The Art of Installing Patterned Carpet
February 3, 2011
Before we get in to the “how-to” aspect, I feel that as an installer, I am compelled to make some important statements. I have installed patterned carpets for more than 30 years. I have traveled the country trouble-shooting, inspecting and teaching techniques for patterned-carpet installation.
All patterned carpets are NOT created equal. The installation of patterned carpet will in most cases require additional time, cost and expertise. The installation of patterned carpet requires communication, preparation and the services of a “qualified installation professional” that is well experienced in the installation of patterned carpets.
I would recommend that the services be utilized of well-trained, professional installation contractors whose reputations are that of “patterned carpet specialists,” proficient with the installation of patterned materials.
In many cases “above-and-beyond” installation techniques and additional time are required to satisfy the end user’s expectations. ALL parties involved should understand that the installation contractor should not be the SOLE party carrying the burden of time, labor, expertise and cost.
Inspection of the MaterialAs when starting any installation, first identify the construction of the material you will be working with, such as tufted, woven, attached cushion, etc. While many of the principles may be the same, the installation techniques can change slightly depending on the type of material you are going to install.
Next, identify and measure the exact pattern match within the material. Do this both in length and in width. This will now allow you to create a cut sheet that will be used to prepare the material for the job. Remember to allow one full repeat to every cut. You may at this time also want to identify the type of pattern with which you are going to be working.
Set Match: A set match type pattern refers to a pattern in a carpet that continues straight across the breadth. It will only match directly across from itself and nothing in between. When connecting lines to each pattern repeat point; squares or rectangles would be visible. (Photo 1)
Half-Drop Match: In a half-drop type repeat, every other repeat is dropped down one-half the repeated design length. Generally, this produces a larger scale effect often enhancing a diagonal pattern alignment across the width. (Photo 2)
Quarter-Drop Match: In a quarter-drop type repeat, the pattern will typically consist of four units in every length repeat. Each length repeat drops down one unit or the quarter of a repeat. This will usually give a diagonal effect to pattern when all breadths are joined.
Identify Any Pattern DeviationSkew: Skew or Bias – This condition exists when the carpet face yarn is set on secondary backing in such a way that the face yarn is not square with the backing nor with the selvage edge of the material. Distortion is noticeable when the pattern on one side is slightly ahead of the pattern on the opposite side. (Photo 3)
To properly check for skew:
• Utilize a laser square, carpenter’s square, “T” square or even the 3-4-5 rule along with a straight edge and dry line. This process is to ensure that you can achieve a 90-degree angle to the lineal edge of the material.
• Position the square at selvage edge of carpet and align with pattern along the length. Lay straight edge on top of or beside square aligned across the width.
• Using a dry line or laser extend this line 12-feet across the width of the carpet from one side to the other. Measure the pattern on the left side up to your dry line. Measure the exact same pattern point on the right side to the dry line. The variation between the two measurements is the skew.
• Example: A variance of 1-inch from one side to the other is communicated as a 1-inch skew in 12 feet.
Bow Width: A “Bow,” when viewed across the width is distortion that is visible as wavy or crooked lines. The lines occur in the width of either patterned or even plain carpet. This condition usually occurs when the carpet is not perfectly straight across the width as it is being manufactured. (Photo 4)
To properly check for a width bow:
• Begin by locating a pattern on the left side of the carpet. Next, locate the identical pattern line on the right side of the carpet.
• Pull a dry line from the pattern on the left to the identical pattern on the right.
• From the dry line, measure any of the identical patterns that do not line up and note the greatest distance.
• Example: The greatest distance from the dry line measures 1-inch. This would be communicated as a 1-inch bow in 12-feet
Elongation: Pattern Elongation/Pattern Run-off is due to a variation in pattern size from one breadth of carpet to the next. This is a condition that accounts for the pattern growing along a seam. This is usually caused by a lack of equal tension across the range during manufacturing or as the secondary backing is applied. (Photo 5)
To properly check for elongation prior to cutting the material you may want to perform a “pattern count.”
To perform a pattern count, simply take a certain number of patterns that encompass anywhere from 6-to 12-feet.
Note: Larger patterns have less counts and larger distance compared to the smaller patterns that have a much higher number of counts.
Once the count number is determined, count that number of patterns on one side of the material. Measure the distance exactly of the number of patterns counted.
Example: 20 patterns measure exactly 10-feet, 4 ½-inches.
Next, measure 20 patterns exactly on the opposite side of the material
Example: 20 patterns measure exactly 10-feet, 5 ½-inches.
There is a pattern elongation variance of 1-inch in 10-feet, 5-inches present.
Edge Deviation/Trueness of Edge: Edge deviation, sometimes referred to as a “length bow,” appears when the pattern along the length does not run in a straight line. (Photo 6)
To properly check for trueness of edge:
Locate two common pattern points along the edge of the material, approximately 10-to-12 feet apart. Pull a dry line between the patterns points.
Measure any deviation of common pattern points that deviates from the dry line. This is considered the amount of edge deviation.
I recommend that you take photos of any deviation that is present so that you can easily present them to the manufacturer if requested. I usually recommend a minimum of at 2 to 3 pictures. One should be taken from a slight distance that shows that you understand the correct way to determine the deviation. The other is taken directly over the top of the tape measure that shows the exact amount of deviation.
Most manufacturers of patterned carpets usually have a tolerance level for all of the above deviations. The manufacturing tolerances will vary between manufacturers and are subject to change from time to time by the manufacturer. During the writing of this article, I spoke with many of the manufacturers. The average tolerance that was quoted from several manufacturers was 1-1/2 inches across the board for all of the above deviations. I did find a few manufacturers that still had a bow tolerance of ¾-inch in 12- feet and several others are somewhere in between.