Unit 10 • Drywall CARPENTRY tech connect Drywall materials are often used in interior finishing. Drywall is versatile, easy and fast to install, and provides a good base for paint, wallpaper, or other interior finishes. Some types of drywall have their own decorative finish and require no additional finishing. The name "drywall" is used because these materials require little or no water for application. Objectives ——————— 1. Choose the benefits of using drywall. 2. Choose types of base or construction where drywall is used. 3. Match types of drywall to their uses. 4. Select types of finishes that may be applied to drywall. 5. Identify tools, equipment, and accessories used to install drywall. 6. Identify tools used to finish drywall. 7. Review the procedure to estimate materials needed to drywall a structure. 8. Estimate materials needed to drywall a structure. (Assignment Sheet) 9. Install drywall on a wooden frame. (On The Job Activity) 10. Install drywall on a metal frame. (On The Job Activity) TechConnect - STUDENT WORKBOOK 10 - 1 Drywall - Unit 10
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Unit 10 • Drywall
CARPENTRY
tech con
nect
Drywall materials are often used in interior finishing. Drywall is versatile, easy and fastto install, and provides a good base forpaint, wallpaper, or other interior finishes.Some types of drywall have their own decorative finish and require no additionalfinishing. The name "drywall" is usedbecause these materials require little or nowater for application.
Objectives ———————
1. Choose the benefits of using drywall.
2. Choose types of base or constructionwhere drywall is used.
3. Match types of drywall to their uses.
4. Select types of finishes that may beapplied to drywall.
5. Identify tools, equipment, and accessories used to install drywall.
6. Identify tools used to finish drywall.
7. Review the procedure to estimatematerials needed to drywall a structure.
8. Estimate materials needed to drywalla structure. (Assignment Sheet)
9. Install drywall on a wooden frame.(On The Job Activity)
10. Install drywall on a metal frame. (On The Job Activity)
Objective 1:—————— Choose the Benefits of UsingDrywall
Drywall is a rigid sheathing material madewith a noncombustible core (usually gypsum) that is surfaced with treatedpaper or some other sheet material.Drywall is applied to interior finish wallsand ceilings as a base for a finish of somesort.
Drywall is used extensively in residentialand commercial carpentry. Below aresome of the benefits of using drywall.
Easily applied — Drywall can beapplied using nails, screws, andadhesives. Metal corner beads,metal casing beads, and expansion joints are also used.
Economical — Drywall is moreeconomical to use than lath with aplaster finish.
Easily maintained — Onceinstalled, drywall requires little tono maintenance.
Easily repaired — Holes in drywall can be easily repairedusing furring strips to strengthenthe damaged area, a piece of drywall cut to the size of the hole,joint compound, and mesh orpaper tape.
Noncombustible — Drywall hasgood fire resistance propertiesbecause its core is made of gypsum or some other non-burning material.
Provides a good base for applying finish materials —Paint and wallpaper can be easilyapplied to drywall. Some types ofdrywall even come pre-decorated.
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United States Gypsum Companyhttp://www.usg.com
Gypsum Todayhttp://www.gypsumtoday.com
National Gypsum Companyhttp://www.nationalgypsum.com
Visit the followingsites to discover
more about drywall and
drywall installation:
Furring strips — narrow strips ofwood or metal attached to walls orceiling to form a level surface
Gypsum — a white mineral used inthe manufacture of plaster of Paris,gypsum plaster, drywall, cement, andfertilizers
Noncombustible — being incapable ofigniting or burning
• WORDS TO KNOW •
Unit 10 • Drywall
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Objective 2:—————— Choose Types of Base or Construction WhereDrywall is Used.
Drywall can be used with several types ofbase or construction:
Single layer applied to wood structure
Single layer applied to metal structure
Single layer applied directly tomasonry walls
Single layer applied to wood ormetal furring strips
Single layer used as subflooring
Double layer (two-ply) nailed,screwed, or laminated to structure
Objective 3:—————— Match Types of Drywall toTheir Uses.
There are many different types of drywallwhich meet specific building needs inconstruction. Study the following typesand discuss with your instructor the use ofeach.
Backing board – does not have afinished surface. It is usuallyinstalled where it will be coveredwith a finished material like wood ortexture.
Ceiling/soffit (Type X) – has aharder core and thicker paper facings than standard drywall. Bystrengthening the core and thepaper, the drywall has better nailholding ability. It is usually installedas a backing for a suspended ceiling covered with a material likeacoustical tile.
