Carpet Tile Defects Associated with Installation and Manufacturing By Ray Darrah      Carpet tile is commercially used due to the ease of replacement and repairs. The convenience of replacing worn, or damaged, areas in commercial settings saves time and money, not to mention eliminating the inconvenience of having offices and workstations in disarray with a full flooring replacement. The Carpet Tile concept has caught on with building and business management companies with architects, decorators and designers eager to specify carpet tiles with company logos, or patterns, using the expansive array of designer colors and textures now available.      With the increased use of carpet tiles comes the increase number of tile failures due to either manufacturing deficiencies or installation errors. The major players manufacturing Commercial Carpet Tiles are Milliken, Mannington Mills, Designweave, Lees Carpets, J&J Industries, Mohawk Commercial Carpet, Mohawk International, Shaw Contract, Masland, Endura, Interface and Eurotex. The small specialty manufacturers are located throughout the world adding to the number of manufacturers, but produce a small percentage of the installed sales in North America.      Carpet tiles, also called Modular Carpet, are manufactured in broadloom widths then cut into squares using sharp knife blades set in a template, cutting the carpet into squares from the back side, or upside down. Cutting into tile square often results in cutting the tips of the pile leaving edges fuzzing and is characteristic of longer, higher pile, textures. Cutting Saxony, or cut pile, fabrics, leaves pile heights cut shorter at edges leaving joints visible and is also characteristic of carpet tiles, not a defect. Cutting the top of the yarn at leaves seams visible, but no structural damage shortening the life of the product is evident.      The structural components of modular tiles include the yarn tufted into a woven substrate that is adhered to an engineered backing system. The two primary components are the yarn into the tufting substrate and the backing. The backing systems vary with each manufacturer but are engineered to offer dimensional stability, superior tuft bind and minimize edge ravel. The engineered backing system is the core structure allowing carpet to be cut into squares and installed without edges lifting, raveling or loss of dimensional stability.      Manufacturing decencies are usually not detected until the carpet is in use. Should tiles cup, edges lift equally on all sides, edge ravel and delaminate with backing systems coming apart a manufacturing defect is likely. Tiles must be stable and all components must be equal in dimensional stability for tiles to achieve structural balance. Edge lifting, cupping and edges curling are symptoms of inadequate dimensional stability.      Edge curling, cupping and de-bonding of tiles could also indicate an installation or environmental issue. Concrete sub-floors are to be tested to insure low concrete vapor emissions and the specified adhesive, and adhesive spread rate, is required to eliminate the installer and the site conditions as the failure mechanism.      The most common installation errors result in de-bonding from the sub-floor caused by use of non-specified adhesives or improper trowel size and uneven appearance resulting from improper floor preparation to bring the sub-floor into flatness requirements.      Excessive Concrete Vapor Emissions cause the most devastating failure in new construction buildings and do so often. Fast track building and poor scheduling by the construction supervisors leave the building and concrete sub-floors inadequate time to dry to acceptable vapor emission levels. Flooring experts and inspectors are often called in to inspect these failures only to learn the tiles, or other flooring materials, were installed before the windows were installed or the environmental systems operational. Buildings and concrete sub-floors cannot dry to acceptable levels without the building envelope completely enclosed and the environmental controls operational and in use for at least two weeks prior to installation of flooring materials. The experts at www.FloorTekTalk are available for online consultations or you may hire your own carpet tile expert from the list offered at www.FloorReports.com.