Building Service Chapter 4

PSMZA Course Note (Chapter 4)
Ver. 1 (MSH-Jun2013): CC608 Building Services 1
4.0 DEMOLITION WORKS
4.1 Understand on Demolition Works
Demolition is the tearing-down of buildings and other structures. Demolition contrasts with
deconstruction, which involves taking a building apart while carefully preserving valuable
elements for re-use.
For small buildings, such as houses, that are only two or three stories high, demolition is
a rather simple process. The building is pulled down either manually or mechanically using
large hydraulic equipment: elevated work platforms, cranes, excavators or bulldozers.
i. What Is Demolition?
The Occupational Safety and Health Regulations 1996 define demolition and include
regulations which relate specifically to demolition. These are regulations 3.114 to 3.128 in
Subdivision 7, Division 9 of Part 3 of the regulations.
“In the Regulations "demolition" means the complete or partial demolition of a building
or structure by pre-planned and controlled methods or procedures”.
“To demolish or dismantle a structure or part of a structure that is load-bearing or
otherwise related to the physical integrity of the structure, but does not include the
dismantling of formwork, false work, scaffolding or other structures designed or used
to provide support, access or containment during construction work, or the removal of
power, light or telecommunication poles”
- Code of Practice (2009) developed by Safe Work Western Australia
“Demolition means dismantling, razing, destroying or wrecking any building or
structure or any part thereof by pre-planned and controlled methods”
– Malaysian Standard: Malaysia Code of Practice drafted (2009) developed by the
Technical Committee for Construction Practices under the supervision of
Construction Industry Development Board, Malaysia.
Not all work commonly understood to be demolition work is covered by regulations 3.114
to 3.128. These regulations do not apply to the demolition of a building or structure by a
person in the metal fabrication or engineering industry in the course of maintaining,
refurbishing, upgrading, modifying or decommissioning plant.
The exemption applies only to these particular regulations. Demolition work in mines is
covered by the Mines Safety and Inspection Act and regulations made under that Act.
Larger buildings may require the use of a wrecking ball, a heavy weight on a cable that is
swung by a crane into the side of the buildings. Wrecking balls are especially effective against
masonry, but are less easily controlled and often less efficient than other methods. Newer
methods may use rotational hydraulic shears and silenced rock-breakers attached to
excavators to cut or break through wood, steel, and concrete. The use of shears is especially
common when flame cutting would be dangerous.
ii. Types And Ways of Demolition
In many circumstances, buildings and structures should be demolished in the reverse
order to their erection; although where partial demolition is involved a more careful evaluation
of the nature of the effects of the demolition is necessary. Normally, the demolition contractor
is able to adopt a method of work which gradually reduces the height of the building or
arranges the deliberate controlled collapse of the building or structure so that work can be
completed at ground level.
The choice of demolition technique will depend on the nature of the building or structure
and its environment. Risks to the public, operatives involved in the demolition process and
adjacent structures and buildings should be considered. Demolition techniques may be
categorized as:-
a. Piecemeal demolition, using hand-held tools or machines, to reduce the height of the
building or structure gradually

b. Deliberate controlled collapse, demolition to be completed at ground level
General guidelines are also given for the design of temporary works and checking of
temporary structures. The code covers common methods typically used in the demolition of
buildings in Malaysia, but exhaustive guidelines for all methods are not given. The code does
not intend to discourage any other demolition methods, which may be used subject to
approval. The content of the unit includes the following topics:
a. Demolition Processes
b. Demolition Methods
c. Machinery used in demolition
d. Demolition Tariffs And Reasons For Demolition
4.1.1 The Objectives Demolition Works
With the increased number of fatal accidents caused by demolition of high rise buildings,
safety in demolition works becomes a great concern to both the government and the public.
The reasons leading to such horrible accidents are many, of which the lack of planning and
supervision are the major ones.
Following the issuance of various practice notes to:
i. Authorized persons
ii. Registered structural engineers
iii. Registered contractors
iv. Regarding the safety measures for demolition works for the protection of the Public
v. The building department has recently prepared a draft of the Code of Practice for
Demolition of Building.
It is intended to be followed by specialist demolition contractors for the demolition of
various building works in Malaysia, aiming at minimizing the risks of injury to persons and
damage to properties, the risks of endangering the health and safety of site personnel and
damage to the environment in the vicinity.
The Code sets out the guidelines for demolition of the buildings from roof level to ground
level and the demolition of basement, underground tanks, as well as certain common civil
engineering structures, but not major civil engineering works such as underpinning,
excavation, highway bridges, dams and nuclear reactors.
4.1.2 The Reasons of Demolition Works
Demolition of buildings usually refers to the act of pulling down a building or part of a
building. There can be various reasons for demolition, it is:
i. Commercials
ii. Aesthetic
iii. Human health
iv. Human safety
v. Build new buildings
vi. Renovation
vii. Structure problems
viii. Environment (near slopes)
ix. Population density
x. Adjacent buildings
xi. Traffic
4.2 Method of Demolition
The sequence in which a building or other structure is demolished can be critical for the
health and safety of workers and the general public. The demolition sequence will depend on
things like the type of construction, location, and demolition method(s) selected. Buildings and
structures should generally be demolished in reverse order to their construction, that is, by
‘sequential demolition’. In particular:

