Construction work can be considered as a product being produced in a temporary factory.
The site being a temporary factory in which the contractor will make the product involve
some form of organisation and tradition. This is because the builder requires men,
materials and plant all of which have to be carefully controlled so that the men have the
right machines and materials in the most advantageous position and not interfering with
the general site circulation and adequate storage space and site accommodation.
Construction-site layout is an important construction planning activity. The optimal
arrangement of different site activities, temporary structures and services with the aim of
achieving maximum efficiency, effectiveness, safety and productivity is what is referred
to as a site layout plan. Site layout planning has significant impacts on productivity,
costs, and duration of construction. Construction site lay out planning involves
identifying, sizing, and positioning temporary and permanent facilities within the
boundary of the construction site. Site layout planning can be viewed as a complex
optimization problem. Although construction site layout planning is a critical process,
systematically analysis of this problem is always difficult because of the existence of a
vast number of trades and interrelated planning constraints. Site space is a resource that is
as important as money. time, material, labour, and equipment. Despite its importance, site
planning is often neglected, and the attitude of engineers has been that it will be done as
the project progresses. Good site layout, however, is important to promote safe and
efficient operations, minimize travel time, decrease material handling, and avoid
obstructing material and equipment movements, especially in the case of large projects.
In addition, such a problem becomes far from trivial if a construction site is confined due
to the lack of available space, or if the site is very large, then travelling between facilities
can be considerably time consuming.
The Aim of Construction Site Layout planning is to find convenient and feasible
locations for different temporary faci1ities.
When temporary site level facilities are required to be located on a construction site the
locations of buildings to be constructed are assumed to be known. These locations are
used to define available sites for temporary facilities. Then the problem can be defined as
allocation of predetermined facilities like warehouses, job offices, workshops and batch
plants so as to optimize an objective subject to layout constraints and requirements.
The contractor‘s planning officer attempts to find the general site lay out in consultation
with the estimator, contracts manager and plant manager before work actually
commences.
A neatly and efficiently site layout convey to all concerned including the general public,
the sound standards by which an efficiently organised contractor operates.
To obtain maximum efficiency there is an optimum way of laying out the site and also a
correct amount of expenditure to support the proposed site layout. Any planned layout
shou1d be reviewed periodically and adjusted to suit the changing needs of the site
activities. If this is carefully considered, planned and controlled, it will be reflected in the
progress and profitability of the contract.
The following should be given consideration when preparing site layout plans:
6.1.1 Existing services:
The positions of each utility service must be established and should be shown on the site
layout plan or be marked out immediately on site with pegs or other suitable means to
prevent damages occurring during construction work. These utility services are:
i) Existing sewers/drains and any manholes/inspection chambers cesspits,
septic tanks, catch-pits, soak-away pits etc.
ii) Water mains or distribution pipes including any control valves or hydrant
connections.
iii) Electricity cables above or below ground
iv) Gas mains
v) Telecommunication cables above or below ground.6.1.2 Hoardings (Fences):- to secure site, prevent noise and dust to adjoining properties.
6.1.3 Access and Exits:
The size of access would depend on how restricted the site is or the constrainment of the
locality of the site. It also depends on the probable sizes of the delivery vehicles and the
type of plant to be used on site.
Under ―access and exits‖ the following must inevitably be taken into consideration:-
i) Number of access-to-site points allowed by the highways authority so as to
interrupt the general public traffic minimally.
ii) Access and exit road sizes for vehicles and plant movement, and the thickness of
the base depending whether it is permanent or temporary,
iii) Ramps which are necessary for delivery of materials where access would
otherwise be difficult.
iv) Traffic flow directions should be shown to prevent congestion and afford
satisfactory flow of vehicles.
6.1.4 Signs and notices:
The position of important signs and notices should be displayed on site. Other signs can
be erected at the discretion of the site supervisor for the following reasons:-
i) to direct plant materials deliveries
ii) for security and to act as warnings to the public and employees
iii) for ease of location of administration, safety, and welfare facilities,
iv) to show the names and organisations which are party to the contract.
6.1.5 Administration and Other Accommodation:-
Accommodation is considered for each individual site but certain factors will be common
to all sites.
Accommodation for staff is covered by the Construction (Health and Welfare)
Regulations 1966. This document sets out the minimum amount and type of
accommodation, which must legally be provided for the no. of persons employed on site
and the anticipated duration of the contract. Maximum and minimum labour and site staff
numbers must be accessed so that the optimum facilities can be provided to satisfy the
safety, health and Welfare Acts and Regulations and to conform to the agreements
incorporated in the appropriate Working Rule Agreements. Mess huts - for preparing, heating and consuming food and should be serviced
with drainage, hot and cold water supply. To provide a reasonable degree of
comfort, a floor area of 2.0-2.5m2 per person should be allowed. They should be
sited such that they do not interfere with the site development but in such
positions that travel time is kept to a minimum. Drying rooms - Used for depositing and drying wet clothes. A floor area of 0.6m2per person should be allowed to provide sufficient space for equipment and
circulation. They should be sited near or adjacent to the mess room. Toilets- Contractors are required to provide at least the necessary minimum
washing and sanitary facilities as set out in Regulations nos. 12, 13 and 14. Sizing
of toilet units is governed by the facilities being provided and if male staffs are
employed, separate toilet facilities must be provided. Toilets should be located in
a position that is convenient to both offices and mess rooms, which may mean
providing more than one location on large sites. Recommended: Up to 100 people
inconvenience for every 25 persons. More than 100 people 1 convenience for
every 35 persons.
6.1.6 First-Aid rooms:-
Any contractor who has more than 40 persons on site must provide this facility in
accordance with requirements of regulation no.9. It should be sited in a position which is
conveniently accessible from the working areas and must be of such a size as to allow for
the necessary equipment and adequate circulation which would indicate a minimum floor
area of 6m2
6.1.7 Contractor‟s office/Clerk of works: - An area of 3.7rn2 for each supervisory
staff is recommended and should be located in a position which is easily and quickly
found by visitors to the site and yet at the same time will give a good view of site
operations.
6.1.8 Car parking: - Assume space per car 2.3m widex5.5m long and some allowance
for reversing6.1.9 Stores, storage facilities and compound: - The location and sizes of space to be
allocated for any particular material should be planned by calculating the areas required
and by taking ml account all the relevant factors before selecting the most appropriate
position on site in terms of handling, storage and convenience. The following should be
designated on a site lay out plan:- Hard stands for bulk, heavy materials Stores sheds Curing shed for concrete test cubes I Cement and other essential sheds for petroleum, oil and explosives.6.1.10 Workshops:- Positions should be indicated to enable the site supervisor to
arrange for the erection of the following types of workshops:- Fitters shops and work area Joinery shop and machinery area Reinforcement and bar bending area Concrete mixing area6.1.11 Temporary Services:- these are; water supply, electricity, gas, telephone lines
and drainage. These services have to be indicated on the site lay out plan.
6.1.12 Plant and equipment positions:-
Depending on the complexity, size of site and the rate of output expected one would
consider the positions of plant and equipment under two headings:-STATIC &
MOVEABLE
Static Include; Mixers and weight batching points Tower cranes Woodworking machines Hoists Weigh bridgesMoveable Include; Vehicles- lorries, forklift trucks, dumpers Compressors Pumps Cranes (tracked or rubber tyred)
6.1.13 Other Considerations;
Parking yards for staff and operatives vehicles Security lighting positions Viewing platforms Temporary benchmark position and other control points Spoil heaps or dumps Protective measures for existing trees, gardens, pavement and other features,
which are not to be disturbed.
6.2 HANDLING AND STORAGE OF MATERIALS
Materials storage is a very important function since materials wastage can increase
substantially if care is not exercised in the selection of suitable storage points. Preplanning is essential, and the site supervisor who fails to store materials when they have
already arrived on site is not operating in the way in which he was employed.
Requisitioning and ordering
The purchasing officer has a number of duties to perform before orders are placed for
materials. When schedules have been prepared, or requisitions have been received from
various departments or site supervisors, enquiries are made to ~suppliers to enable the
most competitive prices to be accepted. Purchase order then follow the enquiries stage to
the successful suppliers whose quotations come up to expectations. Materials should
always be ordered for in time to give the suppliers ample time to prepare for the delivery.
