Diploma 1st Sem.

CIVIL

BASICS OF CIVIL ENGINEERING

Building construction

Unite -3

Construction : Object created by constructing works, connected to ground, performed from building products with common installations and equipment, or integrated complex with facility or equipment as well as technical - technological units or solo installations connected to the ground. Or units connected to the ground but was not made by construction works, if they change the purpose of the land

Construction works :Performing constructional and other works (preparation, land, and structural, installation, finishing and mounting of construction products, plant or equipment) with which new buildings are built, existing buildings are reconstructed, removed or maintained.

Constructing/Building:Means the process of designing, constructing, usage and removal of the construction (building), everything that is related to the constructing of the new buildings can be applied in an appropiate way to reconstructing, maintance and removal of the old buildings.

Construction site :Is a place,land or buildings (including other areas that are temporarily occupied ) needed to execute the construction works or the application of appropriate building technology and security, on which to build, reconstruct, remove or perform maintenance work building

Basic information to be collected are the following:

• technical-economic documentation of agreed work• geographic and topographic conditions,• meteorological and climatic conditions,• geological and geotechnical conditions,• hydrological conditions,• ability to supply water, energy, etc.• ability to supply material• traffic, and conditions for delivery of materials, machinery, etc.• opportunity for employment of labor force,• property-legal relations,• capacity of eventual subcontractors, suppliers, transportation• companies,• cost of resources to be used in the region in which to build, etc.

Site geography

• The exact geographical location of site,• The nearest villages, centers of possible supply (construction

materials, handicraft workshops and repair shops, banks, post offices, the building materials industry, quarries, gravel pits, desire. stations, ports, airports, pumps for liquid fuels, etc.)

• Economic description of cities, towns and other centers that gravitate future construction, as documentation and background should submit: geographical maps and distances specified in relation to the site.

• Configuration of site has a big influence on the organization of the site, or the disposition of various plants, design and development of access roads, the internal communication at the site, the interior horizontal and vertical transport to the site and the whole works.

• Since the topography of ground depends on what will be applied to the disposition of the site, which transport vehicles to use and how much transportation will cost.

Geological and geotechnical conditions

• When performing work on the building below the ground surface occurs some problems related to groundwater (groundwater elevation, vibration levels at various time periods, the strength of underground springs, etc.).

• Geological complex of ground, geomechanical and geotechnical properties of soil layers on the basis of appropriate tests, and geological sections, geological map of the area generally should exist within the architectural- constructive phase of the project of the building, but contractor has all these elements to check before building.

• Determining the existence of groundwater, and their regime is of great importance to the process of organizing works at zero cycle facilities, as well as for predicting the equipment and installations for water pumping, fencing construction pit, concreting under water, etc., which has great importance for, among other things, calculating and determining the cost of these works.

Meteorological and climatic conditions

Climatic conditions at the site are reflected in two ways:

• the creation of special conditions for life and work, or the hygienic and technical conditions, and the impact on the organization and the construction technique.

• The human activity, climate has a direct effect especially when the works are carried out in the open. It has an impact on the performance of workers and the effect of work generally. Unfavorable climatic conditions create special, difficult living and working conditions of workers on site and reflect on the state of health, and should be anticipated and calculate all necessary safeguards for the health and maintaining good working condition of workers.

Meteorological and climatic conditions

• Climatic conditions are decisive for the annual fund of working time, it is essential that information about climate and weather conditions to be collected for a longer period of observation.

• Such information may be obtained from Hydro-Meteorological Institute. data on rainfall and its distribution throughout the year, with rainfall greater than 1 mm and 10 mm, as well as data on relative humidity. on temperature, average annual, highest and lowest, and the number of days with temperatures below 0 C or lower than -5 C. information about the dominant winds, their direction, intensity and duration. Strong winds can cause major problems at work and in certain areas and to stop work completely. Strong winds have an influence on the stability of the scaffolding, formwork and roof, high pumps, etc.

