The Northwest Masonry Guide - Glossary of Masonry Terminology

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

GALLETING. Insertion of chips or spalls of stone into the joints of rough masonry to solidify the wall, reduce the amount of mortar required, or add detail to the appearance. Also called garretting.
GARGOYLE. 1. An ornamental spout, to discharge water outward from behind parapets. 2. By usage, the carved or molded ornamentation, generally in the form of a grotesque figure, of a projecting gutter spout.
GNEISS. Coarse-grained metamorphic rock with discontinuous foliation caused by planar alignment of platy and lath-shaped minerals.
GRANITE. 1. In technical geologic terms, igneous rock with crystals or grains of visible size and consisting mainly of quartz and the sodium or potassium feldspars. 2. In building stone, crystalline silicate rock with visible grains. The commercial term includes gneiss (a metamorphic rock) and igneous rocks that are not granite in strict sense.
GREEN MORTAR. Mortar that has set but not cured. GREENSTONE. Metamorphic rock altered from basic (low silica) igneous rock. The green color is due to ironbearing silicate minerals. It is quarried and used as a structural and decorative dimension stone.
GROUNDS. Nailing strips placed in or on masonry walls as a means of attaching trim or furring.
GROUT. A mixture of cementitious material and aggregate to which sufficient water is added to produce placing consistency without segregation of the constituents. (UBC) And ASIM C476.
Grout Lift. Is an increment of grout height within the total pour: a pour may consist of one or more lifts. (UBC)
High Lift Grouting. The technique of grouting masonry in lifts for the full height of the wall. (UBC)
Low Lift Grouting. The technique of grouting as the wall is constructed. (UBC) 2412(c). UBC.
GROG. Crushed brick that is blended with clay to form new brick.

HACKING. 1. The procedure of stacking brick in a kiln or on a kiln car. 2. Laying brick with the bottom edge set in from the plane surface of the wall.
HARD-BURNED. Nearly vitrified clay products which have been fired at high temperatures. They have relatively low absorptions and high compressive strengths.
HARSH MORTAR. A mortar that, due to an improper measure of materials, is difficult to spread
HEAD JOINT. The vertical mortar joint between ends of masonry units. Also called cross joint.
HEADER. A masonry unit which overlaps two or more adjacent wythes of masonry to tie them together. Also called bonder.
Blind Header. A concealed brick header in the interior of a wall, not showing on the face.
Clipped Header. A bat placed to look like a header for purposes of establishing a pattern. Also called "false header".
Flare (Flashed) Header. A header of darker color than the field of the wall.
HEADER COURSE. A continuous bonding course of header brick Also called a heading course.
HEARTH. 1. The masonry floor of a fireplace together with an adjacent area of incombustible material that may be a continuation of the flooring in the embrasure or some more decorate surfacing, as tile or marble. See fireplace. 2. An area permanently floored with incombustible material beneath and surrounding a stove.
HERRINGBONE WORK. A pattern of setting in which the units in a floor wall are laid aslant, instead of flat, with the direction of incline reversing in alternate courses, forming a zig zag effect. In floors or paving, the units are set at approximately a 45 degree angle with the boundary of the area being clad, alternate rows reversing direction to give a zig-zag horizontal pattern, and the unit in one row filling the triangle between two units in the adjacent row.
HEWN STONE. Stone shaped with mallet and chisel.
HIGH-CALCIUM LIME. A lime that contains mostly calcium oxide or calcium hydroxide and not over five percent magnesium oxide or hydroxide.
HIGH-MAGNESIUM LIME. A lime produced by calcining dolomitic limestone or dolomite and thereby containing more magnesium oxide than limes made from calcite of high-calcium limestones and marbles. High-magnesium limes range from 37 to 41 percent MgO content, and high calcium limes have less than 2.5 percent MgO Also called (incorrectly) dolomitic lime.
HOLLOW BRICK. See brick.
HOLLOW MASONRY UNITS. A masonry unit in which the net cross-sectional area in any plane parallel to the bearing surface is less than 75 percent of its gross cross-sectional area measured in the same plane.
HONED FINISH. In stone, a very smooth surface, just short of polished, imparted by a hand or mechanical rubbing process.
HOLLOW TILE. Masonry units in which the coring exceeds ^25%of the gross cross section area of the unit.

IGNEOUS ROCK. Rock formed by change of the molten material called magma to the solid state.
IMI. International Masonry Institute.
INITIAL RATE OF ABSORPTION. The weight of water absorbed expressed in grams per 30 sq. in. of contact surface when a dry brick is partially immersed for one minute. Also called suction. See ASTM Specification C67.
INITIAL SET. The first setting action of mortar, the beginning of the set.
INTERLOCKING JOINT. A joint in which a protrusion on one stone complements a groove or slot on another to prevent displacement or movement.
INTRADOS. The concave curve that bounds the lower side of the arch.
ISODOMUM. An extemely regular masonry pattern in which stones of uniform length and uniform height are set so that each vertical joint is centered over the block beneath. Horizontal joints are continuous, and the vertical joints form discontinuous straight lines.

JAMB STONE. A stone constituting part of a vertical side in a wall aperture, such as a door or window opening.
JAMB BLOCK. A unit especially formed for jambs.
JOINT. The surface at which two members join or butt. If they are held together by mortar, the mortar-filled aperture is the joint.
Joint Reinforcement. Any type of steel reinforcement that is placed in or on mortar bed joints. Also called horizontal reinforcement.
Jointing. The finishing of joints between courses of masonry units before the mortar has hardened.
Joint Type. See illustration below.

Joint Types

JUMP. A step in a masonry foundation.

Back to WSCMC Home

Masonry Institute of Washington

You are visitor number since May 21, 1998