California CSLB C-35 Lathing and Plastering Examination

A contractor is estimating sand for a cement plaster job. The mix calls for one part cement to three parts sand by volume. For a job requiring 12 cubic feet of cement, how much sand is needed?

• A36 cubic feet
• B48 cubic feet
• C12 cubic feet
• D24 cubic feet

When estimating material quantities for a three-coat stucco wall, which factor most directly determines the amount of base-coat plaster required?

• ATotal wall surface area to be covered
• BAmbient temperature during the application period
• CColor and texture selected for the finish coat
• DBrand of mixing equipment used on site

On a set of construction drawings, the plaster assembly is called out as a three-coat cement plaster system over metal lath. What does this tell the estimator about the number of plaster applications required?

• ATwo base coats and one finish coat are required
• BOne base coat and two finish coats are required
• CA single thick coat is applied in one pass
• DOnly a scratch coat and a finish coat are needed

A contractor is scheduling an exterior stucco job during a period with forecast rain. What is the most appropriate approach to protect the work?

• ACover fresh plaster with waterproof sheeting and reschedule around rain
• BApply plaster in light rain since the water helps cure the mix
• CAdd extra water to the mix to compensate for rain dilution
• DProceed normally because stucco is waterproof immediately after application

When ordering metal lath and accessories for a plastering project, what waste factor is commonly added to the calculated material quantity?

• AApproximately 10 percent extra material
• BNo waste factor is needed for metal lath
• CApproximately 50 percent extra material
• DApproximately 100 percent extra material

A wall measures 40 feet long by 10 feet high and has one window opening measuring 3 feet by 5 feet. What is the net lath area to be covered?

• A375 square feet
• B385 square feet
• C400 square feet
• D415 square feet

On a project requiring both plastering and painting, when should the plastering contractor coordinate with the painting contractor?

• ABefore the finish coat is applied to discuss surface preparation and timing
• BAfter all plastering is complete and the surface is fully dry
• CDuring planning to coordinate cure time before paint is applied
• DOnly if the painting contractor requests coordination

A contractor estimates that a three-person crew can apply scratch coat to 300 square feet of wall per day. For a 2,400-square-foot project, how many crew-days are needed for the scratch coat alone?

• A6 crew-days
• B10 crew-days
• C12 crew-days
• D8 crew-days

When reviewing contract documents for a plastering project, which item would typically be part of the plastering contractor's scope?

• AInstalling metal lath, scratch coat, brown coat, and finish coat
• BFraming the wood studs and sheathing that support the lath substrate
• CInstalling the windows and exterior doors
• DApplying exterior paint over the cured stucco

A three-story building requires exterior stucco. What is the most efficient method for delivering plaster materials to upper floors?

• ACarrying bags up stairs by hand throughout the entire project
• BUsing a hoist or pump to lift materials to upper levels
• CStoring all materials on the ground and mixing only at ground level
• DHaving workers toss bags up to the scaffolding platform

A project has 800 square feet of stucco over wood framing with metal lath and 400 square feet of plaster over masonry. The wood-framed area requires three coats and the masonry area requires two coats. What is the total number of coat applications to estimate?

• A2,400 coat-applications
• B3,600 coat-applications
• C3,200 coat-applications
• D1,200 coat-applications

Cement plaster materials are typically ordered and batched using which measurement approach?

• ABy volume using measured cubic feet or sacks of cement
• BBy weight using pounds only
• CBy surface area using square yards
• DBy volume using sacks of cement and measured sand

Before submitting a bid for a plastering project, what should the contractor evaluate at the job site?

• ASubstrate condition, access, and existing surface preparation needs
• BOnly the color selections made by the owner and architect together with paint samples
• CThe landscaping plan for the building exterior
• DThe brand of tools preferred by the crew

A three-story building exterior measures 50 feet wide per side, with three sides requiring scaffolding. If each side is 30 feet high, what approximate scaffolding area must be rented?

• A3,000 square feet of scaffolding for the three sides
• B4,500 square feet of scaffolding
• C1,500 square feet of scaffolding
• D6,000 square feet of scaffolding

When ordering plastering accessories for a residential stucco project, which items are typically needed at external corners and wall bases respectively?

• ACorner beads at corners and control joints at vertical bases
• BCasing beads at corners and corner beads at the wall bases
• CCorner beads at corners and weep screeds at bases
• DControl joints at corners and casing beads at bases

What is the primary purpose of building paper installed behind metal lath on exterior framed walls?

• ATo increase the fire rating of the exterior wall assembly
• BTo improve the mechanical bond between the scratch coat and the lath mesh
• CTo add structural stiffness to the wood wall framing
• DTo shed water that penetrates the stucco and protect the framing

When attaching self-furring expanded metal lath to wood framing, which fastener is most appropriate?