Meteorological and climatic conditions

• Climatic conditions are decisive for the annual fund of working time, it is essential that information about climate and weather conditions to be collected for a longer period of observation.

• Such information may be obtained from Hydro-Meteorological Institute. data on rainfall and its distribution throughout the year, with rainfall greater than 1 mm and 10 mm, as well as data on relative humidity. on temperature, average annual, highest and lowest, and the number of days with temperatures below 0 C or lower than -5 C. information about the dominant winds, their direction, intensity and duration. Strong winds can cause major problems at work and in certain areas and to stop work completely. Strong winds have an influence on the stability of the scaffolding, formwork and roof, high pumps, etc.

Site hydrology

• When it comes to the performance of buildings in the vicinity of surface water, rivers, lakes, canals, must be familiar with the water regime because it has a direct impact on the groundwater regime.

• Based on the collected data should find the optimal technological solution and make a study of evacuation from the building of underground water tanks - wide excavation

Site organization – phase 1

• In the first phase of works is formed and performed:

– Traffic and site access

– Fence site and input (s)

– Earthworks on the site, digging pits

– Building site road (part of)

– Interim and secondary buildings on the site (part of)

– Energy and installation needed on site (part of)

Classification of buildings

National building classification –national building code(NBC)

NO GROUP TYPE OF BUILDINGS

1 A RESIDENTIOL

A-1 lodging house

A-2 Family private dwelling

A-3 dormitories

A-4 apartments

A-5 hotels

2 B EDUCATIONAL

3 C INSTITUTIONAL

C-1 hospital

C-2 Penal institution

4 D ASSEMBLY BUILDINGS

5 E BUSINESS BUILDINGS

6 F MERCANTIALE BUILDING

NO GROUP TYPE OF BUILDINGS

7 G INDUSTRIYAL BUILDINGS

8 H STORAGE BUILDINGS

Classification OF building STRUCTURE1. LOAD BEARING

STRUCTURE

these type of structure adopted at places, where hard strata available at shallow depths.

the load transfer to slab or roof and floors are transmitted through wall as firm soil.

upper story wall thickness less then lower story

reduces building carpet area

2-3 story constructed these thye structure

RCC FRAMED STRUCTURES• they are consist of a cross-beams main beams, columns , plinth, footings • there are all element rigid-joins constructed .• Its subjected to external loads,• Compresive ,tensile ,torsion

DESIGN LOAD1. DEAD LOAD

it consists of self weight of different parts of the building like floor ,roof, walls, plaster, door, windows.

unit weight KN/m3

RCC- 25

PCC- 24

2. LIVE LOAD

live load consists of moving or variable loads due to people or occupants their furniture ,temporary story, machinery.

DESIGN LOAD3. WIND LOADS

P=K.V2 p=wind pressure

k= coefficient. of size of structure

v= wind velocity

4. EARTHQUAKE LOADS

acts in horizontal direction .

earthquake force =m.∞

m= w/g

M=mass of buildings G=gravitational acceleration

∞= acceleration of earthquake

Different type of foundation

FOUNDATION shallow foundation deep foundation D<B D>B spread pile Combined coffer

dams Strap Raft grillage

Component Parts of a BuildingThe basic requirements a building should satisfy in design and performance are:•It must be strong enough to withstand the loads coming on it including the self-weight, live load, wind load and earthquake load.•It must not deflect under the loads.•It must give comfort and convenience to the inhabitants.

BUILDING COMPONENTS

A building broadly consists of three parts:•Foundation•Plinth•Superstructure

1 Foundation•The foundation is the most critical part of any structure and most of the failures are probably due to faulty foundations. •Hence, it is highly essential to secure good foundation to maintain the stability of the structure. •A good foundation must remain in position without sliding, bending, overturning or failing in any other manner.

The foundation of any structure should be laid much below the surface of the ground in order to attain the following:•To secure a good natural bed.•To protect the foundation courses from atmospheric influences.•To increase the stability of the structure against overturning due to wind uplift.

