper on standard drywall panels?
To extend over the long edges
Which type of drywall panel is marked as 'Fire-Resistant' or 'Type X' on the back?
Type X panels
What is the fire rating of the 13mm (1/2") thickness Type X panel?
45 minutes
What is the fire rating of the 16mm (5/8") thickness Type X panel?
60 minutes
What is the fire rating of the 19mm (3/4") thickness Type X panel?
120 minutes
When are the fire ratings of Type X panels achieved?
When installed in an approved system
What advantage do longer sheets of drywall offer?
Fewer joints to finish
When should standard drywall be used?
When there are no special requirements
Which drywall panel thickness is suitable for most rooms in houses or office buildings?
13mm (1/2")
What is the advantage of using standard drywall as a wall covering?
Versatility in most rooms
Which drywall panel is recommended for covering existing wall and ceiling surfaces?
16mm (5/8")
What should be considered when weighing the advantage of longer sheets of drywall?
Number of joints to finish
Which type of drywall panel has higher fire resistance than Type X and is installed in three and four hour systems?
Super fire rated panels
What is the main purpose of using Type X panels?
To provide extra protection
What is the main advantage of using foil-back panels?
They create a waterproof membrane
What happens if foil-back panels are used as a base for tile or other highly moisture-resistant coverings in hot, humid climates?
The panels will warp, sag, crumble or mildew
What is the purpose of following joint finishing procedures when using Type X panels?
To prevent fire and heat from going around between the panels
What is the main disadvantage of using drywall panels with foil backing in hot, humid climates?
They absorb and trap moisture
What is the purpose of using Type X panels instead of multiple layers of standard drywall?
To allow for the use of thinner drywall
What is the main advantage of using Type X panels instead of standard drywall panels?
They provide high fire resistance
What is the main disadvantage of using Type X panels instead of standard drywall panels?
They are not suitable for steel or wood framing
Which areas are good candidates for Water-Resistant Panels?
Kitchens and baths
What color is the facing paper on Water-Resistant Panels?
Light green
What is added to the gypsum core of Water-Resistant Panels to prevent moisture absorption?
Asphalt or silicon compounds
In what situations should fire resistant Water-Resistant Panels be used?
In areas with fire separation requirement and potential exposure to high moisture
What should be used in the taping and filling process of Water-Resistant Panels to maintain their water-resistant properties?
Water resistant joint compound
What are the available thicknesses of Water-Resistant Panels?
13mm (1/2") and 16mm (5/8")
What is the thickness of Interior Ceiling Panels?
13mm (1/2")
What is the main advantage of Interior Ceiling Panels?
Sag resistance
Should a vapor barrier be used behind Water-Resistant Panels?
No, never
Which type of drywall panel is suitable for ceilings where heavy, water-based textures will be applied and framing is 61 cm(24") on center?
Exterior Ceiling Panels
Where should exterior drywall ceiling panels be used?
On horizontal overhead surfaces
What is the width of exterior ceiling panels?
1.2m(4')
What is the thickness of the fire-code rated exterior ceiling panels?
16mm(5/8")
Where should exterior drywall sheathing panels be installed?
On vertical surfaces
What is the purpose of using exterior drywall sheathing panels?
To add fire resistance to the structure
What is the recommended method of finishing the joints of exterior ceiling panels?
Using battens
What is the length range of exterior ceiling panels?
2.7m(9') to 3.7m(12')
What type of surfaces are exterior drywall sheathing panels designed for?
Vertical surfaces
What is the main advantage of using exterior drywall sheathing panels?
Enhanced fire resistance
Which type of gypsum panel is used as the form for poured gypsum concrete roof decks?
Gypsum Formboard
What is the thickness of gypsum coreboard designed for solid gypsum partitions without framing members?
25mm (1")
What type of edges does coreboard have for use in solid partitions?
V-shaped, tongue-and-groove longitudinal edges
Which type of coreboard is recommended when putting up partitions with spaced core sections?
Square-edge coreboard
What intervals is square-edge coreboard scored at to break easily into sections?
20cm (8")
In what areas are beveled coreboard panels used with special metal studs?
Elevator shafts and stairwells
What is the recommended method of finishing the joints of exterior ceiling panels?
Leaving the joints unfinished
What is the main advantage of using gypsum panels with beveled edges for decorative coverings with no finish applied to the joint?
Enhanced aesthetic appearance
What is the purpose of leaving the formboards in place after the gypsum concrete sets up?
To serve as a ceiling surface
Which one of the following finishes is NOT suitable for covering exterior drywall sheathing?