Care should be taken where materials have been delivered too early as there is chance of
damages loss arising due to vehicle and other mechanical damage, damage due to
weather, pilfering and theft.Receipt and Checking of deliveries from suppliers or contractor‟s own yardNotification from suppliers of impending deliveries should be made to enable the storage
area be prepared and to allow the technical team inspect the materials from the suppliers
yard. Delivery notes should accompany delivered goods and must be presented by the
delivery drivers as proof of the consignment‘s quantity and quality. The delivery notes
should not be signed until goods are checked, and if damages have arisen during transit or
there are discrepancies between the deliveries, the amounts should be indicated on both
copies.
Offloading and handling.
Careless off-loading and handling of materials adds to wastage on site and each
supervisor is advised to pay sufficient attention to the methods used depending on the
materials being dealt with. Prior discussions with the supplier with, perhaps an agreement
on methods of delivery and off loading could save the site supervisor time and effort in
dealing with each consignment.
At commencement of a contract, a site layout plan should be drawn up to outline the
construction working areas and to show all the site facilities and material storage areas
which are codified for the various key bulk or valuable materials. A storage compound
layout would also serve to highlight to everyone concerned where the various delivered
materials are to be kept so that if the site supervisor is occupied when there is delivery,
other supervisors, store men etc may be able to direct the delivery drivers to appropriate
unloading points by referring to the layout retained in the main site office. The following
are a few pointers regarding storage.
1. Hardstands for heavy materials should be provided.
2. Provide concrete blinded area for loose, materials such as sands and gravels with
separate bays for different grades.
3. Show clear marks and laid out areas for different materials, such as reinforcement
bars and mesh, concrete products, blocks, tiles, timber etc.
4. Provide huts for bags of cement, plaster and lime, taking care to stack materials ‗~
that the earliest deliveries are used first. (FIFO-First In. First Out)
5. Ensure there are level beds for bricks, etc with covering provided (polythene or
tarpaulin) until materials are require
6. Be sure that stacked materials should not have to be moved to allow operations to
be completed, such roads, services and building works.
7. Lay drainage pipes on their sides in neat stacks, using wooden wedges to prevent
movement.
8. Stack steelwork, reinforcement bars and fabric flat on timber runners off the
ground, with polythene covers to prevent undue rusting and to keep them clean
especially if not required for some time.
9. Move the residue of any discontinued pile of material, especially bricks, along to
an existing or new work area to prevent burials, breakages or misuse.
10. Store windows and door frames in a covered compound area, or stack them
perfectly flat oil the ground on sleepers/runners and covered to protect. If standing
vertically care should be taken to prevent twisting.
11. Put valuable small items in the charge of a store keeper or supervisor. Individuals
should be made to sign for them when required.
12. Store scaffolding fittings in strong bins and not sacks, although the later facilitates
ease of handling at the work place. Scaffold poles when not in use should be
stored in racks in compound area.
Definition of terms
(1) “Block” means a masonry unit having 1 dimension exceeding 15 inches
(375mm), and 1 of its other 2 dimensions exceeding 7 inches (175mm)
(2) “Brick” means a masonry unit which is not a block.
(3) “Chain” means a series of metal links connected to. or fitted into, one another.
(4) ―Lay‖ means the lengthwise distance required by a single strand to make 1
complete spiral around the rope
(5) “Rigging equipment” means chain, wire rope, fibre rope, synthetic rope, sling,
and their accessories and includes hoisting lines
(6) “Rope” means and or series of strands of fibre, synthetic or wire braided woven
or twisted together.General provisions; storage(1) All material shall be stacked, racked, blocked, interlocked, or otherwise secured
to prevent sliding, falling, or collapse during storage or transit
(a) Structural steel, poles, pipe, bar stock, and other cylindrical materials, unless
racked, shall be stacked and blocked so as to prevent spreading or tilting
(2) Before material is unloaded from a railcar or vehicle or removed from storage, the
load or pile shall be examined to ascertain if the material has shifted, binders or
stakes have broken, or the load or pile is otherwise hazardous to an employee. If a
hazardous condition is found, an attempt shall not be made to remove the load
until corrective measures are taken that will ensure the safety of the employee
who is exposed to the hazardous condition
(3) The maximum safe load limit in pounds or kg per square metre of a floor or roof
of a building shall be conspicuously posted in all storage areas, except a slab on
grade. The maximum safe load limit shall not be exceeded
(4) Except for masonry and mortar, material shall not be stored within 4 feet (1 .2 m)
of a working edge during overhand bricklaying or related work
(5) Gravel, sand, and crushed stone shall be withdrawn from a pile or barrow area in
a manner that prevents overhangs and vertical faces
(6) Storage areas, aisles and passageways shall be kept free of the accumulation of
materials that constitutes a hazard to the movement of material-handling
equipment and employees. Such areas shall he kept in good repair.
(7) Difference in road or work levels exists. Ramps, grading, or blocking shall be
provided to ensure the safe movement of material-handling equipment
(8) A railcar, truck, or semitrailer shall be chocked or otherwise secured during
loading and unloading if the movement of a railcar, truck, or trailer could create a
hazard for the employee
(9) A load line shall not be wrapped around the material being lifted
(10) A material shall not be stored with any other material with which it could react
and cause a hazardous condition
(11) While roofing work is being performed, materials and equipment shall not be
stored within 6 feet (1.8 m) roof edge, unless guardrails are erected at the roof
edge
(12) Materials that are piled, grouped. or stacked near a roof edge shall be stable and
self-supporting
(13) Material stored inside buildings under construction shall not be placed within 6
feet of any hoist way or inside floor openings, nor within 3metres of an exterior
wall that does not extend above the top of the material stored
(14) Non-compatible materials shall be segregated in storage
(15) Storage areas shall be kept free from accumulation of materials that constitute
hazards from tripping, fire, explosion, or pest harbourage. Vegetation control shall
be exercised when necessary.
(16) Materials shall not be stored on scaffolds or runways in excess of supplies needed
for immediate operations
(17) Portable and powered dock boards shall be strong enough to carry the load
imposed on them
(18) Portable dock boards shall be secured in position by being anchored and equipped
with devices that will prevent slipping
(19) Handholds, or other effective means, shall be provided on portable dock boards to
permit safe handling.
(20) Positive protection shall be provided to prevent railroad cars from being moved
while dock boards or bridge plates are in position.1. Storage of bagged material, brick, and block(1) The height of a manually stacked pile of bagged material weighing more than
13.6kg per bag, shall not exceed 5 feet.
(2) Bagged material on a pallet shall be all of the following:
(a) Not more than 36 inches in height.
(b) Secured to prevent displacement from the pallet before moving.
(c) Stacked not more than 2 pallets high.
(d) Stacked by stepping back the layers and cross-keying the bags at least every 10
bags high.
(3) A loose brick or tile stack shall be all of the following:
(a) Tapered back 2 inches in every foot of height above 4 feet.
(b) Not exceed 6 feet in height.
(c) Cross-keyed at each 2-foot level.
(4) A loose block ~4k shall be all of the following:
(a) Not exceed 6 feet in height.
(b) Cross-keyed at each 3-foot level.
(5) Brick on a pallet shall be all of the following:
(a) Not more than 30 inches in height.
(b) Secured to prevent displacement from the pallet before moving.
(c) Stacked not more than 2 pallets high.
(6) Block on a pallet shall be all of the following:
(a) Not more than 46 inches in height.
(b) Cross-keyed every course or secured to pallet.
(c) Stacked not more than 2 pallets high
(7) Brick or block in a banded cube shall not be stacked more than 2 cubes high.
2. Storage of lumber
(1) Lumber shall be stacked on level and solidly supported sills so as to be selfsupporting and stable.
(2) The width of a pile of lumber shall be no less than 1/2 the height
(3) A pile of lumber manually stacked, and a pile of lumber to be manually unstacked shall not exceed 6 feet in height
(4) Lumber which is mechanically stacked shall not exceed 10 feet in height. This
lumber shall not be re-handled manually.