The primary function of the foundation is to transmit the anticipated loads safely to the soil below.

The foundation in a building structure is supposed to satisfy the following basic requirements in their design and construction:

•To distribute the total load coming on the structure over a large bearing area so as to prevent it from any movement.•To load the bearing surface or area at a uniform rate so as to prevent it from any movement.•To prevent the lateral escape or movement of the supporting material or alternatively to ensure the stability of the structure against sliding.•To secure a level or firm natural bed upon which to lay the course of masonry and also support the structure.•To increase the stability of the structure as a whole to prevent it from overturning or sliding against the disturbing forces such as wind, rain and frost.

Plinth

This is the portion of the structure between the surface of the surrounding ground and the surface of the floor immediately above the ground. The thickness of the plinth wall depends upon the weight of the superstructure and the width of the foundation concrete. The minimum height of the plinth is usually kept as not less than 4.5 cm.

The plinth wall should satisfy the following requirements in a building structure in its design and construction:

•To transmit the load of the superstructure to the foundation.•To act as a retaining wall so as to keep the filling in position below the raised floor or the building.•To protect the building from dampness or moisture.•To enhance the architectural appearance of the building.

SuperstructureThe primary function of the wall is to enclose or divide space. Piers are usually in the form of a thickened section of a wall, placed at intervals along the wall to take concentrated vertical loads or to provide lateral support to the wall. A load-bearing wall should satisfy the following requirements:•Strength: A wall should be strong enough to take up the loads safely. The loads coming in the wall include its own weight, weight by superimposed loads and bilateral pressures like wind.•Stability: It should be stable against overturning by lateral forces and buckling caused by excessive slenderness.•Heat Insulation: It should be possible for walls to attain insulation against heat.•Sound Insulation: The walls should be made of such materials and by such technique so as to insulate the building against sound.•Privacy and Security: The walls should provide sufficient privacy and afford security against theft.

FloorsThe main function of a floor is to provide support for occupants, furniture and equipment of a building, and the function of providing different floors is to divide the building into different levels for creating more accommodation within the limited space .A floor should satisfy the following requirements:•Strength and Stability: All the floors, whether basement, ground or upper should be strong enough to support the floor covering and other superimposed loads.•Durability and Damp Prevention: The floors provide a clean, smooth, impervious, durable and wear-resisting surface.•Heat Insulation: Insulation against heat should be provided in case of ground and basement floors, especially when suspended and ventilated timber floors are used.•Sound Insulation and Fire Resistance: The insulation against sound and fire should be provided in the case of upper floors as they act as horizontal barriers for the passage of sound and fire in a vertical direction.

Doors and windows

The main function of doors in a building is to serve as a connecting link between internal parts and to allow free movement to the outside of the building. Windows are generally provided for proper ventilation and lighting and their number should be determined according to the requirements.

Doors and windows should satisfy the following requirements:

•Weather Resistance: They should be strong enough to resist the adverse effects of weather.•Sound and Thermal Insulation: They should be capable of being made air tight to achieve insulation against sound and heat.•Damp Prevention and Termite Prevention: They should not be affected by white ants and the moisture penetration as this will reduce the strength and durability.•Fire Resistance and Durability: They should offer fire resistance and should be durable.•Privacy and Security: They should offer sufficient privacy without inconvenience or trouble and security against theft.

Sills, lintels and weather shades

•Window sills are provided between the bottom of the window frame and the wall below to protect the top of the wall from wear and tear. The openings are provided in the wall of a building to accommodate the doors and windows. •The actual frame of a door or window is not strong enough to support the weight of the wall above the opening and a separate structural element is, therefore, introduced between the top of the window frame and the wall coming over it. •This is known as the lintel. Weather shades are generally combined with lintels of windows to protect them from the weathering agencies.

