2015

CITY AND GUILDS IN

CONSTRUCTION TECHNOLOGY

Engineers design the Architect design the

Bone of building
Appearance of the building

ENGR. DANIEL CHILEKEZI

EASTERNAL HEARTLAND TECHNICAL CENTER
8/13/2015
Building construction.
Building construction is the process setting up buildings. Building is a structure with a roof and
walls.
Building is the process of setting out and erecting a building. It involves site preparation, setting
out, foundation, erecting of walls, windows, doors and roofs. Before a building is erected, the
first thing is to determine, what type of building, the purpose the building is going to serve and
where is the building going to be erected. (Land).
TYPES OF BUILDING
There are different types of building ranging from:
i. Bungalow
ii. Duplex
iii. Multi-purpose building
iv. School building
v. Hospital building, etc.

Basically building can be categorized into two broad groups namely;

 Residential building and
 Commercial building

Characteristics of a good building:

For a building to be adjudge good, it must satisfy all or most of the following requirement
1) Correct and proper use of tested material
2) Correct site preparation resistance to moisture
3) Structural stability
4) Incorporation of structural piers
5) Good thermal insulation
6) Good sound insulation
7) Safe access internally and externally
8) Suitable refuse disposal
9) Ample light and ventilation
10) Correct floor to ceiling height
11) Adequate heating arrangement
12) Sufficient cold and hot water supply and storage
13) Simple drainage system
14) Functional practical and aesthetical pleasing.

Author by; Engineer Chilekezi Daniel. O

 Forms of building
Building can describe by their forms such as circular building, polygonal building and curve –linear
building.
The form that a building take will be determine by the following;-
1. The function which the building will serve
2. The designer’s aesthetic interpretation
3. The material available
4. The structural method used.

Form must be well balanced with materials, craftsmanship and structural method to enhance
environmental blend.
Factors affecting the choice or form of construction
i. Invention of new material
ii. Functional requirement
iii. The client taste
iv. Scarcity of materials
v. Rising cost or scarcity of labour.

Process of construction
There are two major process used for constructing a building and they are;
1. Design process: this process involves the determining of the size and shape of the
building and the allocation of space in the building.
2. Production process: this concern with the nature and sequence of building operations
and it is this that determines the method which can be adopted in in carrying out the
operation.

Trade, Profession and interest in the building industry.

Trade in the building means craft work, bricklayer, plaster, carpenter, plumber, labour or ganger
concrete, ganger or concreter, Manson plaster, painters, tillers etc.
Profession this is a form of occupation or employment that is possible only for an educated person
after training in some special branch of knowledge, such as architecture, survey, building
technology, civil engineering etc.
NB. A building project can be executed by direct project or through contract depending on the
size of the project.
BUILDING TEAM
Building are divided into two groups i.e. design team and construction team.
Building team is headed by the client or the employer or the building owner. He employs
everybody involve in the construction of the building.

Author by; Engineer Chilekezi Daniel. O

Design team; - includes
1. Architect; he is engaged by the owner as his agent to design\, advise and ensure that
the work is kept within cost.
2. Engineers: - are specialist such as structural engineers, heating and ventilating engineer,
service engineer (electrical, sanitary etc.) who are employed to work with the architect
on particular aspect of the building design.
3. Quantity surveyor: - is a cost consultant and adviser. He is engaged to prepare bills of
quantities check tenders, prepare interim valuation and advise on the cost of variation.
4. Clerk of work: is employed in large contract. He is the architect site representative to
supervise the contractors.
Contractors team: includes
i. Main contractor: he is employed by the building owner on the architect advice
to carry out the construction work.
ii. General foreman: he is sometimes called the site agent, his duty varies from one
form to the other. He is the contractor site representative, responsible for the
day to day running of the site.
iii. Trades foreman: is charge of a group of trade/trade gang.
iv. Operatives: are the major work force on the site, they include tradesmen,
apprentice and laborers.

Other people in building construction are;

i. Trade union or craft union: their interest is to watch the interest of their members in
such matters like wages, working conditions etc.
ii. Insurance policy in building: fire and burglary insurance, an employer is liable to pay
compensation for injury caused to his employers arising in course of their employment.
iii. Government agent and supervisory personnel: enforcement of local building regulation
on the site. He is an employee of the local authority.
iv. Building inspector: he sees to the keeping of or enforcement of local building regulation
on the site. He is an employee of the local authority.
v. Public health inspector: he sees to keeping of health regulation on the site by the
contractor.
vi. Federal inspectors of factory: they check on the safety of men and equipment on the
site.
Feature of commercial building.

