All you need to know about Construction Formwork

1. Formwork
4th Credit Research - Construction
Means and Methods
Ankit Singhai
singhai2@Illinois.edu
CEE420 – Construction Productivity
Prof. Liang Y Liu

2. Formwork and Formwork System
• Formwork is defined as a temporary structure whose purpose is to provide support and
containment for fresh concrete until it can support itself
• Molds the concrete to the desired shape and size, and controls its position and alignment
• Also called shuttering, concrete formwork, concrete form
• Formwork has been in use since the beginning of concrete construction
• Formwork System: The total system of support for freshly placed concrete
• Including the mold or sheathing which are in contact with the concrete
• Also includes supporting members, hardware, and necessary bracing
• Engineered structures - required to support loads such as fresh concrete, construction
materials, equipment, workers, impacts etc.
• Should be able to withstand all these loads without collapse or excessive deflection

3. Economy of Formwork
• Largest cost component of a concrete structural frame
• Cost of formwork exceeds the cost of the concrete and/or steel
• Design of formwork - proper design considerations lead to a significant cost
saving
• Saving includes both direct and indirect costs
• Formwork efficiencies accelerate the construction schedule
• Increased jobsite productivity, improved safety, better quality and reduced
potential for errors
• Formwork cost accounts for 40 to 60 percent of the cost of the concrete
frame and for approximately 10 percent of the total building cost

4. Design of Formwork
• Economy in formwork begins with the design of a structure
• And continues through the selection of form materials, erection, stripping,
care of forms between reuses, and reuse of forms
• It is possible to modify the design slightly to achieve economy without
impairing the usability of the structure
• The designer can integrate constructability into the project by allowing
three basic concepts:
• Design repetition
• Dimensional standards
• Dimensional consistency

5. Design Considerations
• Preparing structural and architectural designs simultaneously – improved
constructability
• Choosing materials and methods that will be required to make, erect, and
remove the forms
• Design the structural members to comply with the standard dimensions of the
forms
• Design for reuse
• Same size of columns, beams, slabs etc.
• Equal spacing or similar placement as much as possible or practicable
• Specify the same widths for columns and column-supported girders to reduce
or eliminate the cutting and fitting of girder forms into column forms
• Specify beams of the same depth and spacing on each floor by choosing a
depth that will permit the use of standard sizes of lumber, without ripping, for
beam sides and bottoms, and for other structural members.

6. Integrated Concrete Formwork Life Cycle

7. Formwork Material
• Materials used for forms for
concrete structures include
• Lumber, plywood, hardboard,
fiberglass, plastics, fiber forms,
corrugated boxes, steel, aluminum,
magnesium, and plaster of paris
• Additional materials include nails,
bolts, screws, form ties, anchors,
and other accessories
• Forms frequently involve the use of
two or more materials

8. Properties of Formwork Material
• Material should be cheap and re usable,
• It should be practically water proof, so that
it should not absorb water from concrete,
• Swelling and shrinkage should be minimum,
• Strong enough to with stand all external
loads,
• Deflection should be minimum,
• Surface should be smooth, and afford easy
striping,
• Light in weight, so that easy to transfer,
• Joints should be stiff, so that lateral
deformation and leak is minimum

9. Lumber
• Lumber used for formwork
that is finished on all sides
is considered as Surfaced-
4-Sides (S4S) lumber
• Cross-sectional dimensions
of lumber are designated by
nominal sizes
• Actual dimensions are less
than the nominal
dimensions
• It is surfaced on all sides
and edges
• Available in lengths that are
multiples of 2ft (18ft max)
Nominal&dressed
sizesofS4SDryLumber

10. Plywood
• Plywood is used extensively for formwork for
concrete
• Used for sheathing, decking, and form linings
• Gives smooth surface finish to the concrete
• Easy handling during construction
• Most common material used for formwork
• Available in varied thickness and lengths
• Plywood may be manufactured with interior glue
or exterior glue
• exterior-glue plywood used for formwork

