Term | Definition |
---|---|
Nail Pop | The protrusion of the nail usually attributed to the shrinkage of or use of improperly cured wood framing. |
Nail Popping | The loosening of nails holding gypsum board to a wall or ceiling. It produces a bulge in the surface of the gypsum panel. |
Natural Fibers | Fibers found in nature, such as wool and cotton. |
NBFU | National Board of Fire Underwriters, now merged into the American Insurance Assn. |
NBS | National Bureau of Standards, a federal agency. |
NCSBCS | National Conference of States on Building Codes and Standards, a nonprofit organization formed to increase interstate cooperation and coordinate intergovernmental reforms of building codes. |
Neat Plaster | A gypsum plaster with no aggregates or fillers added. Sometimes called unfibered gypsum. |
Needle Beam | A steel or wood beam that is run through an opening in a bearing wall and used to support the wall and related loads as work on the foundation below the wall is performed. |
Neutral Axis | The plane through a member (at the geometric center of the section in symmetrical members) where the fibers are neither under tensile nor compressive stress. |
NFiPA | National Fire Protection Assn., an international technical society that disseminates fire prevention, fighting and protection information. NFiPA technical standards include the National Electrical Code which is widely adopted. |
NFoPA | National Forest Products Association. |
Noise Reduction Coefficient (NRC) | A single number indicated by the amount of airborne sound energy absorbed into a material. The arithmetic average of sound absorption coefficients at 250, 500, 1000 and 2000 Hz. |
Nominal | Term indicating that the full measurement is not used; usually slightly less than the full net measurement, as with 2" x 4" studs that have an actual size when dry of 1&1/2" x 3&1/2". |
Non-Conforming Use | A particular use of land or a structure which is in violation of the applicable zoning code. Generally, if the use was established prior to the code rule which it contravenes, it may continue to exist. |
Nonbearing | Refers to a structural part that does not carry a load. |
Noncalcerous Clays | Clays containing silicate of alumina, feldspar, and iron oxide. |
Noncombustible | Definition excerpted from the ICBO Uniform Building Code: 1. Material of which no part will ignite and burn when subjected to fire. 2. Material having a structural base of noncombustible material as defined, with a surface not over 1/8" thick that has a flame spread rating of 50 or less. The term does not apply to surface finish materials. |
Nondestructive Testing | Methods of testing an item that do not destroy the item being tested. |
Nonferrous | Metallic materials in which iron is not a principal element. |
Nonheat-Treatable Alloys | Alloys that do not increase in strength when they are heat treated but that do gain strength by the addition of alloying elements. |
Nonprestressed Units | Concrete structural members in which the reinforcing steel is not subject to prestressing or post-tensioning. |
Nylon | A synthetic plastic made from coal, tar, and water. |