The features needed for commercial building are

i. Merchandising, showroom and demonstration area.
ii. Area provided for comfort of customers and employee, i.e. (a) living room (b)
sanitation etc.
iii. Working area: for preparation, receiving, shopping, administration, record areas, cash
registration etc.,
iv. Storage area: ware houses, stock room, special lockers, space vaults, refrigerator etc.

Author by; Engineer Chilekezi Daniel. O

 v. Outdoor areas: parking an access for automobile, transport facilities, sport, tracks
landscapes etc.
vi. Provision for feature: more land for horizontal expansion, proper design of foundation
wall for vertical expansion.
vii. Utilities i.e. lighting and electrical services, ventilation and air conditioning, plumbing,
sewage, gas, water stream etc.
viii. Provision for tears, cranes, truck, provision for mobile equipment.

Exercise
1. With a neat sketch, explain the use of ten building tools. Including builder square,
corner profile and gauge rod.
2. List and explain the uses of five plants used in construction work.
3. Explain the following terms.
i. DPC
ii. Over site concrete
iii. Gable roof
iv. Lintel
v. Dwarf wall.

WORKSHOP/SITE SAFETY RULES AND REGULATION

Safety of men and materials should always be put into consideration at all times on the site in
other to reduce accident rate ion the site.
To ensure this, the following points must be observed;
1. Protective clothing must always be worn by workmen on the site or workshop such as
i. Overall
ii. Goggle
iii. Helmet cap
iv. Hard cover shoe
v. Gloves
2. Materials tools and equipment must be properly stored in appropriate position, tools
must not be left carelessly in the workshop or on the site.
3. Poisonous materials and inflammable materials must be labelled and properly stored.
4. Safety or warning signs must be put at required location in the work on the site e.g.
i. KEEP OFF
ii. DANGER
iii. NO SMOKING etc.
5. Adequate lighting must be provided in the workshop.
6. The necessary conveniences should be made available to the workmen on the site or
the workshop e.g. clerk room toilet, bathroom, cleaning/drinking water e.tc.
7. Workshop must be properly ventilated.
8. There should be no horseplay or unnecessary conversation on the site/workshop.
9. Site must be properly secured and conducive for men and materials.

Author by; Engineer Chilekezi Daniel. O

 10. Machines/plant should be operated by competent persons.
11. Use the right tool for the right job.
12. Deep excavation must be surrounded by barriers or timber.
13. Inspect and check the condition of the wiring at regular intervals to prevent electrical
shock.
14. There must be a provision of first aid at the workshop or site.
15. Workers must always be alert and check that they place their feet and hands safely.
16. When working on a roof, you must;
a. Erect scaffolding up to the lower level of the roof to safe anyone who slips down a
roof slope.
b. Place craw board to spread the load of the building worker weight when moving up
and down the slope.

Site preparation
Before a building is erected the piece of land that is to be used is called the site. This site is to
be prepared before setting out for foundation.
Therefore; site preparation is the process of clearing, uprooting, gruping trees and unwanted
element from the ground. This can be done by the use of cutlass, shovel, spade, pickaxe,
bulldozer, etc.
There are two categories of tools used in site preparation and these are;
1. Mechanical tools: - such as bulldozer, tractor shovels, graders, chain saw, excavators
etc.
2. Hand tool: - cutlass, wheel barrow, head pan, hoe, auger, auger, axe, rake etc.

Setting out
Setting out is the process of transferring the building plan (foundation plan) in full scale to the
ground by the use of lines and pegs.
To set out a building requires the knowledge of building drawing and the ability to read
drawings accurately.
A building is set out in order to clearly define the outline of the excavation and the center line
of the walls, so that construction can be carried out exactly according to the plan. The center
line method of setting out is generally preferred and adopted.

Author by; Engineer Chilekezi Daniel. O

PROCEDURE

Fig.1: Example plan to be set out on the ground

1. From the plan (fig 1), the center line of the walls are calculated. Then the center lines of the
rooms are set out by setting perpendiculars in the ratio 3:4:5. Suppose the corner points are a,
b, c, d, e, f and g which are marked by pegs with nails on top.