11. • Lengths from 4-ft widths and 8-ft
• Thicknesses from ¼ in. through 1¹⁄8 in.
• Larger sizes also available, such as 5ft wide and 12ft long
• Manufactured to precise tolerances
• Tolerance within 1/16 in. – both width, length and thickness
• Plywood is made in panels consisting of odd numbers of plies
• Each placed at right angles to the adjacent ply
• Waterproof glue used to join them together and edges sealed against moisture
• Plywood grades (graded by the veneers of the plies) –
• Veneer Grade N or A - highest grade level; Grade N is intended for natural finish;
Grade A is intended for a plane-table surface; has no knots or restricted patches
• Veneer Grade B has a solid surface but may have small round knots, patches,
and round plugs - commonly used for formwork
• Veneer Grade C – lowest grade of exterior-glue plywood

12. Plyform
• Special product produced by plywood industry for use in forming
concrete
• It is exterior-type plywood limited to certain species of wood and grades
of veneer
• Ensures high performance as a form material
• Proprietary term - applied only to specific products that bear the trademark of
APA—The Engineered Wood Association
• Available in two classes
• Plyform Class I and Plyform Class II
• Class I is stronger and stiffer than Class II
• Recommended where formwork is subjected to very high pressures during
concreting, or where conditions like marine environment exists
• Coated with High-Density Overlay (HDO) - surface treatment of hard, smooth,
semi-opaque, thermosetting resin-impregnated materials

13. Tempered Hardboard
• Sometimes used to line the inside surfaces of forms
• Manufactured from wood particles
• Impregnated with a special tempering liquid and then
polymerized by baking
• Produces concrete surface free of blemishes and joint
marks
• Can be bent – advantageous for casting curved members
• Standard sheets - 4ft wide by 6, 8, 12, and 16ft long

14. Fiber Form Tubes
• Fabricated as round fiber-tube forms
• Available in lengths up to 50ft with inside diameters ranging from
12in. to 48in. - increments of 6 in.
• Waterproof coatings for Fiber Form Tubes:-
• Plasticized treatment – used where the forms are to be removed and a
clean finish is required
• wax treatment - used where the forms will not be removed or where the
condition of the exposed surface of the concrete is not important
• Fiber form tubes can be used only once
• Manufactured by wrapping successive layers of fiber sheets spirally
and gluing them together to produce the desired wall thickness
• Spiral effect on the surface of the concrete
• Seamless also available but more expensive

15. Steel Forms
• Steel forms are stronger, durable and have longer life than
timber formwork and their reuses are more in number
• Steel forms can be installed and dismantled with greater
ease and speed.
• The quality of exposed concrete surface by using steel
forms is good and such surfaces need no further
treatment.
• Steel formwork does not absorb moisture from concrete.
• Steel formwork does not shrink or warp
• Two broad types
• prefabricated into standard panel sizes and shapes
• fabricated for special uses

16. Aluminum Forms
• Forms made from aluminum are in many respects similar to
those made of steel
• Aluminum forms are lighter than steel forms
• Primary advantage when compared with steel
• Wet concrete can chemically attack aluminum
• Desirable to use aluminum alloys in resisting corrosion from the
concrete
• Aluminum alloy truss used in flying forms
• Cast aluminum alloy molds are used to form ornamental
concrete products
• Also used to produce textures on the surfaces of concrete walls

17. Plastic Forms
• Fiberglass plastic forms used for
unique shapes and patterns in
concrete
• forms are lightweight,
• easy to handle and strip, and
• they eliminate rust and corrosion
problems
• Can be manufactured in factory
setting only – requires careful
temperature and humidity controls

18. CONSTRUCTION OF FORMWORK
• Propping and centering: The props used for
centering may be of steel, timber post.
• Shuttering: Shuttering can be made up of timber
planks or it may be in the form of panel unit made
either by fixing ply wood to timber frames or by
welding steel plates to angle framing.
• Provision of camber: Certain amount of deflection
in structure is unavoidable. It is therefore desirable
to give an upward camber in the horizontal
member of concrete structure to counteract the
effect of deflection.
• Surface treatment: Before laying concrete the
formwork should be cleaned of all rubbish
particularly the sawdust savings & chippings etc.
Before laying concrete the face of formwork in
contact with concrete shall be cleaned & treated
with release agent like raw linseed oil or soft soap
solution as to prevent the conc. getting struck to
the formwork