Vinyl
What is the width of the 13mm (1/2") panels with V-shaped, tongue-and-groove edges?
61 cm (2')
What is the length range of the 1.2m (4') wide exterior sheathing panels?
2.4m to 3.7m (8' to 12')
What is the purpose of backing board gypsum in a multi-layer gypsum wall or ceiling?
To serve as the first layer
Which surface of the backing board is covered with liner paper?
Both surfaces
What is the width of the backing board?
1.2m (4')
What is the thickness of the moisture-resistant backing board?
13mm (1/2")
What must be done to the cut edges of backing board to keep it water resistant?
Sealed
Which type of gypsum board is suitable for use as structural roofing members?
Gypsum planks
What is the thickness of gypsum formboards?
25mm (1")
Which type of gypsum board is used as the base for plaster on walls and ceilings?
Gypsum lath
What is the width range of gypsum formboards?
61cm, 81cm, and 122cm (24", 32" and 48")
Which type of gypsum board is faced either with manila paper suitable for decorating or with vinyl?
Gypsum formboards
What is the length range of gypsum planks?
2.4m, 3.1m or 3.7m (8', 10' or 12')
What is the thickness of gypsum planks?
5cm (2")
What is the purpose of gypsum lath?
To provide a smooth, continuous surface for plaster
What is the core of gypsum lath made of?
Gypsum
What is the width of gypsum lath?
61cm, 81cm, and 122cm (24", 32" and 48")
Which thicknesses are available for gypsum lath?
10mm and 13mm
What is the purpose of using perforated lath in plastering?
To increase the bond between plaster and the board
What are partition blocks made of?
Gypsum and fibers
How are gypsum radiant heating panels installed in walls?
Fastened directly to the studs
What is the thickness of partition blocks used in solid gypsum partitions?
5cm to 15cm
What is the width of gypsum lath?
41cm and 61cm
What is the length of gypsum lath?
1.2m and 2.4m
How are gypsum radiant heating panels installed in suspended ceilings?
Installed in suspended ceilings
What is the height of partition blocks used in solid gypsum partitions?
30cm
What is the length of partition blocks used in solid gypsum partitions?
75cm
Which type of gypsum panel is used when you want to apply a veneer plaster coating to the surface?
Veneer base drywall
What is the thickness of the panels that come 1.2m (4') wide and are 1.2m, 2.4m, 3.7m (4', 8' or 12') long?
16mm (5/8")
What type of panels are not used for ceiling applications?
Decorated drywall panels
What is the thickness range of the veneer plaster coating applied to the veneer base drywall?
1.6mm to 2.9mm (1/16" to 3/32")
What are the panel edges of decorated drywall or vinyl-faced panels?
Tapered
What is the purpose of special moldings used with decorated drywall panels?
To cover and protect corners and panel joints
What is the main advantage of using veneer finishes on interior applications?
Durability and wear-resistance
What are the panel edges of veneer base drywall (blueboard)?
Square
What is the recommended method of installation for decorated drywall panels?
Color-matched nails
What type of gypsum panel is standard drywall covered with decorative paper or vinyl?
Vinyl-faced panels
What is the width of veneer-base drywall?
1.2m (4')
What are the thickness options for standard veneer-base drywall?
10mm (3/8''), 13mm (1/2'') and 16mm (5/8'')
What are the thickness options for Type X (fire-code rated) veneer-base drywall?
13mm (1/2'') and 16mm (5/8'')
What are the length options for veneer-base drywall?
2.4m, 3.1m, 3.7m (8, 10 and 12)
How can veneer-base drywall be installed?
Nails, screws or adhesive
What is used to reinforce the joints of veneer-base drywall?
Fiberglass tape and plaster
What is the recommended application for Cement Interior Tile Backer Board?
Ceramic wall and floor tile
What can be used to apply Cement Interior Tile Backer Board over wood or steel framing?
All of the above
What is the UL-listed application of Cement Interior Tile Backer Board?
Wall shield and floor protector
What is the purpose of leaving the formboards in place after the gypsum concrete sets up?
To maintain the shape of the concrete
Which type of gypsum panel is lighter than conventional plaster?
Veneer plaster construction
What advantage do gypsum partition systems offer over masonry assemblies?
Reduced material-handling expense
What is the main advantage of using gypsum systems over more massive constructions?
Lower installed costs
What is the purpose of using hollow-type constructions in gypsum systems?
To provide ample cavity for insulation
What advantage do gypsum systems offer in terms of material-handling costs?
They reduce material-handling expense
What type of gypsum board is considerably lighter than conventional plaster?
