Wastage Control

1. WASTAGE CONTROL
IN CONSTRUCTION
BY RAJIV NEHRU
Director General,
Real Estate Academy for
Developers

2. MINDS AND PARACHUTES
ARE SIMILAR
BOTH WORK ONLY WHEN
THEY ARE OPEN

3. TRAINING DOES NOT TELL
YOU WHAT TO DO
IT TELLS YOU WHAT YOU
ARE NOT DOING

4. DEFINITION OF WASTAGE
 Construction material wastages
can be defined as the difference
between the value of materials
delivered and accepted on site
and those properly used as
specified and accurately
measured in the work.

5. DEFINITION OF CONSTRUCTION
MATERIAL WASTAGE
 Construction material wastages can be
defined as the difference between the
value of materials delivered and
accepted on site and those properly used
as specified and accurately measured in
the work, after deducting the cost saving
of substituted materials transferred
elsewhere in which unnecessary cost and
time may be incurred by materials
wastage.

6. WHAT IS WASTE & WASTAGE
 The term ‘wastage’ should be
distinguished from the term ‘ waste’. The
former is a technical term used to bring
out the negative variance, if any,
between the intended and actual
consumption of an individual item or
total-factor consumption of all inputs.
The latter, in common parlance, refers to
unplanned waste or useless remains of
any input that occur at construction
sites.

7. WASTAGE AT CONSTRUCTION
SITE
ABOUT 5 – 10 PERCENT OF
BUILDING MATERIALS END UP AS
WASTE ON BUILDING SITES.
KNOWLEDGE CHECK – WHICH IS THE
ELEMENT USED AND WASTED THE
MOST IN A PROJECT BUT NOT
TREATED AS A MATERIAL………..

8. COST OF WASTAGE
 IF COST OF CONSTRUCTION IS
RS 550 PER SFT AT AVERAGE 10
PERCENT WASTAGE LIMIT AS
AGAINST THE STANDARD 3.5
PERCENT, THEN WE HAVE A
SCOPE TO SAVE ATLEAST RS 35
– 40 PER SFT.

9. WHY WASTE CONTROL
 IN A PROJECT OF 10 LAKH SFT
WE CAN SAVE UPTO Rs 3------
LAKHS JUST ON WASTAGE, IT
MAY BE EQUIVALENT TO COST
OF MANY APARTMENTS, DOES
THAT JUSTIFY THE EFFORT TO
CONTROL WASTE…. YOU
DECIDE!

10. WASTAGE BENCHMARKS

11. Construction Materials Wastage Benchmarks
SI No. Type of Materials Normal Wastage
1 Cement 2%
2 Sand 10%
3 Aggregate 5%
4 Concrete structural 2%
5 Concrete blinding (lean) 10%
6 Reinforcement steel bars 3%
7 Reinforcement steel mesh 10%
8 PVC sheeting 15%
9 Steel for windows 7%
10 Timbering in trenches 5%

12. 11 Stone masonry 5%
12 Marble lining 20%
13 Wood for door frames 5 to 7.5%
14 Wood for shutters 10%
15 Sheet roofing 2.5%
16 Tile roofing 5%
17 Floor tiling 2 to 5%
18 Wall tiling 3%
19
Pigments (for colours
other than natural grey)
5%
20 Paints 5%

13. RESOURCES AND WASTE
 A PROJECT NORMALLY USES THE
FOLLOWING MAIN RESOURCES ;
 MATERIALS
 MANPOWER
 MACHINES
WASTE CONTROL CAN BE DONE TO CONTROL
ALL OR ANY OF THE ABOVE RESOURCES.
THE SCOPE OF THIS PRESENTATION IS
LIMITED TO WASTE CONTROL OF
MATERIALS.

14. CAUSES OF MATERIAL WASTE AT
SITES
 A. General
 Lack of materials management system
 Poor house keeping
 Poor storage conditions
 Poor quality control
 Adhoc procurement
 Contractors negligence
 Unconcerned supervisory staff
 Untrained labour
 Non-use of left over materials

15.  Non adherence to standards
 Short supply
 Thefts and pilferage
 Changes in designs and
specifications
 Improper handling
 Loss during transport and
application

16.  B. Specific
 Excess mortar/concrete preparation
 Misuse of various grades of
materials
 Silt content in sand
 Improper cutting of steel and non-
utilisation of cut pieces of steel
 Use of dry cement and Mishandling
of cement

17.  C. Project delays
 Delays in the preparation and receipt
of drawings from consultants
 Delays in approval of designs and
specifications
 Changes in designs, specifications and
materials
 Errors in project planning
 Unrealistic labour planning
 Wrong prediction of completion dates
of activities
 Delays in approval from government
authorities

