civil engineering

1. BUILDING
CONSTRUCTION

2. FLOORING

3. TYPES OF FLOORS
Normally the following types of floors are generally
used:
• Brick floor.
• Earth floor.
• Cement concrete floor.
• Mosaic or Terrazzo floor.
• Tile floor.
• Marble floor.
• Wooden floor.

4. MATERIALS FOR FLOORING
The materials used for Ground floor
construction are:
• Stones.
• Bricks.
• Concrete.
• Marble.
• Chips.
• Asphalt.

5. FACTORS AFFECTING SELECTION OF FLOORS
1- INITIAL COST
• The cost of floor covering is the most important thing.
• The expensive types of floor coverings are marble and terrazzo
(chips).
• Tiles and asphalt are less expensive whereas concrete and
brick are the cheapest and are commonly used.
2- APPEARANCE
• Color, texture and architectural beauty are the factors taken
into consideration.

6. FACTORS AFFECTING SELECTION OF FLOORS
( -CTD- )
3- DURABILITY
• Resistance to wear and tear is an important factor for a floor
covering.
• Resistance to temperature changes, humidity, disintegration and
decay has also to be taken into account.
• Tiles, marble and concrete floor covering offer good resistance to
these factors. Wherever heavy floor traffic is not anticipated bricks
and wood blocks can be used.
4- CLEAN LINESS OF FLOOR
• A floor should be non-absorbent and capable of being easily
cleaned.
• All joints should be simple so that they can be made water tight as
possible.
• Glass strips used for making panels, should not be more than 16 sq.
ft. i.e.. (4`x4`).

7. FACTORS AFFECTING SELECTION OF FLOORS
( -CTD- )
5- DAMPNESS
• Moisture should not penetrate in the floor.
• They should be completely water tight.
• Wood, Rubber are not suitable in damp places,
whereas tiles, bricks, concrete and Terrazzo is
suitable for use on flooring which are subjected to
dampness.
6- INDENTATIOIN
• Marks, depression due to furniture legs or ladies shoes
should not make any impression on the floor.

8. FACTORS AFFECTING SELECTION OF FLOORS
( -CTD- )
7- NOISELESSNESS
• This is not an important factor for ground floor constructions,
but it should be noiseless when traveled over.
• Rubber coverings and cork covering are most suitable.
8- MAINTENANCE
• For keeping floor in perfect condition it is necessary to clean,
repair and apply any other treatment from time to time.
• Marble and concrete floors require less repair whereas wood
blocks, need frequent maintenance.
• Concrete surfaces cannot be repaired easily while tiles can be
replaced quickly.

9. CONSTRUCTION OF FLOORS
1- BRICK FLOORING
• Brick flooring is commonly used.
• The filling over which this floor is to be laid should be well
compacted.
• Generally two types of beds are provided.
• In the first type, after excavation the surface is leveled and a
layer of 3// sand is spread over which a course of bricks is laid.
• In the second type, a lean cement concrete (1:6:18 P.C.C) of
10 to15 cm in thickness is laid on the compacted bed.
• Flat brick flooring is laid into1:6 C/S mortar over a bed of ¾ //
thick cement sand mortar.

10. CONSTRUCTION OF FLOORS ( -CTD- )
2- CEMENT CONCRETE FLOORING
• This type of floors are most commonly used both in
residential and commercial buildings.
• The two components of a concrete floor are Base &
Wearing surface (top surface).
• The flooring can be constructed either monolithic or
non-monolithic.
• In monolithic floors, a base layer is laid and then
immediately a concrete topping is provided and in
non-monolithic the topping is laid after the base has
set.

11. CONSTRUCTION OF FLOORS ( -CTD- )
CEMENT CONCRETE FLOOR DETAILS
• Topping is laid in panels over a base thickness
which varies 1// to 3//.
• If the thickness is 1-1/2// then it can be laid in
single layer and if it is exceeding then it is laid
in double layer.
• To avoid cracks due to shrinkage, the area of a
panel is restricted to 4/ x 4/ (i.e.. 16 sq. ft.).