2. The setting of the corner point is checked according to diagonals ac, bd, cf and eg.

3. During excavation, the center points a, b, c, d, e, f, g may be removed. Therefore the center
lines are extended and the center points are marked about 2m away from the outer edge of
excavation. Thus the points A1, A2, B1, B2 and likewise, are marked outside the trench. Centre
line is shown clearly by stretching thread or rope. The center points fixed 2m away from the
excavation are marked with sit out pegs.

4. From the plan details, the width of excavation to be done is also marked by thread with pegs
at appropriate positions.

5. The excavation width is then marked by lime or by with furrow with spade.

6. If the plan is much too complicated and follows a zigzag pattern, then the center pegs are
kept at suitable positions according to site conditions.

Setting-out of a building – marking of a building position, size and shape in terrain.

Author by; Engineer Chilekezi Daniel. O

 Setting-out plan – plan where a projected building is drawn and numeric values of setting-
out elements are written.
Land survey for setting-out:
1. creation of a setting-out net (measurement, calculation and marking of survey stations
which can be used for setting-out)

2. setting-out of the spatial position of a building = setting-out of the building main

position line (= frontage), setting-out of the axis or the main points of a linear structure
(road, railway, watercourse)

3. detailed setting-out = setting-out of a building size and shape.

NB:

All setting out operations are carried out from information given on drawings produced by a building
designer, architect or construction company. On larger sites the site engineer carries out the setting out
of buildings and associated roads. It is however also quite common for the site supervisor to set out
individual plots on a housing estate. Drawings should be produced to BS 1192 ‘Recommendations for
Drawing Office Practice.

Drawings must be approved by the local authority for the area in which the building is being
constructed. On approval of the drawings for Planning Permission (Planning Department), and Building
Regulations (Building Control), the setting out can safely commence.

The following information relevant to setting out must be shown on drawings submitted for local
authority approval:
• Position of proposed buildings in relation to existing boundaries or roads.
• Position and levels of new roads and drains.
• Levels of new buildings at foundations, floors etc.

The site plan will show exactly where the building is to be situated on the land. This is often drawn to a
scale of 1:200 or 1:500.

Often the two front corners of the building are dimensioned from existing set features on the site such
as boundary walls or intersections, gate posts etc., allowing initial positioning of the base (or ‘frontage’)
line of the building.

The building layout or general location plan, often produced to a scale of 1:50, will contain the
dimensions of the building, including the internal room sizes.

Dimensions on drawings
When setting out, measurements have to be made on site from dimensions ‘taken off’ from a drawing.

Dimensions on construction drawings are most commonly stated in millimeters, although sometimes
meters may be used.

Author by; Engineer Chilekezi Daniel. O

When taking a dimension from a drawing it should always be double checked to ensure it has been
read properly. If the dimension is unclear or any other problem is found report this immediately to the
site supervisor and await instructions before continuing.

Measurements made on site from drawing dimensions should be regularly checked for accuracy. An
accuracy of 1:1000, i.e. 1mm in every 1 metre, should be achieved for general construction work.
NOTE!
All information to be used for setting out any building must be checked before setting out
commences.

NB: All information to be used for setting out any building must be checked before setting out
commences.

Author by; Engineer Chilekezi Daniel. O

Methods of Dimensioning Drawings

On construction drawings, dimensions are stated in a variety of ways:

• Running dimensions.
• Separate dimensions.
• Separate ‘string’ and overall dimensions.

1. Running dimensions
All dimensions along a line are stated as a distance from a single point, e.g. the corner of a building.

This is the most accurate method because errors in individual measurements will not accumulate along
a line of dimensions, when used for setting out a building.

2. Separate dimensions
All dimensions are stated separately and are not able to be checked. This is not recommended for
setting out purposes.

3. Separate ‘string’ and overall dimensions.

This method allows separate dimensions stated along a line to be checked for accuracy against an
overall dimension.

By checking that individual dimensions tally up to the overall dimension, the reader becomes
confident that the dimensions are correct.

Author by; Engineer Chilekezi Daniel. O

 Removal of Vegetable Soil

Before any setting out commences, it is good practice to remove turf and vegetable soil from
the area on which the building will stand. The reasons for this are:

• Setting out markings will be clearly visible and distinct on soil but not on grass.
• ‘Topsoil’ is unsuitable to build on as it has a low bearing capacity.
• The soil may also allow plant growth to continue, even when covered by a building, and this could
result in timber decay.