i. Sequential demolition should be carried out in reasonably even stages, commencing from
the roof or top of the building or structure being demolished.
ii. Multi-storey buildings or structures should be demolished storey by storey
iii. masonry and brickwork should be taken down in reasonably even courses.
There is a range of demolition methods that may be used, either separately or in
combination. Control measures should be selected on the basis of the demolition method(s)
used. However, no matter what method is used, the building or structure to be demolished
and all its components should be maintained in a safe and stable condition so as to prevent
the unexpected collapse of part or all the structure. Temporary braces, propping, shoring, or
guys may need to be added for stability.
4.2.1 Manual Demolition
The demolition works by manually should be:
a. Manual demolition includes any technique where hand tools such as jackhammers,
sledgehammers and picks are used.
b. Manual demolition has many of the hazards that are present in other major demolition
activities including unexpected collapse, falls, falling objects, manual handling and
exposure to noise, dust and hazardous chemicals.
c. To manage the risk of unplanned collapses, the condition of roofs, walls and floors of
the building should be assessed by a competent person before commencing
demolition work.
d. Where concrete members are being demolished manually, the reinforcement shall
not be cut while breaking of the concrete is in progress.
e. Where pre and post-tension demolition work is undertaken competent person advice
should be sought as to demolition sequence. More information on the demolition of
pre and post- tensioned concrete is at Section 6.1 of this Code.
f. Areas where debris will fall should be barricaded off and signs erected to prevent
persons from entering before demolition starts.
i. Manual Demolition of Roofs
Where it is not reasonably practicable to demolish a roof using mechanical means or
to remove the roofing from work platforms below the roof, then careful consideration
should be given to the most suitable method of protection for workers engaged in the
removal of the roofing. For example, roof trusses should be removed using safe
temporary work platforms. It is important to ensure that the removal of trusses does not
cause wall instability.
Controlling the risk of falls of persons or objects is an important consideration for roof
work. Prior to commencing roof demolition or dismantling, you should consider:
a. Fall hazards
b. Structural stability
c. Condition and strength of the roofing material and the identification of fragile roofing
d. Identification of fragile panels or skylights in solid roofs
e. Crane access
f. Safe worker access and egress
g. Fall protection requirements including issues such as perimeter protection, the
availability
and strength of anchor points for static lines, inertia reels and lanyards and the
suitability of roof structure for the use of safety nets
h. Means of rescuing persons from safety nets or safety harnesses
i. The condition of any roof mesh or safety mesh
j. Methods of raising and lowering equipment and materials
k. Assessment of manual handling problems
l. Electrical safety including the location of nearby power linen
m. Worker competency and training needs

ii. Fragile Roofs
Before working on the roof, the roof should be inspected to identify that it is
structurally adequate to work on and whether there is any brittle material or if the roof has
a fragile aspect to it (for example, a skylight or worn section).
Brittle or fragile roofing material can include roofing made of asbestos cement,
cellulose cement, glass panels, fiberglass, acrylic or other similar synthetic molded or
fabricated material used to sheath a roof or contained in a roof.
If asbestos cement roofing is involved, the work must be undertaken in accordance
with the asbestos related requirements of the WHS Regulations. Further information can
be found in the Code of Practice: How to Safely Remove Asbestos.
Where it is necessary for work to be carried out or adjacent to any part of a fragile
roof, you should:
a. Inspect the underside of the roof to determine the extent of the fragile roof material,
the
existence of any safety mesh and its fixings, and the structural soundness of the roof
material
b. Complete the work from a temporary work platform
c. provide temporary walkways as a means of access to and egress from any work area
on the roof where permanent walkways are not provided
d. secure and fix cleats to walkways on high pitch roofs (for example, where the slope
of the roof exceeds 1:6)
e. provide temporary roof ladders for steep roofs (for example, in excess of 35 degrees)
f. provide other fall protection as necessary (for example, work positioning or fall arrest
system).
iii. Roof access
The person conducting a business or undertaking where persons are employed to
work on roofs has a responsibility to ensure that the access from the ground to the actual
work area is safe and without risk to health. Access arrangements may include personnel
hoists, scaffolding, temporary work platforms and ladders.
iv. Purlin Trolleys
Purlin trolleys are plant designed to travel on top of purlins (horizontal beams running
along the length of a roof) and can be used to support material and roof workers. They
are sometimes used during the removal of roof coverings.
Purlin trolleys should be provided with a
holding brake and a device to prevent their
accidental dislodgment from the supporting
purlins. Where it is intended that the roof workers
be supported by the trolley, the trolley should be
provided with suitable safety harness anchorage
points. Before a purlin trolley is placed on a roof
structure:
a. A competent person (e.g. a structural
engineer) should have considered whether
the roof structure is suitable for the particular
purlin trolley and its operational loads
b. The purlin trolley should be designed and
constructed to withstand the loads placed
on it and for the purpose of the safe
movement of materials and/or persons across
the roof surface.
Figure 4.1: Demolition to access

