an upward, elongated tenting displacement of a roof membrane frequently occurring over insulation or deck joints. Ridging may be an indication of movement within the roof assembly. View Glossary Photo Example

The formation of a Buckle.

A filled joint in drywall which becomes visible due to natural expansion and contraction of the materials.

A mound-like swelling on the outer layers of a roll, lengthwise to the tape. It is removed prior to application. Most frequently found on double-coated tapes and label stock.

The appearance of a series of circumferential ridges and valleys around a roll of product, where the roll appears to be corrugated like a tin can. The height and spacing of the ridges is very uniform. This is often considered a sign of poor product quality, and is usually caused by the design of the embossing pattern. One solution to this problem is described in the article "Using Laser Engraving in Tissue Embossing" by Carl Ingalls and Ed Giesler.

A mound-like swelling on the outer layers of a roll' lengthwise to the tape. Usually found on the more moisture-sensitive materials' such as cellophane.

when ice floes collide, causing their edges to crumple together

process that occurs when wind, ocean currents, and other forces push sea ice around into piles that rise and form small mountains above the level sea ice surface; ridges are initially thin and transparent with very sharp edges from blocks of ice piling up; also see keels. Ridged sea ice. (Photo courtesy of Don Perovich, U.S. Army Cold Regions Research and Engineering Laboratory.)

In gear teeth, a form of plastic flow characterized by a rippled appearance on the surface.