18.  Problems in contract
administration
 Poor coordination of activities
of contractors and consultants
 Delays in procuring technical
expertise
 Non-availability of water,
power & other infrastructure
facilities
 Adverse climatic conditions
 Law and order problems

19.  Contractors problems
 Labour problems
 Breakdown in construction
equipment
 Lack of finances
 Delay in material selection and
approval
 Delayed procurement of materials
 Delay in getting advances and
settlement of bills

20. CASE STUDY
 A field study was conducted on
the following sites to study
wastage, the sites were
(bangalore):
 20 MLD STP – SPCL
 70 MLD STP – L&t
 ADONIS (COMMERCIAL BUILDING) -
JMC

21. RESULTS
 GENERAL MATERIAL WASTAGE
 Figures in percent
Material SPCL L&T JMC
Cement 3.65 2.2 2.5
Steel 3.165 3.42 2.02
Aggregate 3.45 2.62 1.2
Sand 2.5 2.15 3.8

22. GENERAL OBSERVATIONS
 L&T was using a batching plant, with
transit mixers and concrete pump.
 JMC used RMC from a nearby birla
plant.
 SPCL were using mixers for concrete
preparation.
 JMC barbending was done at their
central yard as per barbending
schedule.

23. Other survey results
Design Attributes Points
Design changes while
construction
5
Inexperience of
methods/sequence
4
Lack of attention to dimension 4
Lack of knowledge about std
sizes
4
Lack of information in drawings 3
Complexity of detailing 4
Errors in contract documents 1
Incomplete contract document 2
Selection of low quality products 3

24. Operational Attributes Points
Damages to work done due to
subsequent trades
5
Errors by tradesmen / labourers 4
Required qty. unclear due to
improper planning
4
Delay in passing information to
the contractor
3
Use of incorrect material thus
requiring replacement
4
Accidents due to negligence 3
Malfunctioning of equipment 2
Inclement weather 3

25. Material Handling Attributes Points
Inappropriate storage 4
Material supplied loose 5
Damages while transporting 4
Unfriendly attitudes of project
team and labourers
3
Use of materials close to
workplace
2
Theft 3

26. Procurement Attributes Points
Lack of possibility to order small
quantity
4
Ordering errors (too much or too
little)
3
Purchase not comply with
specifications
3

27. Waste Preventing Attributes Points
Proper storage facility 5
Accountability system for sub
contractors for extraordinary
waste
4
Effective wastage accounting
system
4
Selecting proper equipment and
qualified operators
5
Having updated plans /
schedules
3
Employ material controller 3
Improve site security
requirement
3

28. Material wastes – causes and
solutions for savings
 Lack of quality management system
aimed at waste minimisation e.g. lack of
waste management plan.
 Untidy construction sites e.g. waste
materials are not segregated from useful
materials.
 Poor handling e.g. breakage, damage,
losses.
 Over-sized foundations and other
elements e.g.over design leads to excess
excavation and cut-offs

29.  Inadequate protection to
finished work e.g. finished
concrete staircases are not
protected by boarding.
 Limited visibility on site
resulting in damage e.g.
inadequate lighting in
covered storage area

30.  Over ordering e.g. over ordering of
concrete becomes waste.
 Method of transport e.g. materials
drop from forklift
 Inadequate data regarding time and
method of delivery e.g. lack of
records concerning materials
delivery

31.  Poor storage e.g. pallet is not used
to protect cement bags from
contamination by ground water.
 Poor workmanship e.g. poor
workmanship of formwork.
 Waste generation inherited with
traditional construction method e.g.
timber formwork, wet trade

32. HOW TO SAVE WASTAGE - GENERAL
The following factors are most critical to
the control of wastage of materials in
construction sites.
 Functional and cost efficient designs,
which leave out all cosmetics to be
done by occupiers later on.
 No change in designs and technical
specification after approval.
 Industrialization of construction and
mechanized construction.

33.  Employment of skill certified
workmen.
 Experienced project manager
 Award of work on turnkey lump sum
contracts
 Monthly re-conciliation of materials
and labour records.

34.  Materials re-conciliation:
 It should be done on monthly basis
 Preparing monthly materials re-
conciliation statements should be
made mandatory to all projects.
 Engineer-in-charge should be held
responsible and accountable for
preparation and submission of
monthly re-conciliation statements.

35.  The statement should be made
unit-wise or structure-wise.
 Material re-conciliation
statements should accompany
monthly bills for payment of
contractors.
 Manipulation of consumption
should be viewed seriously.

36.  Recommendations in Design
 Existing landscaping and contours
should be used to avoid over
excavation.
 Minimize waste by designing
standard ceiling heights and building
dimensions. Simplify building
geometry.
 Avoid waste from structural over-
design (Use optimum-value
engineering/advance framing)

37.  Durable materials should be
specified for the construction
and finishes
 Use salvaged building materials
when possible
 Specify reusable or recyclable
materials for hoarding,
scaffolding and formwork.

