Drywall Glossary | Terms & Definitions

A

Acoustic (Soundproof) Drywall: A denser, multi-layer or dampened drywall panel built to block sound transfer between rooms or units — commonly used in shared walls, home theatres and legal basement suites.
Angle Bead: A metal or vinyl strip installed on outside drywall corners to keep the edge straight and protect it from impact damage before mudding and sanding.

B

Beadboard: A decorative panel with narrow, evenly spaced vertical grooves, often installed over or instead of flat drywall on lower walls, wainscoting and ceilings for a classic look.
Blueboard: A specialized gypsum board with a treated blue paper facing designed to bond with veneer plaster instead of standard joint compound, used for a very hard, smooth plaster finish.
Bullnose Corner: A rounded, soft-edged corner (instead of a sharp 90° angle) formed with a flexible bullnose bead, popular in newer homes for a smoother, more modern look.
Butt Joint: The seam where two ends (not the tapered long edges) of drywall sheets meet. Butt joints are flat rather than recessed, so they take extra skill to tape and feather smooth without a visible hump.
Basement Drywall: Boarding, taping and finishing drywall for a basement development — framing walls around a concrete foundation, insulating, vapour-barriering, then hanging and finishing board for a livable lower level.

C

Casing Bead: A trim bead installed where drywall meets a different material (a window frame, brick, or an exposed edge) to give a clean, finished transition line.
CGC / Type X Drywall: Type X is a fire-rated gypsum board (often manufactured by CGC/USG) with added glass fibres in the core, giving it roughly one hour of fire resistance per layer. It's required by code in garages, furnace rooms and shared walls between suites.
Corner Bead: A metal or vinyl strip run down an outside drywall corner before mudding, giving the corner a straight, durable edge that resists dents and cracking.
Ceiling Texture: The finish applied to a ceiling — smooth (Level 5), light orange peel, or knockdown — sprayed or hand-applied over taped drywall to hide minor imperfections and match the rest of the home.
Ceiling Repair: Fixing cracks, water stains, sagging board, nail pops or damaged texture on an existing ceiling, then blending the patch into the surrounding texture so it disappears.

D

Drywall Screw: A coarse or fine-threaded screw (coarse for wood studs, fine for metal studs) used to fasten drywall to framing. Correct screw depth is critical — too deep tears the paper, too shallow leaves the head proud.
Drywall Anchor: A small plastic or metal fastener that expands or grips inside a drywall wall, letting you hang shelves, TVs or mirrors on drywall where there's no stud behind it.
Drywall Boarding: The first stage of a drywall job: cutting and screwing gypsum panels to wall and ceiling framing before any taping or mudding happens.
Drywall Clip: A small metal bracket used at the edge of a wall or ceiling, in place of extra framing, to support and fasten the edge of a drywall panel.
Drywall Lift: A mechanical jack used to raise and hold heavy drywall sheets (especially ceiling panels) in place while they're screwed off, reducing strain and improving accuracy on solo or two-person jobs.
Drywall Removal & Demolition: Stripping out old, damaged or water-affected drywall down to the studs so a room can be reframed, re-insulated and re-boarded from scratch.

E

Expansion (Control) Joint: A flexible metal or vinyl strip installed in a long, uninterrupted span of drywall to absorb building movement and prevent the board from cracking along that line.

F

Feathering: Spreading joint compound out in progressively thinner layers past the edge of a seam or patch so the repair blends invisibly into the surrounding wall, with no visible ridge or hump.
Fire Taping: A minimum, code-required taping pass (embedding tape and one coat of mud over every joint and fastener) on fire-rated assemblies like garage ceilings, done for fire separation rather than a paint-ready finish.
Fire-Rated Drywall: Type X or Type C gypsum board built into a wall or ceiling assembly specifically to slow the spread of fire between spaces — required by Alberta building code in garages, furnace rooms and between attached suites.
Five Levels of Finish (L0–L5): The industry-standard scale for how smooth a taped drywall wall is finished, from Level 0 (no taping at all) up to Level 5 (a full skim coat over the entire surface for a flawless, glare-free finish under any lighting).
Furring Strips (Furring Channel): Thin wood or metal strips fastened to an uneven wall, ceiling or masonry surface to create a flat, level plane for drywall to be screwed to.

