Carpet bowing, skewing, and other pattern alignment issues are one of the most difficult tasks a carpet installer will face. Pattern distortion that is manufacturer-related related like 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 and 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 who do not frequently work with patterned carpet often find 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. They have observed that carpet installers specializing in commercial carpet installation are generally more skilled. These installers excel 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 carpet’s 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 provide reimbursement. This compensation is for the additional time needed to correct the problem. The manufacturer must be informed of the issues beforehand. This should happen in advance of or during the installation, 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 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
The installer should always follow the manufacturing guidelines during the pattern matching of a carpet. This ensures they are working correctly with the product. 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 in the pattern. This condition can occur in both patterned and non-patterned carpets. Industry tolerance for pattern bowing is commonly 1 inch in twelve feet. Not all manufacturers have the same tolerance. As an example, Masland may be 3/4-inch in 12 feet while Shaw may be 1.5-inch in 12 feet. Both of these, as well as other manufactures often have different tolerances on different products.
Common Cause – Bowing usually occurs when carpet is not perfectly straight as it is being manufactured.
Pattern Skewing (Bias)
Skewing the pattern is out of square, with portions of the tufted or printed pattern deviating from a straight line. There is no industry tolerance of pattern skew; most manufacturers seem to be at 1.5 inches in 12 feet, though you will find others as much as 2 inches in 12 feet. Check the manufacturer’s guidelines for the carpet being installed.
Common Cause – This condition occurs when the carpet face yarn is bonded to the secondary backing. The bond results in the face yarn not being square with that backing. The skew is noticeable. The pattern on one side of the roll does not align 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) happens due to unequal tension across the product. This occurs during manufacturing or when applying the secondary backing.
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 the carpet edge. This should be at or very close to the 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. This misalignment occurs 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.
Manufacturers often direct carpet installers to the installation guidelines of the CRI – Carpet and Rug Institute for installing carpet. Even with these manufactures, they will usually have additional installation guidelines for some of their products. The manufacturers’ guidelines for a stretch-in carpet and a glue-down carpet refer to different tolerances. Therefore, 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. They do not regard them as manufacturing defects.
Learn more about Certified Flooring Installers certification and training: Download the CFI Flooring Installation Guide
Correcting Bow and Skew with 4″ Pattern Adjustments
If you’re dealing with carpet bowing, skewing, or pattern match issues, consider a professional inspection. It can identify the cause. It can also help you find the best solution. TW Group Flooring Inspections offers trusted residential and commercial evaluations, providing expert assessments to ensure your flooring meets industry standards. Contact TW Group today for reliable, unbiased carpet inspections and peace of mind.