• ARoofing nails with a minimum head size sufficient to hold the lath flat against the sheat…
• BDrywall screws with fine threads designed for gypsum board
• CGalvanized roofing nails with washers to prevent pull-through
• DStaples from a light-gauge hand stapler

When installing building paper horizontally behind lath, what is the correct lap direction?

• ALower courses lap over upper courses to seal against wind
• BEdges are butted together with no overlap required
• CUpper courses lap over lower courses to shed water downward
• DVertical joints are taped and horizontal joints are sealed with caulk

Why is furring used behind self-furring metal lath when installed over wood sheathing?

• ATo create a decorative shadow line between the stucco finish and the adjoining wall surfa…
• BTo eliminate the need for building paper behind the lath
• CTo create a space that allows the scratch coat to key into the back of the lath
• DTo increase the total wall thickness for better insulation value

Which type of lath is most commonly used for exterior cement plaster over wood framing?

• AGypsum lath panels typically used for interior plaster
• BWood lath strips nailed horizontally to the studs
• CPlastic lath mesh designed for chemical environments
• DSelf-furring expanded metal lath or wire lath

When fastening metal lath to wood studs with sheathing, what is the maximum fastener spacing along each stud?

• AEvery 12 inches along the stud using nails with washers at each edge
• BEvery 16 inches centered on the stud with a single row of fasteners
• CEvery 6 inches along vertical framing members
• DEvery 24 inches with heavy-duty staples for economy installations

What is the likely result if metal lath is installed loose or wavy instead of tight against the substrate?

• AThe stucco will cure with a smoother surface because the lath naturally absorbs minor wal…
• BThe lath will tighten automatically as the plaster cures and shrinks
• CThe plaster may crack and delaminate as the lath moves under application pressure
• DThe only effect is a slightly thicker scratch coat in some areas

When installing metal lath on cold-formed steel studs, which fastener type is appropriate?

• AGalvanized roofing nails driven through the steel stud flange
• BConstruction adhesive designed for metal-to-metal bonding applied to the stud flange
• CSelf-drilling screws with washer heads that penetrate the steel flange
• DPowder-actuated pins driven into the face of the stud

What is the purpose of a corner bead installed at external corners of a plaster wall?

• ATo create a hidden joint that allows the corner to flex with building movement
• BTo serve as a decorative trim piece that covers imperfections in the finish coat
• CTo provide additional insulation at the corner where two walls meet
• DTo form a straight, durable edge that protects and reinforces the corner

Where should control joints be placed in a stucco wall to manage cracking?

• AAt regular intervals to divide large wall areas into smaller panels
• BOnly at the base of the wall where the weep screed is located, which would not divide the…
• CExclusively around window and door openings
• DAt every external corner of the building

What is the minimum side lap required between adjacent sheets of metal lath?

• ANo lap is needed if the edges are wired together at the seam
• BA minimum of 6 inches to ensure full structural continuity
• CAt least one-half inch but not less than the mesh spacing
• DAt least 2 inches with building paper sandwiched between layers

When lathing an external corner, how should the metal lath be arranged at the corner line?

• AStop the lath at the corner and start a new sheet on the adjoining wall
• BInstall separate pieces on each wall with a gap for the corner bead to bridge
• CWrap the lath continuously around the corner to avoid a seam at the edge
• DButt the lath against the corner bead and fasten it on both faces independently

What is the purpose of a weep screed installed at the base of a framed exterior stucco wall?

• ATo provide a decorative transition between the stucco and the foundation
• BTo serve as a horizontal control joint for crack management at the wall base
• CTo act as a termite shield that prevents insects from entering the wall
• DTo terminate the stucco and allow trapped water to drain out of the wall

What should be done if the building paper behind the lath is torn or punctured during installation?

• ACover the tear with an additional layer of paper lapped over the damaged area
• BApply a thick scratch coat to seal the opening from the exterior side
• CNothing, as the stucco will seal the gap when it cures over the lath
• DCaulk the torn area with elastomeric sealant before applying lath, which does not restore…

How should metal lath be stored on the job site before installation?

• AStacked flat and elevated off the ground, protected from moisture
• BLeaning vertically against the wall where it will be installed the next day
• CRolled loosely and placed directly on the slab for easy access
• DStored in direct sunlight to keep the metal warm and pliable

What is the purpose of casing beads in a lath and plaster installation?

• ATo reinforce external corners against impact damage during daily use
• BTo provide a decorative reveal line in the middle of a large wall panel, which is an aest…
• CTo act as a horizontal flashing that directs water out of the wall
• DTo create a clean termination edge around openings and where plaster meets other materials

When installing expanded metal lath, which direction should the mesh openings face to ensure proper plaster key?

