Seam Failure, no seaming adhesive

This report was commissioned by the mill and the problem reported was pulled yarns.

THE CARPET
FIBER:    Nylon
ID METHOD:    According To Manufacturer
FIBER COLOR:    Multi-Color, Mainly Green
CONSTRUCTION:    Conventional Tuft
YARN STYLE:    Cut & Loop
SQUARE YARDAGE:    1000
BACK SYSTEM:    Conventional Tuft
PRIMARY BACKING:    Polypropylene
SECONDARY BACKING:    Polypropylene
INSTALLATION STATISTICS
TYPE LOCATION:    Commercial
METHOD:    Direct Glue Down
SUBFLOOR:    Concrete Slab
AREA INSTALLED:     Offices & Hallways On The Sixth And Seventh Floors
USE & MAINTENANCE STATISTICS AT THE TIME OF THE INSPECTION
LITERATURE RECEIVED WITH PURCHASE: Not Determined
NUMBER OF EMPLOYEES    100
TEMPERATURE: 72.2°F - 22.3° C RH 36%
VACUUM TYPE:    Upright
VACUUM FREQUENCY:    Nightly
ENTRY-MATS:    In the Downstairs Lobby
SOIL:    None Noticed
HEATING TYPE:    Forced Air Gas
COOLING TYPE:    Central - Electric
CLEANING:    Never Been Cleaned
GEOGRAPHICAL INFORMATION
This carpet is located in a high-rise office building on the western edge of the San Fernando Valley, just north of the 101 Freeway, approximately 40 miles west of downtown Los Angeles.
SITE CONDITIONS
This high-rise office building is approximately ten years old and is part of a complex with a hotel, shopping center and movie theater. A multi-level parking garage connects these buildings with bridges. Furnishings and maintenance of these facilities appeared to be very good.
BACKGROUND INFORMATION MADE TO THE INSPECTOR
According to the claimant, both the seventh and sixth floors were installed over the Christmas holiday of 2000 while many employees were on vacation. The seventh floor was done first because there were more time restraints on the sixth floor installation than on the seventh floor.
Approximately 35 employees work on the seventh floor of which this claimant occupies half of the floor. The remaining 65 work on the sixth floor of which the claimant occupies the entire floor.
No pulled loops were noted immediately after the installation on the sixth floor, but gradually since then, approximately 150 pulled loops have been repaired. Reportedly, the sixth and seventh floor came from different production runs, but was of the same style and color. Only one spot on the seventh floor had any pulled loops and that was reportedly after moving heavy boxes over the carpet. The claimant reported that the dealer's theory is that the carpet on the sixth floor is defective.
DESCRIPTION OF PROBLEM AREA BY THIS INSPECTOR
The claimant directed this inspector to the west side of the sixth floor where approximately two dozen different areas of pulled loops were seen. All of these areas were in seams and in a couple of cases; yarns were missing, forming gaps. In other cases, a single yarn was snagged, but still attached to the carpet. Transparent tape had been placed by the claimant over the pulled yarns. These pulled loops existed in hallways and under desks. Seams elsewhere were barely noticeable and had no apparent problem.

On the eastside of the sixth floor, there were only three areas of pulled loops in the seams, all in close proximity to one another and all in walkways. On the seventh floor, the single pulled loop problem was located in a short hallway where boxes were being stored. One panel of this seam was measured at 12 feet and zero inches.
This inspector took notice of the footwear of the employees of the claimant and there where no high-heeled shoes seen on the day of the inspection. Instead, all employees present were seen wearing flat leather or rubber soled-shoes.
ON-LOCATION FIELD TESTING
An ultra-violet light was shone to find evidence that seaming adhesive was used properly. On the seventh floor a faint neon glow was seen, see picture 1. No similar reflection could be found in seams with pulled loops on either the seventh or sixth floor.
Other uses of the ultra-violet light were to draw a reflection from substances with fluorescent dyes. Yellow reflections will come from most urine stains while blue or lavender reflections will come from inappropriate detergents. The results of this testing revealed that there were no reflections.
Numerous moisture tests were performed using a Delmhorst Moisture Sensor that would indicate the presence of moisture locked-up in the same compounds mentioned above, but these tests revealed that there were no moisture readings either.
THE ISSUE
The question that I have been asked to address is to determine what caused the carpet yarns to pull.
GUIDELINES FOR EVALUATING THE ISSUE
Pulled loops can occur when:
1. There is excessive foot traffic and/or improper maintenance
2. There is a manufacturer's defect
3. There is a failure to meet minimum standards of installation
INDUSTRY STANDARDS & DEFINITIONS
Concerning carpet's edges, the CRI104-1996 says this:
8.2 Layout - Carpet should be unrolled in the area in which it is to be installed 24 hours prior to actual installation, with room temperature between 65° F and 95° F (18° C - 35° C). Carpet should be cut 3-4 inches longer than the area measurement. If the carpet is patterned, allow for pattern repeat. Align all breadths, or sections of carpet, in their proper position, and trim the edges to be seamed.
8.5 Seam Adhesive - To prevent fraying and raveling at seams, a 1/8-inch (3.2 mm) continuous bead of seam adhesive should be applied to the base of the first edge where the face yarn enters the backing. (See figure 1.) This will seal the first edge as well as the second when the edges are butted together to form the seam.
THE INSPECTOR'S ANALYSIS
Pulled loops can be a common occurrence where footwear such as high-heeled shoes snag the carpet and thus create a pulling force greater than the normal designed limitations of the carpet. When this does happen, pulled loops normally exist in the trafficked area, not just in the seams. Improper use of maintenance equipment and/or chemicals can also contribute to a pulled loop problem. This inspector has ruled out excessive foot traffic and/or improper maintenance problems with these carpets because:
1. No high-heeled footwear was found on the day of the inspection and pulled yarns were found only in the seam
2. No inappropriate maintenance could be found in the Ultraviolet light and moisture testing.
Latex and/or bonding adhesive is what holds yarns in place on tufted carpets such as this one. When latex and/or bonding adhesive fails to perform due to defects in manufacturing, the problem will likely exist throughout the installation, not just in the seams. Carpet such as these carpets, also come in twelve-foot widths where several inches on each side are meant to be trimmed, (reference CRI104, section 8.2). The reason behind this is because the latex is sparse at the carpet's edge. In most cases, having one inch trimmed on each side of the carpet will eliminate pulled loops in the seam. The panel that measured at 12 feet on the seventh floor does not appear to have been trimmed properly. Variations in carpet width over 12 feet are not uncommon and the width of the carpet before installation has not been reported. However, pulled loops on the seventh floor would appear to be installation related.
Failure to comply with CRI104 on applying seaming adhesive can also lead to pulled loops. On the sixth floor, panels appear to be properly trimmed, but there is a lack of evidence of seaming adhesive coming from the ultraviolet light test. Most, but not all seaming adhesives have dyes that shine under ultraviolet light. Detection after installation can vary. In this case, however, seaming adhesive was detected in a good seam, but not in the ones with pulled loops. Based upon this, this inspector's opinion is that installation again is the cause of the pulled loops on the sixth floor.
CONCLUSION
Based upon the background information, observations, and field-testing done at the time of the inspection, it is the inspector's professional opinion that the pulled loops are due to installation errors. This inspector's opinion is that no defects in manufacturing exists in either the sixth or seventh floor carpets.