Almost every carpet job has at least one seam, and a lot of people do not realize that until installation day. Then they see two pieces of carpet being joined in the middle of the room and wonder whether something has gone wrong.
It has not. Seams are a normal part of carpet. What matters is where they go, how they are made, and whether the carpet is stretched properly around them. Carpet is what we sell and install more than anything else, so here is how seams work, how we decide where they fall, and what a good one looks like.
Why carpet has seams
Most residential carpet comes on a roll 12 feet wide. A few styles come wider, but 12 feet is the standard. Any room wider than the roll in both directions needs more than one piece, and wherever two pieces meet, there is a seam.
Seams also show up in places people do not expect:
- Closets often take their own piece, joined to the room at the closet doorway.
- Doorways between two carpeted rooms usually have a seam where one room's carpet meets the next.
- Odd-shaped rooms sometimes use a fill piece to cover an alcove or a bay window.
A good layout uses as few seams as the room allows, and puts the ones it cannot avoid where they will be seen and walked on the least. How to measure a room for flooring explains how the roll width shapes the amount of carpet a room needs.
Where a seam should go
We plan the seams before the carpet is ordered. These are the rules we follow, in rough order of importance.
- Out of the traffic. A seam takes more wear than the carpet around it. It should not run down the path from the door to the bed or across the main walkway of a living room.
- Not across a doorway, if it can be helped. A seam that crosses the opening where everyone walks gets stepped on, scuffed and pulled every day. Where a seam has to fall near a door, it is better at the doorway line, between rooms, than a foot or two into the room.
- Toward the main window. Seams that run in the same direction as the light coming in from the main window are much less visible than seams that run across it. Light hitting a seam from the side casts a tiny shadow along it. Light that runs along the seam does not.
- Under the furniture. In a bedroom, the ideal seam often runs under where the bed will sit. Ask us where the seam will be before installation day, so you can tell us where the furniture is going.
- Away from the focal point. Nobody wants a seam running through the middle of the spot in front of the fireplace or the TV.
Sometimes those rules pull against each other, and the right answer is a trade-off between seam placement and how much carpet the room uses. A layout that puts the seam in a better spot can mean a bit more carpet. We will explain the choice and let you decide.
How a seam is made
On a properly installed carpet, the two pieces are not taped together on top or stapled down. The method most installers use is a hot-melt seam:
1. The edges are trimmed straight. Factory edges are not clean enough to join, so each edge is cut along a row of the backing so the two pieces meet without a gap or an overlap. 2. The pile has to run the same way. Carpet pile leans in one direction, and both pieces have to lean the same way. If one piece is turned around, the two sides catch light differently and look like two shades of the same color. 3. The edges get sealed. A seam sealer is run along the cut edges so the yarn cannot work loose. This matters most on loop carpets like berber. 4. Seam tape and a seaming iron. A strip of heat-activated tape goes underneath, the iron melts the adhesive, and the two edges are pressed down into it and joined as the iron moves along. 5. Then the carpet is stretched. A seam is only as good as the stretch around it. A power-stretched carpet holds the seam flat and tight. A carpet that is only pushed into place with a knee kicker is more likely to loosen over time, and that slack tends to show first as a ridge or a ripple at the seam.
What is normal and what is not
Even a well-made seam can usually be found if you go looking for it, especially in low, raking light early in the morning or late in the day. That is normal. Carpet is a textile, and a perfectly invisible join is not always possible.
These are not normal:
- A visible gap where you can see backing between the two pieces.
- A raised ridge, sometimes called peaking, where the seam stands up above the carpet on either side.
- Two different shades on either side, which usually means the pile direction does not match.
- Fraying or loose tufts along the seam line.
- A seam that separates or opens up when you push on it.
If you see any of those, call the installer. Most can be fixed, and the sooner the better, because a loose seam gets worse when it is walked on.
Loop carpet and seams
Berber and other loop carpets look great and wear well, but their seams need extra care. If a loop gets caught and pulled at a cut edge, it can run down the row like a snag in a sweater. A properly sealed seam prevents that, and so does keeping pets with sharp claws and vacuums with aggressive beater bars away from the seam. Cut pile, frieze or berber? explains where loop carpet works and where it does not.
Living with a seam
- Vacuum along the seam, not across it, where you can.
- Do not pull at loose tufts. Trim them level with scissors instead.
- Do not drag furniture across a seam. Lift it.
- Watch for ripples. A ripple near a seam usually means the carpet has loosened and needs restretching, not replacing. When to replace carpet goes through which problems can be fixed and which cannot.
Ask before it goes down
The best time to talk about seams is at the estimate, before anything is ordered. At a free in-home estimate we measure the rooms, show you where the seams will fall and why, and bring samples you can see in your own light. Book one here or call 573-471-8700. We are on Virginia Street in Sikeston and work across the area, including Matthews, Lilbourn and Cape Girardeau.
