Glossary of Masonry Terminology
by Masonry Institute of Washington





DAB. To surface a stone with a pointed tool.

DAMP COURSE. A course or layer of impervious material which prevents capillary entrance of moisture from the ground or a lower course.

DAMPROOFING. Prevention of moisture penetration by capillary action.

DIMENSION STONE. Stone that is selected for or trimmed or cut to desired shapes and/or sizes. Used as building stone, markers, paving blocks or flagging, curbing, cut or carved ornaments and novelties, furniture (e.g., tabletops, laboratory bench tops and sinks), and industrial equipment that requires stone in shaped form (e.g., pebble mills or furnace liners).

DIMENSIONS OF MASONRY UNITS. For masonry units, dimensions are normally given thickness first, height second, and length third.

DOG'S TOOTH. Brick laid with their corners projecting from the wall face.

DOLOMITE. 1. Mineral form of calcium-magnesium carbonate. Constituent of some building limestones. 2. Limestone consisting principally of the mineral dolomite.

DOLOMITIC LIME. A trade term for high-magnesium lime. Also a misnomer as the product does not contain dolomite.

DOLOMITIC LIMESTONE. Limestone that contains more than ten percent but less than eighty percent of the mineral dolomite.
A splayed tenon that is shaped like a dove's tail, that is broader at its end than at its base and that fits into the recess of a corresponding dovetail slot.

DOWELS. Spliced reinforcement bars where continous bars are not possible.(UBC)

DRAFT. Tooled border around the face of a stone cut approximately to the width of the chisel. Also called a margin draft.

DRESSED STONE. Stone that has been worked to its desired shape and that has had its exposed face smoothed.

DRIP. Groove or slot cut beneath and slightly behind the forward edge of a projecting stone member, such as a sill, lintel, or coping, to cause rainwater to drip oft and prevent it from penetrating the wall.

DRY MASONRY. Masonry work laid without mortar.

DRY MORTAR. A mortar in which the constituents are so proportioned that it is markedly stiffer than usual, yet has sufficient water for hydration.

DRY PACK. Amixture of portland cement and fine aggregate, earth-moist dampened, but not to the extent that it will flow. Usually 1 part portland cement, 3 parts sand.

DRY-PRESS BRICK. Brick formed in molds under high pressure from relative dry clay powder.

DRY WALL. A self-supporting rubble or ashlar wall laid up without mortar.

DUTCHMAN. 1. A small piece of stone inserted as a filler in a patched area on a larger piece of dimension stone. 2. A small piece of stone inserted in an ashlar wall.




The normal distance between the centroidal axis of a member and the parallel resultant load. (UBC)

EDGESET. A brick set on its narrow side instead of on its flat side.

EDGESTONE. Stone used for curbing.

EFFECTIVE HEIGHT. The height of a member to be assumed for calculating the slenderness ratio. (UBC)

EFFECTIVE THICKNESS. The thickness of a member to be assumed for calculating the slenderness ratio. (UBC)

EFFLORESCENCE. A deposit or encrustation of soluble salts, generally white and most commonly consisting of calcium sulfate, that may form on the surface of stone, brick, concrete, or mortar when moisture moves through and evaporates on the masonry. Often caused by free alkalies leached from mortar, grout, adjacent concrete, or in clays.

EMPIRICAL DESIGN. A design based on the application of physical limitations learned from experience or observations gained through experience, without a structural analysis.

ENCLOSURE WALL. An exterior nonbearing wall in skeleton frame construction.

ENGINEERED DESIGN. A design based on a rational analysis, which takes into account the interrelationship of the various construction materials, their properties, and actual design loads, in lieu of empirical design procedures.

ENTABLATURE. In classical architecture, the elaborated beam member carried by the columns, horizontally divided into architrave (below), frieze, and cornice (above).

ENTASIS. Intentional slight convex curving of the side profiles in a tapered column to over come the optical illusion of concavity that characterizes straight-sided columns.

EPOXY JOINT. A visible joint filled with epoxy resin adhesive in place of mortar or caulking.

EPOXY WELD. In cut stone fabrication, a joint at an inside angle that is cemented by an epoxy resign to form an apparent single unit.

EXFOLIATION. Peeling or scaling of stone or clay brick surfaces caused by chemical or physical weathering. (Also called flaking)

EXPANSION BOLT. An anchoring device (based on a friction grip) in which an expandable socket swells, causing a wedge action, as a bolt is tightened into it.

EXPANSION JOINT/CONTRACTION JOINT. Joint or space to allow for movement due to temperature or seismic changes and/or material conditions.


back to top          next page

Masonry Institute of Washington
Washington State Conference of Mason Contractors

© 2007 Masonry Institute of Washington - All Rights Reserved
Web Design By: Focus Design, Studios, LLC