12. CONSTRUCTION OF FLOORS ( -CTD- )
3. MOSAIC OR TERRAZO FLOORING
• The base for terrazzo floor is of plain cement concrete (1:2:4).
• The topping shall not be less than 3/8// thick and shall be laid with a
bottom layer of cement concrete (1:2:4).
• The total thickness of topping of cement concrete should not be less
than 1-3/8//.
• Normally 2// thickness is used, 1-1/2// concrete (1:2:4) and ½// mosaic
• The mosaic topping shall consist of one part of cement (including15%
to30% marble powder) and two parts of marble chips.
• The mosaic topping shall be laid while the bottom concrete is still
fresh preferably on the next day or after 24 hours to have better bond.
• The surface should be rough to get better bonding.

13. CONSTRUCTION OF FLOORS ( -CTD- )
4. TILE FLOORING
• Tiles of various shapes, sizes, thicknesses, color and surface
finishes are manufactured for used as surface covering for
floors.
• Floorings tiles are set on the concrete base with mortar.
• Special bedding made up of asphalt or Portland cement is
available for use over concrete base.
• The concrete bedding is generally 5// thick and is laid evenly
with a slight rough surface at the top.
• After a period of 2 to3 days, a mortar layers of 1:1 mix is
spread on the concrete bed and the tiles are set evenly with a
thin a thin paste of cement applied to their sides.

14. CONSTRUCTION OF FLOORS ( -CTD- )
• They are slightly topped till the cement comes out
through the joints to the top surface.
• This extra cement is wiped off and the joints are
cleaned.
• After 2 to3 days, these joints are rubbed to chip off all
the projecting edges or surfaces.
• The whole surface is then polished with a very soft
carborundum stone.
• Finally the surface is washed with soap. If the tiles
have glazed surfaces then this rubbing process is not
suitable.

15. CONSTRUCTION OF FLOORS ( -CTD- )
5. GLASS FLOOR
• Glass floors are used wherever it is desired to admit light into
the basements through the upper floor.
• The glass blocks are fitted within the frames of various
thicknesses to transmit light at an angle to the farther areas in a
room.
• Structural glass is available in the form of tiles or slabs and its
thickness ranges from 12 to 30 millimeters.
• The framework is spaced closed apart so the glass can
withstand loads coming over it. Glass flooring is not commonly
used.

16. CONSTRUCTION OF FLOORS ( -CTD- )
6. ASPHALT FLOORING
• Asphalt mastic is a mixture of fine aggregates (sand), natural or
artificial asphalt and coarse aggregates.
• It can be mixed hot and laid in continuous sheets or pressed into
blocks which can be used as flooring.
• It can also be mixed with a mineral oil and asbestos and applied
cold.
• While heating, the asphalt is stirred thoroughly so that the layer at
the bottom may not get burnt, when the whole quantity is fused,
sand or aggregates equal to twice the volume of asphalt is added
gently and mixed thoroughly. This mixture is then ready for
laying.

17. CONSTRUCTION OF FLOORS ( -CTD- )
7. WOODEN FLOORING
• This type of floor construction is not
extensively used but is popular for special
purpose floors, e.g. in auditorium, hospitals.
• For the fixing of wooden floors on concrete
slabs, longitudinal railing strips are provided.

18. ROOFS
The covering provided over the top of an
enclosure made for a building to keep out the
sun, rain, wind and to protect the interior from
exposure to the weather is known as roof.
(Sloping roofs are suitable for the area where
rainfall and snowfall are heavy, whereas, flat
roofs are suitable for the area where rainfall is
meager i.e.. of low intensity, and there is no
snowfall)

19. ROOFS (-ctd-)
A good roof is as essential as a safe foundation of a building.
• Roofs must, therefore, be well designed and constructed to meet
the requirements of different climates and covering materials
locally available.
• The form of construction of a roof is governed by the plan of a
building, span, the type of covering material locally available and
the architectural appearance required.
• The roof covering to be provided should be economical and most
suitable according to the nature of the building.