Figure 4.3: Demolition of members and floor
Figure 4.2: Demolition of
wall
v. Manual Demolition of Walls
Glass should be removed from the windows, doors or
openings before the commencement of the demolition work.
Walls and gables should be demolished course by
course. All work should be performed from safe working
platforms. Workers should not work from the top of a wall or
partition being demolished. A wall or partition should not be
permitted to stand, unless it is effectively supported against
collapse, including being supported against lateral loads from
wind and other forces.
If the demolition work involves the demolishing course by
course of any walls, columns, piers or other vertical structural
members, the demolition contractor should check that:
a. Risks to persons and property from falling collapsing and
rebounding material are laminated or minimized
b. The remaining portion of the building or structure, if any,
can withstand any loads, impacts and vibration caused
by felling or other environmental factors such as wind.
vi. Manual Demolition of Floors and Members
All floors and other surfaces used to support workers, plant, equipment or materials
should be assessed as capable of supporting the load. Suspended floors and their
supporting members should not be loaded by workers, plant, falling or accumulated
debris/materials to the extent that there is excessive deflection, permanent deformation or
danger of collapse. If water is used, the increased weight of the watered debris should be
taken into account.
Openings in floors, through which a
person may fall, shall be properly
guarded or boarded over and the
boarding secured against accidental
removal. Any covers or boarding of
openings in floors should be of sufficient
strength to withstand any expected
loads that may be imposed on the floor,
for example elevating work platforms,
people and material.
Drop zones should be isolated
and/or guarded to protect workers and
the public from falling objects. When
jack hammering concrete floors,
sufficient reinforcing steel should be left
in position as protection against collapse
or to prevent persons falling through the floor.
vii. Manual Demolition of Frameworks
Before any framework is demolished or removed, all reasonably practicable
precautions should be taken to prevent the rest of the building collapsing as a result.
A competent person (for example, a structural engineer) should undertake an
assessment to determine the necessary supports required when cutting members.
Members should not be cut unless they are supported safely and effectively. Measures
should be taken to prevent sudden spring, twist, collapse or other movement of the
framework when it is cut, released or removed.

Any framework which is not demolished should be strong enough to remain safely in
position, or should be guyed or otherwise supported to ensure that it will be stable in any
adverse weather conditions. Framework members should be lowered in a controlled
manner. Tag lines should be used on loads where necessary to control the load.
4.2.2 Mechanical Demolition Work
Mechanical demolition involves the use of powered mobile plant, such as excavators,
cranes, loaders and bulldozers. There may be a mix of hand and mechanical demolition
methods applied.
All powered mobile plant used for demolition work must be fitted with a suitable
combination of operator protective devices. Operator protective structures should be designed
to the appropriate standard that eliminates or minimises the risk, so far as is reasonably
practicable, of operator injury due to:
i. Roll over and consequent cabin impact damage
ii. Objects falling on or over the cabin
iii. Objects penetrating the cabin
iv. Hazardous noise
Demolition should be planned to be systematic and sequential. That is, a structure should
be demolished in the reverse order to which it was constructed. Mechanical demolition
generally involves the use of large machinery with attachment to dismantle the building from
outside. The common mechanical methods include the use of a pusher arm, wire rope and
clam shell. These methods shall only be applied to isolated buildings on relatively flat ground.
The concerns and good practices of the mechanical demolition generally included the
following:
a. The machine shall be operated on smooth and firm ground. It shall also have
adequate counter-weight to prevent overturning during the operation;
b. The equipment and accessories such as attachments and rope shall be inspected
frequently and shall be repaired or replaced whenever necessary;
c. The impact of the collapsed structural sections on the floor or ground shall be
checked to prevent the potential overloading of the suspended floor, vibration and
disturbance to adjacent properties and damage to underground utilities;
d. The site shall have full time security to prevent unauthorized personnel entering the
site. No person shall stay within the working area of the machine and the building
while the machine is operating;
e. Sufficient water spray or other anti-dust precautions shall be provided to minimise air
pollution by dust;
f. The cab of the machine shall be equipped with impact proofed glass and its
construction shall be robust enough to protect the operator from flying debris;
g. A spot person shall be on site full time to provide guidance and assistance to the
operator in the demolition process.
In addition to the above, specific criteria for each mechanical method are discussed in the
following sections:
a. Deliberate Collapse Mechanical
b. Wire Rope Pulling
c. Saw cutting
d. Cutting and lifting
e. Clam Shell
f. Non explosive demolition agent
g. Thermal lance
h. Water Jet
i. Crane and the demolition ball
j. Pneumatic impact tool
k. Pusher Mechanical Arm
l. Explosive