(5) Used lumber shall have all protruding nails removed or bent into the lumber
before stacking.3. Storage of material in bins or hoppers(1) A bin or hopper that has a bottom discharge shall have sloped sides to allow
material to flow freely.
(2) A hopper shall have a top opening that is 42 inches or less above the ground or
working surface and shall be equipped with grillwork over the opening which is
capable of supporting any intended load and which has a mesh that is not more
than 6 by 6 inches to prevent employee entry.
(3) An employee required entering or working on stored material in a silo, hopper.
bin, tank, or similar storage area shall be provided with a personal fall arrest
system for working in hazardous spaces and Confined or enclosed spaces; testing;
and neutralizing hazard.
4. Clearances.
(1) Material stored an electrical distribution or transmission line shall maintain the
following clearances:
(a) Line rated 50 kV or less--10 feet plus length of material stored
(b) Lines rated 50 kV or more-- 10 feet plus 0.4 inch for each 1 kV over 50 kV plus
length of material stored or 10 feet plus 4 inches for each 10 kV over 50 kV plus
length of material stored
(2) All equipment used to store material near energized electrical lines shall conform
to Part 10 Lifting and Digging Equipment. and Part 13 Mobile Equipment
(3) An employee shall be designated to observe the clearance and give timely
warning if it is difficult for the operator to maintain the prescribed clearance by
visual means.
(4) An employee storing or handling material shall not come closer than the
prescribed clearances of subrule (1) of this rule.5. Disposal of waste materials(1) The area onto and through which material is to be dropped shall be completely
enclosed with barricades not less than 36 inches or more than 42 inches high and
not less than 6 feet back from the opening and area receiving the material. Signs
warning of the hazard of falling materials shall be posted on the barricades at each
level containing the barricades. Removal of signs shall not be permitted in this
lower area until debris handling ceases above
(2) If material is dropped through more than 1 level, the opening shall be enclosed
between the upper and lower levels, or an enclosed chute provided, or the
intermediate levels barricaded as prescribed in subrule (1) of this rule. If the drop
is more than 40 feet inside a building, then only an enclosed opening or chute
shall be used. The chute or enclosure shall extend through the ceiling of the
receiving level
(3) A material chute shall be constructed to withstand any impact load imposed on it
without failure.
(4) A material chute, or section of a material chute. at an angle of more than 45
degrees from the horizontal shall be entirely enclosed, except an opening may be
provided at or about each floor level for insertion of materials. The opening shall
not exceed 48 inches in height measured along the wall of the chute. At all stories
below the top floor, the openings shall be kept closed if not in use
(5) A material chute shall fit a floor or wall opening, or the space between the chute
and the floor or wall opening shall be covered
(6) If material is dumped from mechanical equipment or a wheelbarrow, then a toe
board or bumper not less than 4 thick x 6 inches high nominal size shall be
secured to the floor at each material chute opening
(7) A gate capable of withstanding the load imposed on it shall be installed at or near
the discharge end of a material chute. A trained employee shall be in charge of
opening the gate and loading of trucks
(8) If the drop is more than 20 feet outside the exterior of the building, then a chute as
prescribed in subrules (3) to (6) of this rule shall be used, and extend to within 8
feet of the lower level
(9) Material, barricades, and chutes shall not be removed until material handling
ceases above. (10) All scrap lumber, waste materials, or rubbish shall be removed
from the immediate work area as the work progresses
(11) Disposal of waste material or debris by burning shall comply with local fire
regulations.
(12) All solvent waste, oily rags, and flammable liquids shall be kept in fire resistant
covered containers until removed from the worksite.6. Rigging equipment(1) Rigging equipment for material handling shall be inspected at the time of
installation, before each job, and at the beginning of each shift if in use, by an
employee qualified to perform this inspection. Defective rigging equipment shall
be removed from service
(2) If not in use, rigging equipment shall be stored in a manner which is not
hazardous for an employee.
(3) Rigging equipment, other than a sling, hoisting line, and alloy steel chain, shall
not be loaded in ‗excess of its recommended safe working load.7. Natural and synthetic fibre rope; specifics(1) A natural or synthetic fibre rope used for hoisting, lowering, or pulling shall
consist of I continuous piece without a knot or splice, except an eye splice at the
end of the rope.
(2) An eye splice for manila rope shall contain not less than 3 full tucks, and short
splices shall contain not less than 6 full tucks, 3 on each side of the splice centre
line.
(3) An eye splice for stranded synthetic fibre rope shall contain not less than 4 full
tucks, and short splices shall contain not less than 8 full tucks, 4 on each side of
the splice centre line. An eve splice for other types of synthetic fibre rope shall be
made as prescribed by the rope manufacturer.
(4) An eye sp1iced or natural or synthetic fibre rope shall be of a size to provide an
interior angle at the splice of not more than 60 degrees when the eye is placed
over the load or support.
(5) A natural or synthetic fibre rope eye shall be equipped with a thimble if the eye is
placed over or around an object with a sharp corner
(6) Strand end tails from an eye splice shall not be trimmed flush with the surface of
the rope immediately adjacent to the full tucks. This applies to both eye and short
splices and all types of fibre rope.
(a) Tails from an eye splice for a fibre rope less than 1-inch in diameter shall project
not less than 6 rope diameters beyond the last full tuck
(b) Tails from the eye splice for fibre rope 1-inch or more in diameter shall project
not less than 6 inches beyond the last full tuck
(c) Projecting tails may be tapered and spliced into the body of the rope using not less
than 2 additional tucks, which shall require a tail length of approximately 6 rope
diameters beyond the last full tuck or they may be taped or wired down
(7) A natural or synthetic rope shall not be used for load carrying service if any of the
following apply:
(a) It is frozen or has been subjected to corrosive chemicals or extreme temperature
(b) It has begun to unravel
(c) It has external abrasions, cuts, or broken fibres, decay, burns, softness, or
variation in size roundness.(d) It has internal presence of grit, broken fibres, mildew or mold, color change,
powdering, or lose fibres.
(8) Natural or synthetic rope shall not be used if there is exposure to corrosive
substances, chemicals. or heat.8. Hooks, shackles, and other accessories(1) A hook, ring, oblong link, pear-shaped link, welded or mechanical coupling link,
or other attachment, when used with alloy steel chain, shall have a rated capacity
equal to the chain or rope to which it is attached, and the load shall not exceed the
rated load. Shackles and other accessories shall have a rated capacity equal to or
greater than the load to which it is attached
(2) A hook shall be discarded if either of the following applies:
(a) The throat opening is more than 15% greater than the manufactured size
(b) The hook has more than 10 degrees twist from a vertical centre line drawn through
the hook centre.
(3) A closed hook shall be used if there is a probability of the load becoming
disengaged.
(4) Special custom designed grabs, hooks, clamps, and other lifting accessories, for
such units as modular panels. prefabricated structures and similar materials, shall
be marked to indicate the safe working loads and shall be proof tested to 125% of
their rated load
(5) A job or shop hook and link, or a makeshift fastener, formed from a bolt, rod, or
other such accessories, shall not be used, unless tested in accordance to subrule (4)of this rule. (6) A shackle and connecting pin, and other accessories, shall be
discarded if the diameter is reduced by more than 10%.Chains.(1) Chains used for material handling shall be made of alloy steel
(2) A welded alloy steel chain shall have a permanently affixed tag showing the size,
grade, rated capacity, and manufacturer‘s name
(3) If wear at any point of any chain link is more than that shown in table 2, then the
chain shall be repaired or replaced. The repair shall return the chain to its rated
capacity
(4) A load-carrying chain shall be repaired only by the manufacturer.Shackles and hooks safe working loads(I) Determine the safe working loads of various sizes of shackles from the catalogue,
except that higher safe working loads are permissible if recommended by the
manufacturer for specific identifiable products, provided that a safety factor of not
less than 5 is maintained .
(2) The manufacturer‘s recommendations shall be followed in determining the safe
working loads of the various sizes and types of specific and identifiable hooks. All
hooks for which manufacturer‘s recommendations are not available shall be tested
to twice the intended safe working load before they are initially put into use. The
employer shall maintain a record of the dates and results of such tests.