20. TYPES OF SLOPING ROOFS
Shed Roof Gable Roof
Hipped Roof Gambrel Roof

21. TYPES OF SLOPING ROOFS (-ctd-)
1. Shed Roof:- A slopping roof having slope only in one direction
is called a Shed Roof. This is the simplest type of sloping roof
and is used for smaller spans.
2. Gable Roof:- A sloping roof having slope in two directions is
called a Gable Roof. This type of sloping roof is used for larger
span.
3. Hipped Roof:- A sloping roof having slope in four directions is
called Hipped Or Hip Roof. This type of sloping roof is mostly
used for buildings in hilly area.
4. Gambrel Roof:- A sloping roof having slope in two directions
with a break in the slope is known as Gambrel Roof. This type
of sloping roof is mostly used for buildings in hilly area.

22. Mansord Roof Saw Tooth or North Light Roof

23. TYPES OF SLOPING ROOFS (-ctd-)
5. Mansord roof:- A sloping roof having slope in four
directions with a break in slope is known as Mansard
Roof
6. Saw tooth or north light roof:- A sloping roof
having glazing fixed on the steep sloping sides of the
roof is called Saw Tooth Or North Light Roof. This is
generally used in factories where more light is
required.

24. IMPORTANT TECHNICAL TERMS
Ridge:- The highest point or line of a sloping roof where the two
opposite slopes meet is known as ridge.
Ridge piece:- A horizontal piece of timber which runs the highest
level (bridge) of a sloping roof is called ridge piece.
Eaves:- The lowest edges of the surfaces of a sloping roof are called
eaves.
Eave’s board:- A wooden board fixed along the eaves at the end of
common rafters is known as eaves board or facia board. Gutter
is usually supported at eaves board.

25. STAIRS AND STAIR CASES
• A series of steps which provides access from one
floor to another is called a stair and the part of the
building accommodating the stair is known as stair
case.
• A stair may be constructed with steps either rising
continuously or with a break in the form of landing
in between.
• All the steps should be so designed and constructed
that up and down movements from one floor to
another can be made with ease, comfort, quickness
and safety.

26. STAIRS AND STAIR CASES (-ctd-)
• The stairs may be consisting of any suitable material such as
timber, bricks, stones, steel, reinforced cement concrete etc..
• The provision of a stair in a building is essential for the
movements of inmates from one floor to another floor or
roof of that building.

27. IMPORTANT TECHNICAL TERMS
Step:- The combination of a tread and a riser supported by a string
is called a step.
Tread:- The horizontal top surface of a step on which foot is placed
while going up or coming down a stair is known as tread.
Riser:- The vertical face of a step is called riser.
Going or run:- The horizontal distance between any two adjacent
risers in a stair is called going or run.
Rise:- The vertical distance between any two adjacent treads in a
stair is called rise.
Bull-nose step:- The step with one or both ends rounded is known
as bull nose step. This type of step is generally provided at the
bottom of a flight and is always projecting beyond the face of
the newel post.

29. IMPORTANT TECHNICAL TERMS (-ctd-)
Nosing:- The projecting edge of a tread beyond its riser in a step is called nosing.
The line joining nosing of all steps in a flight is known as line of nosing.
Pitch or slope:- It is the slope or angle of stair
String or stringer:- The inclined support to which the ends of treads and risers of
a stair are fastened is called a string or stringer.
Hand rail:- As inclined member at a convenient height projecting above steps of
a stair to provide assistance and safe-guard to the users is called hand rail.
Balusters:- The vertical members provided in between the steps and the hand rail
are called balusters. These members act as intermediate supports to the
hand rail.
Newel or newel post:- The posts provided at the bottom, top and all the turning
points in a stair to support the hand rail are known as newels or newels
posts.

31. IMPORTANT TECHNICAL TERMS (-ctd-)
Soffit:- The under surface of a stair is called soffit.
Flier:- A step of uniform width is called flier. This type of step is rectangular in plan. Such steps
are always preferred even at turning points of a stair as they are safe for quick movements
of the uses.
Winder:- A step of non-uniform width is known as winder. This type of step is usually triangular
in plan. Such steps are only provided for changing the direction of a stair and should be
avoided as far as possible since they are dangerous for quick movement of the users.
Landing:- The horizontal platform provided in between any two flights of a stair is called
landing. The landing which provides 90° turn in the layout of a stair is known as quarter
space landing and if the turn is through 180°, it is called half-space landing
Flight:- A series of steps without any break in between is known as flight.
Head room:- The height between the line of nosing to the soffit of a flight or ceiling of roof
immediately above is called head room.
Width of a stair case:- The width of enclosure accommodating the stair in a building is called
width of stair case. It depends upon the layout and width of the stair.