Veneer plaster construction
What advantage do gypsum partition systems offer in terms of structural movement?
Resistance to cracking
What advantage do gypsum systems offer in terms of thermal and sound insulation?
Ample cavity for insulation
What advantage do gypsum systems offer in terms of fixture attachment and mechanical installation?
Simplifying fixture attachment
Which material is used for taping in room heaters and stoves?
Fiberglass tape
What advantage does gypsum or cement board construction provide in terms of fire resistance?
It releases water of crystallization which helps retard the spread of flame
What type of construction meets fire resistance and flame spread requirements for all model building codes?
Gypsum construction
Which type of gypsum construction offers excellent resistance to airborne and impact sound transmission?
Gypsum construction with resilient attachment
What feature of veneer plaster finishes makes them suitable for high-traffic areas?
High-strength and abrasion-resistant
What is the maximum available fire resistance rating for gypsum construction assemblies?
4 hours
What are the requirements that gypsum construction assemblies meet for sound transmission control?
STC/MTC and IIC requirements
What is the recommended method of finishing the joints of exterior ceiling panels?
Tape and cementitious materials
What is the durability of veneer plaster finishes?
High
Which type of drywall installation requires different types of board and framing members?
Veneer plaster installation
What type of nails are commonly used for hanging regular drywall?
Annular ring nails
What is the correct depth of penetration for nails used in hanging drywall?
Exactly 25mm (1 inch)
Which type of drywall panel is used as the base for plaster on walls and ceilings?
Veneer base drywall panel
What is the main advantage of using veneer plaster systems compared to gypsum drywall?
Faster installation
What type of gypsum construction eliminates costly winter construction delays?
Gypsum drywall construction
What type of fasteners are available for different types of drywall installations?
Both nails and screws
What is the purpose of having a head design that does not cut the face paper for nails used in hanging drywall?
To prevent damage to the drywall
What is the main advantage of using gypsum panels with beveled edges for decorative coverings with no finish applied to the joint?
Reduced joint visibility
What is the main advantage of using hollow-type constructions in gypsum systems?
Reduced weight
Which tool should be used to screw in the screw by hand?
Phillips screwdriver
What should be done if screwing in the screw by hand is not successful?
Remove the screw and replace with a new one
What are drywall screws designed with?
Self drilling, self-tapping threads
What are drywall screws used to attach drywall to?
Metal framing
What advantage do drywall screws offer in terms of fasteners?
They require fewer fasteners
What is the main purpose of using screws in drywall installation?
To prevent damage to the core
What type of threads do drywall screws have?
Coarse threads
What is the recommended method of screwing in the screw?
Screwing in by hand with a screwdriver
Which type of nail is recommended for drywall installations that require taping and finishing?
Chemically-etched nail
What is the length range of chemically-etched nails available for drywall installations?
35mm (1 3/8") - 48mm (1 7/8")
Which type of nail is recommended for special applications such as installing double layers of drywall or nailing drywall that will be covered with paneling or acoustic tile?
Cement-coated cooler nail
What is the length range of cement-coated cooler nails available for special applications?
35mm (1 3/8") - 41mm (1 5/8")
What is the term used to describe the unsightly condition when fastener heads push out the finishing material on the surface of the wall and become exposed?
Nail pops
How can nail pops be corrected?
Driving the popped nail back into place with a nail set and filling the hole with fresh finishing material
What is the recommended method of correcting nail pops by driving a new nail into place?
Applying pressure to push the board against the framing member
Which type of fastener is suitable for all types of metal or wood framing?
Screws
What is the purpose of using staples in drywall installation?
To hang drywall for ceilings with stick-on acoustical tile
What is the main advantage of using adhesives for drywall installation?
To eliminate the need for nails or screws
What is the length range of drywall screws available for various combinations of board thicknesses?
22mm (7/8") to 6cm (21/2")
Which type of fastener is used for attaching metal framing members together?
Screws
What type of fastener is generally used only for the first layer of a double-layer drywall installation?
Staples
Why are staples not used for the top layer of a double-layer drywall application?
They cannot be recessed without cutting the face paper
What is the main advantage of using staples for fastening drywall to framing members in a special application?
They are fast and economical
What is the purpose of leaving the formboards in place after the gypsum concrete sets up?
To support the weight of the gypsum panels
What is the main advantage of using veneer finishes on interior applications?
To provide a smooth, finished surface
Which type of adhesive is packed in tubes like caulking compound for installing drywall panels directly on wood framing?
Contact adhesive
What precautions are necessary when using solvent-base adhesive for drywall installation?