9. Synthetic webbing (nylon, polyester, and polypropylene).(1) The employer shall have each synthetic web sling marked or coded to show all of
the following:
(a) Name or trademark of manufacturer.
(b) Rated capacities4 the type of hitch.
(c) Type of material.
(2) Rated capacity shall not be exceeded.
(3) Synthetic webbing shall be of uniform thickness and width and selvage edges
shall not be split from the webbing‘s width.
6.3 MINIMISING WASTE ON-SITE
It is recognised that wastage of materials will result on a construction site due to many
reasons, therefore estimators, when pricing for work, allow within their "unit-rate" (cost
to do a unit of work i.e. cost per square metre of brickwork, cubic metre of concrete) a
wastage percentage ranging from as little as 1% to 15% which may or may not be
necessary, but which is neither an advantage to the contractor nor the client and which
unfortunately increases prices generally for both parties.
Contractors who are able to reduce wastage through being well organised on-site can
estimate more competitively than others who are not conscious to the benefits of sound
supervision regarding material handling and increase their chances of bidding
successfully for work and create more wealth for shareholders and employees alike.
Wastage of materials can result from either the head office or site staff's inability to
schedule materials accurately with delivery rates inconsistent with requirements leading
to possible storage difficulties because of inadequate space on confined sites, and the
inability of site supervisors to control the whole aspect of materials receipt, storage,
distribution and correct storage. However, if a contract is large enough and costs allow it,
suitable handling facilities, access and storage space or accommodation will generally
result in an overall improvement regarding reduction of material breakages and its
misuse.
The most common problems relating to material supply, usage etc. constitute the
following:
1. Taking-off and scheduling
2. Requisitioning and ordering
3. Receipt and checking of deliveries from supplier's or contractor's own yard.
4. Off-loading and handling
5. Storing and protecting
6. Issuing/distributing
7. Use of materials
8. Quality control and supervision
| 1. | Taking-off and scheduling |
| The buyer/purchasing officer can have the responsibility to take-off and schedule | |
| materials from the bills of quantities or from the production/working drawings. Where | |
| the site supervisor is given this role he/she must be careful to ensure that correct | |
| quantities and details of quality of materials are extracted from drawings and | |
| specifications. It is emphasised that it is necessary to make allowances for material | |
| wastage, and adherence to a realistic percentage from correctly recorded estimator's or | |
| purchaser's figures obtained through previous experience must be made. |
| 2. | Requisitioning and ordering |
| The purchasing officer has a number of duties to perform before orders are placed for | |
| materials. When schedules have been prepared or requisitions have been received from | |
| various departments or site supervisors, enquiries are made to suppliers to enable the | |
| most competitive prices to be accepted. Purchase orders then follow the enquiry's stage | |
| to the successful suppliers whose quotations come up to expectations. | |
| Where bulk orders have been previously placed with the suppliers by purchasing | |
| department in a centralised purchasing set-up and supervisors are given the responsibility | |
| to call forward these materials when required, care must be exercised in calling forward | |
| sufficient for the storage areas available and sufficient to maintain the levels of | |
| production without the need to load. Where materials arrive too early on-site before they |
are required, there is more chance of damages and loss arising due to vehicle and other
mechanical damage, damages due to the weather, pilfering and theft.
| 3. | Receipt and checking of deliveries from supplier's or contractor's own yard. |
| Site Supervisors should expect some notification from the supplier or sender of materials | |
| of impending deliveries. This can be by a posted advice note or by a telephone call, | |
| unless when an order was made originally, phased delivery dates had been agreed | |
| between the parties. If forwarded of eminent deliveries, the site supervisor can make | |
| arrangements for safe storage and labour and plant can be provided to facilitate off | |
| loading and other essential handling procedures to prevent undue damages. | |
| Delivery notes should accompany delivered goods and must be presented by the delivery | |
| drivers as proof of the consignments' quantity and quality. Delivery notes should not be | |
| signed until the goods are checked, and if damages have arisen during transit, or there are | |
| discrepancies between the delivery notes and deliveries, the amounts should be indicated | |
| on both copies of the delivery notes and records should be made for future reference. | |
| Material transfers from other sites should be accompanied by a copy of a Materials | |
| Transfer Sheet. A check should again be made to ensure that the materials agree with the | |
| Transfer Sheet before a signature is added. | |
| In all cases when there is a receipt of materials/goods on an entry should be made on | |
| Material/Goods Received Form for the eventual despatch to the head office, or an entry | |
| could be made in the Daily/Weekly Report. |
| Name of Contractor: A.K BuildersMATERIALS/GOODS RECEIVEDContract: Name of Building Contract No: Prepared by: NO: 12 | |||||
| Date | Delivery Note No. | Supplier | Materials/goods and quantity | Rate | Total Value |
- rate and value to be filled by head office
- the rest by Site Supervisor
| Name of ContractorTRANSFER OF MATERIALS NO: Date: | ||
| From Site | To Site | |
| Description | Quantity | |
| Issued by: | Received by: | Drivers Signature: |
This document is made out in triplicate: Top copy to the head office, Second to Site
receiving materials, third copy retained.
| 4. | Off-loading and handling |
| Careless off-loading and handling of material adds to wastage on-site an each supervisor | |
| is advised to pay sufficient attention to the methods applied depending on the material | |
| being dealt with. Facing bricks may be delivered on packets which, unless the delivery | |
| lorry is self-loading, fork-light trucks should be on hand. The alternative is to unload | |
| manually, which is time consuming and, hence useful. | |
| Tipper lories for the delivery of certain bricks may be acceptable on some contracts, but | |
| generally palleted or bundled bricks have a few cost saving features e.g. ease of handling | |
| with correct plant; ease of storing in neat stacks, and less breakages and waste because |
the bricks are man handled very little. The banding keeps the bricks together until the
work for which they were ordered commences.
The lifting of small loose materials are facilitated better if the suppliers pack their goods
in boxes, cases, bags, tins or baskets which helps to prevent breakages and reduce waste.5. Storing and ProtectingThis is a more important element where material wastage can increase substantially if
care is not exercised in the selection of suitable storage points. At commencement of a
contract, a site layout plan should be drawn up to outline the construction working areas,
and are codified for the various key buck or valuable materials. A storage compound
layout would also serve to highlight to everyone concerned where the various delivered
materials are to be placed for safe keeping, so that if the site supervisor is occupied when
there is a delivery, other supervisors, store men etc may be able to direct the delivery
drivers to appropriate unloading points by referring to the site layout plan retained in the
main site office.
The following points must be noted regarding storage:
1. Hardstands for heavy materials should be provided.
2. Provide concrete blinded areas for loose materials such as sands and gravels,
with separate bags for different grades.
3. Show clear marks and laid-out areas for different materials such as
reinforcement bars and mesh, concrete products, blocks, tiles, timber etc..
4. Provide units for bags of cement, 15-20cm2 above shed floor, 30cm between
wall and gags of cement, plaster and lime taking care to stack materials so that
the earliest deliveries are used first.
5. Ensure there are level beds for bricks etc with covering provided (polythene)
until materials are required.
6. Be sure that stacked materials should not have to be moved to allow
operations to be completed, such as road, services and building works.
7. Stack steel work, reinforcement bars flat on timber runners off the ground,
with polythene covers to prevent undue rusting.
8. Store windows and doorframes in a covered compound area or stack them
perfectly flat off the ground on sleepers/runners and covered to protect. If
standing vertically, care should be taken to prevent twisting.
9. Put valuable small items (nails, screws, locks, paint) in the charge of a
storekeeper and only the quantity for immediate usage should be issued and
signed for.
