Wood and Laminate Flooring Inspector flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Wood moisture content formula

MC% equals wet weight minus oven-dry weight, divided by oven-dry weight, times 100. A 100 g sample drying to 90 g is 11.1% MC.

Equilibrium moisture content

The moisture content wood reaches when it stabilizes with surrounding air at a given relative humidity and temperature. A floor installed at one EMC and exposed to another will move.

Cupping definition

A board condition where edges are higher than the center, producing a convex top surface. It usually indicates moisture gain from below the floor, such as a wet subfloor or slab.

Crowning definition

A board condition where the center is higher than the edges. It often follows surface moisture exposure or sanding a cupped floor before it fully dries.

Seasonal gapping

Gaps between boards that open during dry heating season and close in humid months. Document gap width and indoor relative humidity history before assigning cause.

Subfloor flatness tolerance

Wood flooring commonly requires the subfloor flat within 3/16 inch in 10 feet, or 1/8 inch in 6 feet. Verify with a straightedge before installation.

Calcium chloride test

ASTM F1869 test that measures moisture vapor emission from a concrete slab in pounds per 1000 square feet per 24 hours. It measures vapor, not in-situ slab moisture.

In-situ RH probe

ASTM F2170 test using probes placed in drilled holes in a concrete slab to measure relative humidity inside the slab. Results are reported as RH percent.

Plainsawn vs quartersawn

Plainsawn boards show growth rings at a shallow angle and move more in width with humidity changes. Quartersawn boards show steeper rings and move less across their width.

Inspection documentation

Record indoor temperature and relative humidity, HVAC operation, moisture readings of flooring and subfloor, flatness measurements, and dated photos of each defect location.

Wood floor acclimation

Allowing flooring to adjust to the installation environment before installation, typically by storing it in the conditioned space and verifying moisture content matches expected in-service conditions.

Wide plank movement

Wider boards accumulate more total width movement than narrow boards for the same moisture change, so wide plank floors show larger gaps and more pronounced cupping.

Subfloor moisture barrier

A vapor retarder or barrier placed over concrete or in crawl spaces to limit moisture vapor reaching the wood floor. Missing or damaged barriers often precede cupping complaints.

Pin vs pinless meters

Pin meters measure resistance between electrodes driven into the wood. Pinless meters use capacitance or radio frequency and read a shallow zone. Species and temperature corrections apply to both.

Wood floor inspection order

First document site conditions, then measure moisture in flooring and subfloor, then check flatness, then map and photograph defects. Sequence prevents attributing movement to the wrong cause.

Laminate construction

Laminate is a composite of a wear layer, decorative print, high-density fiberboard core, and backing. The core absorbs water and swells, which is generally irreversible.

Expansion gap requirement

Laminate needs a perimeter gap, commonly 1/4 to 3/8 inch, at walls and fixed objects. Missing gaps cause buckling, peaking, or tenting at seams.

Floating floor rule

Laminate is normally a floating floor, not fastened to the subfloor. Inspect for fasteners, glue-down errors, or missing underlayment that violate the installation method.

Laminate subfloor flatness

Laminate commonly requires the subfloor flat within 3/16 inch in 10 feet. Correct low spots with leveling compound and high spots by grinding before installation.

Laminate acclimation

Cartons should sit in the room at normal living conditions for the manufacturer's stated period, often 48 hours, before installation. Verify with delivery and installation records.

Peaking or tenting

A raised ridge at laminate seams, usually caused by inadequate expansion space, tight fits against walls, or core swelling from moisture. Check perimeter gaps and moisture exposure.

Core swelling

Water absorbed by the fiberboard core causes edges to swell and seams to lift. Swelling is generally permanent and indicates a moisture source that must be corrected.

Laminate wear layer

The transparent top layer that resists abrasion, stains, and fading. Wear-through appears as dull patches or print loss and usually indicates traffic or abrasive debris, not installation error.

Underlayment function

Underlayment provides cushioning, sound reduction, and sometimes a vapor barrier beneath laminate. Wrong type or missing underlayment can cause noise, movement, or moisture problems.

Laminate moisture testing

Test the subfloor with a calcium chloride test or in-situ RH probe on concrete, and a moisture meter on wood. Laminate itself is not a moisture barrier.

Transition profiles

Strips or moldings covering the gap between laminate and other flooring or at doorways. Improperly installed profiles restrict movement and can cause buckling at the transition.

Laminate joint separation

Gaps opening at the locking joint, often from subfloor movement, moisture swelling, or inadequate expansion space. Measure gap width and check perimeter clearance.

Laminate cleaning damage

Wet mopping and standing water cause edge swelling and delamination. Inspect for water staining at seams and ask about cleaning methods during the interview.

Laminate inspection evidence

Document joint gaps, core swelling at seams, underlayment type, vapor barrier presence, perimeter clearances, and transition details with measurements and dated photographs.

Laminate vs wood movement

Wood moves with humidity and can recover after drying. Laminate core swelling from water is generally permanent, so moisture damage is a stronger defect indicator in laminate.

Laminate vapor barrier

A polyethylene film or attached backing that blocks moisture vapor from concrete or crawl spaces. Missing barriers on slabs often precede swelling and seam failures.

Laminate defect mapping

Mark each damaged seam, swollen edge, and raised area on a floor plan with measurements from reference walls, then photograph with a scale to support the report.