Ensuring proper ventilation and avoiding open flames, sparks, or smoke
Which type of adhesive is designed for installing drywall on metal framing?
Solvent-base adhesive
What is the main advantage of water-base adhesive over solvent-base adhesive for drywall applications?
Water-base adhesive is less flammable
What type of adhesive requires the hanger to position the drywall panel properly before it contacts the surface being covered?
Solvent-base adhesive
What is the potential danger associated with using solvent-base adhesive for drywall installation?
Highly flammable vapors
What is the main advantage of using contact adhesive for drywall installation?
Versatility for various applications
What is the main disadvantage of using solvent-base adhesive for drywall installation?
Strong odor
What type of adhesive allows tools to be easily and quickly cleaned with water?
Water-base adhesive
Which type of adhesive is commonly used for double layer drywall installation to provide better sound control and a higher fire rating?
Contact adhesives
What type of adhesive is used when drywall is applied over an existing plastered wall in remodeling work?
Contact adhesives
What type of adhesive does not provide instant bonding and requires 24 hours to dry?
Joint compound
What is the form of joint compound that is mixed with water at the work site?
Dry powder
What type of adhesive is needed to clean tools used to apply solvent-base adhesive?
Lacquer thinner
What type of adhesive is sometimes used for laminating two sheets together in a double layer application?
Joint compound
What is the common use of contact adhesives in drywall applications?
To provide better sound control and a higher fire rating
What is the common use of joint compound in drywall applications?
To laminate two sheets together in a double layer application
What is the common use of lacquer thinner in drywall applications?
To clean tools used to apply solvent-base adhesive
Which type of bead is attached with filler?
Paper faced metal bead
What is the purpose of beads in drywall installation?
All of the above
What are the three kinds of beads most often used in the industry today?
Metal bead, paper faced metal bead, and plastic bead
Which type of adhesive is not recommended for applications where time is the major consideration or where moisture is present?
All of the above
What is the major factor in selecting the type of adhesive for drywall installation?
The type of application
What is the main advantage of using adhesive glue when attaching metal or plastic bead?
Better bond strength
What is the purpose of using beads in drywall installation?
To reinforce the corners
Which type of bead has a smooth and rounded finishing edge?
Metal bead
What are the factors that determine the type of adhesive for drywall installation?
The type of application and availability
Which type of bead is attached with fasteners or compression fitted?
Plastic bead
Which type of bead is recommended for areas where contact with the finishing edge is unlikely?
Plastic bead
What is the advantage of using paper faced metal bead over metal corner bead?
Paper faced metal bead requires less filler to achieve a finished surface
Which type of bead has a partial metal lining for rigidity?
Paper faced metal bead
What is the main advantage of using plastic bead?
All of the above
What type of bead can be applied to any wallboard surface whether there is backing or not?
Paper faced metal bead
Why is paper faced metal bead not affected by the movement of framing members?
It is bonded along the entire length
What skill is required for the application of paper faced metal bead?
Different skill
Why can't you fill paper faced metal bead immediately after application?
The filler needs time to dry
What is the main advantage of using metal bead over plastic bead?
Metal bead is more durable
Which type of bead provides better paint adhesion and can withstand bumps and knocks without chipping or edge cracking?
Paper faced metal bead
Which type of metal bead forms the most positive bond to the wallboard?
Paper faced metal bead
What is one disadvantage common to all metal beads?
They form a weak bond with the surface
What is the purpose of the holes punched in the metal bead?
To attach the bead to the wallboard
How can metal bead be attached to the surface of the wallboard?
Nailing, screwing, stapling, or clinching
What happens when the teeth of a clincher cut the flange of the metal bead?
The tangs or metal are forced into the corner of the wallboard
Where are compression fitted beads placed?
Over the rough edge of the wallboard
What is one disadvantage of the smooth, finished surface of metal bead?
It provides a weak bond with the filler
What is the material used for the paper faced metal bead?
Joint tape paper
What prevents metal bead from rusting under normal use and filling conditions?
Electro-galvanization
How are fasteners applied to metal bead to hold it in place?
Nailing, screwing, stapling, or clinching
Which type of bead is used to finish the rough edge of wallboard?
Edge trim
Which type of corner bead has a large radius that results in a round corner?
Bullnose corner bead
What is the purpose of using corner bead?
To provide support for the full width of the flange
What is the difference between narrownose and bullnose corner bead?
The size of the radius
Which type of edge trim is used to finish the rough edge of wallboard?
Edge trim
What are the two basic shapes of edge trim?
J-bead and L-bead
What is the difference between J-bead and L-bead?