The Building Regulations require the vegetable soil to be removed from the building area. This is either
stored in convenient on-site ‘spoil heaps’, or removed from the site totally if no storage room is
available (and if it is not to be reused for landscaping).

Structural Elements of a building.

Engineers also use the medium of graphic to express what they have design.

Engineer’s drawings are more to technical drawing that was an outcome from the design
procedure.

In this chapter, students will be introduce with structural system of a building that are
designed by civil engineer as for building is one of the field that need the expertise of a civil
engineer.

This system is later documented in the civil engineering drawing plan.

Building structural components
Civil engineers are well known to practice engineering knowledge in the applications
designs, constructions, maintenances etc. of buildings.
Buildings are supported by a structural systems that is designed and constructed to support
and transmit applied loads safely to the ground without exceeding the allowable; loads
(stress) and deformation (strain) in its member.
This system is divided to superstructure system and substructure system.

Building superstructure

The superstructure system is the vertical extensions of building physical structure above the
foundations

 Columns
 Beams
 Load bearing walls
 Slab

Author by; Engineer Chilekezi Daniel. O

  Trusses
 Staircase

Columns
Columns are rigid, relatively slender structural members design to support axial compressive
loads applied to the ends of the members.
Beams
Beams are rigid structural members designed to carry and transfer loads across space to
supports elements mostly a columns

Load bearing walls

A load bearing wall is a wall that bears the load resting on upon it by conducting its weight to a
structure or beam.
Slab
Slab is a plate structure that are rigid, planar, usually monolithic structure that disperse applied
loads in a multidirectional pattern, with the loads generally following the shortest and stiffest
routes to the supports.
Truss
Truss is a structure comprising one or more triangular is a structure comprising one or more
triangular are connected at joints referred to as widely nodes.

Author by; Engineer Chilekezi Daniel. O

Staircase
Stairs provide means for moving from one level to another. Landings of stairway should be
logically integrated with the structural system to avoid overly complicated framing conditions.

Building substructure
The substructure is the underlying structure forming the foundation of the building. This
systems a later to be discuss in geotechnical engineering drawing. That’s in drawing building
plans section. This comprises of the foundation footing, earth filling, hardcore, oversight-
concrete and floor screeding.
Other structure details of building are referred to as the basic elements of building.
Elements of building

The following are the basic elements of a building:

1. Foundation
2. Plinth
3. Walls and columns
4. Sills, lintels and chejjas
5. Doors and windows
6. Floors
7. Roofs
8. Steps, stairs and lifts
9. Finishing work

Author by; Engineer Chilekezi Daniel. O

10. Building services.
The functions of these elements and the main requirement of them is presented in this article.

1. Foundation: Foundation is the most important part of the building. Building activity starts
with digging the ground for foundation and then building it. It is the lowest part of the building.
It transfers the load of the building to the ground. Its main functions and requirements are:

(a) Distribute the load from the structure to soil evenly and safely.
(b) To anchor the building to the ground so that under lateral loads building will not move.
(c) It prevents the building from overturning due to lateral forces.
(d) It gives level surface for the construction of super structure.

2. Plinth: The portion of the wall between the ground level and the ground floor level is called
plinth. It is usually of stone masonry. If the foundation is on piles, a plinth beam is cast to
support wall above floor level.

At the top of plinth a damp proof course is provided. It is usually 75 mm thick plain
concrete course.
The function of the plinth is to keep the ground floor above ground level, free of dampness. Its
height is not less than 450 mm. It is required that plinth level is at least 150 mm above the road
level, so that connections to underground drainage system can be made.

3. Walls and Columns: The function of walls and columns is to transfer the load of the structure
vertically downwards to the foundation. Apart from this, wall performs the following functions:
(a) It encloses building area into different compartments and provides privacy.
(b) It provides safety from burglary and insects.
(c) It keeps the building warm in winter and cool in summer.

