Components of a building

COMPONENTS OF A BUILDING

A building structure consists of Foundation or Substructure, Basement and Superstructure. Fig. 1 shows the different components of a single storey building with R.C.C. flat roof.

1. Foundation: Foundation is the portion of a building below the Ground Level (G.L.). It transmits the load coming from the superstructure to the soil.

2. Footings: Footings are stepped courses in the foundation. These are constructed in brick or stone (Random Rubble / Course Rubble) masonry or concrete under the base of the wall or column. Footings distribute the load of the superstructure over a larger area.

3. Basement: Basement is in-between Ground Level and Plinth Level. There will be one or two masonry footings in the basement. Space between the floor and ground is filled with sand.

Note: The floor constructed below the ground level is known as Basement Floor. The above explanation of basement is valid only where there is no basement floor.

Basement provides a raised platform for the floor. It serves as a base for laying the floor. The exterior wall in the basement retains the earth filling.

4. Super Structure: Super Structure is the portion of the building above the plinth (floor) level to the roof. It includes: (i) Plinth, Flooring and Damp Proof Course, (ii) Masonry Walls, (iii) Doors, Windows and Ventilators (iv) Lintels and Sunshades, (v) R.C.C. Roof Slab including Weathering Course and (vi) Parapet Wall and Coping.

5. Flooring: It forms part of the basement. The top level of flooring is called Floor Level. It coincides with Plinth Level. Flooring will be in plain cement concrete (P.C.C.) of 1:4:8 mix of about 130 mm thick. It is plastered with cement mortar of 1:3 mix of 20 mm thick.

Floor Area: Floor Area of a building is the total area of the floor in-between walls. It consists of areas of rooms, verandah, staircase, entrance hall, stores, toilets, sit-out, etc.

Floor Area = Total Area of the floor in between the walls = Plinth Area – Area occupied by walls. Area occupied by the walls may be 10 to 15% of plinth area.

Carpet Area: Carpet Area of a building is the useful area or livable area. It is the floor area, excluding entrance hall, verandah, passages, kitchen, etc.

Plinth Area: Plinth Area is the built-up covered area of a building, measured at floor level of any storey. It is calculated by measuring the external dimensions of the building at the floor level. Open areas, balconies, etc., projections are not included in the plinth area.

6. Damp Proof Course (D.P.C.): It is a layer of an impervious material provided at the plinth level to check dampness in walls and to prevent moisture from getting through the foundation.

7. Masonry Walls: Masonry walls are of brick or stone.

8. Sill: It is the bottom horizontal frame of a window or door.

9. Lintel: Lintel is a horizontal member placed over the openings such as door or window, to support the structure above the openings. It is made of either R.C.C., wood or stone.

10. Sunshade: It is a projection from the wall provided above the window or door.

11. R.C.C. Roof Slab: It is a flat or inclined structure provided as a cover to the building. R.C.C. roof slab is used to protect the building from weathering conditions, viz., rain, sun, wind, etc. Generally, roof slab is constructed of R.C.C. of about 125 mm thick.

12. Ceiling: The lower level of the roof slab exposed to the room is known as Ceiling. The height of all rooms for human habitation shall not be less than 2750 mm measured from the surface of the floor to the bottom of the roof.

13. Weathering Course: It is 100 mm thick brick jelly lime concrete. It is laid over the roof slab. It protects the roof from weathering actions of sunshine, rain, wind, etc.

14. Parapet Wall: It is a short wall of about 450 mm to 600 mm built over the roof all around the building. It prevents anybody, especially, children, from falling from the top of the roof of the building. Also, it fulfills the architectural requirement of the building.

15. Coping: It is a projection of the top of the parapet wall on outside or both sides.

16. Steps: Steps are in brick-work in cement mortar 1:5 laid on P.C.C. base.