Crane and the Demolition Ball
Balling machines generally comprise a drag-line type crawler chassis fitted with a lattice
crane jib. The demolition ball, with a steel anti-spin device, is suspended from the lifting rope
and swung by the drag rope.
Balling should only be carried out by skilled operatives under the control of experienced
supervisors using well maintained machines adequate for the proposed duty and standing on
a firm, level base. The manufacturer should be consulted before a machine is used for balling
to establish any restrictions on the type or length of jib or the weight of the ball. Balling
operations subject cranes to dynamic stresses and wear, and the ball chosen should have the
minimum weight necessary for effective use.
In many cases, demolition balls of quite light weight will be adequate. Floors should be
demolished by dropping the ball on the highest remaining floor and allowing the debris to fall
inside the building. The debris should be removed regularly to prevent excessive weight
accumulating on the lower floors. Walls or columns can be demolished either by swinging the
ball in line with the stationary jib, using the drag rope, or by slewing the jib. The ball should
not swing by derricking the jib.
The wrecking ball application consists of a crane equipped with a steel ball. The
destruction of the building is by the impact energy of the steel ball suspended from the
crawler crane. The wrecking ball operates outside the building. This method is suitable for
dilapidated buildings, silos and other industrial facilities. However, the operation requires
substantial clear space. The application also demands high level skill operators and well-
maintained equipment. Figure 4.16 illustrates the operation of Wrecking Ball.
The recommended criteria for the use of wrecking ball are presented in the following:
i. Except for special application, the balling of each section of the structure shall proceed
from top to bottom. Care shall be taken to maintain the stability of the structure
ii. Recommended techniques for the wrecking ball operations include:
a. Vertical Drop - free falling of the wrecking ball onto the structure;
b. Swing in line - swinging of the ball in-line with the jib. A second dragline will normally
connect to the ball horizontally to control the ball motion. The ball shall be swung into
the building. The ball shall strike at the top of the member so as to avoid the member
from falling outside the building.
Slewing the jib is not recommended. The motion of the ball by slewing the jib is
difficult to control. It demands expert knowledge of the machine and structure as well
as operating skills to safely perform the task. Slewing can potentially induce a
tremendous amount of stress on the jib, as such; its use shall be avoided
iii. The jib or boom shall be operated with no less than 3 m above the portion of the structure
being demolished
iv. Clear space for operation between the crane and the structure being demolished shall be
50 % of the height of structure, the clear distance between the site boundary and the
building to be demolished shall not be less than 50 % of the building height plus an
additional 6 m for the crane to manoeuvre, this criteria shall apply to all sides of the
building to be demolished by wrecking ball
v. The demolition ball shall be connected with swivel type anti-spin device to prevent
twisting and tangling of the wire during operation
vi. The wire and boom of the machine used for balling shall have a rated capacity, at the
working radius, of at least 5 times the weight of the ball
vii. The strength of the wire shall be at least twice the tensile strength of the nominal steel
reinforcement of the floor slab and beams. The high strength wire allows the pullout of the
wrecking ball from potential traps

viii. To ensure that the crane is in good condition, the wire connecting to the ball, the boom
components and connecting pins shall be inspected twice daily
ix. A sufficient length of the wire shall be provided to allow the ball to drop to the lowest
working level plus an addition of 10 % of the wire length and no less than 3 drums.
x. For swing in-line method, there shall be sufficient length of the dragline wire to allow the
ball to fall in the event that the ball is entangled with the falling debris
xi. The operation shall not be performed adjacent to overhead power lines
xii. The site shall be entirely fenced off to forbid public access. A 24-hour security guard shall
be assigned to the site to enforce the access restriction; depending on the relative
location between the fence and the building, and fence shall be designed to withstand
accidental impact by the wrecking ball
xiii. During the use of the demolition ball, except for the crane operator and the spot person,
all other workers shall be kept away from the demolition ball’s working radius. No body
shall stay inside the building
xiv. To minimise the dust impact on the surrounding area, the structure to be demolished shall
be pre-soaked with water before demolition. Water spraying shall continue on the
structure during demolition
xv. Since the safety and success of the project depend highly on the operator and site
personnel, the operator must have proven experience and skill for operating the wrecking
ball to the satisfaction of the approval authority
xvi. A spot person shall be on site during the operation to assist the operator and to ensure
site safety. The spot person shall have extensive knowledge and experience in the use of
wrecking ball. The qualification and experience of the spot person shall be equivalent to
those of the wrecking ball operator
Pneumatic Impact Tools
What are pneumatic impact tools? : A pneumatic tool or air tool is a tool driven by a gas,
usually compressed air supplied by a gas compressor. Pneumatic tools can also be driven by
compressed carbon dioxide (CO2) stored in small cylinders allowing for portability. Pneumatic
tools are commonly cheaper and safer to run and maintain than their electric power tool
Figure 4.4: Crane and the demolition ball

counterparts, as well as having a higher power-to-weight ratio, allowing a smaller, lighter tool
to accomplish the same task.
Air tools were formerly unpopular in the market, but are becoming increasingly popular,
and have always been ubiquitous in industrial and manufacturing settings. The example of
pneumatic impact tools includes:
i. Nail drivers
ii. Demolition hammers
iii. Chipping hammers
iv. Riveting hammers
v. Air impact wrench
vi. Jackhammer
vii. Pneumatic angle grinder
viii. Pneumatic drill
They are driven by way of a pneumatic cylinder (tacker, nail driver) or by way of
oscillating linear motors (demolition hammers, chipping hammers, riveting hammers, needle
descales).The samples tools function:
i. Air drill for the same applications as you would an electric drill.
ii. Air sander for sanding wood and metal or for removing rust from a vehicle before painting.
iii. Air stapler to lay a carpet or upholster furniture with ease.
iv. Concrete demolition tools that fall under this category include paving breakers and
chipping hammers. Its can use paving breakers to demolish concrete floors, patios,
sidewalks, driveways, parking lots and other hard surfaces.
v. Chipping hammers allow to chisel away specific areas of concrete.
vi. Impact wrench to tighten or remove bolts quickly, an air impact wrench can come in
handy. When choosing an air impact wrench, keep in mind the size of the bolts can will
tighten and the amount of torque you will need.
vii. Nail guns to specifically designed for a number of purposes including framing, roofing,
fencing, siding, flooring and finishing.
viii. Sandblaster to remove rust or old paint from boat hulls, swimming pools or masonry work
using a rented air sandblaster.
Figure 4.5: A single phase demolition breaker
Figure 4.7: A gas breaker on a
deconstruction site
Figure 4.6: A compressor for running a
pneumatic jackhammer and air drill