The shape of the bead
What is the difference between corner bead and edge trim?
The purpose they serve
What is the difference between narrownose corner bead and bullnose corner bead?
The size of the radius
What is the purpose of edge trim?
To finish the rough edge of wallboard
Which type of bead is used to finish the rough edge of wallboard where it abuts a wood, plaster, concrete-block wall or T-bar ceiling?
L-bead
What is the purpose of using L-bead after the wallboard is in place?
To form a straight, level edge
What type of bead is used when there is no backing to nail or screw?
J-bead
What is the advantage of using J-bead around a valance or a closet opening that has slightly to provide a tight fit?
It provides compression
Which type of J-bead does not require filling and has an exposed finished edge?
Metal square-nose J-bead
What is the purpose of plastic square-nose J-bead in drywall installation?
To act as a vapor barrier between the window and the wallboard
What is the difference between metal square-nose J-bead and plastic square-nose J-bead?
Metal square-nose J-bead requires filling, while plastic square-nose J-bead does not
Which type of J-bead is used as a vapor barrier between the window and the exposed core of the wallboard?
Plastic square-nose J-bead
What precaution must be taken when applying plastic square-nose J-bead?
Ensuring it does not bend during application
Which type of bead is the best to use when a corner must be plumbed or straightened?
Veneer bead
What is the purpose of leaving an expansion or control joint on walls where wallboard is joined on a wide framing member?
To allow for movement from settlement of the building or shrinkage of the wood
What is the main advantage of using filler to attach veneer bead?
It creates a sandwich effect
What is the correct method to attach veneer bead in bowed-in corners?
Staple both ends of the bead
What is the correct method to attach veneer bead in bowed-out corners?
Staple at the furthest point out on the bow
What is the correct method to attach veneer bead in out-of-plumb corners?
Staple at the end that is angled out
What type of bead is used when a smooth finish is specified?
Expansion bead
What is the purpose of the vinyl strip in the expansion bead?
To create a clean gap that will open or close with the movement of the wall
What is the main advantage of using veneer bead as a corner bead?
It is the strongest and best wearing of the corner beads
What type of attachment does stapling provide when attaching veneer bead?
Solid attachment
Which type of bead offers the advantage of easily achieving a straight line in the angle?
Splay bead
What is the flange angle of splay beads?
135°
Which type of bead consists of two strips of galvanized metal laminated to paper tape?
Flex bead
Which type of bead can be formed to fit any inside or outside angle?
Flex bead
Which type of bead provides a very accurate guide for filling on internal angles greater than 90°?
Flex bead
Which type of bead requires more skill to apply than rigid splay bead?
Flex bead
Which type of bead offers the advantage of being able to fit any degree of angle?
Flex bead
What is the main advantage of using splay bead?
Easily achieving a straight line
What is the main advantage of using flex bead?
Fitting any degree of angle
Which type of snips are recommended for measuring and cutting beads and trims?
Aviation snips
What is the result of using short cutting strokes when cutting a bead?
A ragged cut
How should the flanges of a bead be cut?
In one motion
What should be done if the bead is all the way through on both sides?
Bend the bead back and forth until it breaks
What must the cutting blades of the snips do when measuring and cutting?
Contact each other for the full length of the blades
Which type of snips are most commonly used for measuring and cutting?
Straight cut snips
What is the advantage of using aviation snips for measuring and cutting?
They give a clean cut
What is the purpose of using a pair of snips that suit you when measuring and cutting?
To cut narrow strips
What is the result of using short cutting strokes when cutting a bead?
A ragged cut
Which tool can be used to measure corners for bead installation?
A tape measure
What is the recommended gap to leave at the bottom of a vertical bead when pushed tight to the ceiling?
3mm (1/8")
What is the consequence of cutting the bead at an angle to the corner?
The bead will bind
What is the purpose of cutting a vertical bead 6mm (1/4") shorter than the required length?
To prevent the bead from binding
What is the recommended gap to be shared by the two ends of a horizontal or vertical bead for corners with closed ends?
3mm (1/8")
When can the bead be held up to the corner and marked?
When there is enough room to put the bead flush against the wall
Why should a vertical bead that goes to the floor be cut shorter than the required length?
To ensure a tight fit
Which type of joint requires the finishing edges to be cut square?
Straight line joint
When joining two pieces of bead in a straight line, what should be done to the flanges?
Cut them on a slight angle away from the joint
How should bead that meets at an inside corner be cut?
To fit tightly with no gap between the finishing edges
For rectangular openings beaded on all sides, which beads should be measured and attached first?
