Flooring glossary

Wear layer — the protective top layer on engineered wood and vinyl. It decides how long the floor survives and, for engineered wood, whether it can be sanded at all. Acclimation — leaving material in the room at normal living conditions before install so it stops moving afterward; the NWFA installation guidelines address jobsite conditions and acclimation for wood floors.

Expansion gap — the deliberate space left between the floor and the walls, hidden by baseboard. Without it, floating floors peak and buckle. Lippage — one board or tile sitting higher than its neighbor. Small amounts are normal; you feel it with a bare foot before you see it.

Subfloor — the structural sheet material over the joists. Underlayment — the layer between subfloor and finish floor, budgeted at roughly $3.40–$5.30 per square foot for carpet and laminate systems. Vapor barrier — a moisture layer, commonly about $100–$150 per room for vinyl over a slab.

Dye lot — the production batch. Two boxes of the same product from different lots can differ visibly. Transition strip — the trim between two flooring materials at a doorway, $10–$40 each. Screen and recoat — light abrasion plus a new finish coat at about $1–$2.50 per square foot, as opposed to a full sand and refinish at $3–$8.

How to choose

Ask for wear layer as a number

Marketing names for wear layers mean nothing across brands. The measurement does.

Look for 'expansion gap' on the quote

Its absence from an install spec for a floating floor is a warning sign.

Ask what lippage tolerance they work to

A contractor who has an answer has thought about flatness. One who hasn't, hasn't.

Record your dye lot

It's on the box label. You need it for any future repair.

Know the difference between recoat and refinish

$1–$2.50 per square foot versus $3–$8. Contractors sometimes quote the second when you need the first.