• AHorizontal so the long dimension of the diamond runs along the wall
• BIt does not matter as long as the lath is fastened at the required spacing
• CVertical so water can drain through the mesh if it penetrates the stucco
• DWith the small opening dimension facing the substrate for maximum key

Why should metal lath not span continuously across control joints in a stucco wall?

• AContinuous lath creates a stronger wall and should always span across joints
• BThe lath must be cut at the joint so the stucco panel can move independently
• CContinuous lath causes rust at the joint due to galvanic reaction
• DBuilding paper behind the joint prevents lath from spanning effectively

When installing metal lath over masonry substrates such as concrete or block, what preparation is required that differs from wood framing?

• ANo preparation is needed because masonry provides an excellent plaster bond
• BThe surface must be prepared and a bonding agent applied if lath is not used
• CBuilding paper is not required since masonry is already moisture resistant
• DFurring strips must always be installed to create an air gap behind the lath

When must control joints be installed at intersections of different framing materials or wall planes?

• AOnly when the architect specifically details the joint on the drawings
• BControl joints are never needed at framing transitions if the lath is continuous, which i…
• CAt all locations where different substrates meet to prevent differential movement cracks
• DOnly at concrete-to-wood transitions, not at wood-to-steel transitions

In a three-coat cement plaster system over metal lath, what is the correct sequence of coats from first to last?

• AScratch coat, brown coat, then finish coat
• BBond coat, scratch coat, then finish coat
• CBrown coat, scratch coat, then finish coat
• DScratch coat, finish coat, then a second finish coat

How long should the scratch coat be allowed to set before the brown coat is applied?

• AThe brown coat can be applied immediately while the scratch coat is still wet
• BOnly a few minutes is needed if a bonding agent is used in the mix, which is insufficient…
• CAt least 48 hours to ensure full cure before the next coat
• DLong enough to achieve initial set, typically several hours to a day

What is the purpose of scoring the scratch coat before it sets?

• ATo create a rough surface that helps the brown coat bond mechanically
• BTo create a decorative texture pattern that shows through the finish coat
• CTo reduce the thickness of the scratch coat to save material
• DTo prevent the scratch coat from cracking as it cures

What is the approximate thickness of a scratch coat applied over metal lath?

• AOne-quarter inch, just enough to embed the lath
• BOne-eighth inch applied as a thin slurry coat
• CThree-eighths to one-half inch to build out the wall
• DOne inch or more to create a thick monolithic base for added strength

What is the primary purpose of the brown coat in a three-coat plaster system?

• ATo provide the final visible color and texture of the wall surface, which is the function…
• BTo create the mechanical key into the metal lath
• CTo serve as a waterproof barrier behind the finish coat
• DTo build out thickness and create a true, flat surface for the finish coat

How should the brown coat be finished before the finish coat is applied?

• ALeft with a smooth troweled surface to ensure the finish coat adheres evenly
• BFloated to a moderately rough, open texture that promotes a strong finish coat bond
• CScored with deep grooves like the scratch coat for maximum key
• DPolished to a hard glossy surface to resist moisture penetration

What is a common mix ratio for a cement plaster scratch coat?

• AOne part cement to one part sand for maximum strength
• BOne part cement to six parts sand for economy installations
• COne part cement to four or five parts sand by volume
• DOne part cement to two parts sand for a rich decorative finish

What is the total minimum thickness for a three-coat cement stucco system applied over metal lath?

• AOne-quarter inch total for all three coats combined
• BOne inch total to ensure adequate structural performance
• CFive-eighths inch total for the three coats combined
• DThree-eighths inch total for lightweight stucco systems

What is the most common cause of map cracking across a stucco surface?

• AApplying coats too thin or using too rich a mix that shrinks excessively during curing
• BUsing sand that is too coarse for the finish coat texture
• CApplying the finish coat in cool, humid weather conditions
• DInstalling the metal lath with insufficient overlap at the seams, which is a lath install…

How soon after applying the brown coat can the finish coat typically be applied?

• AImmediately after the brown coat is placed, while both coats are still wet
• BAfter the brown coat has cured for at least seven days
• CAfter the brown coat has set and surface is prepared, typically a day or more
• DThe finish coat must be applied within one hour of the brown coat

What is the purpose of damp curing freshly applied cement plaster?

• ATo accelerate the set time so subsequent coats can be applied sooner, which is the opposi…
• BTo wash excess sand from the surface and create a smoother finish
• CTo prevent rapid moisture loss that causes shrinkage cracking and ensures proper hydration
• DTo increase the surface hardness by saturating the cement paste

What is a dash bond coat and when is it used?

• AA thin slurry coat dashed onto the substrate to improve adhesion before applying base coa…
• BA decorative splatter texture applied as the final finish coat
• CA waterproof coating applied over cured stucco to resist water penetration, which is a su…
• DA corrective coat used to fill low spots in an uneven brown coat