Top and bottom horizontal beads
What is important when attaching the vertical beads in rectangular openings beaded on all sides?
The ends must fit tight and be on the same plane
For rectangular openings where three sides are beaded, how should the beads be measured and attached?
Single horizontal bead, then two vertical beads
What should be ensured when attaching the single horizontal bead in rectangular openings where three sides are beaded?
The corner must be tight and in the same plane
When joining two beads in a straight line, what will happen if there is a gap between them?
Filling cannot make a continuous line between the two beads
What should be done to the inside flanges when cutting bead for inside corners?
Cut them back a little to avoid interference with the finishing edges
Which type of beads must be mitred at outside corners?
Narrownose beads
What is the purpose of mitring the beads at outside corners?
To make the finishing edges stay apart
Which side of the template is used to mitre the vertical side of the upper left-hand corner?
Face
What is the miter angle of the beads at outside corners?
Slightly more than half of the angle of the outside corner
How many corner beads meet at outside corners?
Three
What would happen if the beads at outside corners were simply overlapped?
There would be a gap at the point
What is the recommended miter angle for a 90° outside corner?
45°
Which type of corner requires measuring the bead slightly longer and cutting one end to fit tight when attaching the beads?
Outside corner
What is the recommended gap to allow at the unmitered end when measuring bead for outside corners where only one end is mitered?
1/8"
What should be measured when determining the length of the bead for outside corners where only one end is mitered?
The overall length of the bead
When measuring bead for outside corners, where should the measurement be taken?
At the finishing edge
What should be done to ensure that the three finishing edges of the miter angle come to a point?
Align the miter angle with the finishing edge
What is the purpose of allowing a gap at the unmitered end when measuring bead for outside corners?
To accommodate expansion and contraction
Which type of corner requires measuring the bead longer and cutting one end to fit tight when attaching the beads?
Outside corner
Which type of bead is used on outside corners where three bullnose corner beads meet?
Bullnose bead
What should be checked before applying any bead on a corner?
The plumbness of the corner
What should be the distance between the corner and the point of the bead edge above the surface of the wallboard?
Equal to the height of the finishing plumb
What is the purpose of a cap used on outside corners where three bullnose corner beads meet?
To provide additional support
What should be done if one of the sides of a corner is not plumb or straight?
Apply that side first and make necessary adjustments
What is the material used for a pre-fabricated plastic corner that is fastened into place on outside corners where three bullnose corner beads meet?
Plastic
Which tool can be used to check the straightness of a bead?
Straight edge
What should be done if a corner is out of plumb?
Attach the bead at the bottom first
What can happen if a bead is pulled out too much to correct an out of plumb corner?
Both of the above
How can a long horizontal bead be kept straight?
Using a chalk line
What should be done if the corner is not level when using a chalk line?
Adjust the line down from the low side
What is the width of the flange away from the corner when using a chalk line?
The width of the flange
What is the maximum length of a bead that can be straightened using a chalk line?
2m (6')
What can happen if a bead is pulled out too much to correct an out of plumb corner?
Both of the above
Which of the following is NOT a common method of attaching metal corner beads?
Taping
When should clinching be used to attach metal corner beads?
When the corners are straight and plumb
What is the main disadvantage of using clinching to attach metal corner beads?
The bead can be easily knocked off
Which part of the metal corner bead should be placed tight to the ceiling?
The square cut end
What type of framing can clinching be used on?
Steel studs
What is the purpose of attaching the flange of the metal corner bead on the line?
To align the bead with the chalk line
What is the main advantage of using nails, screws, or staples to attach metal corner beads?
Stronger bond to the framing member
When should adjustments be made to the bead and snap a new line?
When the bead is off from the chalk line
What can happen if clinching is used on wood studs instead of steel studs?
The bead may not be aligned with the corner
Which tool should be used to tap the finishing edge of the bead into the apex of the corner?
Hammer
What is the recommended distance between each tapping, holding, and fastening point?
30 cm (12")
Where should nails be driven when fastening the bead?
Through the metal
How should the end of the bead at the ceiling be fastened?
Using two sets of nails or screws
What is the recommended distance between each fastening point when attaching the bead to the floor?
30 cm (12")
What is the main advantage of driving nails through the metal when fastening the bead?
Stronger and tighter fit
What is the purpose of double fastening the bead at the ceiling and floor?
To prevent the bead from twisting
Which part of the clincher should be struck with a mallet to push the bead tight and square against the wallboard?
The head
What should you do if the teeth of the clincher have not dug in about 3 mm (1/8") after striking the head?
Strike the head again
What is the recommended distance between each strike of the clincher's head when moving it towards the ceiling?