Coreboard (shaftwall liner) – hasa gypsum core encased with strongliner paper. It is commonly used inlaminated partitions. The paper lineris usually treated with to resist moldand mildew.
Fire-code – has a surface coatingthat retards the spread of fires. It isusually installed in garages andwherever fire retardant materials arerequired by the building codes.
Insulating – is an exterior wallmaterial with a moisture-resistantgypsum core and liner. The paperliner is usually treated to resist moldand mildew. It provides a backingfor a variety of exterior finishes.
Moisture-resistant (M-R board) –resists moisture. It is usually recognized by its green or bluecolor. It is usually installed in bathrooms, kitchens, laundry rooms,restaurants, and other interior areasthat exposed to moisture. The paperliner is usually treated to resist moldand mildew.
Pre-finished – is available in a variety of surface materials,designs, and patterns. It requires notaping, painting, or other finish. It isusually installed vertically becauseof the difficulty in matching and finishing the butt joints.
Standard – is usually made of gypsum filler mixed with other ingredients and faced with treatedpaper. It is the most commonly useddrywall in both residential and commercial carpentry.
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Butt joints or joints — the placewhere the edges of two pieces of drywall meet or "butt up" againsteach other
Objective 4:—————— Select Types of FinishesThat May Be Applied toDrywall
One of the advantages of using drywall isthat it will accept many different types offinishes.
Acoustical tile – This type of finishis usually used for ceilings and isattached to an acoustical tile gridframe. Acoustical tiles are fiberboardproducts designed for interior deco-ration and sound insulation.
Ceramic tile – This type of finish isused primarily in the kitchen, bath-room, mudroom, and laundry room.Ceramic tiles come in a variety ofpatterns, shapes, sizes, and colors.They are made from clay or similarmaterials that are baked in a specialover at high temperatures.
Paint – This type of finish is themost commonly used finish on theexteriors and interiors of homes.Paint provides both protection anddecoration.
Paneling – This type of finish isveneer or solid wood and is used tofinish interior walls. Paneling can beapplied directly over drywall and isusually installed vertically.
Texture – This type of finish issprayed or rolled over drywall to cre-ate a textured surface. Texture maybe applied lightly or heavily, depend-ing on the desired effect.
Wallpaper – This type of finish ispatterned paper or vinyl backed withan adhesive. It is used to decorateinterior walls. Wallpaper requires aneven surface with attention given todrywall joints, nailheads, and metaltrims. It comes in a wide variety ofpatterns, materials, and finishes.
Objective 5:—————— Identify Tools, Equipment,and Accessories Used InDrywall Installation
Using the right tool for specific tasks willimprove efficiency and reduce labor costs.Before installing drywall be sure to havegathered the following drywall installationtools.
FIGURE 1
Carrier lifter – used to lift and carrysheets of drywall (Figure 1)
FIGURE 2
Caulking gun – used to apply drywall adhesive to drywall (Figure 2)
FIGURE 3
Circle cutter – used to cut circles indrywall sheets (Figure 3)
FIGURE 4
Corner bead clincher – covers and protects the exposed outsidecorners of drywall (Figure 4)
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Unit 10 • Drywall
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FIGURE 5
Divider – used to lay out a circleand/or divide distances along astraight line (Figure 5)
FIGURE 6
Drywall foot lift – a lifting devicethat is tapered on one end and has asupport on the bottom (Figure 6)
FIGURE 7
Drywall hammer – used to drive fas-teners into drywall (Figure 7)
FIGURE 8
Drywall lift – used to lift and position drywall to side walls and ceil-ings (Figure 8)
FIGURE 9
Drywall rasp – a coarse file used toshape drywall (Figure 9)
FIGURE 10
Drywall saw – used to cut straightedges on drywall (Figure 10)
Objective 7:—————— Review the Procedures for Estimating Materials Needed to Drywall a Structure.
Perimeter – the edges or boundary of an area
Square footage – the sum of an area's length multiplied by its width (measured in feet)
Drywall is estimated in square feet. Several types of calculations are necessary in drywall materials estimates. Study and practice the following procedures.
Estimating square footage and number of sheets of drywall needed
1. Determine total square footage to be covered in drywall by following these steps.
A. Check plans and compute square footage of wall and ceiling space in structure.Ignore openings such as doors and window.
square footage of wall = (total perimeter of walls x wall height)square footage of ceilings = + (ceiling width x ceiling length)
total square footage to be drywalled
Unit 10 • Drywall
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FIGURE 34
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CARPENTRY
EXAMPLE: For a 12' x 16' room with a wall height of 8', the total squarefootage to be drywalled is:
((12+12+16+16) x 8)+ (12x16)
(56 x 8) + (12 x 16)
448 + 192
640 sq. ft.
