Technical Terms of Stone Masonry (Part-1)

Technical Terms of Stone Masonry (Part-1)

The meaning, attached to some technical terms used in the masonry, are given below for ready reference. Some of these terms are common in Stonework as well as in brickwork. These technical terms are as follows :

1) Natural Bed :

• The building stones are obtained from rocks. These rocks have a distinct plane of division along which the stones can easily be split. This plane represents the natural bed.
• In stone masonry, the direction of natural bed should be perpendicular or nearly so to the direction of the pressure.

2) Sill :

• The bottom surface of a door or a window opening is known as a sill.
• Sill stones are so dressed that they prevent the entry of water to the interior of the building.

 

3) Corbel :

• A corbel is a projecting stone which is usually provided to serve as support for roof truss, beam, weather shed, etc.
  
  
  
• The corbels are generally moulded & given ornamental treatment.
• The corbels should extend at least two-third of their length into the wall.

4) Course :

• A layer of stones or bricks is known as a course.
  
  
  
• Its thickness is generally equal to the thickness of a stone or a brick plus the thickness of one mortar joint.

5) Cornice :

• A cornice is a course of stone provided at the top of wall.
  
  
  
• It is generally moulded & given ornamental treatment.
• It is weathered & throated to dispose off rain water.
• In order to prevent the overturning of the cornice, sufficient bearing & extra weight at the top in the form of a parapet wall should be provided.

6) Coping :

• A coping is a course of stone which is laid at the top wall so as to protect the wall from rain water.
  
  
  
• This course is generally provided at the top of a compound wall or a parapet wall & it is suitably weathered & throated.
• Sometimes the term coping is used to refer to cutting of the stones by means of feathers, plugs & wedges.

7) Weathering :

• The upper surface of stones used for sill, cornice & coping is dressed in a sloping way so that the water may flow off easily. This is termed as weathering.
• The term weathering is sometimes used to denote the wearing of stone surface by the action of weather.

8) Throating :

• A groove is provided on the underside of sill, cornice & coping so that the rain water can be discharged clear of the wall surface. It is known as throating.
  
  
  
  
  

9) Plinth :

• The projecting course at ground floor level is known as the plinth.
  
  
  
• It is also used to indicate the height of ground floor level from ground level.
• The course protects the interior of a building from rain, water, frost, etc.
• It is sometimes moulded & given ornamental treatment.
• The offset at plinth level is sometimes omitted for the architectural purpose.

10) String Course :

• The horizontal course provided at suitable levels between the plinth & the cornice is termed as a string course.
  
  
  
• It breaks the monotony of a plane surface & it is sometimes moulded & given architectural treatment.
• The string course is suitably weathered & throated so as to throw off the rain water clear of the wall surface.

11) Lacing Course :

• The horizontal course provided to strengthen a wall of irregular small stones is known as a lacing course.
  
  
  
• It may be in the form of either ashlar masonry or coursed rubble masonry or brick masonry.

For the remaining Technical Terms of Stone Masonry click on the video given below :