Carpet seams showing is often the difference between and ordinary carpet installation and a masterpiece. While invisible carpet seams are not always possible, it is the goal of many great installers to construct invisible seams. While this is an admirable goal, invisible seams should never be promised.
The wise salesperson will be upfront with the consumer and assist them in selecting a style that will better hide the seams.
Having performed carpet inspections in the thousands, the author has seen many seams. The best installer will not be able to hide every seam. Several years back I had purchased a new house and had a high-quality carpet installed. You had to look hard to find the seams, except for one. That seam was in the living room, right off the main entry. The seam was constructed perfectly, yet the lighting in the room made the seam very visible
The good news is that the appearance of many seams get better with time. In my liviing room the seam appeared less visible when the window treatments were installed.
The Carpet Installer
Most carpet installers are capable of making good seams. It is not time in the trade alone that makes an installer good at seaming. An installer may have 20 years of experience and still be a hack. Other installers with much less experience are seaming artists. What makes the artist is the willingness to learn, practice and take the time to do the job correctly.
Following are common examples of concerns that consistently lead to the complaint of carpet seams showing. Many of these concerns are easily avoidable. Many carpet seams showing complaints may be a bit more difficult to avoid though a competent carpet installer will do their best to avoid them.
Carpet Seams Showing and Related Problems
- Failing to explain to the consumer in advance where seams will be placed.
- Failing to explain that the seams cannot be guaranteed invisible
- Not running the seams into the major light source may result in what appears as a sidematch condition.
- Extra seams in traffic lanes to save yardage.
- Failure to seal or improper sealing of seams, allowing tufts to pull out.
- Leaving gaps at the end of seams.
- Overheating the seaming tape a sure fire way to have carpet seams showing.
- Under heating the seaming tape.
- Unlevel seams due to seaming over the cushion instead of a seaming board.
- Seam zippering and delamination due to absence of or misapplied seam sealer.
- Puckered seams from overheating.
- Severely peaked seams not only result in carpet seams showing they also may result in what appears as two shades of carpet due to light variations.
- Wide gaps and overlaps at the seam edge.
- Failing to take a wide enough trim at the seam.
- Back or trace cutting when row cutting would have made a better seam.
- Shading and discoloration at seams from excessive or trapped heat.
- Light or dark dye edges on the carpet that should have been trimmed off.
- Failure to match the pattern. Patterns not matched will almost always have the carpet seams showing.
- Failure to work with a pattern to correct pattern elongation.
- Multiple narrow lines along the seam from using the wrong seam roller.
- Going ahead with an installation without the manufacturer authorization on a carpet that cannot be properly seamed due to a manufacturing problem.
- Seams opening due to urine damage, which is a consumer, related problem.
- Too much filler in latex bonding the primary and secondary back. (Manufacturer)
- Weak backing laminate strength. (Manufacturer)
Carpet Seaming Concerns
Areas of Loose Secondary backing Along the Edge
During installation the installer may find that the carpet is delaminated along the edge of the roll. This is a visible manufacturing related condition called “Off Tenter,” that developed during the coating process and unless the area can be cut off or repaired the job should be halted and the manufacturer advised. Failing to do so will most like result in a later complaint of the carpet seams showing.
Sometimes the delamination is not severe at the time of installation and is not observed by the installer but later delaminates. In this situation the delamination at the seams will extend a few inches as opposed to lack of seam sealer which is at the edge of the seam.
Type of Claim: Manufacturer and is the result of the carpet and/or the secondary backing failing to be hooked on the pins or the tenter chain of the coater resulting in poor lamination. If it is suspected that the strength of the laminate is low, submit a test sample.
Correction: If not too bad, correctable by bonding with a seaming adhesive.
Band Appearance along Seam 1″ to 2″ Wide Pattern Trim
This appearance is most common on a carpet that is a patterned commercial style. The narrow band occurs when the edge of the carpet is improperly trimmed resulting in the pattern being off and the consumer complaining about the carpet seams showing.
Type of Claim: Installation related condition.
Correction: Sometimes corrected by reseaming.
Carpet Seams Showing Band Appearance along Seam
Carpet seams showing what appears as a band 0f a different shade. The band will be 4″ to 6″ wide, the width of the thermal plastic seaming tape
The band will be on both sides of the seam and directly above the seaming tape.
Type of Claim: This installation related claim developed from the use of too hot of a seaming iron, no heat shield, or heat being held in from the use of a metal tray or other object that held heat and change the pile setting.
Correction: Steaming should be tried but this installation related condition is often not correctable.
