Most manufacturers provide established tolerances and specific Luftkvalitetstester Skåne instructions for their patterned goods, although most do not guarantee an exact pattern match. Factors affecting an acceptable pattern match on the job site include, but are not limited to, the method of installation, the condition and levelness of the subfloor, and the type carpet backing system selected. It is imperative that realistic levels of expectation be clearly agreed upon between all parties before the carpet is installed.

A successful patterned carpet installation requires a thorough understanding of patterned carpet characteristics by designers, specifiers, and all others involved with the carpet selection and installation process. There should also be an understanding about the additional carpet that must be allowed for pattern match. Carpet is a textile fabric subject to inevitable processing variations. Installation of patterned carpet requires more time and expertise, often requiring the use of power stretchers and additional staffing, thus affecting the cost of installation.

The following overview describes how patterns in carpet are created.

Using pre-colored or pre-dyed yarns, patterns may be created in any of the following construction methods:

• Woven – Axminster Weave, Wilton Weave, Velvet Weave
• Knitted
• Tufted – graphics or various computer controlled techniques

Patterns can also be produced after the carpet is woven or tufted using undyed yarns and the pattern applied afterwards – a post-dyeing method. Commonly used are:

• Screen Printing – flat and rotary
• Injection Dyed – computer controlled processes whereby colorant is injected into the carpet pile

Regardless of the method of construction, slight variations in yarn tensions, yarn feed, etc. can create changes in pattern configuration.Patterns created by the tufting process, tufted graphics, as well as screen printed and injection dyed carpet, require processing and finishing after the pattern is created. All of the subsequent finishing processes affect the size, straightness, and squareness of the pattern.

Because there are no “industry standards” for pattern variation, the carpet manufacturer should be responsible for providing, before the installation, written specifications as to the degree of variations expected, the degree of installed mis-match (if any) considered acceptable, and any guarantees or warranties of pattern match offered.

When planning the installation, remember:

• Although exact pattern match is usually not guaranteed, manufacturers will provide tolerances and specific installation instructions.
• The installation method selected may influence the degree of pattern adjustment that can be realistically expected. The amount of adjustment possible will vary with the backing system selected.
• Pattern adjustment during installation is possible and expected.
• Relaxing carpet by unrolling in a room for 24 hours under controlled conditions as directed by CRI-104, Standard for Installation of Commercial Carpet will help facilitate adjustment for pattern variations.
• Power stretchers and stay nailing are commonly required even in glue-down installations.
• Time requirements, thus labor costs, will not be the same as for installation costs of plain goods.