10. Heavy items must be kept near the crane or hoist for ease of handling.
| 6. | Issuing and distributing |
| An efficient storekeeping system needs to be set up on site as soon as possible to ensure | |
| the workers are issued when required, with the correct quantity and quality of materials. | |
| A booking out system of special operatives in using the materials should be operated so | |
| that carelessness by operatives in using the materials issued can be pinpointed which | |
| although damages or loss cannot be charged to operatives puts the issued operatives in an | |
| awkward position making them more careful in the future and further contributes to | |
| reducing material loses. |
| 7. | Quality control and supervision |
| Materials used should confirm to the types and standards laid down in the specification. | |
| If un specified materials were used and were rejected later by the clerk of works, it would | |
| be expensive to cut out and provide with the proper type. Stricter control by the | |
| supervisors would prevent this kind of inconvenience and expensive rejection occurring. | |
| Where the architect designs and supervises the works, he/she expects specimen materials | |
| to be submitted by the main contractor so that they can be used as a guide to everyone, | |
| particularly the quality expected. A typical sample usually takes the form of a brick | |
| panel being built as a display to show the bonding, mortar thickness, and the standard of | |
| pointing and straightness of the courses. |
Supervisors, site engineers or other designated employees may have the responsibility to
ensure that tests on materials received or about to be used are checked and they should
have some knowledge of the tests and check to be made to each type. One should never
allow materials to be unloaded if there is doubt about their standard.8. Use of MaterialsMost operatives appreciate the value of materials with which they work and act
responsibly when using them (Bricklayer using half bricks, breakages, concrete-mixes
sufficient material, short ends of timber retained by a conscious carpenter).
There will always be the careless and irrespective operatives who have little or no regard
for others property particularly the contractor‘ operatives. These individuals need
controlling and where necessary approached to highlight the materials value.
Some of the misuses of materials are shown as follows:
| - | insufficient care in the use of off-cuts |
| - | Operatives‘ inability to measure lengths of wood to obtain the most |
economical cuts which result in waste.
- Longer controls being used where shorter ones are available.
- Small cutting off full plywood sheet when there are off-cuts already in
existence.
| - | Plasterers allowing too much plaster to fall to waste on floor. |
| 9. Security | |
| On most sites, security of materials poses the biggest problem to site supervisors. Theft, | |
| filtering, vandalism and other losses add to the value of materials to be written of as a | |
| loss or waste. To reduce/minimise the serious problem of waste, a suitable system of | |
| materials control should be adopted using specially designed forms to show; present | |
| stock, deliveries, amounts used and % waste. This monitors material used and hence | |
| material wastage. |
6.4 ORGANISATION AND CONTROL OF SITE PLANT AND EQUIPMENT
6.4.1 Location of machinery and equipment on sites
A large variety of equipment is used on construction projects and their location should be
properly done to maximize their output. When preparing equipment layout. the following
points should be considered: Equipment should be placed near the place of‘ its use as well as near materials it
is supposed to utilize. Provide shelter for costly equipment Repairs, maintenance should be done at site Layout should be such that safety can be ensured by security staff Sufficient space should be available for scaffolding erection and for removal and
shifting of the equipment to places ~~here it can be fully utilized There should be adequate space for parking transport vehicles Adequate safety measures and fire prevention equipment should be provided in
the lay out.
6.4.2 Maintenance of Plant and Equipment
Plant whether mechanical or non-mechanical should be maintained in a sound condition
if economic levels of utilization are to be obtained. This is the responsibility of the plant
department but the site supervisor cannot stand idly by if plant brakes down on site; is
being operated in a dangerous state; or the efficiency is below the standard expected
according to the contract programme and progress chart. Not only will the site supervisor
be accountable for the progress made on site, but also would be answerable particularly
where dangerous, unworthy road vehicles are being used.
Maintenance of all plant is essential for the following reasons:
It contributes towards the safety of employees and third parties. Any accidents, no
matter how they are caused, are expensive and unnecessary. It ensures efficiency of the mechanical plant because there are fewer breakdowns,
which can reduce output.
It prevents frustration in operatives, particularly if their earnings are affected by
plant breakdowns and poor outputs. Site supervisors are kept happy where the plant department offers efficient
servicing of mechanical plant. Plant with a poor performance record should not be
issued but should be got rid of by the plant department. It enhances the value of plant and hence depreciation is slowed down. It is generally a guarantee that operatives take more care when using the plant.
Dilapidated plant is more misused and abused because operatives treat it with
contempt. Well-kept plant is a good public relations exercise. Those from outside tend to
recognize the firm as an efficient, well managed unit where the vehicles, plant and
equipment are clean and well loe4I after. Major breakdowns of mechanical plant are reduced if a sound maintenance
scheme is in operation. The work and responsibility of the firm‘s safety officer is simplified and
management is pleased. Little or no trouble is experienced with the police as far as the firm‘s vehicles are
concerned.
If maintenance is to be effective the supervisor should understand that most plant
managers insist on the following divisions as far as mechanical plant is concerned:
a) Servicing and cleaning
b) Preventative maintenance
c) Planned maintenance.a) Servicing and cleaningThe responsibility for servicing is the site supervisor‘s who then generally delegates the
responsibility to the charge hands, foremen or gangers who have plant within their
control. Each should ensure that their machines are regularly SERVICED BY: Topping up engines and other working parts, oil levels. Greasing the points recommended by the manufacturer‘s catalogue.
Filling fuel tanks. Providing water for the cooling system Maintain anti-freeze levels in winter or draining off water at the end of a working
day. Inspecting for fuel, oil or water leaks Tightening loose screws and bolts where the services of a trained mechanic/fitter
are not required.b) Preventative maintenanceThis is the responsibility of the plant manager or plant hire firm. Naturally the site based
engineer/fitter/mechanic acts on behalf of the plant department or plant hire firm ensuring
breakdowns are kept to a minimum. A regular servicing arrangement is provided to
prevent deterioration and breakdown of plant and the typical areas in which maintenance
is carried out relate to the following:
i) engine oil change
ii) replacing oil and air filters
iii) flushing of coolant systems
iv) sparkplugs adjustments or replacement carrying out tests
vi) Thorough body checking.
vii) Exchanging other parts of the plant which are worn or have broken
viii) Carrying out tests to ensure machines etc are working correctly.
| c) | Planned maintenance |
| It is obvious that sound servicing and preventative maintenance reduces breakdowns and | |
| excessive wear and provides safe machinery. However, there comes a time where | |
| mechanical plant ceases to work efficiently, it is therefore the plant manager‘s | |
| responsibility to assess from experience, and records at what time vital parts require to be | |
| adjusted or changed. This prevents expensive and inconvenient breakdowns occurring | |
| which could seriously affect output on site and lead to further additional damage to plant. |
The plant department keeps records on each piece of mechanical plant so that when the
time is right for temporary withdrawal of plant for planned maintenance, it can be
conducted with minimal disruption. Withdraw from circulation would take place when
one site has returned the plant to the yard; the planned maintenance would take place
before redistributing to another site.
6.4.3 Plant and Equipment Record
The plant manager opens up a file on each piece of plant purchased and all relevant
details are recorded regarding the plant history. Details recorded include: manufacturer‘s
handbook, date of purchase and cost. Supplier‘s name and address, modifications, fuel
consumption, maintenance, expected life, depreciations. worked hours etc. Some forms
associated with the use of plants are:
Plant Utilization Sheets Plant Transfer Sheets Plant in and out Charts Plant hire charges Inspection Records and Maintenance Sheets Driver‘s log book Inspection records and testing results forms.
Site managers are advised, when requisitioning or ordering plant not relies entirely on
phone call but to verify the order in writing to ensure that the correct type of equipment
and size are received. This reduces disputes between plant department and site
supervisors. Also charging out of plant is more accurately predicted as the date of
requirement is shown on the requisition form.