32. REQUIREMENTS OF A GOOD STAIR
• It must be well designed so as to provide maximum
comfort, ease and safety.
• It should be centrally located in a building.
• All the steps should have uniform width and height
• The pitch or slope of a stair should neither be more than
40° nor less than 24°.
• The width of a stair must not be less than 0.85 m in any
case.

33. REQUIREMENTS OF A GOOD STAIR(-ctd-)
• The maximum number of steps in a flight should not be more
than 15 (optional).
• The head-room must not be less than 2.1 m vertically.
• The height of the hand rail should neither be more than 0.85 m
nor less than 0.75m measured vertically from the line of nosing
to the top of hand rail.
• It must be constructed of sound materials.
• It should have good workmanship.
• It must be properly ventilated and lighted.

34. PRINCIPLES TO BE OBSERVED WHILE PLANNING
AND DESIGNING A STAIR
1. Relation between going and rise of a step
• 2 x Rise + Going in cm = 55 to 60 cm
• Going x Rise, both in cm = 400 to 430 cm2
• While designing steps, take 30 cm going and 14 cm rise as a standard value.
• The following dimensions of going and rise are generally used for different
buildings:-
Residential buildings = 25 cm x 16 cm
Public buildings such as theatres, colleges, banks etc.
=27 cm x 15 cm or 30 cm x 14 cm.
Industrial buildings = The going should not be less than 25 cm
and rise not more than 19 cm.
• It should be noted that the rules given above only act as guide but the actual
dimensions of going and rise depend upon the space available, height of the
building and layout of the stair.

35. PRINCIPLES TO BE OBSERVED WHILE PLANNING AND
DESIGNING A STAIR
2. Pitch of the stair:- The pitch or slope of the stair should not be
more than 40° and should not be less than 25° for comfortable
ascend and descend.
3. Width of stair:- The width of a stair must not be less than 0.85 m
so that a person going up can pass a person coming down without
any difficulty. The minimum width of stair in a residential
building should be 1.05 m whereas in case of a public building, a
minimum width of 1.5 m is desirable.
4. Length of flight:- The number of steps in a flight should not be
more than 15 otherwise it becomes difficult to move up and
down the flight. The minimum number of steps in a flight should
be 3.

36. PRINCIPLES TO BE OBSERVED WHILE PLANNING AND
DESIGNING A STAIR (-ctd-)
5. Width of landing:- The width of landing should not be
less than the width of its stair case.
6. Head room:- An adequate head-room must be
provided. It should not be less than 2.1 m.
7. Hand rails and balustrades:- A stair should be
provided with a hand rail along with balustrades to
provide assistance, comfort and safety to the users. The
height of hand rail should neither be more than 0.85 m
nor less than 0.75m.

37. PRINCIPLES TO BE OBSERVED WHILE PLANNING AND
DESIGNING A STAIR (-ctd-)
8. Materials:- The stair should be constructed from sound
materials preferably of fire resisting quality. It should
be constructed of R.C.C. according to building bye-laws
being followed in the locality.
9. Location:- The staircase should be located in such a
position that it is easily and quickly approached. A
central position in a building would be ideal. Both light
and ventilation should be available especially at turning
points. In a residential building, the stair should be
located near the main entrance and screened from
outside for privacy. In public buildings, it should
preferably be located obvious from the main entrance.

39. CLASSIFICATION OF STAIRS ACCORDING TO THEIR
LAYOUT
1- Straight flight stairs:- The stair which rises from one floor to
another in one direction is known as straight flight or simply
straight stair (see fig. 2 a). This type of stair may be
constructed with or without landing. This type of stair is only
suitable for a long and a narrow staircase.
2- Quarter turn stairs:- The stair which turns through 90° either
to the left or to the right is known as quarter turn stair (see fig.
2 b & c). This type of stair may be provided with winders as
shown in fig. 2 (b) or with a quarter-space landing as shown in
fig 2(c). This type of stair is suitable where the width staircase
is more but it has got limited length.
Read Yourself

