How to Specify Carpet Tile

Along with their ability to be custom cut to fit, carpet tiles offer a unique advantage over broadloom carpet: Stained and snagged modules can be replaced without anyone being the wiser.
Also called modular carpet or carpet squares, tiles can help unify otherwise disparate programmatic areas. Carpet tile currently accounts for about 25 to 30 percent of carpets installed today, and is suited for projects on a time crunch since tiles do not require a separate carpet pad. Below are the qualities in a good tile, both on and off the spec sheet.
Dye Method
How the carpet fibers are imbued with their color is a clue to how their hues will withstand use, if it is solution-dyed, the color will hold up in high-traffic areas or areas exposed to intense sunlight, because the carpet is dyed all the way through the material. If it is a printed or piece-dyed carpet, I know I can get a great range in color and pattern, but it may not hold its color long-term under a lot of foot traffic because the carpet fibers are only coated with color dye on the top.
Ounce Weight
The more fiber per square yard of carpet, the plusher the carpet will be, and the more wear and tear it can take. Builder-grade carpet is about 25 ounces per square yard, while anything 50 and up is pretty plush.
Construction
Each [construction] type contributes something to the overall look, from a woven to a loop to a tip sheer. It all depends on the look and feel we are going for in the space.Construction options listed on a spec sheet may include tufted pattern loop, patterned loop, and cut and loop pile. Low, dense carpet with a loop pile will show traffic patterns the least. Beware cut-and-loop or tip-sheared carpet with a high percentage of tip shear as the pattern could dissipate as the carpet mats down.
Pile
Pile height measures the yarn from the tile backing to top. An entry will require a lower pile height and stronger, more durable fibers than a space that receives less traffic or is designed to evoke a residential feel. Dense pile will also provide more of a barrier to dirt and stains than will loose pile.
Backing

Tiles can be peel-and-stick, attached to the flooring substrate with glue-free stickers or with a thin film of adhesive that prevents lateral movement but also enables easy removal. The right type of integrated backing will help with performance, longevity, sound control, and even occupant comfort. Typical options include foam rubber, urethane, plastic, and jute. Adhesive on a foam rubber backing may eventually break apart the foam. Urethane and plastic last longer, and jute lasts the longest but is the most expensive and hardest to find.