19. Forms for Footings
• Concrete footings and foundations are defined as those components of
structures, relatively low in height, whose primary functions are to support
structures and equipment
• Wall footings and low foundation walls
• Column footings
• Footings for bridge piers
• Foundations for equipment
• Footings are usually constructed in excavated ground trenches
• Materials used for forms include lumber, plywood, hardboard, steel, and
fiber tubes

20. Formwork for Foundation Walls & Grade Beams
Concrete footing and foundation wall
All-wood form panels for concrete footings
• Foundation walls are constructed on and along wall footings
• Height - usually varying from 2ft to 6ft, so the pressure on the forms will be less than that on
forms for major walls
• Panels 2ft wide, in lengths that are multiples of 2ft, up to 8ft, will permit the use of 4x8ft sheets
without waste
• Forms for Grade beams are similar to foundation walls; height being comparatively smaller

21. Erection of Formwork for Footings

22. Formwork for Concrete Footing
• The selection of forms for
concrete footings will depend
on the size and shape of the
footings and the number of
times the forms can be reused
without modification
• Rectangular footings with
constant cross sections are
easily formed; stepped footings
are more complicated
• Formwork for footing can be
erected and stripped rapidly and
reused many times if other
footings have the same
dimensions
• many types of forms that can be
used for concrete footings,
depending on the footing shape
Formwork for footing

23. Formwork for large footing
Formwork for stepped footing
Formwork for circular footing

24. Formwork for Walls
• Forms for walls may be divided into one of three categories:
• Those that are built in place, using plywood for sheathing and lumber for studs and wales
• Prefabricated, job-built panels, using plywood sheathing, attached semi-permanently to forms
made from lumber, such as 2 × 4 or 2 × 6 S4S lumber
• Patented form panels, using plywood facings attached to, and backed up by, steel or wood, or a
combination of steel and wood forms 1⁄16
• For a single use, built-in-place forms are usually the most economical
• For multiple uses, where standard-size panels can be reused without modification
• it may be desirable to use either job-built or patented-type panels
• if there are enough reuses, patented panels may be cheaper than job-built panels because of the
longer life and possible lower labor costs for erecting and dismantling them
• The common thicknesses of 4-ft-wide by 8-ft-long sheets of plywood used for wall forms
are 3/4, 7⁄8, and 1 in
• Smaller thicknesses may be used as form liners.
• Thicknesses of 1 in. and 11⁄8 in. are available for heavy formwork

25. Terms related to Job-Built formwork for wall
• Sheathing is the plywood on each side of the
wall against which the fresh concrete is placed.
The sheathing provides resistance to the
pressure of the freshly placed concrete.
• Studs are the members to which the sheathing
is attached. Studs provide support for the
sheathing.
• Wales, are usually double 2 × 4, 2 × 6, or larger
lumber with separators, are installed on
opposite sides of wall forms, perpendicular to
the studs, to hold the studs in position, to
ensure good alignment for the forms, and to
receive the form ties. Other names by which
this member is called are walers or waling. The
wales provide support for the studs.
• Strongbacks sometimes are installed
perpendicular to wales to provide additional
strength and rigidity to high forms.

26. Terms related to Job-Built formwork for wall
• Top plates are installed and fastened to the tops of
studs as parts of the panel frames.
• Bottom plates are installed and fastened to the
bottoms of studs as parts of the panel frames.
• Sole plates are placed and fastened along each side
of wall footings to provide initial alignment and
support for wall forms. Also, the use of sole plates
permits easy use of form ties near the bottom of wall
forms.
• Braces, fastened to one side of the forms and to
stakes set in the ground about 8 to 10 ft apart,
prevent the forms from shifting when the concrete is
placed. If the sole plates are not securely fastened to
the footing, braces should also be attached to the
bottoms of the forms on one side of the wall.
• Form ties, with a clamping device on each end, are
installed through the forms to resist the bursting
pressure exerted by the concrete. Form ties provide
support for the wales

27. Span length and spacing of
components of wall form
Forms for walls with batters
Forms for walls with offsets

28. Forms for walls with offsets
Details of wall form with pilaster/ wall corner

29. Forms for wall with counterforts

30. Forms for wall of circular tank,
less than 30 ft in diameter
Forms for wall of circular tank,
30 ft or more in diameter

