Guide · For the trade
Commercial carpet: how to write an office carpet specification
Commercial carpet is carpet built to a performance sheet rather than a look: solution-dyed nylon type 6 or 6,6 in a dense loop or low cut pile at 1/4 inch or under, a TARR appearance-retention rating of Heavy (3.0) or Severe (3.5), a Class I radiant panel rating of 0.45 W/cm² or more, a CRI Green Label Plus certificate, static under 3.5 kV, and a backing suited to glue-down or a cushion-back tile. An office carpet specification lists those lines, chooses tile or broadloom by the plan, and names the installation method; pattern and color come last and matter least to whether the floor still looks right in year eight.
This guide is for the designer writing a commercial spec for an office, a professional suite, a hotel corridor or a showroom, and for the junior turning a residential habit into a contract sheet. It covers what makes a carpet commercial grade, the lines on the sheet, tile against broadloom, backings and installation, and the mills in our library that publish full commercial data. Office chairs on residential carpet are in the home office carpet guide; the tile decision in detail is in the carpet tile vs broadloom guide.
What makes a carpet commercial grade
Construction, fiber and documentation. The construction is dense and low, usually a level or multilevel loop or a tip-sheared cut-loop at 1/8 to 1/4 inch with a density (face weight in ounces times 36, divided by pile height in inches) above 5,000, often 6,000 to 8,000 for corridors. The fiber is solution-dyed nylon almost without exception, the only synthetic that combines resilience with permanent color and bleach resistance; wool appears on executive floors and in hospitality. The documentation is what residential carpet lacks: a published TARR rating, a radiant panel class, smoke density, static, lightfastness and an emissions certificate, each tied to a named test on the mill's sheet.
Commercial carpet specifications: the lines and the numbers
| Line | Test | What to specify for an office |
|---|---|---|
| Appearance retention | TARR, ASTM D7330 and CRI TM-101 | Heavy (3.0) for open office and private offices; Severe (3.5) for corridors, lobbies, elevator landings |
| Flammability | ASTM E648 radiant panel; DOC FF 1-70 pill test | Class I (0.45 W/cm² or more) in corridors and exits; Class II (0.22 to 0.44) acceptable in rooms where code allows; the pill test is mandatory everywhere |
| Smoke | ASTM E662 smoke density | 450 or less, flaming mode |
| Emissions | CRI Green Label Plus or FloorScore; CA 01350 | Required for LEED v4 low-emitting materials; pad and adhesive certified separately |
| Static | AATCC 134 | 3.5 kV or less; 3.0 kV in rooms with electronics |
| Lightfastness | AATCC 16 | Rating of 4 or better at 40 hours; 80 hours in a glazed lobby |
| Pile height | Measured | 1/4 inch or under on accessible routes (ADA limit is 1/2 inch); under 3/8 inch for chairs on casters |
A mill that publishes all seven lines is a commercial mill. Milliken publishes them on all 282 of its styles in our library, every one Class I and Green Label Plus, in its WearOn solution-dyed nylon; Masland lists Class I and Green Label Plus on its EnVision nylon styles; Bloomsburg weaves Zeftron solution-dyed nylon and worsted wool in Pennsylvania with Green Label Plus on most of the line. Those three cover most office specs we quote. The low VOC carpet guide explains the emissions labels; the ADA figure applies to any route a wheelchair uses, with the carpet firmly attached.
Office carpet tiles vs broadloom
Tile is the office default for four reasons: a damaged square is replaced rather than a room re-carpeted, under-floor data access stays open, waste runs 3 to 5 percent instead of 10 to 15, and a 24 by 24 inch grid or an 18 by 36 inch plank lets the plan change color at the workstation groups without a seam. Broadloom is the choice where the look wants no grid: a boardroom, a partner's office, a hotel corridor in Axminster. Many offices use both, tile on the open floor plate and broadloom in the rooms off it. Specify tile with a cushion back where acoustics matter, a hard back where tiles will be lifted often.
Backing, adhesive and installation method
An office carpet is glued, not stretched. Direct glue-down puts the carpet on the slab with a pressure-sensitive or releasable adhesive and gives the firmest surface for chairs and carts; double glue-down adds a 1/4 inch dense commercial pad glued to the slab, with the carpet glued to the pad, for corridors and reception areas that should feel like a hotel. Tile uses a releasable adhesive so a square lifts clean. Commercial broadloom backings are woven polypropylene (Action Bac), a unitary backing that locks the loops for glue-down, or a polyurethane cushion or moisture-barrier back for hospitality; a jute secondary has no place in a contract spec. Write the slab test into the spec (ASTM F2170 at 75 percent relative humidity or ASTM F1869 at 3 pounds), the adhesive by name, and the seam layout from the mill's diagram, because a floor plate at 12 or 15 feet wide seams every bay.
What to write, in order
- Product: mill, style, color, construction, fiber, pile height, face weight, density, gauge, width or tile size.
- Performance: TARR class, radiant panel class, smoke density, static, lightfastness, Green Label Plus number.
- Backing and installation: backing type, adhesive by name, direct or double glue-down, slab moisture limit, seam diagram.
- Pattern: repeat dimensions and seam matching; quarter-turn or monolithic for tile.
- Attic stock: 5 percent of each color, left on site.
- Maintenance: the mill's cleaning schedule attached, with the spotter the warranty names.
Commercial carpet for stairs and the rest of the building
Stairs take the Severe TARR class and a Class I rating, in a dense loop with a wrapped nosing, never a loose runner; a wool Wilton is the executive-floor alternative, and the best carpet for stairs guide covers both. Reception and lobby take the lightfastness and the Severe rating. Private offices can step down to Heavy and a cut pile at 1/4 to 3/8 inch. Everything on an accessible route stays at 1/4 inch and firmly attached.
Questions designers ask
What makes a carpet commercial grade?
A dense low construction in solution-dyed nylon, and a spec sheet that publishes the tests: a TARR appearance-retention rating, a radiant panel class, smoke density, static, lightfastness and an emissions certificate. A carpet with those seven lines is commercial; a residential carpet in a commercial color is not.
Tile or broadloom for an office?
Tile on the open floor plate, for replaceability, access to the floor and 3 to 5 percent waste; broadloom in boardrooms, executive offices and corridors where the look wants no grid. Both can be glued over the same slab with a flush transition.
What is a TARR rating?
The Texture Appearance Retention Rating, from ASTM D7330: the carpet is walked or rolled for a set number of cycles and graded 1 to 5 against photographic standards. Moderate is 2.5, Heavy 3.0, Severe 3.5. Offices specify Heavy, corridors and lobbies Severe.
Can a residential carpet be used in a small professional office?
A dense solution-dyed nylon loop from a residential line will perform in a two-room suite with light traffic. The difference is the paperwork: without the published ratings, the client's lease, insurer or building inspector may not accept it, so ask us for the commercial sheet on the style first.
What does a LEED office need from the carpet?
A Green Label Plus or FloorScore certificate for the carpet, a certified pad and a low-VOC adhesive, together satisfying the low-emitting materials credit; recycled content and an environmental product declaration help the materials credits. The low VOC carpet guide has the credit language.
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