40. CLASSIFICATION OF STAIRS ACCORDING TO THEIR LAYOUT
3- Half turn stairs
The stair which turns through 180° is known as half turn stair (see fig. 2 d
&c). In such stairs, the adjacent flights are in opposite directions separated by
half-space landings, two sets of winders or two quarter space landings
according to the space available.
• Half turn stairs are further classified into the following two types:-
(a) Dog-legged stairs:- A half turn stair with no space between its flights is known as
dog legged stair (see fig. 2 d). This type of stair is suitable where the width of the
stair case is limited and is commonly used for single or double storied modern
buildings.
(b) Open well stairs:- A half turn stair with a space (called well) between its flights is
known as open well stair (see fig. 2 e and f). This stair is also known as an open newel
stair when the well left between the flights is of rectangular shape see fig. 2 (e). If the
space for this type of stair is limited, a short flight is introduced on the narrow side of
the well with two quarter space landings as shown in fig. 2 (f).This type of stair is
suitable for multi-storied buildings as in this case the well allows for top lighting.
Read Yourself

41. CLASSIFICATION OF STAIRS ACCORDING TO THEIR LAYOUT (-ctd-)
4. Geometrical stairs: A half turn stair in which the dwell is of curved shape
between the forward and backward flights is called geometrical stair (see fig. 2
g). In this type of stair, the change in direction is obtained by winders. It
provides easy turning but is tiresome as it is generally without landing. This
type of stair is suitable for single or double storied buildings.
5. Circular stair:- The stair which is provided in a circular stair case is called
circular stair (see fig. 2 h). In this stair, the strings and the hand rails are
continuous and the change in direction is obtained by winders. All the steps
may be supported by a newel at the center or there may be a circular well hole.
A circular stair having all is steps radiating from a central newel is known as
spiral stair. This type of stair is suitable when a limited space is available for
the stair case. Iron spiral stairs are very suitable for back door entrance as they
occupy very little space.
6. Bifurcating stairs:- This stair having its bottom flight wide which is divided
into two narrow flights at the landing at right angles in the opposite direction
is called a bifurcating stair (see fig. 2 i). This type of stair is suitable for public
buildings, assembly halls, railway foot bridges etc..
Read Yourself

42. MAINTENANCE OF BUILDINGS
• The art of keeping up the different parts of buildings
in their best conditions to ensure neat appearance
and a fair life of service of those parts is called
maintenance of buildings.
• Maintenance of buildings may include cleaning
overhauling, general repair and replacement of
defective parts and special repair of defects occurring
due to their poor design and workmanship.
• The object of building maintenance is to ensure neat
appearance and stability of the building

43. CLASSIFICATION OF BUILDING
MAINTENANCE JOBS
Maintenance jobs of building are divided into
following two categories
1. Routine maintenance
2. Special Repair

44. (a) ROUTINE MAINTENANCE
Def: The day to day or thorough repairs which are carried
out in buildings after specified periods are known as
routine or periodic maintenance
Explanation: Routine maintenance of buildings includes
the following items of work
• Repair of damaged plaster surface
• White washing and color washing
• Distempering
• Painting of timber and steel surface
• Repair to damaged part flooring

45. ROUTINE MAINTENANCE (-ctd-)
• Removal stains from concrete and terrazzo floor
• Re-polishing a terrazzo and mosaic flooring
• Repair to worn out timber floor polishing and waxing
• Replacement of glass panes
• Replacement of decayed timber and replacement of
fittings
• Easing of doors and windows
• Cleaning of fire chimneys, gutters, etc.

46. (B) SPECIAL REPAIRS
Def: The repairs that are done to overcome special problems as
soon as they occur are known as special repairs. These repairs
are very difficult and require more attention for their carrying
out.
Explanation:
Special repairs of the buildings include the following items of
maintenance works:
• Strengthening of foundations and foundations soil
• Rectifications of Leaking roofs

47. SPECIAL REPAIRS(-ctd-)
• Repair to damage concrete surfaces
• Repair to cracks in masonry walls
• Repairs at the window sills & joinery works at the
roof level of building
• Providing damp proof course in the existing building
• Repairs to the damp floors
• Anti-termite treatment in the maintenance of
buildings
• Repairs to expansion joints