Masonry and All important Terminology used in Masonry Construction

A unit construction made by bonding either bricks, stones, or concrete blocks together with the help of mortar is termed Masonry. Depending upon the units bonded together using mortar the masonry is termed as brick masonry, stone masonry, concrete block masonry, etc. 

Mortar is a thin material made by mixing either cement and sand, lime and sand, or cement, lime, and sand in paste form using an adequate quantity of water. The mortar should be neither too harsh nor too thin to ensure adequate workability. Mortar not only binds the building units like bricks, stones or concrete blocks together, but also fills up the usual cavities around them, and make them to act as a single unit.

The type of masonry to be adopted depends upon the purpose for which it is intended. The purpose-based masonry walls are subdivided as follows.

1. Load bearing walls. These walls carry the load of the structure and hence should be strong enough to bear the imposed load. Stone, precast solid concrete block, or thick brick masonry is generally used to construct load-bearing walls.

2. Non-load bearing walls. These walls are also known as a partition or curtain walls. These walls are generally constructed in framed structures. In framed structures, the entire structural load is carried by a system of beam and column connections. The walls are non-load bearing and are intended just to provide an enclosure and as a shield from external elements like sun, rain, and wind. Since these are non-load-bearing walls they need not be of greater strength. Thin brick, Hollow concrete block masonry is sufficient for such kinds of walls.

3. Retaining Walls. This is a huge term in case of other structures like bridges, hill roads, irrigation structures, etc., but as far as buildings is concerned this is a small wall constructed to retain the backfill, usually the earth. Verandah walls and all external walls at the plinth level may come under this category. In buildings, the pressure from backfill is usually smaller and there is no possibility of tensile stresses developing within the wall. So ordinary type of masonry sufficiently thick enough to retain the backfill may be adopted.

TYPES OF MASONRY

Depending upon the units bonded together the masonry is divided as,

1. Brick masonry

2. Stonemasonry

3. Precast solid concrete block masonry

4. Precast hollow concrete block masonry

5. Solid wall tile masonry

6. composite masonry

TERMINOLOGY

1. Stretcher. The lengthy face of the brick is known as a stretcher.

2. Header. The face of the brick which shows the width and length is known as the header.

3. Bed. The lower surface of a course on which it rests is called a bed.

4. Face. The external surface exposed to the weather is called the face. Depending upon the material used for facing it may be called brick facing, stone facing, tile facing, etc.

5. Back. The internal surface which is not exposed to the weather is called back. Depending upon the material used, the back may be called brick backing, stone backing, concrete block backing, etc. Sometimes for rich external appearance as well as economy stone block facing with brick or concrete block backing is used.

6. Hearting. The portion of wall between face and back is called as hearting

7. Joints. The junction of two or more bricks or stones is called a joint. The vertical joints separating the bricks are called perpends. For good bond, the perpends in alternate courses should be exactly vertical one above the other.

8. Course. A horizontal layer of bricks or stones in masonry is called a course. In the case of brick masonry, the thickness of course is usually 10 cm whereas in stone masonry the thickness of course varies from 40 to 70 cms.

9. Bond. The arrangement of courses of bricks by which continuous vertical joints are avoided in successive courses is called a bond.

10. Quoins. The external comers of walls are called quoins. The stones, bricks used at quoins are called quoin stone, quoin bricks, etc.

11. King closer. The part of brick obtained by cutting the triangular corner portion from the middle points of width and length of a brick is called a king closer.

12. Queen closer. This is a part of a brick obtained by cutting a brick longitudinally into two equal parts. Half brick cut into two pieces longitudinally gives two nos of half queen closers.

13. Bevelled closer. It is similar to king closer and is obtained by cutting triangular portions of the brick half width and full length. Thus the beveled closer has a queen closer face at one end and a full header face at the other end.

14. Mitred closer. This is obtained by cutting one full width of the header face at 450 to 60°.

15. Bat. This is a piece of brick obtained by cutting along the length. The brick half to its length is called a half-bat and 3/4th of brick is called a three-quarter bat.

16. Frog. A triangular, square, or rectangular depression made on the top surface of a brick is called a frog. Frog affords a good key for the mortar. It should be ensured that the frog shall remain on the upper side in each course.

17. Natural bed. This is an important term and is applicable in stone masonry. The original layers of stones along which they have formed are called the natural bed. The stone easily splits along these planes. Hence in stone masonry, the stone should be so laid that the natural bed is perpendicular to the direction of pressure.

18. Through stone. This is a single stone that is fixed at regular intervals joining face and back. This is intended to give a good bond between the face and back of a stone wall. If the stone wall is too thick two through stones overlapping each other may be provided.

19. Spalls. Pieces of stones are called spalls. Spalls are used to fill cavities in the hearting of stone masonry.

20. Plinth. The projecting course of stone or brick masonry at the ground floor level is called a plinth. It indicates the height of the building's ground floor level from the natural ground level around the building. The plinth height varies from 20 to 60 cms depending upon the surroundings. The raised level of plinth protects the interior of the building from rainwater, frost, etc. Sometimes the plinth offset is omitted from an architectural point of view.

21. Plinth course. The topmost course of the plinth which is flush with the ground floor level is called a plinth course.

22. Damp proof course. An impervious course laid at plinth level to prevent rise of water from foundations to superstructure by capillary action is called as damp proof course.

23. Sill. The horizontal bottom course at a window or door opening which supports the vertical members of the frame is called a sill.

24. Jambs. The inner vertical sides of a finished surface of a door or window opening are called reveals.

25. Reveals. The outer vertical sides of a finished surface of a door or window opening are called reveals.

26. Lintel. This is a horizontal member of stone, brick, wood, steel, or reinforced cement concrete provided to support the masonry above an opening.

27. Arch. An arch serves a similar purpose for which a lintel is intended. Arch is generally curved in appearance.

28. Parapet. This is a low wall constructed around an open terrace to prevent persons using the terrace from falling from it.

29. Gable. This is a triangular-shaped wall at the end of a sloped roof.

30. Pier. A thickened section of masonry forming an integral part of a wall, placed at intervals along a wall to increase the stiffness of the wall or to carry a vertical concentrated load.

31. Buttress. A pier of masonry built as an integral part of a wall and projecting from either or both surfaces, decreasing in cross-section the area from base to top

32. Thresholds. The arrangement of steps provided from ground level to reach plinth level at external doors and entrances like verandahs is called as thresholds.