Glossary of Industry Terms



Jagged edges

Irregularities left on the edges of the tile due to the use mainly of hand cutting tools.

Jasper ware

A vitreous, opaque, colored unglazed ceramic ware having white or contrasting relief-decorations and containing a substantial amount of barite. Originally developed by Josiah Wedgwood. (ASTM C 242).


Forming ceramic ware from a plastic body by differential rotation of a profile tool and mold, the mold having the contour of one surface of.the ware and the profile tool that of the other surface. (ASTM C 242).


A grate tamper for pushing coarse . aggregate slightly below the surface of a slab to facilitate finishing.

Joint, control

See Expansion joint.

Joint, contraction

See Contraction joint.

Joint, expansion

See Expansion joint.

Joint filler

Compressible material used to fill a joint to prevent the infiltration of debris and to provide support for sealants.

Joint sealant

Compressible material used to exclude water and solid foreign materials from joints.

Jointer (concrete)

A metal tool about 6 in. (150 mm) long and from 2 to 41/2 in. (50’to 100 mm) wide and having shallow, medium, or deep bits (cutting edges) ranging from 3/is in. to 3/a in. (5 to 20 mm) or deeper used to cut a joint partly through fresh concrete.


An experienced reliable worker who has learned his trade and works for another person.