| Quarter turn | Turning the carpet pile pile direction 90 degrees, and usually joining at a carpet seam. While this practice is acceptable on stairs, a color difference will develop at flat seams |
| Quarternary | A cationic cleaning agent used for disinfection. |
| Quat | Slang term used for the family of Quarternary disinfectants I.e. quarternary ammonium chloride. |
Carpet installation is the single biggest problem with new carpet purchases. Often, once the installation goes bad, the entire purchase begins to sour. Carpet installation should be carefully researched to make sure the carpet installer uses CRI 104 -CRI 105 Carpet Installation Standards. Failure to follow recommended installation procedures can allow for a shoddy installation. Always preserve about 1 square foot piece of the original uninstalled carpet. Some manufacturing defect analysis only can be performed on unused (untrafficked) carpet. Also, should the carpet fail (which is rare), it is helpful to evaluate a new piece versus a sample that has been trafficked. Attic stock (preserved carpet) also can be used to plug damaged areas or heavily stained or soiled areas.