Pusher Mechanical arm
The crusher attachment breaks the concrete and the reinforcement by the hydraulic thrust
through the long boom arm system. The hydraulic crusher can be operated from the ground
outside the building. This method is also suitable for dangerous buildings, silos and other
industrial facilities.
For environmental reason, it should be used wherever practicable because of its
quietness. Articulated, hydraulically-powered pusher-arm machines are normally mounted on
a tracked or wheeled chassis, and have a toothed plate or hook for applying for applying a
horizontal force to a wall. The machine should stand on a firm level base and apply force by a
controlled movement of the pusher arm.
Figure 4.8: Long arm hydraulic machine with crusher
Figure 4.9: Long arm hydraulic machine with jackhammer

Explosive
If explosives are to be used for demolition, the planning and execution, include pre-
weakening, should be under the control of a person competent in these techniques. For large
demolition, the competent person is likely to be an experienced explosive engineer; for
smaller work, a shot-firer may be sufficient.
When the use of explosives is contemplated, it is usual to employ a technique that will
ensure the total demolition of the whole building by staging a controlled collapse. The
explosive charges are set and fired in a sequence that will weaken the structure in such a way
that the building collapses in upon itself. Although we tend to think of explosives as devices
producing spectacular bomb-like explosions, the use of non-explosive "explosives" is now at
an advanced stage. These non-explosive techniques are essentially expanding charges that
achieve the same results as explosives but without the noise and initial devastating blast.
The term building implosion can be misleading to laymen: the technique is not a true
implosion phenomenon. A true implosion usually involves a difference between internal
(lower) and external (higher) pressure, or inward and outward forces, that are so large that
the structure collapses inward into itself.
In contrast, building implosion techniques do not rely on the difference between internal
and external pressure to collapse a structure. Instead, the technique weakens or removes
critical supports so that the building can no longer withstand the force of gravity and falls
under its own weight.
Numerous small explosives, strategically placed within the structure, are used to catalyse
the collapse. Nitro-glycerine, dynamite, or other explosives are used to shatter reinforced
concrete supports. Linear shaped charges are used to sever steel supports. These explosives
are progressively detonated on supports throughout the structure. Then, explosives on the
lower floors initiate the controlled collapse.
A simple structure like a chimney can be prepared for demolition in less than a day.
Larger or more complex structures can take up to six months of preparation to remove
internal walls and wrap columns with fabric and fencing before firing the explosives.
As part of the demolition industry, the history of building implosion is tied to the
development of explosives technology. One of the earliest documented attempts at building
implosion was the 1773 razing of Holy Trinity Cathedral in Waterford, Ireland with 150 pounds
of gunpowder, a huge amount of explosives at the time. The use of low velocity explosive
produced a deafening explosion that instantly reduced the building to rubble.
Figure 4.10: Building demolition with blasting

The late 19th Century saw the erection of-and ultimately the need to demolish-the first
skyscrapers, which had more complicated structures allowing greater heights. This led to other
considerations in the explosive demolition of buildings, such as worker and spectator safety and
limiting collateral damage. Benefiting from the availability of dynamite, a high-velocity explosive
based on a stabilized form of nitro-glycerine, and borrowing from techniques used in rock-
blasting, such as staggered detonation of several small charges, building demolition edged
toward efficient building implosion.[citation needed]
Following World War II, European demolition experts faced with massive reconstruction
projects in dense urban areas gathered practical knowledge and experience for bringing down
large structures without harming adjacent properties. This led to the emergence of a demolition
industry that grew and matured during the latter half of the twentieth century. At the same time,
the development of more efficient high-velocity explosives such as RDX and non-electrical firing
systems combined to make this a period of time in which the building implosion technique was
extensively used.
General concerns and good practices in controlled demolition by blasting are discussed in the
following:
i. Pre-weakening of the structure shall be designed to ensure the structural stability before the
implosion;
ii. To minimise the dispersion of building debris into adjoining land after blasting, a trench or
bund wall shall be installed outside the building to contain the debris, unless a basement
exists;
iii. A good design will cause the structure to fall towards the centre of the building and/or within
the protected area;
iv. A good design will provide adequate and sufficient time delay to allow only one or two floors
of the building debris to fall on ground level at a time in order to limit the magnitude of the
impact on the ground;
v. The design must also identify an exclusion zone to evacuate all residents or inhabitants
during the blasting. The impacts of noise and dust generated during the blasting shall be
considered. Radius of the typical exclusion zone shall not be less than 2.5 times the building
height;
vi. If there are slopes and earth retaining walls or features, a geotechnical assessment shall be
conducted to ensure that the blasting will not affect the stability of these features;
vii. The entire site shall be under 24-hour security from the installation of explosive until final
blasting. The implosion expert shall have proven experience and track records in design and
supervision of blasting similar building structures. The blasting expert shall have acquired the
relevant training and practical experience in using the proposed explosives. The blasting
expert shall obtain permission from the Police before carrying out blasting. All personnel must
be evacuated from the site before and during blasting;
viii. The Registered Specialist Contractor (Demolition) must co-ordinate with the government and
local community to determine the best procedures in notification, schedules for the events,
traffic routing, design for the sequence of events, evacuating residents, clear out personnel
from the building and assigning responsibilities during blasting. For the purpose of crowd
control, blasting should be carried out in the early morning of a Sunday or public holiday;
ix. An emergency plan shall be prepared to handle emergency situations such as premature
explosion, misfire or interruption due to bad weather including thunder and lightning;
x. After the explosion, the blasting expert must check to make sure that there is no unfired
explosive left on site. The entire area must remain clear and under security control until the
unfired explosives have been detonated or safely dealt with by the blasting expert;