31. Gang Forms
• Prefabricated form panels connected together
to produce large reusable units.
• Large sections, or complete details of modular
panels, are assembled first and then moved
into position for pouring the concrete.
• Gang forms are usually lifted by crane or
rolled to the next location
• Advantages:-
• Safe construction - With the installation of
cages, safety boards, handrail and working
board, Gang- form will prevent any job accidents
• Improved concrete quality - Excellent concrete
finish on buildings of 30 floors even or more.
• Reduced Cost - Produced at the factory, jobsite
workers only need to assemble and install the
Gang-form, thus, it allows a reduction of labor
time and cost.
• Parallel concrete finishing - Workers can finish
the concrete and form setting on 4th and 5th
level of working boards at the same time, which
reduce duration of work.

32. Jump Form System
• Jump form systems (taken to include systems often described as ‘climbing form’) comprise the
formwork and working platforms for cleaning and fixing the formwork, steel fixing and concreting.
• The formwork supports itself on the concrete cast earlier so does not rely on support or access
from other parts of the building.
• Jump form systems are suitable for construction of vertical concrete elements in high-rise
structures, such as core walls, lift shafts, stair shafts and bridge piers.
• Systems are normally modular and can be joined to form long lengths to suit varying construction
geometries.
• Three types of jump form are in general use:
• Normal jump or climbing form units are individually lifted off the structure and relocated at the next
construction level using a crane.
• Guided-climbing jump form units also use a crane but often provide greater safety and control during
lifting as the units remain anchored to or are guided by the structure.
• Self-climbing jump form systems do not require a crane as they climb up rails on the building by means
of hydraulic jacks, or by jacking the platforms off recesses in the structure. It is possible to lift multiple
units in a single operation.
• Working platforms, guard rails and ladders are generally built into the completed formwork
systems, along with complete wind-shield protection when necessary.

33. Jump Form System

34. Formwork for Columns
• Conventional formwork for columns is made of
sheathings nailed together to form rigid sides. Typically,
formwork for concrete columns has four sides.
• Column form sides are held together by yokes or clamps.
Another function of these yokes is to prevent the
buckling of sheathing resulting from the horizontal
lateral pressure when the fresh concrete is placed
• Concrete columns are usually one of five shapes: square,
rectangular, L-shaped, octagonal, or round
• Forms for the first four shapes are generally made of
Plyform/plywood sheathing backed with either 2 × 4 or 2 ×
6 vertical wood battens.
• Column clamps surround the column forms to resist the
concrete pressure acting on the sheathing.
• Forms for round columns are usually patented forms
fabricated of fiber tubes, plastic, or steel.
• However, all shapes of columns can be made of fiberglass
forms
Forms for square column

35. Column form with steel clamps and steel wedges
Forms with rotating locking device

36. Modular Column Forms
All-Metal Forms for Rectangular Forms

37. Spring-Open Round Fiberglass FormsRound Column Forms – Plastic/Steel

38. Formwork for Floor Slabs
• Floor Slabs: - There are many types of concrete floor slabs, including, but not limited
to, the following:
• Concrete slabs supported by concrete beams
• Concrete slabs of uniform thickness with no beams, designated as flat slabs
• Fiberglass dome forms for two-way concrete joist systems
• Metal-pan and concrete-joist-type slabs
• Cellular-steel floor systems
• Corrugated-steel forms and reinforcement floor systems
• Concrete slabs on steel floor lath
• Forms for concrete beams and slabs should provide sufficient strength and rigidity at
the lowest practical cost, considering materials, labor, and any construction
equipment used in making, erecting, and removing them.
• Consideration must be given to both the static dead load and any impact loads that
may be applied to the forming system

39. Related Terms
• Decking is the solid plywood panels that form the floor of the formwork against which the
fresh concrete is placed. It provides resistance to the vertical pressure of the freshly placed
concrete.
• Joists are the members under the decking that provide support for the floor decking
• Stringers are members under the joists that provide support for the joists
• Shores are members that support the joists and stringers and beam bottoms for beam-slab
forming systems
Forms for concrete beams and slab with intermediate stringers