Delamination Urine
Carpet seams showing severe separation of the primary and secondary back. There are additional chemical factors in the urine composition that will delay drying. Deposits of urine salts will hold water in a carpet back. Continued walking across the damp backing and the chemicals and organisms within the urine damage the latex causing the delamination which results in the seams opening.
Common Identifying Characteristics
Urine odor, which can be increased for testing with a spray of warm water.
Sprouting or at seams, groups of tufts protruding above the pile surface.
A weak tuft bind in the area of the damage and a normal bind outside of it.
Fluorescence under ultra violet
Wet reading with moisture meter. (Urine salts hold moisture.)
Greasy feeling on back of carpet or seam tape.
Type of Claim: Consumer. If the latex appears chalky and the urine damage is minor, the manufacturer may be responsible. Obtain a sample of undamaged carpet for testing.
Correction: If not too severe, cleaning and laminating once the source of the problem has been controlled.
Delamination Flooding or Improper Cleaning
When a carpet remains wet for an extended period of time and receives heavy traffic it will cause delamination. All too frequently in places such as taverns where the cleaner is doing a lot of extraction to remove spills that cause resoiling, the carpet is left wet. These places are often closed for short hours and it results in heavy traffic over a damp backing. While cleaning with water is a good method, speed drying with fans should be used in this type of situation. Failure to properly and quickly dry the carpet will lead in both the carpet backs showing do to seam delamination and overall delamination in the traffic lanes.
Type of Claim: Consumer or cleaner. Manufacturer if the latex is a poor consistency that can not stand any amount of water. Will need a sample of carpet for testing.
Correction: None unless minor where the backing can be laminated.
Light and Dark Edges
Carpet seams showing light and dark edges. This occurs when the carpet shifts out from under the dye application causing the edge of the carpet not to be dyed or the selvedge can fold over during steaming which will cause dark edges. If light it is can sometimes be improved with dyeing.
Type of Claim: Going ahead with the installation without trimming off the problems turns a manufacturing condition into an installation condition.
Correction: These edges must be trimmed back prior to installation.
Pattern Not Matched on Multicolored Saxony or Sculptured Print
This often appears as a straight line running through the carpet at the seam. The carpet normally has a splotchy pattern with no repeat and the seam is running straight through the splotchy pattern. When carpet has been printed or dyed with a system that has no pattern repeat in sculpture or dye, the pattern must be “monkey matched” as good as is possible. Since there is no pattern, it is usually impossible for the installer to hide all of the dark/light lines. The fact that this carpet does not match does not make it a defective carpet. The consumer needs to be made aware of these characteristics to prevent a carpet seams showing complaint.
Type of Claim: This condition is a natural characteristic of this style of carpet.
Correction: It is advisable to explain this characteristic to the consumer at the time of purchase.
Seam Poorly Constructed
Carpet seams showing what may give the appearance of a straight line. The affected seam is unusually quite visible. You may have gaps in the seam. (Gaps up to the thickness of a credit card are acceptable.) The seam may be overlapped or not level. The outside row of tufts, at the seam, may be crushed down to the primary backing. You may have a large gap at the seam edge due to the first row of tufts being cut short.
Type of Claim: Installation
Correction: Usually corrected by taking apart, trimming and reseaming.
Seaming Roller Tooth Marks (Spur Roller)
Carpet seams showing lines that are very close together located on both sides of the seam and about the width of the seaming tape are usually from the teeth of a spur roller that was used by the installer.
Type of Claim: This claim develops when the installer uses a spur roller on a dense cut pile carpet and the warm yarn is reset.
Correction: Steaming may improve but may not totally correct the problem. To prevent this problem use a smooth surfaced seam roller on smooth textures.
Delamination or Zippering at Seam Edges
CRI 104 & 105 states, “Trimmed seam edges should be sealed with an appropriate seam sealer. Unsealed seams can lead to seam delamination of tufted carpet or loss of face yarns with unsightly results
CRI installation guidelines states, “To prevent fraying and raveling at the seams, a 1/8″ continuous bead of seam adhesive should be applied to the base of the first edge where the face yarn enters the backing. This will seal the first edge as well as the second when the edges are butted together to form the seam.”
Type of Claim: Installer if no seam sealer used or not properly sealed. If thought to be a manufacturer-related problem obtain a sample for testing.
Correction: Possible repair such as insert or reburl.
Do you have a seam concern in Oregon or Washington that you need analyzed? Contact Kevin Weinheimer at TW Group, previously The Weinheimer Group. He is an expert Certified Carpet Inspector and co-author of the Carpet Inspectors Handbook. Kevin serves the states of Oregon and Washington and is available for travel.