Roofs

A roof is the uppermost part of a building whose main function is to enclose the space and to protect the same from the effects of weather elements. A good roof is just as essential as a safe foundation. A roof should satisfy the following requirements:•Strength and Stability: The roof structure should be strong and stable enough to take up the anticipated loads safely.•Weather Resistance: The roof covering should have adequate resistance to resist the effects of weather elements.•Heat Insulation: The roof should provide adequate insulation against heat.•Sound Insulation: The roof should have adequate insulation against sound from external sources.•Fire Resistance: The roof should offer an adequate degree of fire resistance in order to give protection against the spread of fire from any adjacent buildings and to prevent early collapse of the roof. The form of construction should also be such that the spread of fire from its source to other parts of the building by way of roof cannot occur.•Day Lighting: The roof provides daylight in buildings with large floor area.

Steps and stairsA step usually consists of a tread and riser supported by strings. A stair is a structure consisting of a number of steps leading from one floor to another.

Steps and stairs should satisfy the following requirements:•Strength and Stability: The stairs should be designed like floors such that they are strong and stable enough to carry the anticipated loads safely due to the weight of the people using them and also the weight of the furniture or equipment being carried up or down through them.•Sound Insulation: The stairs should have adequate insulation against sound from external sources.•Weather Resistance: The stairs if exposed to open air should offer sufficient resistance to weather elements such as rain and heat.•Comfort: The proper design of steps and proper location of stairs in a building offer several advantages such as comfort and efficiency in vertical movement, natural light and ventilation and safety in emergency.

Finishes for walls

Finishes of several types such as pointing, plastering, painting and distempering and decorative colour washing are applied on the walls.

The main functions of these finishes are as follows:

•They protect the structure, particularly the exposed surfaces, from the effects of weather.•They provide a true, even and smooth finished surface and also improve the aesthetic appearance of the structure as a whole.They cover up the unsound and porous materials used in the construction

Masonry is generally a highly durable form of construction. However, the materials used, the quality of the mortar and workmanship, and the pattern in which the units are assembled can significantly affect the durability of the over all masonry construction.

Masonry

GENERAL PRINCIPLES IN BRICK MASONRY•The bricks used should be hard, well burnt and tough with uniform colour, shape and size.•The bricks should be laid on their beds with the frogs pointing upwards.•The courses should be truly horizontal and should have truly vertical joints.•Use of brickbats should be avoided to the maximum possible extent.•Generally, the height of the brick masonry construction in a day is limited to 1.5 m.•In order to ensure continuous bond, the walls should be stopped with a toothed end at the end of each stage of construction.•Finished brickwork should be cured for at least 2-3 weeks where lime mortar is used and for 1-2 weeks where cement mortar is used.

TYPES OF BRICK MASONRY WALLS AND STRUCTURES

Spanning Openings in Brick Walls• Brick walls must be supported above openings for windows or doors,

using reinforced concrete lintels, reinforced brick,or steel angles• A corbel is an ancient structural device of limited spanning capability,

that may be used for small openings in brick walls, for beam brackets, and for ornamental provisions.

• Arches can be used instead of lintels to span large openings in walls- Different forms of arches can be built: Segmental Arch, Jack Arch, Tudor Arch, Elliptical Arch, Roman Arch (cylindrical shape), Goethic Arch, Parabolic - Arch Terminologies: Intados, Extrados, Soffit, Spring line, Skewback, Crown, Span, Rise

TYPES OF BRICK MASONRY WALLS AND STRUCTURES

Reinforced Brick Masonry:• A reinforced brick masonry wall in constructed with two wythes of

brick, 2” to 4” apart, placing the reinforced steel in the cavity and filling the cavity with grout. Grout is a mixture of Portland cement, aggregate and water. Grout must be filled enough to flow readily into the narrow cavity and fill it completely - Two methods are used in building reinforced brick walls: Low-lift method: Height of grout filling is not more than 4 feet - Wythes are held together by galvanized steel wire ties at 24” c/c horizontally and 16” c/c vertically - High-lift method: Wall is grouted, one story at a time - Clean out holes are left at the bottom to drive out the debri (from mortar in brick masonry) down with water through the holes - Finally the clean out holes are sealed with a brick and mortar joint