2. Determine number of sheets of each size of drywall needed by following thesesteps.
A. Determine the square footage of a drywall sheet.
EXAMPLES: 4' x 8' drywall sheet has 32 square feet (4 x 8 = 32)4' x 10' drywall sheet has 40 square feet (4 x 10 = 40)
B. Divide the square footage of the area to be covered by the square footagespace of the drywall sheet.
EXAMPLES: Using the previous specifications:640 ÷ 32 = 20 sheets of 4' x 8' drywall640 ÷ 40 = 16 sheets of 4' x 10' drywall
Estimating amounts of fastening and finishing materials needed
1. Estimate the amounts of fastening and finishing materials needed by followingthese steps.
A. Use Table 2 below to find the amount of nails, screws, joint compound, tape,and texture paint needed per 1,000 square feet of drywall
NOTE: Nail spacing should be a minimum of 7" on ceilings and 8" on walls.However, when double nailing is used, nails are spaced 2" apart every 12".
EXAMPLE: If a structure has 640 square feet, as in the previous example, to be cov-ered with drywall and fastened with 1 1/4" drywall screws, then multiply the amountneeded for 1,000 square feet by the square footage to be cover expressed as adecimal:
4 1/4 lb. x (640/1000) = lbs. of drywall screws needed
4 1/4 lb. x .640 = 2.72 lbs. of drywall screws needed.
B. Check manufacturer's recommendations to find the amount of adhesive needed forthe type of adhesive you are using.
NOTE: Each type of drywall adhesive has a different coverage capability; therefore,always follow the manufacturer's recommendation.
C. Check plans and count the number of metal corners needed.
Assignment SheetObjective 8:—————— Estimate Materials Neededto Drywall a Structure.
Equipment and Supplies:
� Equipment and Supplies� Calculator� Pen or pencil
Instructions: The use of drywall is a great convenience to the interior systems carpenter. It saves a great deal of time and money over constructing walls and ceilingsfrom lath and plaster. However, these savings can be quickly lost if materials are poorlyestimated. Estimates need to be accurate to avoid unnecessary handling of drywall ordelays due to ordering too little material. This assignment will help you become proficient in estimating drywall materials.
Part 1
Calculate the square feet of walls and ceilings for the rooms in the structure illustratedbelow. Show your work and write the correct answers in the blanks. Round off youranswer to the nearest whole number.
1. Bedroom #1, closet, with 8' ceiling = _______________________
2. Bath and Hallway with 8' ceiling = _________________________
3. Garage with 12' ceiling = ________________________________
Part 2
Using Table 2, estimate the amounts of the following materials needed to apply and finish drywall for the previous illustrations. Show your work in the space below andwrite the correct answers in the blanks.
Bedroom #1
1. Number of sheets of 8' x 4' drywall = _______________________
2. Pounds of 1 1/4-inch annular-ring nails = ____________________
3. Feet of perforated joint tape needed = ______________________
4. Pounds of ready-mix joint compound needed = _______________
Bath and Hallway
1. Number of sheets of 8' x 4' drywall = _______________________
2. Pounds of 1 1/4-inch drywall screws = _____________________
3. Feet of perforated joint tape needed = _____________________
4. Pounds of ready-mix joint compound needed = ______________
Garage
NOTE: Materials will not be needed for the area where the garage door will be placed.
1. Number of sheets of 8' x 4' drywall = _______________________
2. Pounds of 1 1/4-inch drywall screws = ______________________
3. Feet of perforated joint tape needed = _____________________
4. Pound of ready-mix joint compound needed = _______________
On the Job ActivityObjective 9:—————— Install Drywall On a Wooden Frame
Video
Watch the video titled "Installing Drywall.”
Introduction: Before installing drywall on a wooden frame, the drywall installer may beresponsible for preplanning and/or making sure the construction site is ready for drywall installation. Drywall installation must comply with local building code requirements. Sometimes the installed drywall may require an inspection before tapingis permitted. Some of the following guidelines will help you in the preparation forinstalling drywall and complying with building codes.
Guidelines:
Check the building code inspection sheet for completion and approval.
Inspect to be sure that the electrical, water, gas, heating, and air-conditioningrough-in have been properly completed.
