Glossary of Terms

A concealed arch carrying the back lug of a wall where the exterior facing is carried by a lintel

Rough masonry built behind a facing or between two faces. Or, filling over the extrados of an arch; brickwork in spaces between structural timbers, sometimes called brick nogging

The part of a veneer wall behind the exterior facing which is designed to resist load

A flexible and compressible type of closed cell-foam polyethylene, butyl rubber, or open cell and closed cell polyurethane, rounded at surface to contact sealant. It is installed at the bottom or rear of joint and often described as a filler strip

A bench of timber or stone (may be a single block) on which stone is worked

A dense textured (aphanitic) igneous rock relatively high in iron and magnesia minerals and relatively low in silica, generally dark gray to black, and feldspathic. A general term in contradistinction to felsite, a light colored feldspathic and highly siliceous rock or similar texture and origin. The colors of basalts are very dark green to black and often sold as granites, but unlike granites, basalt contains little or no quartz or feldspars

The squared block terminating a baseboard at the opening

The lowest course or footing of a wall or pier

Stone surface finish produced with parallel tool marks

In granites and marbles a layer or sheet of the rock mass that is horizontal, commonly curved and lenticular as developed by fractures. Sometimes applied also to the surface of parting between the sheets. Or, in stratified rocks the unit layer formed by sedimentation; of variable thickness and commonly tilted or distorted by subsequent deformation; generally develops a rock cleavage, parting or jointing along the planes of stratification

A horizontal joint between stones, usually filled with mortar, lead, or sealant

Horizontal plane of sedimentary stone in the position of its original formation. In the context of stone restoration, especially with materials like limestone, a bedding plane refers to the natural, flat layers within the stone. These planes were formed when the limestone was created over millions of years as layers of sediment settled and compacted. Understanding bedding planes is important for contractors because they can impact the durability and performance of the stone. For instance, limestone may be more prone to splitting or flaking along these planes, especially if the stone was installed with the bedding plane facing the wrong direction. This can affect how you approach restoration, as improper handling or aggressive techniques might cause damage along these natural layers.

A continuous horizontal course of flat stones place in line marking a division in the wall plane. Sometimes called band course, string course, or sill course

Steps formed in quarry by removal of stone following bed joints. Or, a long seat of cubic stone

A bank of earth, such as the piled-up earth against a stone wall

A black, brown, or dark-green mica, a magnesium iron silicate

Dark colored igneous rocks defined by geologists as basalt, diabase, gabbro, diorite, and anorthosite, quarried as building stone, building facings, and specialty purposes and identified as Black Granite when sold

Staining caused by corrosive metals, oil-based putties, mastics, caulking, or sealing compounds

Mixes of different generic raw materials to form a water repellent

Regional sandstone quarried in the Catskill area of New York State and Western Pennsylvania

Clastic sedimentary stone made by fragment angular rocks bonded together. It is divided in polygenetic breccia (when it is made by fragments of rocks with different mineralogy) or monogenetic breccia (when it is made by fragments of rocks of the same mineralogy). The matrix and bonding are generally clay, calcite and silica