NCCER Drywall flashcards
NCCER Drywall · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Type X gypsum board
- Gypsum panel with a glass-fiber-reinforced core, usually 5/8 in. thick, used where a fire-resistance rating is required in assemblies.
- Panel weight per square foot
- Regular 1/2 in. drywall weighs about 1.6 lb per sq ft, so a 4x8 sheet is roughly 51 lb; 5/8 in. Type X is about 2.2 lb per sq ft.
- Screw spacing on walls
- For single-layer screw attachment, space fasteners 8 in. on center along studs and panel edges; use 7 in. on center for ceilings.
- Screw penetration into wood
- Screws must penetrate wood framing at least 5/8 in.; drive heads just below the surface without breaking the paper facing.
- Staggering panel end joints
- Offset end joints between adjacent rows and from joints on the opposite face so four corners do not meet at one point, which reduces cracking.
- Floor gap for expansion
- Hold panel bottom edges about 1/2 in. above the floor and 1/4 in. from abutting walls so movement does not crack the finished surface.
- Back-blocking butt joints
- A method of reinforcing butt joints that fall between framing by gluing and screwing a strip of drywall behind the joint before taping.
- Two-ply joint offset
- In double-layer systems, offset face-layer joints at least 10 in. from base-layer joints and use longer screws to anchor the face layer independently.
- Joint compound drying times
- Setting-type compound cures chemically in 20-90 minutes; drying-type all-purpose compound needs about 24 hours per coat under normal conditions.
- Level 4 finish
- Tape plus three coats of compound over all joints, fasteners, and corners, then sanded smooth; the standard finish for most residential and commercial walls.
- Level 5 finish
- Level 4 plus a skim coat of compound over the entire surface, used where glossy paint or critical lighting would reveal joint and fastener shadows.
- Feathering joint coats
- Each successive coat is spread 2-4 in. wider than the previous one so the joint tapers smoothly into the surrounding panel surface.
- Corner bead fastening
- Press bead into compound on both flanges and fasten every 9-12 in.; fasteners must not protrude past the bead nose or they will show through.
- Sanding grit selection
- Use 120-150 grit to knock down ridges and 180-220 grit for final smoothing; light pressure and a side light reveal remaining defects.
- Priming bare compound
- Bare joint compound absorbs paint unevenly, so apply a drywall-specific primer before finish paint to equalize absorption and hide lap marks.
- Texture test panel
- Spray a scrap piece of board with the same compound, nozzle, pressure, and distance before texturing the wall to confirm the pattern matches.
- Stud spacing for drywall
- Wood framing is typically 16 or 24 in. on center; panels are oriented so long edges land on framing and joints are minimized.
- Framing straightness tolerance
- Studs and joists should be straight and aligned so the finished plane varies no more than 1/4 in. in 10 ft; plane or shim high spots.
- Backing at panel edges
- Install blocking or a continuous nailer wherever a panel edge does not land on framing, such as butt joints and around openings.
- Resilient channel spacing
- Fasten channel perpendicular to joists at 24 in. on center using screws no longer than 1 in. so they do not contact the framing and defeat isolation.
- Control joint placement
- Place control joints in walls and ceilings longer than 30 ft, at intersections of dissimilar substrates, and where framing changes direction.
- Moisture-resistant board use
- Water-resistant gypsum board with a treated core and face paper is used in bathrooms and behind tile; cement board is used in direct wet areas.
- Blocking before close-in
- Install wood blocking for cabinets, grab bars, and heavy fixtures before hanging board, then record the locations for later reference.
- Ceiling framing alignment
- Ceiling joists must be aligned and level so panels lie flat; low spots are shimmed or furred before the ceiling is hung.
- Respirator for sanding
- Drywall dust contains silica and gypsum; wear an N95 or P100 respirator during sanding and ventilate the work area.
- Ladder setup ratio
- Set an extension ladder with a 4:1 base-to-height ratio, maintain three points of contact, and keep the belt buckle between the side rails.
- Drywall lift use
- A mechanical lift holds ceiling panels in place for fastening; it reduces overhead lifting and replaces unsafe standing on buckets or sawhorses.
- Cut-resistant gloves
- Wear cut-resistant gloves and eye protection when scoring, snapping, and routing gypsum board with a utility knife.
- Floor hazard control
- Sweep offcuts, loose screws, and staples frequently; these are common puncture and trip hazards on drywall jobsites.
- Scaffold guardrail height
- Scaffold platforms must be fully planked with guardrails at 42 in. and midrails; climbing cross braces is prohibited.
- Flat panel storage
- Store panels flat on level blocking rather than leaning against walls, because leaning stacks can fall and the board can warp.
- GFCI on jobsite
- Use GFCI-protected circuits for power tools in wet or damp areas and inspect cords for damage before each use.