Inspect to be sure wall insulation has been properly installed.
Check fire codes with the building plans for correct placement and nail length.
NOTE: Fire codes usually require double layering of drywall.
Use the same manufacturer for framing parts and the drywall.
NOTE: Fire tests are rated and tested on framing parts and drywall using materials from the same manufacturer. Mixing products from different manufacturers could result in a lower fire-rating than required.
Use personal protection items when working with drywall.
Handle drywall sheets as if they are fragile to avoid damage to the drywall.
Inspect drywall for dents, scars, or other damage.
Store drywall materials in a dry area and on a flat surface.
Use the longest length of drywall that can be conveniently used.●
Whenever possible, drywall should be installed horizontally on walls. Drywall edges areslightly recessed creating a channel for the joint compound and tape. A smoother finishon the drywall surface will result when the meeting edges are flush.
Nails are the most common way to attach the drywall to the framing. A successful nailinstallation includes using the proper drywall nails and making sure the nails arespaced properly. Always use personal protection equipment when working on a construction site or with building materials and tools and follow all safety procedures.
Equipment and Supplies:
� 2 x 4s for T braces� T square or steel straightedge� Circle cutter� Drywall� Drywall hammer� Drywall jacks and lifts� Drywall rasp� Joint-finishing knives with 4" and 10" blades� Utility/keyhole saw� Metal corners � Nails and nail pouch� Personal protection equipment� Steel tape � Utility knife
PROCEDURE
Ceiling Installation
Step 1: Put on all appropriate personal protection equipment.
Step 2: Layout drywall.
NOTE: Measure 48 1/4" out at each end of the room and mark ceiling joists. Strikea chalk line across all joists at these marks. The extra 1/4" will allow for variations inthe framing.
Step 3: Measure the first full sheet of ceiling drywall.
A. Begin at one end of the room—measure the distance from the end wall to thecenter of the ceiling joist nearest to it, but less than the length of the drywall.Subtract 1/4" from this measurement.
Example: 8 feet minus 1/4" equals 7'-11 3/4"
B. Mark the drywall to the length determined in step "A".
Example: 7'-11 3/4"
Step 4: Cut drywall.
NOTE: Drywall joints must fall on the center of joists.
A. Mark measurements on finished face of drywall.
B. Hold a straightedge or T-square on the marks and use a utility knife to scoreand cut through face paper.
C. Break drywall at the cut.
D. Use a utility knife to cut the paper on the back side of the drywall sheet.
E. Use a drywall rasp to smooth the edge if necessary.
Step 5: Cut openings for fixtures, etc.
A. To cut the openings, measure the distance of the opening from the end andfrom the edge of the drywall.
B. Mark the measurement on the face of the drywall.
NOTE: Openings should be no more than 1/8" larger than fixture. The fixturesmust be secured properly to the metal ceiling joists or hangers.
C. Cut the opening with a drywall saw.
Step 6: Install backing along top plate if it has not already been installed. (Figure 35)
Step 7: Construct two or more T-braces from 2 x 4s, making the vertical member at least1/2" shorter than the distance from the floor to the bottom of the joist. (Figure 36)
NOTE: T-braces are used to support the drywall during ceiling installation.
Step 8: Install the first full sheet.
A. Beginning in a corner, position full sheet of drywall at right angle to ceiling joists. Nailthe ceiling drywall with the longest edge to the joists at the 48 1/4" point and the endpositioned on the center of the ceiling joist. (Figure 37)
FIGURE 36
FIGURE 37
B. Position T-braces to support the drywall sheet and to hold it in place.
Step 9: Using a drywall hammer, nail the drywall to the ceiling joists.
A. Beginning at the center of the sheet and working outward, nail drywall by drivingnails flush and then striking once more to make a dimple.
NOTE: Do not break the surface paper when nailing.
B. Double-nail sheet along joists by placing two nails 2" apart at 12" intervals.
C. Drive one nail every 7" along drywall edges. (Figure 38)
On the Job ActivityObjective 10:—————— Install Drywall On a MetalFrame.
Introduction: Metal studs are primarilyused in commercial application where non-combustible partitions and ceilingsystems are required. However, residential construction is also usingmetal framing for a variety of reasons.Metal framing is economical, non-combustible, and lightweight. One ofthe many advantages to metal framingis the ability to produce a finishedproduct that is straight and true. Metalframing does not warp or shrink like wooden framing.