4. Sills, Lintels and Chejjas: A window frame should not be directly placed over masonry. It is
placed over 50 mm to 75 mm thick plain concrete course provided over the masonry. This course
is called as sill. Lintels are the R.C.C. or stone beams provided over the door and window
openings to transfer the load transversely so as to see that door or window frame is not stressed
unduly. The width of lintels is equal to the width of wall while thickness to be provided depend
upon the opening size.
Chejjas is the projection given outside the wall to protect doors and windows from the rain. They
are usually made with R.C.C. In low cost houses stone slabs are provided as chejjas. The
projection of
chejjas varies from 600 mm to 800 mm. Sometimes drops are also provided to chejjas to improve
aesthetic look and also to get additional protection from sun and rain.

5. Doors and Windows: The function of a door is to give access to different rooms in the
building and to deny the access whenever necessary. Number of doors should be minimum
possible.
The size of the door should be of such dimension as will facilitate the movement of the largest
object likely to use the door.
Windows are provided to get light and ventilation in the building. They are located at a height of

Author by; Engineer Chilekezi Daniel. O

0.75 m to 0.9 m from the floor level. In hot and humid regions, the window area should be 15 to
20 per cent of the floor area. Another thumb rule used to determine the size and the number of
windows is for every 30 m3 of inside volume there should be 1 m2 window opening.

6. Floors: Floors are the important component of a building. They give working/useful area for
the occupants. The ground floor is prepared by filling brick bats, waste stones, gravel and well
compacted with not less than 100 mm sand layer on its top. A lean concrete of 1: 4: 8, 100 mm
thick is laid. On this a damp proof course may be provided. Then floor finishing is done as per
the requirement of the owner.
Cheapest floor finish for a moderate house is with 20 to 25 mm rich mortar course finished with
red oxide. The costliest floor finish is mosaic or marble finishing.
Other floors are usually of R.C.C. finished as per the requirements of the owner.

7. Roof: Roof is the top most portion of the building which provide top cover to the building. It
should be leak proof.
Sloping roof like tiled and A.C. sheet give leak proof cover easily. But they do not give provision
for the construction of additional floor. Tiled roof give good thermal protection.
Flat roofs give provision for additional floors. Terrace adds to the comfort of occupants. Water
tanks can be easily placed over the flat roofs.

8. Step, Stairs and Lifts: Steps give convenient access from ground level to ground floor level.
They are required at doors in the outer wall. 250 to 300 mm wide and 150 mm rise is ideal size
for
steps. In no case the size of two consecutive steps be different. Number of steps required depends
upon
the difference in the levels of the ground and the floor. Stairs give access from floor to floor.
They
should consists of steps of uniform sizes.
In all public buildings lifts are to be provided for the conveniences of old and disabled persons.
In hostels G + 3 floors can be built without lifts, but in residential flats maximum floors
permitted
without lifts is only G + 2. Lift is to be located near the entrance. Size of the lift is decided by the
number of users in peak hours. Lifts are available with capacity 4 to 20 persons.

9. Finishing: Bottom portion of slab (ceiling), walls and top of floor need smooth finishing
with plaster. Then they are provided with white wash, distemper or paints or tiles. The function
of
finishing work is:
(a) Give protective cover
(b) Improve aesthetic view
(c) Rectify defective workmanship
(d) Finishing work for plinth consists in pointing while for floor it consists in polishing.

10. Building Services: Water supply, sanitation and drainage works, electric supply work and
construction of cupboards and show cases constitute major building services.
For storing water from municipal supply or from tanker a sump is built in the house property

Author by; Engineer Chilekezi Daniel. O

near street. From the sump water is pumped to overhead tanks placed on or above roof level so
as to get water all the 24 hours. Plumbing work is made so as to get water in kitchen, bathrooms,
water closets, sinks and garden taps.
For draining rain water from roofs, down take pipes of at least 100 mm diameters should be
used. Proper slopes should be given to roof towards down take pipe. These pipes should be fixed
at 10 to 15 mm below the roof surface so that rain water is directed to the down take pipe easily.
The sanitary fittings are to be connected to stone ware pipes with suitable traps and chambers.
Stone ware pipes are then connected to underground drainage of municipal lines or to the septic
tank.
Many carpentry works are required for building service. They are in the form of showcases,
cupboards, racks etc.
Electric supply is essential part of building services. The building should be provided with
sufficient points for supply of lights, fans and other electric gadgets.