G

Green Board: A moisture-resistant gypsum board with a green-tinted paper facing, traditionally used in bathrooms and laundry rooms in areas that get humid but aren't in direct, constant contact with water.
Gypsum: The soft mineral (calcium sulfate) that forms the solid core of every drywall panel. It's naturally fire-resistant because it releases bound water vapour when heated.
Gypsum Board: The formal name for what's commonly called drywall or sheetrock — a rigid panel made of a gypsum core sandwiched between two layers of paper.
Garage Drywall: Drywall installed in an attached or detached garage, almost always required to meet fire-rated Type X code between the garage and living space or neighbouring unit.

H

Hawk: A flat, handled tool a taper uses to hold a supply of joint compound while spreading it onto the wall with a taping knife.
Hanging Drywall: Trade shorthand for installing (screwing or nailing) drywall panels onto wall and ceiling framing — the boarding stage of a job.

I

Inside Corner: A 90° corner that folds inward (like where two walls meet in a room), usually taped with folded paper or mesh tape rather than a rigid corner bead.
Insulation Installation: Installing batt, blown-in or spray-foam insulation inside wall and ceiling cavities before drywall goes up — standard on basement developments, additions and exterior wall renovations.
Interior Painting: The paint stage that follows a finished drywall job — priming and painting walls and ceilings once taping, sanding and texture are complete and fully cured.

J

J-Bead (J-Trim): A J-shaped metal or vinyl trim piece used to finish a raw drywall edge where it meets another material, such as an open ceiling edge or a wall-mounted fixture cutout.
Joint Compound (Mud): The paste — either pre-mixed or powder-mixed — used to embed tape over drywall seams and build up smooth, feathered coats over fasteners and joints before sanding.
Joint Tape: Paper or fibreglass mesh tape embedded in the first coat of mud over every drywall seam, reinforcing the joint so it doesn't crack as the building settles.

K

Knockdown Texture: A two-step spray texture: compound is sprayed on in stipple peaks, then lightly flattened ("knocked down") with a wide knife before it dries, leaving a subtle, mottled finish popular on ceilings.

L

Lath: The base surface — historically wood strips, later expanded metal mesh — that plaster is applied directly to in older (pre-drywall) homes; still relevant when patching or transitioning old plaster-and-lath walls to drywall.
Level 5 Skim: A thin, full-surface coat of diluted joint compound rolled or sprayed over an entire wall or ceiling (the top of the five levels of finish), eliminating flashing and texture differences for the smoothest possible paint-ready surface.
Legal Suite Drywall: Drywall built to the specific fire-separation and soundproofing assembly required by Alberta code for a legal secondary suite, including rated board, resilient channel and sealed penetrations between units.

M

Metal Stud Framing: Steel C-shaped studs used in place of (or alongside) wood framing for interior walls and ceilings — common in basement developments, commercial spaces and fire-rated assemblies because they don't warp, shrink or feed mould.
Mesh Tape vs. Paper Tape: Two options for embedding drywall joints: self-adhesive fibreglass mesh tape is fast and easy to apply but needs a setting-type compound to resist cracking; paper tape is stronger long-term and the standard on butt joints and corners, but needs more skill to apply bubble-free.
Mud Pan: A narrow metal or plastic tray a taper loads joint compound into and runs a taping knife across to load the blade evenly before applying mud to the wall.
Mudding: General trade term for applying joint compound — embedding tape, building coats over fasteners and seams, and skim coating — as part of finishing drywall to a smooth, paintable surface.

N

Nail Pop: A raised bump in a finished wall where a fastener has worked its way slightly loose or the framing has shrunk, pushing the screw or nail head (and the mud over it) forward. Repaired by re-securing the board and re-mudding the spot.
New Construction Drywall: Boarding, taping and finishing drywall in a brand-new build or addition, coordinated with the other trades on-site (electrical, plumbing, HVAC) before insulation and drywall close the walls up.

O

Orange Peel Texture: A light, fine spray texture that leaves the surface with a subtle bumpy grain resembling the skin of an orange — one of the most common wall and ceiling textures in newer Calgary homes.
Outside Corner: A 90° corner that projects outward (like the corner of a wall you'd walk around), reinforced with a corner bead before mudding to keep the edge straight and impact-resistant.

