by Terry Weinheimer, The Weinheimer Group LLC
Pooling and water marking are forms of shading and pile reversal that the pile of a carpet can experience. Pooling and watermarking are one of the most aggravating and most understood problems in the carpet industry. Pooling can truly result in rapid ugly out of carpet. To pool a carpet need not be soiled nor does it require texture change due to abrasion or foot traffic. Pooling and watermarking is unrelated to a carpets cost, maintenance and traffic. The best and worst maintained carpets can pool. Carpets and rugs of any fiber and any construction can pool and water mark. The worst news is that you may be decorating your home for the first time and unless the carpet in the house has a history of pooling, no on can determine if it is likely to happen to your beautiful new carpet or rug.

My grandson Seth is a little rug rat that loves the water and so do these three bears. While they all appear to be having a good time pooling, this is not the pooling we are talking about.

Carpet pooling is an irreversible, localized change in the orientation of the pile of textile floors covering. The phenomenon has different names in different countries. The terms we are most familiar with in the United States and Canada are “water marking” and “pooling”.

With pooling, some carpets develop areas where the pile appears to have been stained by water, hence, “water marking.”

Some carpets may develop areas that appear dirty. The carpet in this photo is not dirty. The large dark spot is the result of a difference in light reflection due to the pile reversal.

At some installations this appearance takes months to develop. At other installations it develops so rapidly that the consumer believes it to have been there since installation.

The carpet in this picture developed a severe pooling within a week of installation.

The carpet in this photo started to show pooling about five months after installation.

At a single installation the carpet may be installed in several rooms with the condition only developing in one or two of them. The area the condition develops in may be either a major traffic lane or even under furniture.

This condition routinely crosses seams. It even crosses between different color and styles of carpet and maintains a uniform pattern.

The photograph above shows an interface which is a narrow, conspicuous, irregular shaped serpentine line. This interface is often seen with pooling. The pile on the left side sweeps to the left. The pile on the right side sweeps to the right. The interface in the center sweeps upward and the pile in the interface has become very stiff feeling as if it had been starched.

Common Identifying Characteristics of Pooling

• Areas of carpet may look wet as though someone has spilled water on it but the carpet will be perfectly dry.
• Areas reverse in shade when viewed from opposite directions. When the areas are brushed with the hand a sharp difference in pile direction can be seen and felt.
• A narrow, conspicuous, irregular shaped serpentine line (referred to as an interface) usually develops at the edge of the pooled area. The pile at the narrow interface will run in a direction yet. The pile on both sides of the interface will be strongly oriented in opposite directions. As an example the pile at the interface may be oriented north while the pile on one side of the interface is facing east and on the other side it is facing west.
• Water marking often gives the carpet a highly objectionable appearance. Some carpets become downright ugly appearing as if it has been badly stained or allowed to become filthy within a short time of installation. As objectionable and as rapidly as this appearance change may occur, carpet manufacturers consider it a site-related condition and with rare exception will they offer the consumer any type of an adjustment. Water marking is a condition that cannot be permanently corrected.

The CRI States that Pooling is a Site Related Condition

The Carpet and Rug Institute in its manual titled Pile Reversal (“Shading”, “Water Marking”) states: At the present time, the only conclusion which can be drawn is that pile reversal may develop on the surface of some carpet after it is installed, and that pile reversal is not due to the materials which are used to produce the carpet, the manufacturing process, or any combination of these factors.

Some of the more common reasons Water Marking (Pooling) are considered site related is:

• Carpet off of the same roll is installed in different areas and the condition only develops in some areas.
• The condition will cross seams between different color, styles, and textures of different manufactures.
• The condition can sometimes be seen on installed carpet and an area rug above it.
• Replacing the carpet with another carpet of any fiber will often result in a repeat of the same condition. Pooling (Water Marking, Pile Reversal)Pooling and water marking are forms of shading and pile reversal that the pile of a carpet can experience.

Among the mysteries and most misunderstood concerns with carpet is pile reversal, shading, watermarking and pooling. These concerns result in not only the changing appearance of a carpet, they also result in disappointment and often irritation on the part of the consumer when the change takes place. Often this change occurs within days or weeks of installation and the consumer believes they have an inferior carpet when they don’t. The following explanation by the Carpet and Rug Institute is one of the better that I have ran across as it pertains to pile reversal, also known as shading, pooling, watermarking and highlighting.