40. Forms for a flat-slab concrete floor
Form panels for flat-slab concrete floor

42. Formwork for Beams
• A beam is a structural element that is capable of
withstanding load primarily by resisting against bending.
• The bending force induced into the material of the beam as a result of the external loads,
own weight, span and external reactions to these loads is called a bending moment.
• Beams are characterized by their profile (shape of cross-section), their length, and their
material.
• Most beams in reinforced concrete buildings have rectangular cross sections, but a more
efficient cross section for a beam is an I or H section which is typically seen in steel
construction
• A thin walled beam is a very useful type of beam (structure). The cross section of thin
walled beams is made up from thin panels connected among themselves to create closed
or open cross sections of a beam (structure). Typical closed sections include round, square,
and rectangular tubes

43. Forms for a concrete beam and slab
Forms for a spandrel beam

44. Form Details for Beams Framing into Girders
• If Plan A is used, the opening through the side
of a girder form is made equal to the
dimensions of the beam. The beam sides and
the soffit are cut to a length that will permit
them to fit against the girder side, with the
insides of the beam sides and the top of the
beam soffit flush with the opening through the
girder side. The beam soffit rests on, and the
beam sides bear against, cleats attached to the
girder sides. This method is used where the
forms for the beam are to be stripped before
the forms for the girder are stripped
• Using Plan B, the opening through the girder
sides is made large enough to permit the ends
of the forms for the beam to extend into the
forms for the girder flush with the face of the
concrete girder. This plan is used where the
forms are to be stripped from the girder before
the forms are stripped from the beam. The
same methods may be used in framing forms
for the beams and girders into forms for
columns.

45. Forms for Architectural Concrete
• Forms for Architectural versus Structural Concrete
• When concrete is used for structural purposes only and the appearance of the surface is not of
primary importance, the essential requirements of the forms are strength, rigidity, and
economy. This permits greater freedom in the choice of materials for forms, and the demands
of quality of workmanship in fabricating and erecting forms are not as great as for forms used
to produce architectural concrete.
• Architectural concrete differs from structural concrete in that the appearance or color of the
exposed surfaces of the forms may be more important than the strength of the members. The
properties of fresh concrete are such that it may be cast or molded to produce any shape that
forms can be made. A variety of colors may also be obtained by adding a color admixture to
the concrete mix or by adding a surface coating after the concrete has hardened
• Quality of the finished concrete is limited by the quality of the forms, it is necessary to
exercise care in selecting the materials for the forms
• high-quality craftsmanship is required in building and stripping the forms of architectural
concrete if the desired effects are to be achieved with a satisfactory degree of perfection
• It may be desirable to provide 2- by 2-ft samples to the worker before starting construction to
define the quality of workmanship that is required of the final product

46. Form Liners
• Special surface finishes can be achieved by attaching form
liners to the inside faces of forms
• Used for providing surface finish in architectural concrete
• form liners can be used to achieve an extremely smooth surface, or
• to achieve a particular textured finish on the concrete surface
• Different types of materials ca be used as form liners,
depending on the desired finish
• plywood, hardboard, coatings, and plastics
• attached to the sides of forms with screws, staples, or nails
• releasing agent should be applied to the form liner to ensure
uniformity of the concrete surface and to protect the form liner
for possible reuse

47. Patterns of Form liners

48. Wood Molds for Architectural Concrete
• Wood molds are used as formwork to cast ornamental
designs for cornices, pilasters, belt courses, water
tables, and other members for architectural concrete.
• These molds are best adapted to ornaments requiring
the use of standard moldings or moldings that can be
made in a mill.
• A form unit consists of an assembly of several parts and
pieces to produce the specified profile or design for the
concrete
• Even when wood is carefully oiled prior to its use with
formwork, there is a tendency for it to swell when it is
wet.
• For this reason, consideration should be given to the
selection of the types, sizes, and arrangements of the
component parts when detailing wood molds.
• Because wide and thick molds will swell more than narrow
and thin molds, the former are more likely to bind and
damage the ornaments in the concrete.
• Thus, it is desirable to use the narrowest and thinnest
pieces from which the mold can be made with adequate
strength

49. Plaster Waste Molds for Architectural Concrete
• Where the ornamental details for
architectural concrete are so intricate and
complicated that it is impossible to use
wood molds, plaster molds are used.
• Because these molds are destroyed in
stripping, they are called waste molds.
Plaster waste molds are not as common
today as they have been in the past.
• Casting resins, plastics, and synthetic rubber
have replaced much of the architectural
concrete work that has been done in the
past by plaster waste molds.
• Waste molds are made of casting plaster
containing jute fiber, and they are reinforced
to prevent breakage during handling and
erection.