38.  Adopt innovative technology like
prefabrication and precast units
when possible. It is the key to
minimize waste from wet trade.
 Communications between the
designer and contractor is
important so that each realizes
how the design decisions will
affect on site operations and
waste generation.

39.  Mechanization
 With Proper selection and proper
planning of equipment, the wastage
could really be brought down to
negligible levels. In order to
promote mechanization in the
building industry, the following
recommendations are made:
 The use of modern plant and
construction methods should be
incorporated as an important clause
in contract documents.

40.  Ownership of or access to plant
and machinery should be given
more weightage in pre-
qualification of contractors.
 The formation of equipment
leasing and hiring companies
should be encouraged through
liberal financial and fiscal support.

41. WASTAGE CONTROL- ACTIVITY
WISE
 THE BEST WAY TO SAVE
WASTE OF MATERIAL
‘ACTIVITY WISE’ IS TO
CREATE ACTIVITY BASED
CHECKLISTS AND WORK
WITH THEM

42.  Construction Process Wastage
Checklist for waste control
 EXCAVATION AND FOUNDATION
 1 Identify the type of soil to be
excavated and select the type of
equipment accordingly. Do not select a
heavy equipment for soft soil and vice
versa

43.  2 Choose the capacity of
excavation equipment so
that its full capacity is
used, also the other
equipment required for
transportation should
have equivalent or more
capacity to avoid waste of
time in transportation and
refill.

44.  3Foundation trenches should be
dug out to the exact width of
the foundation concrete and the
sides should be vertical or
sloped to angle of repose as per
the soil conditions
 4Do not excavate more than
required, it will waste time and
more under-burden will have to
be handled unnecessarily.

45.  5Excavated earth should be taken out
and kept minimum 2m away from the
edge of pit, this should be done in a
single operation to avoid double handling
 6The bottom of foundation trenches shall
be perfectly levelled both longitudinally
and transversely and the sides of the
trench shall be dressed perfectly vertical
from bottom upto the least thickness of
loose concrete so that the concrete may
be laid to exact width as per design.

46.  BRICK LAYING
 1Avoid over-ordering of bricks
 2Avoid multiple handling
 3Avoid edge breaking of bricks
 4Brick packaging may create a lot of
waste, dispose it separately
 5Segregate broken bricks and brick-
bats from debris and use them for
either waterproofing / landscaping
or backfilling / bedding

47.  6Collect all brick pieces from the site, segregate
size-wise and reuse
 7Do not use new bricks to adjust wall sizes,
collect and use half bricks broken due to handling
 8Do not stack bricks more than a height of 1.2 m
to avoid the crushing of bricks in the lower
layers.
 9Check and avoid wastage of water for curing /
wetting bricks, use spray watering instead of free
flow
 10Wall lengths, pillars and columns not
corresponding to a brick length cause waste. At
the design stage some thought on this parameter
will avoid wastage of bricks

48.  MORTAR AND PLASTER
 1Pre wetting on brick should be done
before laying or plastering
 2Plumbs should be marked and maintained
 3Mortar should be of uniform thickness for
all layers
 4Adding a plasticiser in mortar and plaster
will increase waterproofing capacity and
reduce shrinkage cracks
 5All plastering should be added with a
polymeric admixture to reduce rebound and
shrinkage cracks, use of chicken mesh can
also be done to reduce shrinkage cracks

49.  6All redound plaster should be collected and
reused, if dry should be crushed and used
instead of sand in making fresh concrete or
mortar
 7Plaster thickness should be uniform, excess
use of plaster to retrofit badly constructed
walls will incur huge wastage of mortar
 8Cure freshly laid brick wall and plaster to
avoid cracks and avoid rework
 9Mechanise plastering to gain speed and
increase quality
 10Use single bag mixers (mechanical /
electrical) near application areas to avoid
transportation / spillage of mortar. This also
saves a lot of time.

50.  REINFORCE-MENT
 1Design of reinforcement should as far as
possible match the fractions of standard
length available.
 2Cut lengths should be collected from site
and segregated size-wise.
 3 Cut lengths should be Mechanically lap
spliced (if allowed) and reused
 4Small lengths of reinforcement should be
used in small members like fins, weather
shades, projections etc.
 5Pre-cast RCC chairs should be used to hold
the bent up steel in place and avoid rework

51.  6Use partially of fully automated bending
machine to reduce steel wastage
 7Use prefabricated reinforcement systems
 8Welding steel and reusing it will also
save wastage of steel provided it is
allowed by the local authority
 9Avoid steel corrosion and rusting
 10All scrap steel should be collected by
site in separate bins and recycled

52. THANK
YOU