FOUNDATION
Foundation is the lowest part of thye wall of a building, its that part of the structure which has
direct contact with the ground to which the load are transmitted.
It is the base of which a building rest, it may be founded of stone, concrete or steel but the
most common material ii mordern construction is concrete.
Concrete is a mixture of cement, sand and aggrete (granit, gravel etc.)
Purpose /function of foundation.
The function of foundation is to safely transfer the load of a building to the soil. In such a way
that settlement is limited and failure of the under soil is avioded. From this brief defination
foundation can not be designed without the engineers having fair knowledge of the soil on
which the foundation is rested and this esssence of soil investigation.
Which ever foundation chosen, it should be very strong so as not to
1. Break on or under load.
2. Be destroyed by the roots of trees.
3. Be affected by the present of water.

The building regulation of 1995 part A of schedule 1 states that foundation:

i. Should safely transfer all dead, imposed and wind londs to the ground, without
settlement or other moverment which impel instability of or cause damage to the
building, or any adjouning buildings or works.
ii. The taken down below frost damage or soil moverment level, the resistance attack by
solvents or other delector matter found in the soil.

Chioce of foundation type.

The chioce and dessign of foundation for domestic small industrial and commercial buildings,
depends mainly on;

Author by; Engineer Chilekezi Daniel. O

 i. The type of building
ii. The total load of the building (nature of the loading)
iii. The nature and bearing capacity of the soil. ( i.e the site conditions)

Types of foundation
There are different types of foundation namely;
1. stirp foundation: is a continous deposite of concrete in the foundation trench on which
the walls is of tghe building are constructed. It is the commest ofn foundation.
As the name implies continous. Strip of mass concrete or reinforced concrete or stone
laid on the ground level and along the position of the bad load, walls only. This type of
foundation areb suitable for boundaries walls, domestic buildings of not more than
three stories and retaing walls. They are not suitable on made up ground, very sofy slay
soil or peat. A strip foundation may be stepped in sloppy ground to save excessive
digging atb the higher ground. Strip foundation is generally composed of plain concrete
offer to a mix of 1:3:6 of volume (i.e 1 part of cement, 3 part of sand and 6 part of
concrete), with a thickness been not less than projection of the foundation in no casev
les than 150mm.

Wall

Concrete

Strip foundation is used for simple buildings on firm ground and on wet ground reinforced strip
foundation can be used.
Pad foundation: is a reinforced concrete base on which concrete columns are constructed. Pad
foundation could be isolated pad or reinforced strip foundation. It may be rectangular, circular
or square in section. It is used for storey buildings. The most common types are square, they
are may be of mass or reinforced concrete pad are reserved for the large types of structures.
Pad is used to support isolated loads, such as load in column, piers and heavy machinery in
factories. The thickness must not be less than the projection from the column, unless
reinforced and must be in no case less than 150mm. the size of the foundation can be reduced
by providing steel reinforce towards the bottom of the foundation running in both direction.

Author by; Engineer Chilekezi Daniel. O

 Reinforced concrete pier

Concrete foundation sections. Section A - A

Raft foundation: covers the whole are of the building and usually extend beyond it. It consist
pry of concrete slap up to 30mm thick, which is often thickened under load bearing walls. The
weight of the building is evenly distributed over a large area so that no particular area is made
to receive heavier loads. This type of foundation is back best suitable for use of soft natural
ground is liable subside as in mining areas. Raft foundation may be used together with ground
beams for greater load bearing capability. It is used in soils that cannot support a building by
strip or pad foundations. Raft foundation enables the building to settle as whole and not in
parts. It is normally used in construction in water logged or reclaimed lands. Raft foundation
can be solid, cellular and slab raft.
Wall
D.P.C

Sanding

Hard core reinforcement

Pile foundation: is made of reinforced concrete piles driven through weak and swampy soil to a
firm base. Piles are columns of reinforced concrete driven or cast in the ground to carry a
building structure, usually a high rise building. Piles are also used in many civil engineering
works like bridges and wharfs. Pile foundation is frequently use with multi storey buildings and
in case where is necessary to transmit the building load through weak and unstable soil

Author by; Engineer Chilekezi Daniel. O

conditions to a lower stricter of sufficient bearing capacity. Piles may be classified in several
ways.
1. End bearing piles
2. Friction pile.

End bearing pile: the shaft passes through soft deposit and the base or point rest on the bed
rock or penetrate dense sand or gravel and the pile act as a column.