Pile Reversal – Watermarking, Shading

All pile yarn carpet is subject to pile reversal; however, it is most likely to be observed in smooth surfaced, densely constructed, plush type qualities. This phenomenon is difficult, if not impossible, to predict or prevent. Pile reversal creates a permanent change in the carpet’s appearance caused by the difference in the way light reflects off the sides and tip of a yarn as the pile lays in different directions. Shaded areas appear light from one direction and dark from another direction. After a period of use, carpet may look as though water has spilled on section of the carpet hence, the term “water marking.” Other terms also commonly used to describe pile reversal are “pooling.” And “highlighting.”

Why the carpet pile, which lays uniformly in one direction when installed, changes direction permanently, is often a mystery. In many installations, the pile reversal direction is predictable from the pattern of foot traffic. Carpet pile is pushed away from turning traffic and toward the sides of a corridor.  Shading lines can cross carpet seams even when the manufactured direction of the joined pieces of carpet differ. In other situations, location factors such as an uneven subfloor, are thought to be possible causes for this phenomenon,

Pile reversal is not a manufacturing defect and does not affect the durability of the carpet. Pile reversal is not due to the materials used to produce the carpet, the manufacturing process, or any combination of these factors. Watermarking or shading may develop on a carpet made with any fiber(s) or manufacturing process. Once the condition has developed, it cannot be permanently removed.

When pile reversal takes place, there is little which can be done to return the carpet to its original appearance. Brushing or vacuuming may create some degree or temporary appearance change; however, this change is only at the top portion of the tuft. The pile will return to the reversed position after it is again subjected to foot traffic.

The visual impact of pile reversal depends on the nature of the carpet. Loop pile carpets or cut pile carpets with matte yarns have a low light reflecting quality. Boldly patterned carpets moderate, shading may not be visible even though pile reversal has occurred.

It is not possible to assure that pile reversal will not develop in any carpet.

The above explanation is from:

The Carpet and Rug Institute

Technical Bulletin CRI-03/00

Pile Reversal: An irreversible, localized change in orientation of the pile of a textile floor covering. The phenomenon has different names in different countries. The terms we are most familiar with in the United States and Canada are “water marking” and “pooling”.

Water Marking (Pooling) Some carpets develop areas where the pile appears to have been stained by water, hence, “water marking.” Other names to describe the phenomenon include “pooling” and “highlighting. At some installations this appearance takes months to develop. At other installations it develops so rapidly that the consumer believes it to have been there since installation. At a single installation the carpet may be installed in several rooms with the condition only developing in one or two of them. The area the condition develops in may be a major traffic lane or a lessor used area. This condition routinely crosses seams even between different color and styles of carpet and maintains a uniform pattern.

Common Identifying Characteristics of Pooling

• Areas of carpet may look wet as though someone has spilled water on it but the carpet will be perfectly dry.
• Areas reverse in shade when viewed from opposite directions. When the areas are brushed with the hand a sharp difference in pile direction can be seen and felt.
• A narrow, conspicuous, irregular shaped serpentine line (referred to as an interface) usually develops at the edge of the traffic area. The pile at the narrow interface will run in one direction, the pile on both sides of the interface will be strongly oriented in opposite directions. As an example the pile at the interface may be oriented north while the pile on one side of the interface is facing east and on the other side it is facing west.

Water marking often gives the carpet a highly objectionable appearance. Some carpet become downright ugly appearing as if it has been badly stained or allowed to become filthy within a short time of installation. As objectionable and as rapidly as this appearance change may occur, carpet manufacturers consider it a site-related condition and with rare exception will they offer the consumer any type of an adjustment. Water marking is a condition that cannot be permanently corrected.

Some of the more common reasons it is considered site related are:

• Carpet off of the same roll is installed in different areas and the condition only develops in some areas.
• The condition will cross seams between different color, styles, and textures of different manufactures.
• The condition can sometimes be seen on installed carpet and an area rug above it.
• Replacing the carpet with another carpet of any fiber will often result in a repeat of the same condition.

The causes of this form of pile reversal have not been conclusively determined. The Carpet and Rug Institute in its manual titled Pile Reversal (“Shading”, “Water Marking”) states, At the present time, the only conclusion which can be drawn is that pile reversal may develop on the surface of some carpet after it is installed, and that pile reversal is not due to the materials which are used to produce the carpet, the manufacturing process, or any combination of these factors.