An inspection made by a municipal building inspector after the drywall material is hung with nails and screws (and before taping).

Fibers found in nature, such as wool and cotton.

The protrusion of the nail usually attributed to the shrinkage of or use of improperly cured wood framing.

The loosening of nails holding gypsum board to a wall or ceiling. It produces a bulge in the surface of the gypsum panel.

A substance intentionally engineered to achieve size-dependent properties and functions with one or more external dimensions or an internal structure measuring less than 100 nanometers. https://healthymaterialslab.org/tool-guides/hml-resources

A transparent finish which does not seriously alter the original color or grain of the natural wood. Natural finishes are usually provided by sealers, oils, varnishes, water repellent preservatives, and other similar materials.

National Bureau of Standards, a federal agency.

A set of rules governing safe wiring methods. Local codes—which are backed by law—may differ from the NEC in some ways.

National Conference of States on Building Codes and Standards, a nonprofit organization formed to increase interstate cooperation and coordinate intergovernmental reforms of building codes.

A gypsum plaster with no aggregates or fillers added. Sometimes called unfibered gypsum.

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.

National Board of Fire Underwriters, now merged into the American Insurance Assn.

A substance that can damage the central nervous system. https://healthymaterialslab.org/tool-guides/hml-resources

Usually color-coded white, this carries electricity from an outlet back to the service panel. Also see hot wire and ground.

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.

National Forest Products Association.

The large starting post to which the end of a stair guard railing or balustrade is fastened.

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.

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.

A wall supporting no load other than its own weight.