6.4.4 Plant and Equipment Schedule.
This schedule is prepared before the start of the project to decide the type, number and
dates on which particular equipment is needed, so that it is well arranged in advance and
brought to site as and when needed. The aim of this schedule is to take maximum
advantage of this equipment when on site and remove it immediately as soon as it is not
required in order to gain some savings financially.
| TIMTEK CONSTRUCTION SERVICES LTDPlant and Equipment Schedule/Requisition | |||
| Contact No………………………………. | No…………………… | ||
| Job No…………………………………… | Date…………………… | ||
| Prepared by……………………………… | |||
| Plant type and Equipment | Dates required | ||
| Date on site | Date off site | Plant hire Firm/Supplier | Remarks |
6.4.4.1 Monitoring of Maintenance.
In order that the maintenance policy be executed efficiently, it is necessary to install a
recording and costing system, which shall include: An Asset Register comprising an inventory of each plant item in the fleet, with
information on the date of purchase, registration number, purchase price etc. A maintenance Schedule indicating the type of maintenance and servicing
required on each plant together with the time intervals between each plant
maintenance operation. Job cards to be filled out by the fitter each time maintenance work is performed
and which should include a description of the work done, materials used, time
taken, recurring defects etc. History Record Cards: The information on the job cards is transferred for each
individual machine to its history card together with the hours operated and fuel
used. The monthly records are then abstracted to prepare costs for comparison
with budgeted values. The variances are subsequently used in controlling
maintenance, adjusting the hire rate and ultimately in making decisions with
respect to replacement or sale of the plant.
6.5 IMPORTANT SITE DOCUMENTS
Communication Within and Outside SiteA two way communication should exist between head office and site supervisor to show
how work is progressing, what problems have developed, what information is required to
ensure continuity of flow of work, what materials and equipment are required to maintain
process etc. Most of the information flows from site because of the need to meet
deadlines, while the remainder is to keep management informed of every reasonable
detail so that they are as well placed to deal with any emergency as reports the
supervisor.
Communication in the construction industry generally takes one of the three forms: Oral instructions Written instructions Drawn details
There are standard which are used within an organization to help reduce thinking time an‘
simplify thinking time and simplify clerical/administrative work. Well designed standard
forms are used to inform, notify, request, instruct, advice and report. Whichever method
is adopted they should: Allow information to be easily illustrated Simplify typing or clerical duties Be designated to allow as much as vital and relevant information to be presented
as is necessary Allow for ease of reading and extraction of information Be designed to eliminate the unnecessary.
6.5.1 Oral Instructions
These should be given in a manner that reflects efficiency and enthusiasm. The verbal
instruction should be given to the person concerned; otherwise the message could become
distorted in the process of passing it on. The face-to-face talk will generally have far
more success than the written word; it will also enable questions to be asked and queries
raised without delay.
Oral messages or instructions are often given and received on telephone. The correct use
of this instrument is important as it often reflects an image to the person receiving the
call, who may have never met the caller. The person using the phone should speak clearly
and should give the listener time to reply to any matters arising. It is also a good idea,
before using the phone, to think about the information required. A few notes can be made
of relevant details as this prevents points being missed and saves the necessity of phoning
again.
6.5.2 Written Instructions
The written word comes into many forms of communication found in the building
industry-letters, reports, minutes of meetings, and general documentation. Paperwork has
increased a great deal in modem industry , mainly due to the much more careful control
required to run a successful and efficient business, for documentation provides the
necessary links in the chain of administration. All members of an organization, large or
small, should be made fully aware of the importance of correct paperwork in all its
aspects, from letter writing, which projects a firm‘s image, to site documents that can be
used for future reference and control.
The following are but a few documents that are used on sites:
a) Memoranda (Memo)
These are printed forms used to convey written or typed messages within the
organization‘s own structure, e.g. planning department to estimator. A typical memo
would be as follows:
| A.K. CONTRACTORS LTD |
| MEMO 2 |
| om……………………………… To……………………………. |
| Date: |
| Subject: Window openings |
| ace for message) |
| Name:……….…….…………….. |
| Signature……………..…………. |
There are many occasions and circumstances which require the writing of letters to
convey messages to people outside the structure of the company. A typical letter shown
below illustrates an example of layout:
A.K. CONTRACTORS LTDPlot 5, Mackay road, Kampala
Tel 0414-287340
Our Ref: AK/J/09 Contract:
………………..
Your Ref: VH/N/08 Contract
No……………..
13th December, 2008
Hardware Deals Ltd
Stone road, Kampala
Dear Sir,RE: ORDER 1254/09With reference to the above order, we have to advise you that four (4) of the plastic light
fittings were found broken upon receipt of the order on the l2th December, 2008.
We shall be pleased if you will replace these as soon as possible.
Yours faithfully,
Name: Okello Johnson Designation: Manager
Signature………………………..
6.5.4 Reports
A report is used to relay to someone information regarding, say, an investigation,
something witnessed or something done. The main object of a report should be to
disclose facts for recommendation without adding personal views. Superfluous wording
should be avoided, but care must be taken to ensure readers fully understand what the
report is meant to convey. A report can be divided into five sections:
1) Heading
2) Introduction to report, its purpose
3) The body of the report- use of sub-headings and dividing information into
sections should be the aim
4) A conclusion or summary with any possible recommendations
5) Any data, drawings, tables, references etc.
6.5.6 Notice Boards
These are useful means of conveying information, if placed in convenient locations
where everyone can see e.g. canteen areas.6.5.7 Handbooks and RegulationsCopies of such items as the construction regulations, building regulations and the
Working Rule Agreement should be kept on site in a position where they can be reached
easily for point of reference, not locked away in a drawer or buried under drawings.6.5.8 Site RecordsMany site records have to be made each week regarding labour, plant and materials. It is
important to remember that these documents have a specific use and must, therefore,
always be filled in accurately and when required, whether daily, weekly or monthly.
6.5.9 The Building Site Daily Diary and Daily Report
This has proved to be a most useful document and if well kept, with the right type of
information recorded in it, its value in matters of dispute later in the project cannot be
over emphasized. Even long after project completion, it has often been of utmost
importance in cases that have gone in court. The main objective of the site diary should
be to record events and information that do not warrant special records being kept.
Different supervisors will use the diary in different ways, placing more importance on
certain items than others. As a general rule items which might well be recorded could be: Telephone promises from subcontractors, suppliers, etc. Verbal instructions from the architect Visits to site by building owner, architect, quantity surveyor, factory inspector,
etc. Details of weather conditions Verbal instructions from head office or contracts manager Any matters of unusual occurrence, decisions or actions it is felt should be
recorded.
A weekly report can be extracted from the site diary and daily report and be submitted to
head office for reference.
| A.K. CONTRACTORS LTD SITE DAILY DIARY Contract: Warehouse Contract No:………… Week ending:………. |
| Weather:…………………. Temperature AM |
| PM |
| Own labour ……………………….. ……………………….. Overtime Reasons Manhours: Job stoppages Manhours lost Reasons Visitors on site: Telephone calls to………..……………… From:…………………… |
Labour on siteSubcontractor Nominated subcontractor
……………………….. ………………………….
……………………….. ………………………….
6.5.10 Materials Requisitions
When materials are required on site, the site supervisor can call them forward by using
the here below form. A minimum of two copies would be required: one to be sent to the
purchasing department, the other to be retained on site. The head office purchasing
department would extract the details about the materials from the requisition form and
would confirm the delivery dates with the supplier.
| A.K. CONTRACTORS LTDMATERIALS REQUISITION | Date:………………. No. ……………….. | |||
| Contract: Warehouse No……………… | ||||
| B.O.Q, V.O or drawing ref. | Description | Quantity | Unit | Delivery dates |
| BOQ 3A | Reinforcement bars 18-Y | 18 | Pcs | 20-01-09 |
| BOQ 3/4C | G.32 corrugated iron sheets | 30 | Pcs | 20-01-09 |
| Signed: …………………………….... Designation: ………………………… |
6.5.11 Drawings
These include the drawings and details by architects and engineers to enable the project
to be built. Great care is required to be practiced by the architect to present the drawings
in such a manner that it can not be misread or mistakes made, while on the other hand,
the site staff should have knowledge to understand drawings in order to interpret them
Accidents: Were reports made?
Variation order or Instruction: Plant required ……………………….
……………………………... Plant received……………………….
……………………………..
Progress report and any difficulties:
…………………………………………………………..
…………………………………………………………..
| Signed: …………………... | ……………………………….. |
| Site Manager | Contracts Manager |
correctly. A proper plan chest should be used for storing these plans and details, to ensure
that they don‘t get lost or damaged.
