Arizona ROC CR-8 Floor Covering Examination

Under ASTM F2170, when performing in-situ relative humidity (RH) testing on a 6-inch thick concrete slab on grade that is drying from one side only, to what depth must the test hole be drilled?

• A1.2 inches (20% of slab thickness)
• B2.4 inches (40% of slab thickness)
• C3.0 inches (50% of slab thickness)
• D4.5 inches (75% of slab thickness)

According to ASTM F2170, what is the required probe hole drilling depth for a 5-inch thick elevated concrete slab drying from both the top and bottom sides?

• A1.0 inch (20% of slab thickness)
• B2.0 inches (40% of slab thickness)
• C2.5 inches (50% of slab thickness)
• D3.75 inches (75% of slab thickness)

After drilling test holes and inserting plastic sleeves into a concrete slab per ASTM F2170, what is the minimum required equilibration period before inserting probes and taking official relative humidity readings?

• A4 hours
• B12 hours
• C24 hours
• D72 hours

Per ASTM F1869, what is the exact duration range that an anhydrous calcium chloride test kit must remain sealed to the concrete subfloor to measure Moisture Vapor Emission Rate (MVER)?

• A12 to 24 hours
• B24 to 48 hours
• C60 to 72 hours
• D84 to 96 hours

What is the standard baseline maximum allowable Moisture Vapor Emission Rate (MVER) per ASTM F1869 for standard vinyl composition tile (VCT) installations using traditional water-based acrylic adhesives without moisture mitigation?

• A1.0 lb / 1,000 sq ft / 24 hours
• B3.0 lbs / 1,000 sq ft / 24 hours
• C5.0 lbs / 1,000 sq ft / 24 hours
• D8.0 lbs / 1,000 sq ft / 24 hours

You are preparing to perform ASTM F1869 Calcium Chloride moisture testing on a 6,500 square foot commercial concrete floor slab. What is the minimum number of test kits required?

• A6 kits
• B7 kits
• C9 kits
• D12 kits

Per ASTM F710, how is concrete surface pH tested prior to resilient flooring installation, and what is the typical acceptable pH range for standard water-based adhesives?

• AApply phenolphthalein directly to dry concrete; acceptable pH is 4.0 to 6.0
• BPlace distilled water drops on clean concrete, wait 60 seconds, use pH strip; acceptable…
• CScrape concrete dust into acid solution; acceptable pH is 10.0 to 13.0
• DDrill a 1-inch hole and insert electronic pH probe; acceptable pH is 5.0 to 7.0

What is the minimum 28-day compressive strength required for cementitious self-leveling underlayment installed over concrete in commercial heavy-traffic floor applications per ASTM F710?

• A1,200 psi
• B2,000 psi
• C3,000 psi
• D5,000 psi

When preparing a subfloor for glue-down luxury vinyl tile (LVT) or direct-glue hardwood, what is the maximum allowable surface variation using a 10-foot straightedge?

• A1/16 inch in 10 feet
• B3/16 inch in 10 feet
• C3/8 inch in 10 feet
• D1/2 inch in 10 feet

Which surface preparation method is recommended to remove concrete curing compounds, laitance, and sealers to achieve an ICRI Concrete Surface Profile (CSP) of 3 to 5 prior to applying a heavy moisture mitigation epoxy?

• AAcid etching with muriatic acid
• BShot blasting
• CSolvent wiping with mineral spirits
• DPressure washing with cold water

What chemical phenomenon occurs when standard water-based acrylic floor adhesives are exposed to a combination of high subfloor moisture and elevated alkali surface pH (above pH 11.0)?

• ACarbonation
• BSaponification
• CVitrification
• DPolymerization

What is the primary technical reason for applying an approved acrylic or polymer primer to porous concrete before pouring a cementitious self-leveling underlayment?

