Resources
Flooring Terms Glossary
Plain-English definitions of the flooring terminology you'll encounter when shopping. From wear layer ratings to subfloor types — what the words actually mean and why they matter.
AC Rating
The Abrasion Class rating measures laminate flooring's resistance to wear, from AC1 (light residential) to AC5 (heavy commercial). For a typical home, AC3 or AC4 is sufficient.
Why it matters: A higher AC rating means the floor will hold up longer under traffic, but you don't need to overpay for AC5 in a bedroom.
Acclimation
The process of letting flooring sit in the room where it will be installed so it can adjust to the temperature and humidity. Required for hardwood (typically 3–5 days) and recommended for many LVP products (24–48 hours).
Why it matters: Skipping acclimation is the #1 cause of warped, gapped, or buckled floors after installation.
Click-Lock
A floating-floor installation method where planks snap together via tongue-and-groove joints with no glue, nails, or staples. The floor "floats" over the subfloor.
Why it matters: Click-lock is the most DIY-friendly installation method available. Most LVP and laminate uses click-lock.
Dye Lot
A batch of flooring manufactured at the same time. Different dye lots of the same SKU can have subtle color variations.
Why it matters: Order all the flooring you need at once. If you run short and reorder later, the new boxes may not match.
Engineered Hardwood
Real wood flooring made from a thin top layer of hardwood (the wear layer) bonded to a multi-ply core of plywood or HDF. Distinct from solid hardwood, which is one continuous piece of wood.
Why it matters: Engineered hardwood is more dimensionally stable than solid hardwood, making it suitable for basements, over concrete subfloors, and over radiant heat.
Floating Floor
Any flooring installation that doesn't attach to the subfloor (no glue, no nails). The floor "floats" on top, held in place by its own weight and the perimeter walls.
Why it matters: Floating installations are faster, easier to DIY, and easier to replace later. Most modern LVP and laminate is floating.
HDF (High-Density Fiberboard)
Compressed wood fiber used as the core layer in laminate and many engineered hardwood products. Denser and harder than MDF.
Why it matters: Higher-quality HDF cores resist moisture and impact better than cheap fiberboard.
Janka Hardness
A scale that measures wood hardness by how much force it takes to embed a small steel ball halfway into the wood. Higher numbers mean harder wood.
Why it matters: Janka tells you how dent-resistant a wood species will be. Hickory (1820) is significantly harder than red oak (1290) or walnut (1010).
Laminate Flooring
A floor made from a printed image of wood (or stone, or tile) bonded to a fiberboard core, with a clear protective wear layer on top. Not real wood.
Why it matters: Laminate is cheaper than hardwood or LVP, but it's not waterproof and can't be refinished. Modern laminate looks better than ever, but it's still a budget-tier product.
LVP (Luxury Vinyl Plank)
A multi-layer waterproof flooring product with a printed wood-look design layer and a clear wear layer on top. Made from PVC vinyl.
Why it matters: LVP is 100% waterproof and durable. It's the fastest-growing category in flooring for good reason — it works in kitchens, bathrooms, basements, and high-traffic areas where hardwood doesn't.
MAP (Minimum Advertised Price)
The lowest price a manufacturer allows authorized dealers to publicly advertise for their products. Set by the manufacturer, enforced by contract.
Why it matters: The strikethrough pricing you see on FloorFreight reflects the MAP — the floor of public pricing for that SKU across all authorized dealers.
Mil (Wear Layer Thickness)
A measurement of wear-layer thickness equal to one-thousandth of an inch. LVP wear layers typically range from 6 mil (cheap) to 28+ mil (commercial-grade).
Why it matters: For residential use, look for 20 mil or higher. For high-traffic homes with kids and pets, 22–28 mil. Anything under 12 mil will scratch quickly.
Nail-Down Installation
A hardwood installation method where each plank is fastened to the subfloor with cleats or staples. Standard for solid hardwood over wood subfloors.
Why it matters: Nail-down is the most permanent and stable hardwood installation, but it requires a plywood subfloor (won't work over concrete).
Pre-Finished
Flooring that arrives from the factory already stained and sealed. The opposite of site-finished, where finish is applied after installation.
Why it matters: Pre-finished floors are faster to install (no drying time, no dust), and the factory finish is typically more durable than on-site polyurethane.
Quarter-Round / Shoe Molding
A small molding strip installed where the flooring meets the baseboard to cover the expansion gap.
Why it matters: Floating floors require an expansion gap around the perimeter. Quarter-round hides it. Don't skip it.
Reducer
A transition strip used where flooring meets a lower surface, like transitioning from hardwood to vinyl or carpet.
Why it matters: Quality transitions matter for the final look. Buy reducers, T-moldings, and stair nosings in matching colors when you order your flooring.
SPC (Stone Plastic Composite)
A rigid-core LVP construction made from limestone, PVC, and stabilizers. More dimensionally stable than WPC at temperature extremes.
Why it matters: SPC is the preferred core type for sunrooms, basements, and rooms with significant temperature swings.
Solid Hardwood
Real wood flooring made from one continuous piece of hardwood, typically 3/4" thick. Distinct from engineered hardwood, which is a wood veneer over a plywood/HDF core.
Why it matters: Solid hardwood can be refinished multiple times over its lifetime, making it the longest-lived flooring option (50+ years possible). Not suitable for basements or concrete subfloors.
Subfloor
The structural floor underneath your finish flooring. Usually plywood, OSB, or concrete.
Why it matters: Your finish floor is only as good as the subfloor under it. Uneven, damaged, or moisture-affected subfloor causes most flooring failures.
T-Molding
A T-shaped transition strip used where two floors of equal height meet, typically in doorways.
Why it matters: T-molding allows two floating floors to expand and contract independently while hiding the gap.
Tongue-and-Groove
A method of joining flooring planks where one edge has a protruding "tongue" that fits into a "groove" cut into the next plank.
Why it matters: Modern click-lock floors use a sophisticated tongue-and-groove design that locks mechanically without needing glue.
Underlayment
A thin layer of cushioning material installed between the subfloor and the finish floor. Reduces sound, smooths minor subfloor imperfections, and adds insulation.
Why it matters: Some LVP products (like COREtec) come with attached underlayment built in. Others require it sold separately. Always check.
Vapor Barrier
A plastic sheet installed over concrete subfloors to block moisture from rising into the finish floor.
Why it matters: Required for most flooring over concrete (basements, slab-on-grade homes). Skipping the vapor barrier causes mold, warping, and floor failure.
Wear Layer
The clear protective top layer of LVP, laminate, or engineered hardwood that protects the design layer from scratches, stains, and UV damage.
Why it matters: Thicker wear layer means longer-lasting floor. For LVP, measured in mils. For hardwood, measured by veneer thickness in millimeters (2–3mm = high quality).
WPC (Wood Plastic Composite)
A rigid-core LVP construction made from wood flour, PVC, and foaming agents. Slightly softer underfoot than SPC but more thermally stable.
Why it matters: WPC is comfortable for whole-home installations where you're walking and standing on the floor for hours.