15 cm (6")
What should be avoided when using the clincher to avoid damaging the teeth?
Striking the head too hard
What can happen if too much oil is applied to the moving parts of the clincher?
The head will not move freely
What is the purpose of lightly oiling the moving parts of the clincher?
To prevent the mechanism from jamming
What should be done to ensure the clincher matches the width of the bead flanges?
Use a different size clincher
Where should you start when clinching metal corner bead?
At about the mid-point of the length of the bead
What can happen if the clincher is struck too hard when clinching metal corner bead?
The finishing edge of the bead may get damaged
What should you avoid hitting with the teeth of the clincher when clinching metal corner bead?
The finishing edge of the bead
Which part of the bead should you fasten as close as possible to the ends?
The last foot of each bead
What is the common problem that occurs when attaching beads?
Beads bowing out in the middle
What should you use to check if the bead is straight?
A straightedge
What must be clean in order for the bead to sit squarely?
The groove in the clincher
What happens if the clincher groove wears over time?
The bead twists
What should the teeth of the clincher do?
Make a clean bite into the bead
What is the consequence of a twisted bead?
The bead cannot be repaired
What type of snips are recommended for measuring and cutting?
Aviation snips
What is the purpose of using hollow-type constructions in gypsum systems?
To reduce weight
Which tool should be used when applying paper faced metal bead by hand?
15 cm (6") knife
Which method should be used when applying flex bead?
Pan and knife
When should the hand method be used for applying beads?
For one to ten beads
What are the factors that influence the attaching of paper faced metal bead?
Drying conditions, bonding capacity of filler, bond of paper tape to metal bead, and skill of applicator
Which type of bead is suitable to be applied using the pan and knife method?
Paper faced metal bead
What is the recommended length of the knife when applying beads by hand?
15 cm (6")
How many beads should be applied using the hand method?
One to ten beads
Which method should be used for applying one to ten beads?
Hand method
Which method should be used for applying beads over ten?
Pan and knife
Which tool is used to fill the metal tube with embedding compound?
Pump
What is the purpose of the handle on the corner tool?
To control the tool as it moves up the corner
What is the purpose of the corner shoe on the front of the tube?
To deposit a uniform layer of embedding compound
Which tool is used to embed the bead into the filler?
Exterior corner roller
What must the handle on the corner tool center on?
The corner itself
Which type of corner roller is used for narrow nose styles of corner bead?
Narrow nose corner roller
What should be checked before applying the paper faced metal bead?
All of the above
What is the purpose of the corner applicator?
To apply compound to the corner shoe
What is the purpose of the gates in the hopper for the paper faced metal bead?
To regulate the amount of filler applied to the bead
What should the surface to which the paper faced metal bead is applied be free of?
Grease, oil, and dust
Which type of edge of the wallboard should be pre-filled before applying the bead?
Bevelled edge
What should be the consistency and thickness of the filler when attaching bead with the hopper or corner tool method?
Same consistency as tape application, slightly thicker
What will happen if the filler used for attaching bead is too thick?
Bead will not embed tightly to the wall
What should be the consistency of the filler when using fast-set filler for attaching bead?
Thinner than regular filler
What is the recommended thickness of the filler for attaching bead?
As close to 3 mm (1/8") as possible
Why should the thickness of the filler not be less than 3 mm (1/8") when attaching bead?
Not enough filler to bond the tape
Why should the thickness of the filler not be more than 3 mm (1/8") when attaching bead?
Process becomes too messy
What is the main advantage of using fast-set filler for attaching bead?
Faster drying time
What will happen if the filler used for attaching bead is too runny?
Process becomes too messy
What is the recommended thickness of the filler for the best results in the least amount of time?
As close to 3 mm (1/8") as possible
Which of the following is NOT a reason for allowing the bead to dry for 24 hours before filling?
To ensure a poor bond is formed
What is the recommended depth of filler when applying it to both sides of the walls with a knife?
1/8 inch
Which motion should be used to set the bead in place tight against the ceiling?
Up and down sliding motion
When embedding the bead by hand, where should pressure be applied?
On the metal backing
What should be the position of the roller when embedding the bead with a roller?
Halfway up the bead
What is the purpose of creasing the flex bead slightly more than required?
To allow for shrinkage during drying
Which tool is used to apply filler when using a hopper?
Roller
What should be done to ensure there are no dry spots when applying filler with a hopper?
Adjust the gate of the hopper
Which part of the bead should be pressed when embedding it by hand?
The metal backing
What should be done to ensure a straight and plumb bead when applying flex bead to angles longer than 3 m (9')?