Another useful form of communication is a sketch, and it will often be found to be far
more advantageous than long written documents. The art of sketching therefore is one
which the supervisor should practice regularly to properly convey his messages to his
subordinates.
6.5.12 Advice of Variation
Standard form called Advice of variation should be issued to each site for use by the site
supervisor when he/she receives verbal instructions from either the architect or clerk of
works. A form is completed (in duplicate) by the site supervisor for each instruction
received and the top copy is sent to H/Office or is given to the contracts manager to
enable written confirmation to be sent to the architect within seven(7) days. The architect
should then issue an official written variation order within a further 7 days.6.5.13 Variation Order for SubcontractorIf the main contractor is issued with a variation order from the architect to do work or
supply materials which differ from that which is laid in the contract documents, the order
may also affect the services of a subcontractor. If so, a variation order for subcontractors
would be completed and submitted to the appropriate sub contractor for action to be
taken.
A.K. CONTRACTORS LTD
VARIATION ORDER NO.2TO SUBCONTRACTOR:…………………………………..
CONTRACT: ……………………………………………….
Date………………………………………………………….
Background/scope of works/reference:
Following our last site visit of………….it was noted that light in the conference room is
not enough and therefore proposed that you introduce two more florescent tubes (5ft) as
earlier instructed.Reasons for variation:1. Client‘s instruction 3. Site conditions
2. Increase in BOQ: 4. Omissions
| 5. | Others, specify……………………… ……………………………………… |
| Form of payment: | |
| 1. | Increase in cost: |
Decrease in cost:
2. Payment as per BOQ: Payment fixed price:
3. Payment – not agreed: Payment-agreed rate:Variation cost:
| Item description | Unit | Quantity | Rate | Amounts |
| Cost allocation:Savings in BOQs: | ||
| Contingencies: | ||
| Transfer: | ||
| Signed:……………………. | ………………………. | ……………………… |
| For: A.K. CONTRACTORS | For: Engineer | For: Employer |
| CHAPTER SEVEN | ||
| 7.0 | SAFETY, HEALTH AND WELFARE AT CONSTRUCTION SITES | |
| 7.1 | Definitions |
Health - State of complete mental, physical, social, and spiritual well- being.Safety - State of being safe and protected from danger or harm to the body either directly
or indirectly or state of freedom from danger.Welfare - Health, comfort, happiness and general well-being of a person or group etc.
Construction, which is an occupation, involves building operations and works of
engineering construction, excavation, earthworks, transportation of materials by hand and
vehicles, movements within the site, etc. All these activities carried out at construction
sites are associated with problems, which include injury and death.
7.2 Construction Related Accidents.
An accident can be defined as an unplanned and unexpected occurrence, which upsets the
planned sequence of events and actions, resulting in the loss of production, injury to
persons and damage to plants and equipment. Civil engineers are responsible for
infrastructure (buildings, roads, bridges, and water and sewerage facilities) in planning,
design, construction, operation, and maintenance. Civil constructions, which normally
range from medium to large scale, involve the use of many trades (skilled and unskilled)
along with machines and equipments, which have to be selected with care. Serious
accidents on sites result in personal injury or death of the worker on one hand and they
cause mental tension and financial burden to the employer on the other hand.
Accidents don‘t just happen, 99% are caused by unsafe acts, unsafe conditions or both.
Most accidents result from a combination of contributing causes and one or more unsafe
acts or unsafe conditions.
The unsafe act is a violation of an accepted safe procedure which could permit the
occurrence of an accident. The unsafe condition is a hazardous physical condition or
circumstances which could directly permit the occurrence of an accident.
7.3 Construction safety
Unfortunately the construction industry has become stereotyped as an accident prone
industry, in fact only mining and fishing industries have higher fatalities. Depressingly,
the accident rates experienced closely correlate to the level of activity within the industry,
indicating that when work load is high; safety tends to receive less attention.
It is argued that construction management must have a prime concern for safety and
therefore should have a moral, economic, and legal commitment to ensure workplace
safety on sites. However the responsibility for safety must commence upstream of the
construction phase of a project; architects and ,engineers must have the technical
knowledge to design buildings which can be safely constructed, as well as a commitment
to safe working conditions for site workers.
7.3.1 Construction Safety policy
To generate safety consciousness within construction organizations, a firm lead must be
taken by top management. It is recognized that finance and lost production are convenient
measurements of accidents, but accidents should generate an emotional response, and if
this emotion is genuine it will carry conviction.
A safety policy which is founded upon compassion will more often succeed, since it will
impervious to shifts and changes in construction scheduling and fashion and,
consequently, will be less easily diluted. Contractors should give careful thought to the
role of the full time safety officer. Two basic concepts exist about this role: Safety officers should be advisers to site management Safety officers undertake the safety responsibility on behalf of sites.
In general the role of the safety officer shall consist of the following duties: Formulating the company‘s safety policy Advising management on legislation and safety matters Assisting in drafting of safe working procedures and codes of practice. Reporting and investigating accidents with the preparation and analysis of safety
records. Safety training. Safety assessment of site management. Inspection of sites to ensure compliance with safety measures (safe working
methods, proper use of construction equipments, protective clothing, and
availability of First aid) Providing information to sites on accidents that have happened elsewhere on
similar sites to help generate safety consciousness within working sites.
7.4 Contractor safety responsibilities:
Section 2 of the Health and Safety at Work Act 1974 specifies that employers are to
ensure the health, safety and welfare of al employees. A part from the generalised duty,
employers have detailed responsibilities: To develop systems which are practicable, safe and have no risk to health; To provide plant to facilitate this duty, and this general requirement is to cover all
plant used at the work place; To provide training in the matter of health and safety; employers must provide the
instruction, training and supervision necessary to ensure a safe working
environment; To provide a working environment which is conducive to health and safety; To prepare ~written statement of safety policy and to establish an organisational
framework for carrying out the policy; the policy must be brought directly to the
attention of all employees.
However, employees also have specific duties namely: To take care of their health and safety and that of other persons who would be
affected by acts or an omission at the work place; To cooperate with the employer to enable everyone to comply with the statutory
provisions.
The types of safety and health hazards experienced at construction sites include the
following: Collapse of pits, shafts, tunnels and trenches; Collapse of buildings and structures; Flooding of excavations; Flying of materials due to use of explosives; Generation of dust and fumes during building/demolition operations and similar
works; Accumulation of fumes and gases in excavations and tunnels, from vehicles
transporting materials; Overloading of scaffolds with materials; Unfenced platforms, gangways, runs and stairs; Poor stability of lifting appliances; Unprotected excavations, pits shafts or opening in the ground; Poor ventilation in excavation, pits, holes, tunnels, shafts and in any other
enclosed or confined space at the site; Workers driving vehicles and trucks at site in insecure positions; Live electricity cables; Unguarded rotating parts of machinery; Lifting, carrying and moving excessive loads; Poorly constructed and maintained scaffolds, ladder and working platforms; Projecting nai1~id loose materials Falling materials, tools, objects or articles from height;
Obstructed plat forms, gangways, runs or stairs with materials, rubbish and
projecting nails and; Working on or near fragile materials.
In view of the above hazards usually encountered on construction sites, some measures
are put in place to ensure safety and health of workers. The safety measures include: Enforcement of the Factories Act and Building Construction Rules which provide
guide lines on safe work practices during building operations and work of
engineering construction; Registration of construction sites, to enable regular visiting of the sites; Awareness by contactors that when undertaking building operations or work of‘
engineering, the department of Occupational Safety and Health (OSH) should be
notified of the intention to commence work at the site for the purpose of
registration and to enable regular inspection of the site; All lifting equipment should be subjected to thorough inspections periodically and
examination certificates issued. All defects be attended to immediately and
rectified; In addition to local authorities approving architectural building plans, the
department of OSH should also review and approve them i.e. plans of major
buildings; Any workplace with excavation, pit, hole or enclosed space with fumes, dust that
may be dangerous or injurious to health must be rendered harmless and suitably
tested before workers enter herein; There must be adequate ventilation to prevent workers from inhaling dust or
fumes. Materials should be stacked safely and correct quantities to reduce obstructions.
