Think of carpet as simply a large-scale fabric. When it is installed (and with no furniture in the room to impede installation), it is stretched in multiple directions to make it taut and eliminate wrinkles. Once stretched, the carpet is held in place by “hooking” the carpet edges onto tack strips around the perimeter of the room. Over time, your carpet may exhibit “looseness” or wrinkles which can occur when it pulls from these tack strips, stretches as some fabrics will, or for other reasons.
Many times, a re-stretch can correct this situation. The process for re-stretching is exactly like the initial installation which means that furniture has to be moved out of the subject room so as not to interfere with the stretching process. Two caveats here. First is that carpet with damage such as a delaminated backing (backing provides dimensional stability to the carpet) typically cannot be re-stretched because the carpet’s structural integrity has been compromised. Water damaged carpet can lead to delamination. Second is that carpet that has already been stretched twice (at initial installation and a subsequent re-stretch) is at much greater risk of having the backing delaminate because too much tension has already been placed on the backing.
Carpet, like any fabric, is cut and fitted to a room by seaming the cut pieces together. The seaming process involves seaming (or gluing) two carpet pieces together with seaming tape on the back of the carpet. Like a piece of clothing, seams are not invisible, however to “hide” seams, they are typically placed in such a way as to keep them out of high traffic areas by placing them under furniture pieces and running seams with the light from windows. Seaming tape is a very strong, specialized tape and is difficult to remove from carpet backing. Some of the glue from the tape may well remain so a second tape over a previously made seam may become “thicker” under the carpet making the re-made seam more obvious. Seams can be re-made but caution must be exercised to avoid making a seam you don’t like worse than it currently is.
Carpet, like any fabric, can be recut and refitted. And like any fabric that is cut, it can always be made smaller but to make a repair requiring additional material will require a new piece of carpet. After the initial installation, any larger pieces of carpet should be kept and stored for such repairs. And as an added benefit, such stored extra carpet will be of the same dye lot since it is part of the original carpet. In the absence of extra stored material, it is sometimes possible to “rob” carpet from a closet for the best match in a repair and replace the robbed closet piece with a carpet matched as closely as possible.