xi. As far as practicable, non-electrical initiation systems should be used to avoid the risk of pre-
mature detonation by stray currents, external electro-magnetic waves or radio frequencies.
The installation shall include a redundant system to ensure successful detonation. Nitro-
glycerine based explosives are not permitted to be used
xii. The Registered Specialist Contractor (Demolition) must provide evidence of his capability to
safely perform the demolition and shall illustrate to the approving authorities that the
procedures are safe
xiii. The mode of collapse shall be demonstrated to ascertain that:
a. No part of the building will fall beyond the protected area;
b. The impact of the structural collapse will not cause significant vibration affecting
 Any underground tunnels
 Any underground utilities
 Any adjoining properties
xiv. The structural safety of the building to be imploded shall be checked and certified to be sound
and safe at all stages prior to implosion.
4.3 Safety Procedures and Best Practices of Demolition Works
The choice of demolition method depends on the project conditions, site constraints, and
sensitivity of the neighborhood and availability of equipment.
Top down methods are applicable for most sites, particularly for those situated in busy
urban areas. Other mechanical methods applied from the outside of the building may be
suitable for projects that have sufficient clear spaces. For structural projections, such as
balconies, canopies and verandas extending beyond the building lines, demolition by hand
held tools or the cut and lift process may be a safe solution. Methods using wrecking ball and
explosive should be adopted with extreme care when well-planned adequate precautionary
measures are provided. The applications of demolition methods are summarized in figure
4.11.
The suggested procedures described in this Code of Practice are recommended good
practices for demolition of common structural elements only. Each site has its specific
features and conditions. The method, including detail procedures, shall be designed to
accommodate the specific project requirements. In general, demolition should be carried out
in the reverse order of construction, as far as appropriate.
Figure 4.11: The application of demolition method

4.3.1 License Required For All Demolition Works
A license is required to carry out certain types of demolition work. It is an offence to do
any of the work described as class 1, class 2 or class 3 demolition work unless licensed to do
the work.
i. Class 1
a. Work comprising the total demolition of a building or structure that is 10 metres or
more in height when measured from the lowest ground level of the building or
structure to the highest part of the building or structure
b. Work comprising the partial demolition of a building or structure that is 10 metres or
more in height when measured from the lowest ground level of the building or
structure to the highest part of the building or structure affecting the structural integrity
of the building or structure
c. Work comprising the total or partial demolition of a building or structure; and involving
the use of load shifting equipment on a suspended floor
d. Work comprising the total or partial demolition of pre-tensioned or post-tensioned
structural components of a building or structure
e. Work comprising the total or partial demolition of a building or structure containing
precast
f. Work involving the removal of key structural members of a building or structure so
that the whole or a part of the building or structure collapses
g. Work done to a building or structure involving explosives
h. Work comprising the demolition or partial demolition of a building or structure that
involves the use of a tower crane or any crane with a safe working load greater than
100 tonnes
i. Work involving the removal of an area of brittle or fragile roofing material in excess of
200 m
2
from a building or structure if any part of the area to be removed is 10 metres
or more above the lowest ground level of the building or structure
ii. Class 2,
a. Work comprising the total or partial demolition of a building or structure that is less
than 10 metres in height when measured from the lowest ground level of the building
or structure to the highest part of the building or structure but does not include :
 the total or partial demolition of a single storey dwelling
 work of a kind referred to in paragraphs (c), (d), (e), (f), (g), or (h) of the
definition of class 1;
iii. Class 3
a. Work comprising the removal of more than 200 m² of brittle or fragile roofing material
from a building or structure
4.3.2 Special Safety Considerations
i. Training and Communication
Demolition workers, including plant or equipment operators, shall go through proper
job safety training and be informed of the potential hazards by attending training sessions
as well as on-the-job training.
Site safety and project understanding shall be promoted through an induction meeting
at the beginning of the project, where information related to the project such as the
proposed method and procedures, potential danger during the operation, safety
measures and project specifics can be disseminated to all on site personnel.
The safety concept can be maintained by regular safety meetings throughout the
project period. Site safety attitude may be cultivated by strict enforcement of the safety
regulations by the site supervisor.