• ATo waterproof the slab against hydrostatic pressure
• BTo seal concrete pores, prevent pinholing/air bubbles, and maximize underlayment bond str…
• CTo substitute for mechanical grinding of laitance
• DTo accelerate the drying time of the underlayment from 24 hours to 2 hours

A 1,200 square foot concrete floor requires a self-leveling underlayment pour at an average thickness of 1/4 inch (0.25 in.). If one 50 lb bag yields 0.45 cubic feet of wet slurry, how many bags are required (excluding waste)?

• A25 bags
• B38 bags
• C56 bags
• D72 bags

How should dynamic (moving) structural expansion joints in a concrete slab be treated when preparing the subfloor for finished resilient or hardwood flooring?

• AFill flush with rigid cementitious floor patch and install flooring continuously over the…
• BFill with expanding polyurethane foam and cover with underlayment
• CHonor all expansion joints through the underlayment and floor covering using expansion jo…
• DTape over the expansion joint with duct tape before spreading adhesive

According to NWFA guidelines, what is the maximum allowable moisture content (MC) difference between a wood subfloor and solid strip hardwood flooring (less than 3 inches wide) prior to installation?

• A2% difference
• B4% difference
• C6% difference
• D8% difference

For solid wide-plank hardwood flooring (3 inches or wider), what is the maximum allowable moisture content difference between the wood subfloor and the flooring boards per NWFA guidelines?

• A1% difference
• B2% difference
• C4% difference
• D5% difference

When installing nail-down solid hardwood over wood floor joists spaced 16 inches on center, what is the minimum acceptable thickness for single-layer APA-rated plywood subfloor panels?

• A3/8 inch
• B1/2 inch
• C5/8 inch
• D3/4 inch

Which type of moisture meter takes quantitative readings by driving two insulated electrode pins directly into wood subfloors or hardwood boards?

• ACapacitance impedance meter
• BPin-type resistance moisture meter
• CUltrasonic pulse velocity meter
• DInfrared thermography sensor

Under ASTM F2170, how must reusable in-situ relative humidity probes be verified for accuracy before jobsite deployment?

• AImmersed in boiling distilled water for 5 minutes
• BChecked in a calibration salt bottle / generator within +/- 2% RH of the known salt equil…
• CExposed to ambient air and calibrated to match local airport weather reports
• DWiped with isopropyl alcohol and zeroed in dry silica gel

What is the primary function of an elastomeric crack isolation membrane applied over concrete subfloor hairline cracks prior to floor covering installation?

• ATo structurally weld moving concrete slabs together
• BTo bridge non-structural hairline cracks (up to 1/8 inch) and prevent crack transfer to f…
• CTo act as a high-load structural bearing beam
• DTo increase slab compressive strength by 1,000 psi

What ambient jobsite environmental conditions must be maintained for at least 48 hours prior to conducting ASTM F2170 or ASTM F1869 concrete moisture tests?

• AUnconditioned ambient air with open windows for maximum airflow
• BHVAC system operational maintaining 65°F to 80°F temperature and 35% to 55% relative humi…
• CJobsite heated to at least 95°F with industrial space heaters
• DRelative humidity maintained above 85% to test worst-case conditions

Which ASTM standard provides guidelines for non-destructive electronic moisture meters used for initial qualitative screening of concrete subfloors?

• AASTM F2659
• BASTM F2170
• CASTM F1869
• DASTM F710

Why must Orientated Strand Board (OSB) subfloor panel joints be sanded smooth prior to installing resilient sheet flooring or LVT?

• AOSB panels swell along factory edges when exposed to construction moisture, creating ridg…
• BOSB contains wax coatings that must be ignited with a torch
• CSanding OSB changes the wood panel fire rating from Class C to Class A
• DOSB panel edges expand inward and lock together under mechanical sanding

What is the standard rule-of-thumb minimum curing time for a newly poured 4-inch concrete slab before performing moisture testing under normal drying conditions?

• A7 days
• B14 days
• C28 days
• D180 days

What is concrete 'laitance' and why must it be removed from subfloors prior to adhesive or underlayment installation?