50. Metal Molds for Architectural Concrete
• Metal forms and molds are sometimes used for architectural
concrete.
• Because concrete tends to adhere to galvanized steel, black iron
should be used for formwork. The surface in contact with the
concrete should be oiled with a bond breaker.
• Corrugated metal sheets can be used to form fluting on pilasters,
piers, and spandrel beams

51. Slipforms
• Slipform means a continuously moving form, moving
with such a speed that concrete when exposed has
already achieved enough strength to support the
vertical pressure from concrete still in the form as well
as to withstand lateral pressure caused by wind etc.
• The slipform method of concrete construction is used
for forming both horizontal and vertical concrete
structures. It is often used for forming highway
pavements as a continuous operation
• Following are typical types of concrete structures that
have been constructed with the slipform method:
• Single-cell silos
• Multi-cell silos
• Buildings
• Piers
• Towers
• Water reservoirs
• Vertical shafts for tunnels and mines
• Vertical shafts for missile launching bases
• Chimneys

52. Slipforms
• The forms for the slipform method of construction
consist of the following basic parts:
• Sheathing - For structures that include walls with inner and
outer surfaces, two sets of sheathing are required
• Wales or ribs - They support and hold the sheathing in
position; support the working platform; support the
suspended scaffolding; transmit the lifting forces from the
yokes to the form system; act as horizontal beams
between the yokes to resist the lateral pressures of the
concrete
• Yokes - They transmit the lifting forces from the jacks to
the wales; also hold the sheathing in the required positions
and resist the lateral pressures of the concrete
• Working platform or deck (one or more)
• Suspended scaffolding - The scaffolding suspended under
the forms allows finishers to have access to the concrete
surfaces, which usually require some finishing
• Lifting jacks - Jacks used to lift the forms are of three
types: electric, hydraulic, and pneumatic. The jacks provide
the forces required to pull the forms upward as the
concrete is placed

53. Details of a hydraulic jack
for lifting slipforms
Details of working floor and
scaffold assembly for slipforms

54. Order and Method of Removing
Formwork
• General rule of thumb for formwork removal:-
• Shuttering forming vertical faces of walls, beams & column sides
should be removed first.
• Shuttering forming soffit to slab should be removed next.
• Shuttering forming soffit to beams, girders or other heavily
loaded member should be removed in the end
Formwork Type Removal Time (days)
WALLS COLUMNS & VERTICAL SIDES OF BEAMS 1 to 2
SLABS 3
BEAM SOFFIT 7
REMOVAL OF PROPS TO SLABS SPANNINIG UPTO 4.5M 7
REMOVAL OF PROPS TO SLABS SPANNINIG OVER 4.5M 14
REMOVAL OF PROPS TO BEAMS AND ARCHES SPANNING UPTO 6 MTS 14
REMOVAL OF PROPS TO BEAMS AND ARCHES SPANNING OVER 6 MTS 21

55. Failure of Formwork
• A failure may result in a collapse of part or all
of the forms.
• It may result in a distortion or movement of the
forms that will require the removal and
replacement of a section of concrete.
• Repairs, such as expensive chipping and
grinding operations, may be required to bring
the section within the specified dimension
limitations.
• Failures should not and will not occur if the
formwork is constructed with adequate strength
and rigidity
• Major Causes of Failures of Formwork
• Improper or inadequate shoring
• Inadequate bracing of members
• Lack of control of rate of concrete placement

56. Failure of Formwork
• Major Causes of Failures of Formwork
• Improper vibration or consolidation of concrete
• Improper or inadequate connections
• Improper or inadequate bearing details
• Premature stripping of formwork
• Errors in placement of reshoring
• Improper, or lack of, design of formwork
• Inadequate strength of form material
• Failure to follow codes and standards
• Modifications of vendor-supplied equipment
• Negligence of workers or supervisors