•Masonry is commonly used for the walls of buildings, retaining walls and monuments. •Brick and concrete block are the most common types of masonry in use in industrialized nations and may be either weight-bearing or a veneer.•Concrete blocks, especially those with hollow cores, offer various possibilities in masonry construction. They generally provide great compressive strength, and are best suited to structures with light transverse loading when the cores remain unfilled. Filling some or all of the cores with concrete or concrete with steel reinforcement (typically rebar) offers much greater tensile and lateral strength to structures

Applications

•Brick floor.• Earth floor.• Cement concrete floor.• Mosaic floor.• Tile floor.• Marble floor.• Wooden floor.

TYPES OF FLOORS

FLOORING

MATERIALS FOR FLOORING

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

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

teerrazzo (chips). • Tiles and asphalt are less expensive whereas concrete and

brick are the cheapest and are commonly used.  

2- APPEARANCE• Co lour, texture and architectural beauty are the factors taken

into consideration.

 

3- DURABILITY• Resistance to wear and tear is an important factor for a floor covering. • Resistance to temperature changes, humidity, disintegration and decay has

alsoto 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`).

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.

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 can not be repaired easily while tiles can be

replaced quickly.

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. • The level of the flooring being known, the filling is excavated the

desired depth. • 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 (P.C.C), one part of cement,

6 parts of sand and 18 parts of aggregates of 10 to15 cms 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.

• Bricks on edge flooring are laid into1:6 C/S mortar over a bed of ¾ // thick C/S mortar.

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.

DISADVANTAGES OF MONOLITHIC FLOORS

• The topping is likely to get damaged due to subsequent building operations.

• It is likely to develop hair-like cracks on account of small settlements which may occur in the base course immediately after it is laid.

• When the surface of the topping gets damaged, it is very difficult to repair it.

• The progress is slow since the topping can be laid only after the base course has sufficiently set to allow the workmen to lay the top layer.

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.).

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 mot 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.

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.

• 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. • After2 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.

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 from 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.

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.

7. WOODEN FLOORING• This type of floor construction is not extensively used but is

popular for special purpose floors, e.g. in auditorium, hospitals. • Wooden flooring should have a concrete base or should rest on

joists spanning across walls which are constructed at suitable interval.

• For the fixing of wooden floors on concrete slabs, longitudinal railing strips are provided.

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.

• A roof usually consists of frame work provided with a suitable covering at its top.

• 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.

CLASSIFICAION

• Sloping, pent or pitched roofs

• Flat or terrace roofs

(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)

• Shelled roofs

• Domes

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.

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.

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.

Jack rafter:- The short common rafters which run from a hip rafter to the eave of a sloping roof are called jack rafters.

Common rafters:- The members supporting the battens or boardings under the covering of a sloping roof are known as common rafters.

Gable:- The end of a sloping roof finished in a vertical triangle is called gabled end or gable.

Barge:- The finished edge of slating or tiling over-hanging a gable wall is called barge.

Barge board:- Wooden planks fixed to the ends of the common rafters projecting beyond the gabled end of a sloping roof is called a barge board.

Purlins:- The wooden or steel members laid horizontally to support the common rafters of a sloping roof are called purlins.

Cleats:- The pieces of timber or angle-iron which are nailed or screwed (for timber), riveted or welded (for angle-iron) on the trusses, to support the purlins are known as cleats.

Battens:- The pieces of wood which are directly nailed to the common rafters are called battens. The roof coverings are directly laid over battens.

Pitch:- The inclination of the side of a slopping roof to the horizontal surface is called pitch of the roof. It is usually expressed as the ratio of the rise to the span or in degrees.

Truss:- A frame work of members arranged in triangles is called a truss.

• Reference Books:

1) Elements of civil engineering by Rakesh Ranjan

2) Elements of civil engineering by B.C.Punamia

3) Basic Civil Engineering by L.G.Kulkarni