Renovation Glossary: 70+ DIY and Construction Terms Explained

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Renovation comes with its own language. Keep this page open when you watch tutorials or talk to contractors. Jump to a letter:

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Acclimation

Letting flooring or wood sit in the room for 24–72 hours so it adjusts to the temperature and humidity before installation.

Anchor (wall anchor)

A plug or toggle inserted into drywall or masonry so a screw can hold weight where there's no stud.

Backer board (cement board)

A cement-based panel used behind tile in wet areas instead of regular drywall.

Backsplash

The wall surface behind a kitchen counter or sink, usually tiled to protect it from splashes.

Baseboard (skirting board)

Trim running along the bottom of walls, covering the gap between wall and floor.

Beacons / screed rails (plaster guides)

Metal or wooden strips fixed to a wall or floor and set perfectly level; plaster or screed is then leveled across them with a straightedge.

Bullnose

A rounded edge on tile, trim or countertops, used on exposed edges.

Butt joint

Two pieces meeting edge to edge without overlapping — e.g. wallpaper seams.

Caulk

A flexible sealant (usually acrylic, paintable) that fills gaps between trim, walls and counters.

Circuit breaker

A switch in your electrical panel that cuts power to a circuit when overloaded — and the one you turn off before electrical work.

Corner bead

A metal or plastic angle strip that protects and straightens outside corners of drywall before plastering.

Cure time

The time a material needs to reach full strength (often longer than "dry to touch").

Drywall (plasterboard, gypsum board)

Panels of gypsum sandwiched in paper, screwed to studs to form walls and ceilings.

Drop cloth

A canvas or plastic sheet protecting floors and furniture from paint and dust.

Eggshell

A low-sheen paint finish between matte and satin — popular for living rooms and bedrooms.

Expansion gap

A gap (usually 1/4–1/2 in / 8–12 mm) left at walls so floating floors can expand without buckling. Hidden under baseboards.

Feathering

Spreading compound or paint thinner towards the edges so a patch blends invisibly into the wall.

Flashing (paint)

Dull or shiny spots where paint absorbed differently — usually over unprimed patches.

Floating floor

A floor (laminate, vinyl plank, engineered wood) that locks together and isn't glued or nailed to the subfloor.

GFCI / RCD

A safety device that cuts power in milliseconds when it detects a leak to ground — required near water.

Grout

The mortar that fills joints between tiles. Sanded grout for wider joints, unsanded for narrow joints; epoxy grout is stain-resistant.

Grout float

A rubber-faced trowel used to press grout into joints.

Hot mud

Setting-type joint compound that hardens chemically within a set time (e.g. 20 or 45 minutes).

HVAC

Heating, ventilation and air conditioning.

Isolation (shut-off) valve

A small valve on a supply pipe that lets you turn water off to one fixture without shutting off the whole house.

Joint compound (mud)

Paste used to finish drywall seams and repair walls. See our explainer.

Joist

A horizontal structural beam supporting a floor or ceiling.

Kick plate / toe kick

The recessed panel at the bottom of base cabinets.

Laminate

A floor or surface made from a photographic wood/stone layer on a fiberboard core, sealed with a hard wear layer.

Lippage

When one tile edge sits higher than its neighbor — a sign of poor leveling.

Load-bearing wall

A wall that supports the structure above. Never remove without an engineer.

LVP / LVT

Luxury vinyl plank / tile — waterproof vinyl flooring that looks like wood or stone.

Mortar / thinset

Cement-based adhesive used to set tile.

Miter

A cut at an angle (usually 45°) so two pieces of trim meet neatly at a corner.

Mesh tape

Self-adhesive fiberglass tape for reinforcing drywall joints and cracks.

Nap

The fiber length of a paint roller cover; short for smooth walls, long for rough surfaces.

OSB

Oriented strand board — an engineered wood panel used for subfloors and sheathing.

P-trap

The U-shaped pipe under a sink that holds water to block sewer gases — and catches dropped rings.

PEI rating

A 0–5 scale of wear resistance for glazed tile.

Plumb

Perfectly vertical.

Primer

A first coat that seals the surface and helps paint bond.

Punch list (snag list)

The list of small defects to fix before a job is considered finished.

Quarter round (shoe molding)

Small trim that covers the expansion gap at the bottom of baseboards.

Rough-in

The stage where pipes, wires and ducts are installed inside open walls, before drywall.

Render

A cement-based plaster, used on masonry walls and exteriors.

Screed

A layer of sand-cement or self-leveling compound laid on a floor to make it flat and level before the finished flooring.

Sheen

How glossy a paint is: flat, matte, eggshell, satin, semi-gloss, gloss.

Shim

A thin wedge used to level or plumb doors, windows and cabinets.

Silicone

A waterproof, flexible sealant for tubs, showers and sinks. Not paintable.

Skim coat

A very thin layer of compound over a whole wall to make it smooth.

Spackle

A ready-made filler for small holes and dents.

Stud

A vertical framing member inside walls, usually 16 in (40 cm) or 24 in (60 cm) apart.

Subfloor

The structural floor layer (plywood, OSB or concrete) under the finished floor.

Tile spacers

Small plastic crosses or wedges that keep grout joints even.

Tile leveling system

Clips and wedges that pull adjacent tiles flush to prevent lippage.

Trim

Decorative moldings: baseboards, casings around doors and windows, crown molding.

Underlayment

A thin foam, cork or felt layer under floating floors for cushioning, sound and moisture protection.

Undercut (door jamb)

Cutting the bottom of a door frame so new flooring slides underneath.

Vapor barrier

A plastic sheet that stops moisture moving from concrete or walls into flooring or insulation.

VOC

Volatile organic compounds — fumes released by paints and adhesives. Low-VOC products are healthier indoors.

Wainscoting

Paneling on the lower part of a wall, often painted in a contrasting color.

Waterproofing membrane

A liquid or sheet layer applied behind tile in showers and wet rooms to keep water out of the structure.

Wet edge

Keeping the edge of your paint wet as you work, to avoid lap marks.

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