A.B.C.D.E.F.G.H.I.J.K.L.M.N.O.P.Q.R.S.T.U.V.W-Z

NAP -- The pile on the surface of a carpet or rug
NARROW CARPET -- Fabric woven 27 inches and 36 inches in width, as distinguished from broadloom.
Natural Carnelian (also see Carnelian) - light to medium orange translucent stone, frequently with areas of lighter and darker orange for a banded or mottled look. Some carnelian is more of a bright reddish-orange.
NATURAL CLAY TILE: A ceramic mosaic tile or a paver tile made by either the dust-pressed or the plastic method from clays which produce a dense body and a distinctive slightly textured appearance.
Natural Onyx - a semi-translucent to opaque, light colored stone with some banding. Found in varying degrees of yellowish-white, pale greenish-white, and grey. Also see White Onyx.
NEAT CEMENT: Portland cement mixed with water to a desired creamy consistency. See Pure Coat.
NEEDLEPUNCH --Layers or batts of loose fiber are needled into a core, or scrim, fabric to form a felted or flat-textured material. A needlepunch fabric can be embossed, printed, or laminated to a cushion, or otherwise finished.
NOMINAL SIZE (CERAMIC)-The approximate facial size or thickness of tile, expressed in inches or fractions of an inch.
                      (WOOD)-As applied to timber or lumber, the size by which it is known and sold in the market; often different from the actual size.
NON-VITREOUS TILE: Tile with water absorption of more than 7.0 percent.
NON-WOVEN--A fabric made up of a web of fibers held together by a chemical or fibrous bonding agent.
NOSING (CARPET)- The front dividing line of a step, where the top of a riser joins the front of a tread
             (WOOD)-A hardwood molding used to cover the outside corner of a step, milled to meet the hardwood floor in the horizontal plane, to meet the riser in the vertical plane ( usually used on landings.)
NOTCHED TROWEL: A trowel with a serrated or notched edge. It is used for the application of a gauged amount of tile mortar or adhesive in ridges of a specific thickness.
NTCA: National Tile Contractors Association, Inc.
NTMA: National Terrazzo and Mosaic Association.
NYLON - A man-made material, of polyamides derivable from coal, air, water, which is adapted for fashioning into filaments of extreme toughness, strength, and elasticity.