• AA hard crystalline surface seal that enhances adhesive grip
• BA weak, milky layer of un-hydrated cement paste and fine aggregates that creates a friabl…
• CAn oil-based mold release agent applied by concrete finishers
• DA dense latex polymer film added during concrete batching

What structural feature gives engineered hardwood flooring greater dimensional stability than solid hardwood flooring when exposed to relative humidity fluctuations?

• AA thick solid steel core plate running through each plank
• BCross-ply construction with adjacent wood veneer layers oriented at 90-degree angles
• CHigh-density polyethylene plastic coating completely surrounding the wood grain
• DChemical impregnation of wood fibers with petroleum pitch

According to NWFA installation guidelines, how should solid hardwood flooring be acclimated on the jobsite prior to installation?

• AUnpack boards and submerge them in water for 2 hours
• BStore bundled boxes in an unheated garage for 30 days
• CDeliver to jobsite with HVAC running at normal occupancy settings, break open bundles, an…
• DPlace wood packages directly next to high-output portable propane heaters

What is the standard rule of thumb per NWFA for perimeter expansion clearance when installing 3/4-inch thick solid strip hardwood flooring along vertical walls?

• A1/8 inch expansion gap
• B1/4 inch expansion gap
• C3/4 inch expansion gap (equal to the board thickness)
• D1-1/2 inch expansion gap

What is the NWFA recommended fastener spacing schedule along individual boards when blind-nailing 3/4-inch solid hardwood strip flooring to a plywood subfloor?

• AEvery 3 to 4 inches along board, 1/2 inch from ends
• BEvery 8 to 10 inches along board, 1 to 2 inches from board ends
• CEvery 14 to 16 inches along board, 4 inches from board ends
• DEvery 20 to 24 inches along board, 6 inches from board ends

When using a pneumatic floor nailer to blind-nail tongue-and-groove solid hardwood flooring, at what angle relative to the board face should the fastener enter the tongue?

• A15 degrees
• B30 degrees
• C45 degrees
• D90 degrees (perpendicular)

If floor joists are spaced 19.2 inches on center, what minimum subfloor panel construction is required by NWFA before installing nail-down solid hardwood?

• ASingle layer 1/2-inch CDX plywood
• BSingle layer 5/8-inch OSB panel
• CMinimum 7/8-inch tongue-and-groove APA rated plywood/OSB or double-layer subfloor combina…
• D1-1/2 inch lightweight gypsum concrete over 3/8-inch plywood

What is the function of installing a 2-in-1 foam/polyethylene underlayment pad beneath a floating engineered hardwood floor?

• ATo permanently glue the hardwood planks to the subfloor
• BTo provide a moisture vapor barrier, cushion minor subfloor imperfections, and attenuate…
• CTo elevate the floor by 2 inches to match exterior door thresholds
• DTo eliminate the need for wall baseboard moldings

Which adhesive chemistry is recommended by NWFA for direct glue-down installation of solid or engineered hardwood over clean concrete slabs?

• AWater-based polyvinyl acetate (PVA) yellow wood glue
• B100% solids elastomeric polyurethane or modified silane adhesive
• CSolvent-based contact cement
• DAsphaltic cutback adhesive

You are estimating solid hardwood flooring for a rectangular room measuring 18 feet by 25 feet. Standard practice dictates adding a 10% waste factor. How many square feet of flooring must be ordered?

• A450 sq ft
• B472 sq ft
• C495 sq ft
• D540 sq ft

When installing solid strip hardwood over a standard wood subfloor supported by joists, what is the required board layout direction relative to the underlying floor joists?

• AParallel to the floor joists
• BPerpendicular (at a 90-degree angle) to the floor joists
• CAt a 15-degree shallow angle to the floor joists
• DBoard direction does not matter as long as subfloor is flat

What is the purpose of installing 15 lb asphalt-saturated organic felt paper over a wood subfloor before nail-down solid hardwood installation?