P

Poly-B Patch-Back: Repairing and re-finishing the drywall that was cut open to access and replace Poly-B plumbing pipe — matching the texture and paint so the repair is invisible once the plumbing work is done.
Popcorn Ceiling (Stipple): An older spray-on ceiling texture with a heavy, bumpy, "popcorn" or cottage-cheese look, common in homes built before the 2000s. Usually removed by scraping and skimming to a smooth or modern knockdown finish.
Primer: A sealing coat applied to bare drywall and fresh joint compound before paint, so the porous compound and paper don't absorb the finish paint unevenly (a problem known as "flashing").
Plaster Repair: Patching and re-finishing older lath-and-plaster or veneer-plaster walls and ceilings, which crack and behave differently than modern drywall and often need a different repair approach.

Q

Quick-Set Compound (Hot Mud): A powder joint compound mixed with water on site that chemically hardens (rather than air-drying) in a set time — used to build coats faster on repairs, corner bead and same-day patch jobs.

R

Resilient Channel: A thin, springy metal channel installed between the framing and the drywall to decouple the two, reducing sound transfer through a wall or ceiling — a key part of soundproofing and legal suite assemblies.
Rock Lath: An older term for gypsum lath board (a precursor to modern drywall) nailed to framing as a base for hand-applied plaster in homes built roughly before the 1950s.
Renovation Drywall: Drywall work that's part of a broader renovation — opening up walls, patching around new openings, boarding additions, and re-finishing to blend seamlessly with the untouched original walls.

S

Scaffolding: Temporary platforms set up to safely reach high ceilings, stairwells and vaulted walls for boarding, taping and texture work that's out of normal ladder reach.
Screw Spacing: The code-specified maximum distance between drywall screws along framing (commonly 12″ on ceilings, 16″ on walls) to keep the board securely fastened and prevent sagging or nail-popping over time.
Skim Coat: A thin, wide coat of diluted joint compound applied over an entire surface (not just the seams) to even out texture differences or bring a wall up to a Level 5 finish.
Soundproofing Drywall: A wall or ceiling assembly built specifically to reduce sound transfer — combining resilient channel, mass-loaded or multi-layer drywall, and acoustic insulation — used in shared walls, home theatres and legal suites.
Sound Attenuation: The reduction of sound transmission through a wall or ceiling assembly, measured by its STC (Sound Transmission Class) rating — a key spec for any soundproofing or multi-unit drywall job.
Stud: The vertical wood or metal framing member drywall is fastened to, spaced at a standard interval (commonly 16″ or 24″ on centre) to give the board a secure, even surface.

T

Taping Knife: A wide, flat-bladed hand tool used to spread and feather joint compound over seams — tapers typically carry several widths, from a 6″ knife for embedding tape up to a 12″+ knife for final skim coats.
Texture Matching: Replicating an existing wall or ceiling texture (orange peel, knockdown, popcorn, smooth) over a patch or repair so the finished spot is invisible once painted.
Truss Uplift: A seasonal condition where roof trusses flex slightly with temperature and humidity changes, sometimes causing a hairline crack where an interior partition wall meets the ceiling — a common, largely cosmetic drywall callback in Calgary homes.

U

USG (United States Gypsum): One of the largest gypsum board manufacturers in North America (parent of CGC in Canada); "USG" or "CGC" board is often used generically in the trade the way "Kleenex" is used for tissue.

V

Vapour Barrier: A poly sheet installed on the warm side of exterior wall and ceiling insulation, before drywall goes up, to stop interior humidity from migrating into the wall cavity and condensing — required by code on basement and exterior wall framing.

W

Water-Resistant Drywall: Gypsum board with a treated, moisture-resistant facing rated for damp (not directly wet) areas like bathrooms — distinct from cement board, which is used in direct-water areas like shower surrounds.

Z

Z-Furring Channel: A Z-shaped metal channel fastened to a masonry or concrete wall (like a basement foundation) to hold rigid insulation and create a flat surface for drywall, without building a full stud wall.

Drywall Glossary — Terms Every Calgary Homeowner Should Know

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