Use a dryline as a guide
What should be done to remove excess filler from the flanges of the bead?
Wipe the flanges
Why is checking the bead for straightness and plumbness more important with flex bead compared to paper bead?
Flex bead lacks rigidity
What is the potential consequence of using a blade to clean the finishing edge of the wet paper?
The paper can burr or tear
What should be done if the finishing edge of the bead is not above the wall surface?
Adjust the finishing edge
What can be used as a guide to keep the angle straight when applying flex bead to angles longer than 3 m (9')?
A dryline
What is the purpose of wiping the flanges of the bead?
To remove excess filler
What should be done to ensure that the finishing edge of the bead is clean?
Clean it with a blade
What is the recommended distance between each strike of the clincher's head when moving it towards the ceiling?
Depends on the specific situation
What is the purpose of using a dryline as a guide when applying flex bead to angles longer than 3 m (9')?
To keep the angle straight
Which type of bead is used to attach plastic beads by applying an appropriate glue for PVC materials?
Flange bead
What can be used, in addition to glue, to attach plastic bead?
Staples
How can plastic archway bead be used to fit around round structures?
It needs to be cut at regular intervals
What determines the distance between the cuts on the flange of plastic archway bead for round structures?
The circumference of the structure
What is the recommended starting point when attaching plastic bead to a round structure?
The point closest to the join in the bend
What should be done to the plastic bead after it is attached to a round structure?
Cut it to fit
What should be ensured when fastening plastic bead to a round structure?
Secure attachment of the bead
Which of the following is a consequence of fasteners being too far apart when fastening the bead?
The bead will block and create a flat spot in the circle
What should be used to lightly tap the finishing edge of the bead?
The handle of a hammer
What should be avoided when tapping the finishing edge of the bead?
Breaking or denting the finishing edge
What happens if the bead is not fastened tightly around the entire circumference?
The finishing edge will have flat spots
What should be done to prevent the finishing edge of the bead from having minor flat spots?
Lightly tapping the finishing edge
What can happen if the bead is fastened too tightly?
The finishing edge may break or dent
What is the relationship between the tightness of the radius and the placement of the bead fasteners?
The tighter the radius, the closer the bead should be fastened
Study Notes
Drywall Overview
- Drywall is the most popular wall covering material used in residential and commercial construction in North America.
- Over 90% of homes built in the US and Canada use drywall for interior wall and ceiling coverings.
History of Gypsum
- The oldest preserved use of gypsum was discovered in the ancient city of Jericho, dating back to 7000 BC.
- Gypsum was used to produce the first sheet of drywall.
- Large gypsum deposits can be found in the Middle East and North Africa.
- Gypsum is a mineral rock that is the forerunner of present-day gypsum board.
Properties of Gypsum
- Gypsum is composed of calcium sulfate chemically combined with water of crystallization.
- Gypsum is heated to drive off the dry water, a process called calcining.
- Gypsum becomes anhydrite when heated, making it fire resistant.
Advantages of Drywall
- Drywall has several advantages over plaster, including ease of installation and lower cost.
- Drywall provides better sound damping than some other materials.
- Drywall is a good insulator during a fire due to its low density.
Drywall Production
- The core of drywall panels is made of gypsum.
- Paper is used to sandwich the gypsum mixture in the production process.
- The edges of drywall panels come in various types, including beveled, square, and tongue and groove.
Types of Drywall Panels
- Standard drywall panels are the most common type used.
- Type X panels are fire-resistant and used in areas that require higher fire ratings.
- Water-Resistant Panels are used in areas that are prone to moisture.
- Exterior drywall ceiling panels are used in exterior applications.
- Interior Ceiling Panels are used in ceilings where heavy textures will be applied.
Installation and Finishing
- The recommended thickness of standard drywall panels is 13mm (1/2").
- Different thicknesses of drywall panels offer varying levels of fire resistance and sound insulation.
- Demountable partition systems use panels with square edges.
- The width of drywall panels is typically 1.2m (4 ft).
- The facing paper on standard drywall panels is brown.
Special Requirements
- Foil-back panels are used in areas where moisture is a concern.
- Type X panels are used in areas that require higher fire ratings.
- Water-Resistant Panels are used in areas prone to moisture.
- Exterior drywall sheathing panels are used in exterior applications.
Test your knowledge of gypsum wallboard with our quiz! Learn about the most popular wall covering used in construction, its benefits, and its widespread use in residential and commercial projects. Discover why gypsum drywall is the go-to choice for interior wall and ceiling coverings in the United States and Canada.
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