Apart from instilling the importance of safe attitudes to workers and plant or equipment
operators, they shall be trained by competent instructors on the following to observe safety
precautions:
a. Working at Heights
b. Working in Confined Spaces
c. Working with Lifting Appliances and Lifting Gears
d. Use of Personal Protective Equipment
e. Hot Works
f. Handling of Chemicals
g. Health Hazards in Demolition Works
h. Safe plant operating zones and safe plant manipulation zones.
ii. Equipment Maintenance
All equipment shall be tested and examined before use. They shall be properly stored
and maintained. The equipment shall be inspected daily and results of the inspection
shall be recorded accordingly. A detailed safety instruction shall be provided to cater for
specific situations of the project, if necessary.
iii. Electrical Safety
A properly connected power source from a local electric utility supplier or a mobile
electricity generator shall be utilized in demolition sites.
iv. Fire
All flammable goods shall be removed from site unless they are necessary for the
works involved. Any remaining flammable goods shall be stored in proper storage
facilities. All furniture, timber, doors, etc. shall be removed before any welding work is
performed. Fire fighting appliances shall be provided and maintained in working
conditions.
v. Occupational Health
The health of workers on site shall be properly protected particularly on the following
areas:
a. Exposure to Dust
b. Chemical Exposure
c. Heat Stress and Ventilation
d. Noise Exposure
e. Medical and First Aid Facilities
f. Sanitation
g. Occupational Diseases
h. Poisoning.
vi. Emergency Exit Requirements in Demolition Sites
Emergency exits shall be provided during building demolition. In case of any
emergency evacuations, the emergency exit will serve as a lifeline for transportation of
injured workers. A minimum of one exit route shall be maintained and designated as the
emergency exit at all times during the demolition.
Adequate lighting and fire extinguishing equipment shall be provided. Emergency exit
shall be properly protected, free of obstruction, and properly marked with exit signs or
other indications to clearly show the route. All workers shall be informed about the exit
route.
vii. Vibration
Demolition work will cause vibration to neighbouring buildings or structures to various
extent, depending on the method of demolition. The most serious vibration is caused by
implosion. The effect of vibration caused by implosion are categorised as follows:
a. Permanent ground distortion produced by blast-induced gas pressures
b. Vibratory settlement of foundation materials

c. Projectile impact (i.e. blast fly rock)
d. Vibratory cracking from ground vibration or air blast.
These effects will have to be dealt with specifically in the method statement for implosion.
For other mechanical demolition methods, the vibration effect is usually less than some other
construction processes, such as percussive piling and blasting. In some cases, the traffic
vibrations caused by heavy duty tractors are more significant than that caused by mechanical
demolition. In order to identify the actual cause and effect of vibration. As a general guideline,
the peak particle velocities at any adjoining structure shall not exceed 15mm/sec for
prolonged vibration caused by mechanical demolition.
4.3.3 Environmental Precautions
The general requirements to minimise environmental impacts from construction sites can
also be applied to demolition processes. The following sections contain some of the
procedures to be adopted:
i. Air Pollution
Concrete breaking, handling of debris and hauling process are main sources of dust
from building demolition. Dust mitigation measures shall be adopted to minimise dust
emissions. Burning of waste shall not be allowed.
ii. Noise
Noise pollution arising from the demolition works including, but not limited to, the use
of specified powered mechanical equipment (SPME), powered mechanical equipment
(PME), such as pneumatic breakers, excavators and generators, etc., scaffolding,
erection of temporary works, loading and transportation of debris, etc. affects the workers,
and the sensitive receivers in the vicinity of the demolition site. Silent type PME shall be
used to reduce noise impact as much as practicable. Demolition activity shall not be
performed within the restricted hours.
iii. Water
The discharge of wastewater from demolition sites requires an approval by
Department Of Environment (DOE). Effluent shall be treated to the standards as
stipulated by DOE Regulation before discharge.
iv. Hazardous Materials
Materials such as liquefied petroleum gas (LPG) cylinders in domestic flats, toxic and
corrosive chemicals for industrial undertakings, and any other hazardous materials have
to be identified and properly handled and removed prior to the commencement of the
demolition of the building.
In the summaries, best of practices and environments effect in demolition works were:
i. The stability and structural integrity of the structure at all stages of demolition, including
assembled portions, single components and completed sequentially erected braced bays.
ii. The maximum permissible wind speed for partially demolishes structure.
iii. The effect of the proposed demolition squeeze on stability.
iv. The stability requirements for all components of the structure as it is sequentially
demolished according to adjoin building.
v. The proximity of adjacent of loadings at all stages of demolition.
vi. The provision of clear.
vii. The proposed methods for handling heavy, bulky or awkward components.
viii. The need for specific lifting arrangements to detailed on structural member drawings to
facilitate safe lifting.
ix. The handling, lifting, storing, stacking and transportation of components, depending on
their size, shape and weight.
x. The provision of safe access and safe working areas.

