Installation Guide

6
needlepunched carpet – carpet made of a dense network of yarn fibers having a
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.
patching – Floor preparation process of filling holes, cracks, and imperfections, etc., in a floor substrate prior
to installation of carpet
pattern bow – A distortion visible as wavy or crooked pattern lines when viewed across carpet width.
pattern elongation – A variation of cumulative pattern measurements from one breadth to the next. Often
referred to as “pattern run-off” or “repeat variation.” [Sequencing of cuts minimizes effects.]
pattern skew – 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.
pH – 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.]
power stretcher (i.e. mechanical stretching device) – A carpet installation tool used to stretch carpet for
installation on the tack strip. Consists of a pinned plate that grips the carpet, tubular extensions, a padded
end used to brace against an opposing wall or other structure, and a lever system that multiplies the
installer’s applied stretching force.
riser – The upright part of a step between two stair treads.
seam – In a carpet installation, 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.
seam peaking – The slight elevation of taped seams, which usually renders the seam more visible, resulting
from stretching of the carpet. [Sometimes referred to as “seam stress realignment” peaking is a natural and
sometimes unavoidable condition and not the result of a manufacturing or installation defect. 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.