57. Prevention of Formwork Failures
• The safety of workers is a concern of all parties: owners, designers, and contractors. Safety is
everyone’s responsibility, including workers in the field, supervisors, and top management.
Following is a list of rules that can be used to reduce the potential of formwork failures and provide
a safe working environment during formwork construction and dismantling:-
• Prepare a formwork plan that includes detailed drawings and written specifications for fabricating, erecting,
and dismantling of the formwork. The plan should be prepared by a person who is competent in the design
of formwork
• Follow all state, local, and federal codes, ordinances, and regulations pertaining to formwork, shoring, and
scaffolding
• Ensure compliance of all OSHA rules and regulations
• Follow all instructions, procedures, and recommendations from manufacturers of formwork components
used in the formwork
• Survey the jobsite for hazards, such as loose earth fills, ditches, debris, overhead wires, and unguarded
openings
• Ensure adequate fall protection for workers during erection of formwork, pouring of concrete, and
dismantling of formwork
• Inspect all shoring and scaffolding before using it. Make a thorough check of the formwork system after it is
erected and immediately before a pour
• Post guidelines for shoring and scaffolding in a conspicuous place and ensure that all persons who erect,
dismantle, or use shoring are aware of them

58. Rough Cost Estimation for Formwork
• The total cost of concrete structures includes the cost of material, labor, and equipment
• Formwork - [area of contact – surface area that concrete will be in contact with the forms;
e.g., Square Foot of Contact Area (SFCA)]
• Methods of Rough Cost Estimation: -
• Unit Cost per Function Estimate
• Unit Area Cost Estimate
• Unit Volume Cost Estimate
• Partial Takeoff Estimate
• Rough estimation, cost for formwork is usually calculated as percentage of total concrete
work cost.
• For common nature work, cost is: 30- 40% of the total cost for concrete work.
• For specialty work, cost is: 50- 60% of the total cost for concrete work.

59. Detailed Cost Estimation for Formwork
Costs considered while estimating
the total cost of formwork
• Material Cost
• Plywood Lumber
• Form ties
• Nails
• Clamps (for column forms)
• Oil – for treatment of forms prior to each use
• Form liners (if applicable) – for
textured/architectural finishing
• Labor Cost
• Making, erecting, removing, and cleaning the
forms
• Equipment Cost (possibly)
• Lifting crane for handling material (if
applicable)
• Transportation, Operation and maintenance
Steps involved in Detailed Cost
Estimation
• Determine Material Cost
• Determine Fabrication Cost
• Determine Cost of Erecting formwork
• Determine Cost of Stripping formwork
• Determine Cost of Shoring System, if
applicable
• Add Wastage Factor wherever
applicable
• Obtain Cost per Square-foot by dividing
Total Cost by Total Area

60. Material Cost
• Estimating books like RS Means include tables for estimating material
quantities (e.g., give minimum & maximum of plywood, lumber, form ties
quantities based on wall height)

61. Labor Cost
• Estimating books like RS Means include tables of production rates (e.g.,
give minimum & maximum number of labor-hours required to do a
specified amount of work)
Labor-hours in the table, already,
INCLUDE an adjustment for
realistic efficiency (45-50min per
hour)

62. Material & Labor for Wall Forms

63. Material and Labor Costs for Column and Beam Forms

64. Material and Labor Costs for Concrete Flat Slab Forms

65. Factors Affecting Productivity of Formwork Operation
• Repetition – increases productivity of crew involved in making formwork
• External Disruptions like severe weather, accidents, labor strike etc. decrease the productivity
of crew
• Internal Disruptions like improper sequencing, untimely material supply/delivery, poor
coordination are some of the factors that impede the productivity rates in the worst manner.
• Poor Material Handling also decreases the productivity
• Effective coordination has a beneficial effect on the productivity of crew
• Overtime – Working multiple shifts and overtime for prolonged period of time decreases the
productivity of the crew. The decrease in productivity is not significant initially, but in long run it
has considerable impact
• Rework is always detrimental to crew productivity. It not only decreases productivity, but also
increases the cost
• Formwork shape, size, height, assembly and placement method etc. also have significant
impact on productivity

66. Summary of various factors affecting Productivity
• Manpower Factors: - Lack of experience, absenteeism, misunderstanding among
labors, age, lack of competition among labors, disloyalty
• External Factors: Supervision delay, incomplete/ variations in drawings, design
changes, rework, inspection delays, payment delays, complexity of design, government
laws, level of training
• Communication Factors: change orders from owners and designers, lack of
communication between owner, contractor, subcontractor, disputes with designer and
owner
• Resource Factors: lack of required construction tools, equipment and materials, poor
lighting condition, poor site condition, material storage location, poor access within
construction site, quality of work required
• Miscellaneous Factors: shortage of water/power supply, accidents, weather condition,
working overtime, undefined project objective etc.