Friction pile: is embedded in coarse soil and obtain its support mainly by adhesion or skin
friction of the soil or the surface of the shaft.

Reinforced concrete beam

Short bored piled foundation

Excavation for foundation.
Excavation simply means making holes or trenches in the ground by digging up soil.
In building construction exaction is thee digging and removing the soil to prepare trenches for
construction of foundation. Excavation is done by hand or by the use of machines. (Excavator,
shovel etc.). Hand tools such as rammer, profile board, travellers, line, hoe, shovel, pick axe etc.
Timbering to excavation: timbering, planking or strutting are procedures for providing
temporary support for soils that cannot stand on their own when exposed after excavation.
Timbering prevents the collapse of the sides of the excavation and ensures the safety of the
men working on the sites.

Author by; Engineer Chilekezi Daniel. O

WALLS
Wall is the vertical element of a building which encloses the space within it and which divide the space.
Together with the roof they form the environmental envelope. Walls are also the basic supporting
element.

Types of walls.

I. External wall/load bearing wall/enclosing wall: support load from floor to roof. They are load
bearing walls. They resist side pressure from wind and sometimes from stored materials or
objects within the building.
II. Internal wall/dividing wall/non-loading bearing wall: are non-load bearing walls. They divide
space.

Functional requirement of a wall.

The primary function of a wall is to enclose and divide space. Walls are to provide adequate

I. Stability and strength

II. Wheather resistance
III. Sound insulation
IV. Damp prevention resistance
V. Appearance.
VI. Thermal insulation
VII. Fire insulation.

Wall finishes

A wall finish may consist of painting, plastering, rendering, pointing the joint, Tyrolean application or dry
lining with blaster board.

Plastering: is the application of wet mix of fine cement and sand to the internal surfaces of a wall.
Although, in some cases only cementing materials is used without the addition of sand. Plastering is
primarily intended to provide a flat even surface to the wall.

Rendering: is the application cementing material and sand or without sand on the external surface of
the wall. Rendering is intended primarily to prevent the penetration of water into the wall.

Pointing: is the name given to the method of finish or the joint receives after the wall has been built.
There are three types of pointing, each of which is carried out after the joint has been racked out and
thoroughly cleaned.

Types of pointing

I. Flush pointing
II. Wheather pointing
III. Tuck pointing

Jointing: is the treatment of the joint as the building of the wall proceeds.

Author by; Engineer Chilekezi Daniel. O

Types:

1. Wheather joint
2. Struck
3. Half turn recessed joint
4. Square joint
5. Vee - joint

Purpose of wall finish

1. To provide resistance to moisture exposure

2. To give a more pleasant appearance
3. To protect the structural wall from draining rain and sand storms.
4. To increase fire resistance, sound and thermal insulation properties of the block wall.

Types of pointing.

a. Flushed pointing: is used to obtain a generally sand faced effect to concrete block wall.

Flush pointing

b. Tucking pointing: is used for more of a decorative treatment.

c. Wheather pointing: is used to prevent moisture for penetrating the wall.

Author by; Engineer Chilekezi Daniel. O

 Coping.

Coping is one of the method use at the termination of block wall. These are features at the top of free
standing walls, including parapets, given Wheather protection and at the same time providing a
decorative finished. Coping may be of stone, concrete, brick or metal, they protect the sides of the wall
and are lead to a slope so as to throw water clear. Concrete coping has a throating under each side
projection and a D.P.C to prevent moisture from penetrating through the joints. (D.P.C meaning damp
proof course).

Types of coping

1) Feather edge
2) Saddle back
3) Segmental
4) Buck on edge

1) 2)

Throating

Feathering edge saddle back

2) Brick on edge 4) segmental

Stairs

Stairs consist of a series of steps with accompanied hand rail, stair case or staring lands and balustrades
and other components art in one or more successive flight of stairs. The space occupied by stir case
stands a stir well, with the vertical distance between the floors served by a stair case describe is the lift.

Types

1. Straight flight: is the simplest form of stair. All the steps leads in the same direction from floor to
floor with or without a landing.

Author by; Engineer Chilekezi Daniel. O

 Straight flight

2. Half turn: is stair which rises to half space landing between floors, turn 180°, and the second
flight rising the opposite direction to the one below.

