Carpet bowing skewing and other pattern alignment issues are one of the most difficult task a carpet installer will face. Pattern distortion that is manufacturer related such as bow and skew, usually occurs during the finishing, or backing application process. While less common, carpet bowing and skewing can also occur during tufting or weaving.
Carpet Bowing Skewing and Pattern Alignment Issues
Carpet bowing skewing are difficult issues requiring a skilled installer. When it comes to a cut pile carpet without a pattern, many residential installers perform a remarkable installation. Residential carpet installers that do not work with patterned carpet on a regular basis will usually find working with patterns challenging. When faced with pattern issues of carpet bowing, skewing and pattern alignment these installers are often at a loss.
The Weinheimer group is a nationally known inspection company. It has been their observation that carpet installers that specialize in the installation of commercial carpet are generally more skilled at working with pattern carpet bowing, skewing and pattern alignment issues. Terry Weinheimer states, “We have observed that commercial carpet installers are often better at improving a patterned carpets seamability.”
Additional time will usually be required when working with a product that has pattern alignment issues. The seller of the product should allow for this extra time when making the sale.
When a product has severe carpet bowing, skewing or other issues the manufacturer will often make reimbursement for the additional time to correct. Usually the manufacturer will need to be advised of the issues in advance of or during the installation and not at a later date.
While an experienced carpet installer will bring the pattern into alignment perfection is not always possible. Even with tight tolerances, seams may be visible and, if the walls are not square, the carpet pattern may appear to run off rather than run parallel with the wall or to the adjacent seam.
Set and Drop Patterns
Set Carpet Match Pattern, the figure of the pattern design matches straight across the width (side-to-side). Drop Carpet Match Pattern, the figure of the pattern design matches in the middle of the design.
Pattern Matching Tolerance
During the pattern matching of a carpet the installer should always follow the manufacturing guidelines for the product they are working with. It is important for the carpet installer to be aware that not all carpet manufacturers tolerances are the same.
Pattern Bowing: The pattern will sag at the center. Viewing the carpet across the width, the pattern distortion is seen as wavy or crooked lines of pattern. This condition can occur in both pattern and non-patterned carpets. Industry tolerance for pattern bowing is commonly 1-inch in 12-feet. Not all manufacturers have the same tolerance. As an example, Masland is 3/4-inch in 12 feet while Shaw is 1.5-inch in 12 feet.
Common Cause – Bowing usually occurs when carpet is not perfectly straight as it is being manufactured.
Pattern Skewing (Bias): With skewing the pattern is out of square with portions of the tufted or printed pattern deviating from a straight line. There is not an industry tolerance of pattern skew, most manufactures seem to be at 1.5-inch in 12 feet though you will find others as much as 2-inches in 12-feet. Check manufactures guidelines for the carpet being installed.
Common Cause – This condition occurs when the carpet face yarn is bonded to the secondary backing in such a way that the face yarn is not square with that backing. The skew is noticeable as the pattern on one side of the roll is not in line with the pattern on the opposite side.
Pattern Elongation (run-off): With pattern elongation the patterns size may vary in length or width from one match to the other. The pattern appears as if it is growing along one side of the seam or shrinking on the other. The industry tolerance is routinely 1-inch in 10-feet or 1.5-inches in 15-feet. Check manufactures guidelines for the carpet being installed.
Common Cause – Pattern Elongation (pattern run-off) is the result of a lack of equal tension across the product during manufacturing or at the time the secondary backing is applied.
Trueness of Edge (Edge Deviation Bow in Length): With a lengthwise bow in the pattern, the pattern does not appear in a straight lengthwise line. This can be measured between common pattern points along carpet edge at or very close to edge to be trimmed for seaming. The recommended tolerance is 1/2-inch in 12-feet. May differ per manufacturer.
Common Cause – The pattern is not aligned on the tenter hooks during the application of backing or the sizing process.
Carpet Manufacturers Warning and Technical Assistance
Most if not all carpet manufacturers make warning such as the following in their installation guidelines:
- Attention: Before you start, read this bulletin and other applicable literature pertaining to the installation of this carpet. Any topics not specifically covered in this bulletin should be directed to the Technical Services Center.
- Before starting installation inspect for: Concealed damage, Manufacturing defects and Shipping errors (example: wrong color, style, etc.)
- Warranties specifically exclude claims involving carpet which has been cut and installed with visible manufacturing defects.
For the installation of carpet, manufacturers often refer carpet installers to the installation guidelines of the CRI – Carpet and Rug Institute. Even with these manufactures they will usually have additional installation guidelines for some of their products. The manufactures guidelines on Pete’s article for a stretch-in carpet and a glue-down carpet may refer to different tolerances so again a carpet installer must be familiar with the installation guidelines for the product being installed.
Carpet is a textile product and manufacturers establish tolerances for their products. Most manufacturers consider their tolerances to be within normal limits for the product and do not consider them to be manufacturing defects.
Should you have need for a pattern carpet inspection you may wish to contact Terry Weinheimer or Kevin Weinheimer at the Weinheimer Group
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