Every office flooring quote comes with a carpet tile spec sheet. Sizes, total height, use class, absorption coefficient — plenty of numbers, and rarely a word about what each one actually decides.
If you cannot read the numbers, comparison collapses into price comparison. Read just five items, and the spec sheet alone tells you whether a product fits your space. This guide walks through those five items one by one.
Carpet Tile Formats — 50×50 Tiles and Planks
The base module of carpet tile is the 50×50cm square. Unlike broadloom, it installs tile by tile — and only the stained or worn tiles need replacing. That is why it became the commercial standard.
A plank is an elongated rectangular format. Sizes vary by maker — 25×100cm, 50×100cm, 45.72×91.44cm — and planks are used for directional patterns like herringbone and ashlar.
| 기준 | 50×50 타일 | 플랭크 |
|---|---|---|
| Typical sizes | 50×50cm | 25×100 · 50×100 · 45.72×91.44cm |
| Laying patterns | Monolithic, quarter-turn (grid-based) | Herringbone, ashlar (directional) |
| Spot replacement | Easy tile-by-tile swap | Possible — check direction & dye lot |
| Best fit | Open office, corridors — heavy traffic | Lounge, executive, reception |
Sizes and colors of collections distributed in Korea are listed on the carpet material page.
Thickness — What 6–8mm Total Height Tells You
After format comes thickness. Total Height on a spec sheet is the pile (surface yarn layer) plus the backing, and commercial carpet tiles mostly sit in the 6–8mm range.
For example, ANKER plank collections distributed in Korea state total height as 6±0.5mm or 8±0.5mm. The figure after ± is the manufacturing tolerance between tiles.
Thicker does not mean better. Durability is governed by pile density and yarn construction, not thickness — those factors are covered in our commercial carpet durability guide.
Where thickness does matter is practical: door clearance, level differences against adjacent flooring, and the finished height on a raised access floor. For renovations, start by checking the existing finish thickness.
Use Class — How to Read 33-LC1
If size and thickness are physical dimensions, the use class is a durability summary. It is defined by the Korean standard KS K ISO 10874 (floor covering classification) and the European EN 1307 (textile floor coverings). The first digit is the space type, the second is the intensity.
KS K ISO 10874 is a direct adoption of ISO 10874, so the class system is identical. Imported spec sheets usually carry the EN 1307 notation — read it the same way.
A leading 2 means residential, 3 means commercial. The second digit rises from 1 (moderate) to 2 (general) to 3 (heavy). So 33 is the top commercial rating — Heavy Commercial Use.
| 기준 | 주거 (2X) | 상업 (3X) |
|---|---|---|
| Moderate (X1) | 21 — moderate domestic | 31 — hotel rooms, small offices |
| General (X2) | 22 — general domestic | 32 — general commercial |
| Heavy (X3) | 23 — heavy domestic | 33 — open office, corridors |
The trailing LC is the Luxury Class, from LC1 to LC5. It grades pile texture and comfort, not durability — a separate axis. For office procurement, check the use class first.
Acoustics — αw and ΔLw
After durability comes acoustics. Flooring carries two acoustic figures: αw (weighted sound absorption coefficient) for room reverberation, and ΔLw, the impact sound reduction toward the floor below.
αw condenses reverberation-room measurements (KS F 2805 · ISO 354) into a single 0–1 value under KS F ISO 11654. Closer to 1 means more of the incident sound is absorbed; 0 means full reflection.
The αw 0.25 you often see on commercial carpet tile sheets is low for an absorber, and pile absorption skews to high frequencies. The workhorse for room reverberation is ceiling absorbers with a deep air cavity behind them — carpet plays a supporting role.
Where carpet decisively parts ways with other flooring is impact sound, not absorption. It reduces heel clicks and chair-caster noise at the source, and cuts what transmits to the floor below.
Carpet's acoustic strength is impact sound, not absorption.
ΔLw states how much less of that light-weight impact sound reaches the floor below. It is measured to ISO 10140-3 and rated as a single number under ISO 717-2 — the higher, the better.
The Korean counterparts are KS F 2810-1 (field measurement of light-weight impact sound) and KS F 2863-1 (rating) — the same standard family used for apartment floor impact sound performance.
For a deeper look at absorption metrics, see the NRC guide; for material-by-material performance, the absorber comparison guide.
Installing over Raised Access Floors
Many Korean offices install carpet tile over a raised access floor (KS F 4760) that hides cabling underfoot. Neither tiles nor planks need to match the panel grid — for inspections, you simply lift the tiles over the access point.
What to check instead: releasable tack adhesive (so tiles can be lifted and reinstated), panel levelness and lippage, and the finished height against doors and adjacent floors.
Which Format for Which Space?
Put the items above against your space conditions and the choice becomes simple.
Open office · raised floor
A standard office with frequent cable access and heavy traffic.
Lounge · executive · reception
Front-of-house zones where impression matters.
Corridors · core circulation
The most trafficked runs in the building.
Partial renovation
Replacing flooring in only part of a floor.
For broader selection criteria, see the office carpet tile selection guide; for environmental certification, the eco-friendly carpet tile guide.
Frequently Asked Questions
Q1Is a thicker carpet tile a better one?
Q2Can 50×50 tiles and planks be mixed in one space?
Q3Where do I find the use class on a spec sheet?
Q4How are tiles fixed on a raised access floor?
Q5Do carpet tiles carry a fire performance class?
Glossary
- αw — weighted sound absorption coefficient. A single 0–1 index (KS F ISO 11654) from KS F 2805 · ISO 354 measurements.
- ΔLw — weighted impact sound reduction (dB). Korean rating counterpart: KS F 2863-1.
- KS K ISO 10874 — Korean floor covering use-class standard (adoption of ISO 10874).
- EN 1307 — European textile floor covering classification: use classes and luxury classes.
- LC — Luxury Class. Pile texture and comfort grades (LC1–LC5).
- Pile — the surface yarn layer. Backing — the base layer governing dimensional stability.
- Raised access floor — double flooring for cabling (KS F 4760).
References
- ISO 354:2003 — Acoustics, Measurement of sound absorption in a reverberation room
- ISO 11654:1997 — Sound absorbers for use in buildings, Rating of sound absorption
- ISO 717-2:2020 — Rating of sound insulation, Impact sound insulation
- ISO 10874:2009 — Resilient, textile and laminate floor coverings, Classification
- KS F 2805 — Measurement of sound absorption in a reverberation room (Korean Standard)
- KS F ISO 11654 — Rating of sound absorption for building materials (Korean Standard)
- KS F 2863-1 — Rating of floor impact sound insulation, light-weight impact source (Korean Standard)
- KS F 4760 — Access floor (Korean Standard)
- EN 1307:2014 Floorcovering classification — Centexbel
- Flame-retardance requirements — Korea Easy Law (Act on Installation and Management of Firefighting Systems)
- Effect of the suspended ceiling with low-frequency resonant panel absorber on heavy-weight floor impact sound — Building and Environment (2018)