Landing

3. Quarter turn stair: has a quarter which turn through 90° and continue to the next floor.

Up

Quarter turn

4. Geometric: can be similar to the open newel stair expect instead of quarter space landing, it has
a series of winder arranged in a spiral form. A form of geometrical stair which has no well is
known as a spiral stair.

Winders

Author by; Engineer Chilekezi Daniel. O

 5. Open newel or open well: in this type of stair a rectangular hole and continues from the bottom
to the top of the stairs case.

Half space landing

Queen newel or open well

Stair case is constructed in a building to facilitate the movement of people, equipment and machinery
from one floor to another.

Stair cases are constructed with different stair case is a structural member of a building. The first case is
to see that they are of equal height because they prompt accident.

Functional requirement of stairs.

1. A stair should be constructed of sound materials and workmanship

2. It ascent should be relatively easy. Stairs for public building should have a pitch of 50°, while for
private buildings the itch should not be more than 42°.
3. The riser must be of the same height and the thread should be of uniform width if accident is to
be avoided.
4. The stair case must be adequately lit. The minimum number of steps in a flight is preferable 12
but should not be more than 15.
5. The stirs should be wide enough especially in public buildings to ensure quick exist in case of
emergency.
6. Adequate head room of at least 2meters should be provided.

Parts of stair

1. Riser
2. Balustrade
3. Landing
4. Newel post
5. String
6. Pitch
7. Going
8. Nosing
9. Tread

Determining the Riser, Going and Tread of stair.

Author by; Engineer Chilekezi Daniel. O

Example: to determine the number of riser, treads and going; let’s look at this examples;

The floor height of a building is 2400mm and the total going is 3750. Calculate the number of riser and
treads required for the stair ways. If a straight flight is to be use the riser is 150mm and the going is
250mm.

Note:

2G + G = 550

300 + 250 = 550

riser

Riser = 240 ÷ 150 = 16 risers

tread

2400 riser

Treads: 3750 ÷ 250 = 15 treads

NB: to calculate the number of riser,

Number of riser = height of flight ÷ riser tread

Number of treads = total going ÷ going

Floors

A floor is the horizontal member which is supporting the load on it.

Floors are generally designed to satisfy a number of functional requirement, such as stated below;

Functions of a floor.

i. Floors should be able to withstand any imposed load on it.

ii. It should support its own weight
iii. It should prevent damp penetration.
iv. It should be reasonable in cost and durable.
v. It should provide an accepted surface finish.
vi. It should be sound proof.
vii. It should fire resistance.

Types

1. Solid floor (ground floor)r: over-site concrete (German floor). Over-site are supported with DPC
which is Damp roof course. This is the type of floor that has direct contact with the ground.

Damp prove course is a layer of barrier of concrete to prevent ground moisture for penetrating the
building.

Author by; Engineer Chilekezi Daniel. O

 2. Raised (timber) floors / suspended floor: are those raised above the ground level, leaving space
between the ground and the floor.

Purpose Oversight concrete

To prevent moisture from rising in the building.

Floor materials wall plate hard

core

1. Concrete (1:2:4) earth

filing
2. Bituminous felt
3. Asphalt foundation concrete
4. Slate
5. Engineering bricks
6. Copper, lead etc.

Floor finishes

1. Screeding: is a mixture of cement, sand and water in the other to give a level floor surface.
2. PVC tiles, Quarry (clay) tiles
3. Terrazzo
4. Wood block
5. Marble.

Factors determining floor finish

1. Maintaince
2. Non-slip
3. Ease of cleaning
4. Wear
5. Economical

Note: marble is not good for traffic areas.

Quarry tiles are mostly use in the bathroom, swimming pool etc.

Function of screeding

1. To serve as floor finish

2. To provide thermal insulation
3. To give an even surface to the floor.
4. To provide an easy fall for water flow.
5. To provide a smooth surface to floor finish.

Author by; Engineer Chilekezi Daniel. O

ASSIGNMENT.

1. The floor height of a building is 2100mm and the total going is 4750. Calculate the number of
riser and treads required for the stair ways. If a straight flight is to be use the riser is 250mm and
the going is 400mm.
2. The floor height of a building is 10700mm and the total going is 7500. Calculate the number of
riser and treads required for the stair ways. If a straight flight is to be use the riser is 150mm and
the going is 250mm.

Author by; Engineer Chilekezi Daniel. O