Materials for immediate use only should be evenly distributed around the scaffold
to prevent overloading
Fix warning notices/posters to highlight hazardous points or areas on site for the
benefit of workers and visitors; There should be regular inspections of platforms, runs, gangway, stairs, guardrails, excavated tunnels by competent persons; There should be suitable safety nets or safety sheets well designed, constructed
and installed to prevent injury to persons falling on them; All excavations, pits, holes to be fenced to prevent people falling therein; and Well stocked First Aid Box should be in place.
7.5 Additional measures for Preventing Construction Accidents
Construction sites are dangerous places filled with heavy machinery, large structures, and
moving objects. These conditions mean that construction workers do not have control
over every circumstance at their worksite. Like any accident, a construction accident can
occur unexpectedly at any moment. There are, however, some ways to help prevent
construction accidents: Attend safety training sessions Double-check all harnesses and safety equipment before use Get adequate rest in order to stay alert on the job Wear protective clothing and equipment Follow all rules posted at the construction site Remain aware of equipment conditions and report unsafe or damaged equipment Use extra caution when working with electrical equipment Follow OSHA regulations on the job Create a rescue plan when working in trenches Work with your employer to ensure that construction safety regulations are
observed Report accidents that do occur to help prevent them from happening again
7.6 Construction Safety costs
To many managers who have been brought up to the importance of construction
scheduling, and controlling costs, the economic aspect of safety is the most forceful. In
construction the costs associated with an accident can be immense. For material losses in
which no injury occurs the accounting of loss can be easily assessed; but where human
loss is concerned, the costing becomes more difficult since life or a physical facility
cannot crudely be financially evaluated, yet it has been widely recognized that monetary
compensation to either the injured party or relatives in the event of fatality has to be paid.
Most compensation payments are paid by the contractor‘s insurance company. Insurance
companies will base their premiums upon historical evidence and a poor safety record
will inevitably be reflected in insurance premiums.
However, the loss to a company by an accident can be broken into: Lost working hours of an injured employee. Cost of repair or replacement of property damage, whether it is equipment or an
element of the permanent construction. Insurance premiums increase. Rescheduling costs or even delay costs in some cases.
The following are general costs of construction related accidents on sites:
a) Economic cost; loss of wages loss of production due to stoppage of work cost of labour replacement/training time loss in helping the injured; accident investigation and reporting accidents resulting in failed infrastructure mean loss of investment, retarded
economic growth and bad economic situation. Cost in establishment of safety programmesb) Social cost; construction accidents usually result in injury or loss of life
hardships brought about by reduced earnings human suffering and sorrow that no amount of compensation can wipe outc) Political cost; an accident-prone economy is bad publicity for a company and country at
large.d) Environmental cost; failed infrastructure often lead environmental hazardsCauses of the common construction related accidents and possible remedies;a) Work equipment and plant; inadequate mechanical safeguards to prevent contact with dangerous objects, lack of maintenance of work equipment and vehicles (defective plant and
equipment, unsuitable machines for the job cuts and splinters from blades, corners, sheet metal, tool edges etc. electrical hazards (not properly insulated)b) Workplace (environment); poor housekeeping (bad organization), poor visibility in areas where vehicles and lifting equipment are working, untidiness, poor stacking of materials, Mixing of people and vehicles especially at entrances and exits.c) Workforce; Inadequate training of workers, High labour turn- over, Monotony of work resulting in ignoring safety precautions, Lack of information, instruction, supervision, Poor communication of orders regarding safety.d) Workplace transport; Uncontrolled movement of objects,
People being struck or runover by moving vehicles/equipment or vehicles
overturning.
e) Careless handling of dangerous substances at work
f) Psychosocial factors such as stress, fear, worry, mental tension, emotional
attitude, impulsiveness (without proper thinking), overconfidence, carelessness.
g) Physiological causes; poor eye sight for workers handling machinery like cranes,
vehicles etc, overwork, poor health, old age, intoxication and physical handcup.
Accidents caused by the above hazards can be reduced through regulation and support of
the construction industry by the government as follows: Strict enforcement of existing laws; Urgent revision of relevant laws; Urgent consideration of the proposed Occupational Safety and Health Bill; Development and enforcement of standards; Operationalisation of the local construction industry policy; Education and training of technical managers and operatives; Strengthening of the insurance sector; and Building capacity to respond to national emergency situations of major accidents.
7.7 Construction Regulations
The construction industry falls within the scope of the Factories Act despite its nature of
operations being widely different to those pertaining in a factory. It was recognized that
the whole of the 1961 Act could not apply to construction, but it enabled specific
regulations for construction to be incorporated i.e. the Construction Regulations of 1961
and 1966. They include the following regulations: Construction (General Provisions) Regulations 1961 Construction (Lifting Operations) Regulations 1961 Construction (Working Places) Regulations 1966 Construction (Health and Welfare) Regulations 1966
In any situation covered by the Regulations, an employer will owe duties under Health
and Safety at Work etc Act 1974, the Factories Act 1961 and the Regulations. The same
breach of duty could therefore, constitute an offence under all of these different
provisions.
In the constriction industry statistics show that many accidents are caused by; falls from
ladders; scaffolds, roofs or materials falling, lighting equipment and machinery,
employees striking against objects, excavations and tunneling etc. To take account of
these special notes there are several sets of regulations in the construction industry:
7.7.1 General Provisions Regulations
These regulations apply whenever there are building operations or works of engineering
construction (well defined and Factories Act 1961). Building operations — construction,
structural alterations, repair, or maintenance of building, demolition of a building and
preparation for and laying the foundations of an intended building. Works of
engineering construction — construction of railway lines or sidings or the construction,
structural alteration or repair or demolition of things like docks, harbours, tunnels,
reservoirs, sewers, or gasholders.
The Regulations principally cover: Excavations, shafts, and tunnels Cofferdams, caissons Use of explosives Work in dangerous or unhealthy atmospheres Dangers connected with transport Miscellaneous protection e.g. fencing, protection from falling materials, lifting
excessive weights.
7.7.2 Lifting operations Regulations 1961
These rules cover: Lifting appliances — these must be of good mechanical construction, sound
materials, adequate strength, properly maintained.
Chains; ropes and lifting gear Hoists Carrying people on lifting appliances Secureness of loads Keeping of records
7.7.3 The Working Places Regulations 1966
Scaffolding is one of the principal matters covered by the9e regulations. Their scope also
includes building operations and works of engineering construction. Among the duties
imposed are: Providing safe and suitable access to places of work so far as is reasonably
practical, Providing scaffolds or ladders where work cannot be safely done from the ground
or from another part of the building, Erecting and dismantling scaffolding under the supervision of a competent
person, Providing scaffolds of good construction, suitable and sound material and
adequate strength for their purpose, Properly maintaining scaffolds and ensuring that they are stable, Platforms, gangway and runs should be closely boarded, planked or plated with
material of specified thickness and width resting on sufficient supports and if the
boarding projects at one end, precautions should be taken to prevent tipping, Duties relating to working on sloping roofs, and Duties with regard to safety nets and belts.
7.7.4 The Health and Welfare Regulations 1966
The main duties under these regulations relate to such matters as: First aid equipment and training in first aid treatment Shelters and accommodation for clothing and taking meals
Washing facilities and sanitary conveniences Protective clothing for persons required to continue working in bad weather.
Welfare facilities on sites:
a) Sanitary conveniences (latrines and urinals):- separate for men and women ( 1 latrine for 25 people; if workers ?100; then 1
latrine for 50 people). There should be consideration for the disabled. well ventilated and lit Clean and orderly
Washing facilities: Soap, towels or other means of drying Separate for men and women- hot and cold water
c) Drinking water- container clearly labelled ―drinking water‖
d) Facilities for clothes, rest rooms, rooms for preparing and serving meals at
cheaper rates; if work is to run for more than 1 80days and the number of workers
is more than 100, then a canteen should be provided.
e) Medical facilities; First aid room/equipment
f) Protective clothing, gumboots, jackets, eye goggles, helmets, ear muffles etc.
g) Educational facilities
h) Transportation arrangements
i) Recreational facilities (cinema, shows, indoor/outdoor games, library)