Drywall sheets are usually hung vertically on metal framing and application is usuallyfrom the bottom up. Installing drywall on metal framing may require single, double, ormultiple layers. If the application is double or multiple layers, the first and subsequentlayers are hung horizontally with the final layer being hung vertically.
Ceiling drywall is usually applied after the wall application on metal framing. It is easierto place the drywall sheets and hold the screwgun needed to attach the drywall whenthe walls provide support for the ceiling drywall sheets. Suspended ceilings are usuallyused in commercial construction but may also be used in residential. Drywall furringchannels are used on suspended ceilings to attach the drywall or ceiling tiles withhanger wires, screws, or clips.
Screw-on application is used to attach drywall to metal framing. Like nail application,screw-on application requires that the screws be set at the proper depth (barely belowthe surface of the drywall). If the screw head is above the drywall surface, it will causea bump in the finished product.
NOTE: Screw-on application is sometimes used on wooden framing because of theholding power and fewer repair costs associated with nail pops, bad joints, andcrooked walls and ceilings.
Drywall sheets whether fastened with nails or screws or attached to wooden or metalframing share many installation procedures in common. Drywall installation must comply with local building code requirements. Sometimes the installed drywall mayrequire an inspection before taping is permitted. Some of the following guidelines willhelp you in the preparation for installing drywall and complying with building codes.
Check the building code inspection sheet for completion and approval.
Inspect to be sure that the electrical, water, gas, heating, and air-conditioningrough-in have been properly completed.
Inspect to be sure wall insulation has been properly installed.
Check fire codes with the building plans for correct placement and nail length.
NOTE: Fire codes usually require double layering of drywall.
Use the same manufacturer for framing parts and the drywall.
NOTE: Fire tests are rated and tested on framing parts and drywall using materials from the same manufacturer. Mixing products from different manufacturers could result in a lower fire-rating than required.
Use personal protection items when working with drywall.
Handle drywall sheets as if they are fragile to avoid damage to the drywall.
Inspect drywall for dents, scars, or other damage.
Store drywall materials in a dry area and on a flat surface.
Use the longest length of drywall that can be conveniently used.
Always use personal protection equipment when working on a construction site or withbuilding materials and tools. Follow all safety laws and use proper protection equipmentas required.
Equipment and Supplies:
� Circle cutter� Drywall 1/2" thickness� Drywall lift� Drywall or utility/keyhole saw� Drywall rasp� Drywall square� Metal bead corners� Nail pouch� Screwgun� Screws � Steel tape� Utility knife
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Procedure:
Vertical Wall Installation
Step 1: Put on all appropriate personal protection equipment.
Step 2: Layout drywall.
A. Measure the length of wall and then subtract 1/4" from measured length. The extra 1/4" will allow for variations in the framing.
B. Mark measurements on finished face of drywall.
NOTE: Drywall over door and window openings may be put in position and cut inplace.
C. Hold straightedge or T-square on marks and use sharp knife to score and cutthrough the face paper.
D. Break drywall at cut.
E. Use knife to cut paper on back side of drywall.
F. Use drywall rasp tool to smooth cut edge if necessary.
NOTE: Drywall joints must fall on the center of joists.
Step 3: Cut openings for fixtures, electrical boxes, switches, etc.
A. To cut the openings, measure the distance of the opening from the end and edgeof the drywall.
B. Mark the measurement on the face of the drywall.
NOTE: Openings should be no more than 1/8 inch larger than fixture.
C. Outline openings with pencil.
D. Cut the openings with a drywall saw or utility saw.
Step 4: Install first full sheet of drywall vertically.
A. Beginning in a corner, hold full sheet of drywall tightly against corner. Use the dry-wall lift to hold the sheet in position.
A. Drywall joints should be at no less than six inches from the end of window or doorheaders. (Figure 43)
FIGURE 43
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B. Continue cutting and installing as required to complete drywall installation. (Figure 44)
NOTE: Drywall over door and window openings may be put in position and cut inplace.
FIGURE 44
Ceiling Installation
Step 1: Layout drywall.
NOTE: Measure 48 1/4" out at each end of the room and mark ceiling joists. Strikea chalk line across all joists at these marks. The extra 1/4" will allow for variations inthe framing.
Step 2: Measure the first full sheet of ceiling drywall.
A. Beginning at one end of the room, measure the distance from the end wall to thecenter of the ceiling joist nearest to it, but less than the length of the drywall.Subtract 1/4" from this measurement.
Example: 8' minus 1/4" equals 7'-11 3/4"
B. Mark the drywall to the length determined in step "A".