• ATo act as a high-density structural leveling layer
• BTo act as a vapor retarder and reduce friction squeaks between subfloor and hardwood
• CTo soundproof the room to STC 65 performance
• DTo permanently glue subfloor panels to floor joists

When sanding unfinished jobsite-installed solid oak hardwood with a heavy drum sander, what is the standard grit progression sequence per NWFA guidelines?

• AFine (100 grit) -> Medium (60 grit) -> Coarse (36 grit)
• BCoarse (36 or 40 grit) -> Medium (60 or 80 grit) -> Fine (100 or 120 grit)
• CMedium (80 grit) -> Coarse (36 grit) -> Medium (80 grit)
• DExtra Fine (220 grit) -> Fine (120 grit) -> Medium (80 grit)

What is the minimum recommended end-joint stagger distance between adjacent rows of solid hardwood strip flooring to maintain structural integrity and visual appeal?

• A2 inches
• B6 inches
• C12 inches
• D18 inches

What transition fitting should be installed at a doorway where a 3/4-inch solid hardwood floor meets an adjacent luxury vinyl tile floor of lower profile?

• AMetal carpet gripper strip
• BHardwood reducer threshold or T-molding
• CQuarter round base shoe nailed directly into the LVT floor
• DSquare aluminum edge cap flush with tile

Why does the NWFA prohibit installing 3/4-inch solid hardwood flooring directly over concrete subfloors located below grade (basements)?

• ASolid wood reflects magnetic fields below ground level
• BBelow-grade concrete slabs carry high ground moisture vapor risks, causing solid wood to…
• CSolid hardwood is too heavy for basement concrete slabs
• DTermites automatically infest all below-grade solid wood within 30 days

Which standard industry test scale measures the relative hardness and dent-resistance of various wood flooring species?

• AMohs Hardness Scale
• BJanka Hardness Scale
• CRockwell C Hardness Scale
• DBrinell Metals Scale

When mechanically fastening 1/2-inch thick engineered hardwood flooring to a plywood subfloor, which fastener specification is typically required by manufacturers?

• A16-gauge 2-inch heavy-duty cleat nails
• B18-gauge narrow crown (1/4-inch crown) staples or 18-gauge L-cleats, 1-1/4 to 1-1/2 inche…
• C8d common ring-shank framing nails
• D1-inch drywall screws driven with a power driver

You are installing 3-1/4 inch wide solid oak flooring in a room measuring 24 feet by 18 feet. Factoring an 8% waste allowance, how many square feet of wood flooring should be ordered?

• A432 sq ft
• B467 sq ft
• C500 sq ft
• D540 sq ft

What is the primary cause of 'cupping' in solid hardwood plank flooring, where board edges are higher than the board center?

• AExcessive moisture or high relative humidity at the underside of the board relative to th…
• BOver-sanding the board center with a belt sander during finishing
• CUsing fasteners that are driven too deep into the tongue
• DInstalling wood flooring under intense direct sunlight

When installing engineered hardwood over a hydronic radiant heated subfloor, what is the maximum recommended surface temperature limit for the subfloor?

• A68°F
• B85°F
• C105°F
• D120°F

What is a primary installation requirement difference between click-lock floating LVT planks and glue-down LVT planks?

• AClick-lock LVT requires full spread epoxy adhesive across the entire floor
• BClick-lock LVT requires a perimeter expansion gap (1/4 to 3/8 in.) and flat subfloor, whe…
• CGlue-down LVT can only be installed over outdoor grass surfaces
• DClick-lock LVT must be heat-welded at every joint

When installing glue-down resilient sheet vinyl or LVT, what is the mandatory rolling procedure using a 100-lb 3-section steel roller?

• ARoll once across the center of the room after 24 hours of curing
• BRoll widthwise first, then immediately roll lengthwise to flatten adhesive ridges, transf…
• CRoll only along room perimeter edges using heavy downward arm pressure
• DRoll the subfloor before spreading any adhesive