4.4 Demolition Works Sign
.

4.5 References
Books
Egan M David (1986). The Building Fire Safety Concept. University Technology Malaysia,
Skudai.
Fullerton R. L. (1979). Building Construction in Warm Climates. Volume 1, 2, 3. Oxford
University Press, United Kingdom.
Hall F. (2000). Building Services & Equipment. Pearson Limited, England.
MS EN 81-1:2012. Malaysian Standard. Safety Rules for the Construction and Installation of
Lift- Part1: electric Lifts (first revision). Department of Standards Malaysia.
Nor Rizman (2010). Risk Assessment for Demolition Works In Malaysia. Faculy of Civil
Engineering and Earth Resources, Universiti Malaysia Pahang. Undergraduate
thesis.
Prashant A/L Tharmarajan (2007(. The Essential Aspects of Fire Safety Management In Hihg-
Rise Buildings. University Teknologi Malaysia. Degree of master science thesis.
Riger W. Haines, Douglas C. Hittle (2006). Control System for Heating, Ventilating and Air
Conditioning. Springer-Verlag, New York.
Stein, Benjamin, Reynolds, John S., Grondzik, Walter T., and Alison G. Kwok, (2006).
Mechanical and Electrical Equipment for Buildings. 10th ed. Hoboken, New Jersey:
John Wiley and Sons, Inc., 2006.
Tan, C. W. and Hiew, B.K., (2004), “Effective Management of Fire Safety in a High-Rise
Building”, Buletin Ingenieur vol. 204, 12-19.
Journals
N.H. Salleh and A.G. Ahmad. (2009). Fire Safety Management In Heritage Buildings: The
Current Scenario In Malaysia. CIPA Symposium Kyoto Japan. UIAM and USM.
Code of Practices
Approved Code Of Practice For Demolition: Health And Safety In Employment Act 1992.
Issued And Approved By The Minister Of Labour September 1994.
Code of Practice for Lift Works and Escalator Works. (2002 ed).
Code Of Practice For Demolition Of Buildings 2004. Published by the Building Department.
Printed by Taiwan Government Logistics Department.
Code Of Practice For Demolition Of Buildings (2009). Malaysia Standard Supersede Ms 282
Part 1: 1975. Technical Committee For Construction Practices Under The
Supervision Of Construction Industry Development Board, Malaysia.
Demolition Work Code Of Practice (July 2012). Australian Government.
Work Health and Safety (Demolition Work Code of Practice) Approval 2012. Australian
Capital Territory. By Dr Chris Bourke, Minister for Industrial Relations.
Others Publishing

Coby Frampton. Benchmarking World-class maintenance. CMC Charles Brooks Associates,
Inc.
Electrical Installation and Systems (2006). Training Package UEE06. Industry Skills Council,
Australia.
Fire Safety Manual (2002). Florida Atlantic University USA.
Garis panduan Pendawaian Elektrik di bangunan Kediaman (2008). Suruhanjaya Tenaga
Malaysia. Jabatan Keselamatan Elektrik.
Laws of Malaysia. Act 341: Fire Services Act 1988. Publish by The Commissioner Of Law
Revision, Malaysia Under The Authority Of The Revision Of Laws Act 1968 In
Collaboration With Percetakan Nasional Malaysia Bhd 2006.
Operations & Maintenance Best Practices: A Guide to Achieving Operational Efficiency.
(August 2010). Release 3.0.
Principles of Home Inspection: Air Conditioning and Heat Pumps. (2010). Educational Course
Note.
Routine Maintenance Modules. Part II.
Uniform Building By Law 1984. (1996). MDC Legal Advisers: MDC Publishers Printers
Guidelines For Applicants For A Demolition Licence Issued Under The Occupational Safety
And Health Regulations 1996. Occupational Safety And Health Act 198. The
Government of Commerce, Western Autralia.
Websites
http://en.wikipedia.org/wiki/Electricity
http://science.howstuffworks.com/electricity.htm
http://en.wikipedia.org/wiki/Electricity_generation
https://en.wikipedia.org/wiki/Fire_safety
http://www.usfa.fema.gov/citizens/home_fire_prev/
https://en.wikipedia.org/wiki/Maintenance,_repair,_and_operations
http://academia.edu/406774/Demolition_Work_in_Malaysia_The_Safety_Provisions
http://www.mbam.org.my/mbam/doc/news/010-05Oct09-COP%20Demolition%20Works-
corrected%20on%20%2030th%20sept%202009-1.doc
http://en.wikipedia.org/wiki/Demolition
http://www.safeworkaustralia.gov.au/sites/SWA/about/Publications/Documents/700/Demolitio
n%20Work.pdf
https://en.wikipedia.org/wiki/Air_conditioning
http://www.nasa.gov/topics/earth/features/heat-island-sprawl.html

http://www.projectnoah.org/education
http://unfccc.int/files/methods_and_science/other_methodological_issues/interactions_with_o
zone_layer/application/pdf/subgene.pdf
http://www.cibse.org/Docs/barney2.doc
http://en.wikibooks.org/wiki/Building_Services/Vertical_Transportation

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