67. Formwork Production Rates
Task / Description Slow Ave Fast Units
Ground Beams, < 0.7m2 1.1 1.7 1.8 m2/hr
Ground Beams, 0.7-1.5m2 1.7 1.8 2.5 m2/hr
Ground Beams, 1.5-3.0m2 1.8 2.5 2.6 m2/hr
Ground Beams, 3.0-5.0m2 2.5 2.6 3.5 m2/hr
Beams, on erected falsework, width 100-
200mm
0.9 1.0 1.1 m2/hr
Beams, on erected falsework, width 200-
300mm
1.0 1.1 1.3 m2/hr
Beams, on erected falsework, width 300-
500mm
1.2 1.3 1.5 m2/hr
Walls, Fully Framed Formwork/Struts, 1.0-
2.0m2
0.9 1.8 1.9 m2/hr
Walls, Fully Framed Formwork/Struts, 2.0-
5.0m2
1.0 2.2 2.5 m2/hr
Walls, Fully Framed Formwork/Struts, over
5.0m2
1.2 2.5 2.9 m2/hr
Walls, Construct Kickers 5.3 7.1 10.0 m2/hr

68. Formwork Production Rates
Task / Description Slow Ave Fast Units
Columns, Construct Kickers, direct to slab 3.2 4.1 5.4 no/hr
Columns, Construct Kickers, suspended
from soffit slab
1.2 2.8 3.2 no/hr
Columns, Square Sides, Timber Clamp/Prop,
csa < 0.1m2
1.3 1.6 1.8 m2/hr
Columns, Square Sides, Timber Clamp/Prop,
csa 0.1-0.4m2
1.8 2.1 2.4 m2/hr
Columns, Square Sides, Timber Clamp/Prop,
csa over 0.4m2
2.0 2.3 2.5 m2/hr
Columns, Square Sides, Steel Forms, 1.5 x
1.5 x 9.0m high
7.9 9.5 10.3 m2/hr
Columns, Square Sides, Steel Forms, 2.0 x
2.0 x 9.0m high
6.9 7.5 8.3 m2/hr
Columns, Square Sides, Steel Forms, 2.0 x
4.0 x 9.0m high
8.5 10.2 12.0 m2/hr
Columns, Round Sides, Sacrificial Plastic
Mould, 3.0-4.0m dia
3.5 4.5 6.0 m2/hr
Columns, Round Sides, Steel Mould, 3.0-
4.0m dia
5.2 6.5 7.5 m2/hr
Ground Slabs 1.0 1.5 1.8 m2/hr

69. References – Research Papers and Books
• Shumway, I. V., & James, D. (1992). A comparative analysis of concrete formwork productivity
influence factors. PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF CIVIL
ENGINEERING.
• Hanna, A. S. (1999). Concrete formwork systems. CRC Press.
• Oberlender, R. L. P., & Garold, D. (2011). Formwork-for-Concrete-Structures-4th-Edition.
• Gundecha, M. (2012). Study of factors affecting labor productivity at a building construction
project in the USA: web survey (Doctoral dissertation, North Dakota State University).
• RS Means Building Construction Cost Data, 74th Annual Edition (2016)
• RS Means Building Construction Cost Data, 73rd Annual Edition (2015)
• CEE 422- Construction Cost Analysis - Lecture Notes and Slides
• CEE 498- Construction Equipment & Methods – Lecture Notes and Slides

70. References - Websites
• https://www.wikipedia.org/
• Google Images
• http://www.slideshare.net/
• Google Scholar
• http://theconstructor.org/
• YouTube.com
• http://civildigital.com/
• http://www.methvin.org/construction-production-rates/concrete-
work/formwork