Definition of Terms

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Definition of Terms





A substance that dries to a film capable of holding materials together by surface attachment. Applying adhesive to the floor normally is accomplished with a trowel, airless spray, or roller.

Adhesive transfer

The degree of coverage and penetration of the applied adhesive into the back of carpet while still maintaining full coverage of the floor. The degree of coverage may be influenced by adhesive type, method of installation, open assembly time and other factors.


Having a pH greater than 7.

Attached cushion

Cushion material permanently bonded to the back of carpet by the manufacturer.


A board skirting the lower edge of a wall, covering the junction of the wall and the floor.


Carpet manufactured in a roll format.

Calcium chloride test

ASTM F1869 test method that is used to obtain measurements of moisture vapor emission rates over concrete substrates.

Carpet cushion

Material placed under carpet to provide resiliency, support, insulation qualities and noise reduction; also referred to as carpet lining, padding, or underlay, although “carpet cushion” is the preferred industry term.

Carpet Tiles

Various shapes and sizes of carpet precut during manufacturing with applied backings.


The process of allowing the substrate, carpet, cushion and sundries to relax or acclimate to the proper environment into which it is to be installed as described in the text.

Curing Compounds

Chemicals used to accelerate the curing time of concrete. [These can be adhesive bond breakers]

Dead man

A device used in carpet installation to provide a point of resistance for facilitating stretching procedures.  Construction is a board with strips of tack strip attached to the bottom side.


A separation of the carpet’s primary and secondary backing.

Direct glue down

This is an installation method where carpet is adhered to the substrate using the proper adhesive.

Double glue down

This is an installation method where carpet cushion is first adhered to the substrate, and the carpet is then adhered to the cushion using the proper adhesives.

Double-headed mini-stretcher (crab stretcher)

Hand device used for aligning patterns where a power stretcher cannot be used; also used for removing fullness at seams and closing gaps at seams.

Dry line

This is a length of line or cord, which is stretched slightly above the carpet, but not touching the carpet, and used as a visual reference in pattern alignment.  Lasers also may be used in this capacity.

Edge Ravel

A condition of yarn loss in installed carpet when the edges begin to fray.


The distance between the tack strip and the wall. A gully should always be slightly less than the thickness of the carpet and not exceeding 3/8 inch.


Acronym for “heating, ventilating, and air conditioning” referring to indoor climate control systems.

High Moisture Carpet Adhesive

This is an adhesive that will work in a high moisture environment, however it does not act as a moisture barrier. See adhesive manufacturer for warranty information.


This is an installation tool designed to position carpet, hook and secure carpet onto the tack strip and also perform stair installations.  [NOTE: A knee kicker is not for stretching carpet.]

Open time

The earliest time interval between the spreading of adhesive on a substrate and the placement of a floor covering material into the adhesive for bonding.


Floor preparation process of filling holes, cracks, and imperfections, etc., in a floor substrate prior to installation of carpet

Pattern bow

This is a distortion visible as wavy or crooked pattern lines when viewed across carpet width.

Pattern elongation

This is a variation of cumulative pattern measurements from one breadth/width to the next.  It is often referred to as “pattern run-off” or “Length Pattern Repeat (LPR)”.  [Sequencing of cuts minimizes effects.]

Pattern skew

This is a distortion visible when the pattern on one side is slightly ahead of the pattern on the other side.  Skew, or bias, describes pattern squareness.


A value representing the concentration of hydrogen ions in gram equivalents per liter used to indicate the acidity or alkalinity (base) of a substance on a scale from 0 to 14 with 7 representing neutrality, numbers less than 7 increasing acidity, and numbers greater than 7 increasing alkalinity.  [Use distilled water for laboratory and field testing for pH.]


A substance incorporated into polyvinyl chloride polymer or other polymers to increase flexibility and workability.

Power stretcher  

A carpet tool used to stretch carpet.  Consists of a pinned plate or cotton head that grips the carpet, tubular extensions, a padded end used to brace against an opposing wall or other structure (dead man), and a lever system that multiplies the installer’s applied stretching force.


A preparatory coating placed on a substrate or material to promote adhesion and neutralize pH.


The upright part of a step between two stair treads.


A product used to reduce the porosity of the substrate.


The joints or interface of two pieces of carpet by the use of various securing techniques.

Seam adhesive

A specifically formulated adhesive for securing and protecting cut edges of carpet to be seamed.

Seaming Devices

Tools designed to melt seaming tape.

Seam peaking

The slight elevation of the taped seams which is a (usually renders the seam more visible) result from power stretching of the carpet.  For additional information, refer to CRI Technical Bulletin “Peaking Seams in Stretch-In Carpet Installations”.

Seam sealing/Edge sealing

Common term used to describe the application of seam adhesive to secure and protect cut edges of carpet to be seamed from edge raveling and delamination.

Seaming tape

Tape used for joining two sections of carpet.  [“Hot melt” tape is pre-coated with a thermoplastic adhesive.  Adhesives may be applied separately to other types of seaming tapes.]

Secondary backing

Woven or non-woven fabric reinforcement laminated to the back of tufted carpet, usually with an adhesive, to enhance dimensional stability, strength, stretch resistance, and ease of handling.

Selvage (selvedge)

The lengthwise, factory-finished edge portion of a carpet.

Shoe molding

Wood or plastic strip with one corner edge rounded slightly.  Used to conceal the floor/wall line junction or between larger moldings and floors.

Stair nose

Leading edge of a stair tread.  For carpet installation, it is required that this edge be rounded.

Stay nailing

A technique of temporarily fastening carpet to the floor using nails to prevent movement until permanent fastening with tack strips, adhesives, or other means is possible.  This technique is commonly used to align patterned carpet.


Installation method whereby carpet is placed over separate carpet cushion and is secured in place, under tension, using a power stretcher (mechanical stretching device).


A general term that means any surface below another surface, but which in the floor covering industry, most often refers to the stabilizing layer of material directly beneath the finish flooring.

Tack strip

Wood strip fastened to the floor near the walls of a room, containing either two or three rows of pins angled toward the walls on which the carpet is stretched and secured in a stretch-in installation.  (Also referred to as “tackless strip”)


The gradual appearance of irregularities, imperfections, or patterns from a substrate onto the surface of the carpet which can include seaming tape.


The raised material beneath a door.  This is also known as a “door sill” or “saddle.”

Transition molding

A wooden, metal, vinyl, or plastic strips to cover raw edges of carpet at doorways or where carpet abuts another type of floor covering.  There are two basic types:  1) Applied before


The horizontal part (walking surface) of a stair.


Hand implement used for metering and spreading adhesive to the floor or other substrate.

Trueness of edge/Bow in length

It is generally measured as maximum deviation from a straight line, over a defined distance, between common pattern points along the machine direction of the carpet.

Tufted carpet

Carpet manufactured by the process of inserting pile yarns into a primary backing fabric through needles.

Unitary carpet

Carpet back-coated with a compound intended to increase physical properties normally without the addition of a secondary backing.  

Working time (may be referred to as slip time)

The length of time available after covering the adhesive with carpet to make adjustments or manipulate the carpet.

Woven carpet

Carpet produced on a loom.  The lengthwise (warp) yarns and widthwise (weft or filling) yarns are interlaced to form the fabric.  Carpet weaves, such as Wilton, Axminster and velvet, are complex, often involving several sets of warp and fill yarns for the pile and backing.