METHODOLOGICAL APPROACH TO

REPAIRS

Cracks over openings, sinking and sagging balconies, repairs to decayed floors and
floor joints, example: Jack arch., madras roof terrace, foundation sinking, repairs to
walls. Propping, shoring, strutting and under pinning.
 CRACKS OVER OPEANINGS

Causes for Cracks Over Openings

➢An undersigned or over spanned lintel may sag , causing cracks above either corner of a
window or door openings
➢The cracks usually radiate up from the opening corners inward the center of the
opening

➢This is a lintel problem and does not suggest major distress in the structure
 CRACKS OVER OPEANINGS

Types of lintels
 CRACKS OVER OPEANINGS

Function of a Lintel Connstruction of a Lintel

➢Support the load of

walls above the window
and door and transfer it
to the walls below.
 CRACKS OVER OPEANINGS

Diagonal Crack Over the

window Openings radiating
from the corner of the
window to wards the center
of the window

In case lintels or not

installed at all
 CRACKS OVER OPEANINGS

Diagonal cracking at lintels

➢Diagonal stepped cracking often indicates that the lintel that supports the masonry
above the opening has failed

Diagonal Crack

Lintel

Window sill
 CRACKS OVER OPEANINGS

Diagonal cracking at lintels

➢Lintel Failure often occurs upon the removal of hardwood

windows that were originally designed to bear a substantial
load without distorting and are replaced with standard
UPVC windows which are non-load bearing allowing the
lintel to drop or bow causing sagging of the lintel which is
shown by the diagonal stepped cracking

➢Traditional methods are to remove the lintel and rebuild it, this is an
intrusive method of repair and a slow process typically taking around a
day to properly remove and replace a lintel
https://www.youtube.com/watch?v=kaODgMKF6zk
 CRACKS OVER OPEANINGS

Diagonal cracking at lintels by Twist fix helical

method

➢Lintels can now be repaired using the Twistfix

Helical System by using their Bed Joint
Reinforcement which effectively creates a new
lintel within the existing masonry by removing the
mortar within two bed joints above the lintel and
inserting helical rods encompassed in grout to
create a load bearing lintel which spreads the
structural loads across the length of the bars
preventing further sagging of the lintel

https://www.youtube.com/watch?v=bNs8pgsrvQw&list=PPSV
 CRACKS OVER OPEANINGS

Horizontal cracking at lintels

➢Cracking radiating out horizontally from the tops of door or window openings is often the result of
rusting steel lintels expanding

Horizontal Crack

Window sill
 SINKING AND SAGGING OF BALCONIES AND DECKS

➢Decks and balconies provide residents with great enjoyment and direct access to fresh air and the outdoors

➢What are balconies?

➢A balcony is also a horizontal surface exposed to the outdoors with a walking surface, however, it typically
projects from the building and it is not located over an enclosed living space below
 SINKING AND SAGGING OF BALCONIES AND DECKS

➢What are decks?

➢A deck is a horizontal surface exposed to the outdoors with a walking surface

and located over an enclosed space below, so it is also a roof
 SINKING AND SAGGING OF BALCONIES AND DECKS

➢In addition to walking surfaces such as membranes, wood decking or concrete pavers, decks and balconies
incorporate a variety of components including: guardrails, guard walls, drains, gutters, soffits and vents

Walking Surfaces

Wood decking pathways

Concrete pathways
 SINKING AND SAGGING OF BALCONIES AND DECKS

Guardrails
➢A guardrail is a safety railing or barrier located along a horizontal
surface such as a balcony, deck, or porch

Guard walls
 SINKING AND SAGGING OF BALCONIES AND DECKS

Drains for balconies

Gutters for balconies

 SINKING AND SAGGING OF BALCONIES AND DECKS

Soffits and vents for balconies

 SINKING AND SAGGING OF BALCONIES AND DECKS

➢What is a Deck or Balcony Membrane?

➢A deck or balcony membrane is a waterproof layer installed to protect the underlying structure from
water leakage

➢The membrane may be exposed, acting as the actual walking surface, or may be covered with precast
concrete pavers, wood planking or a concrete topping

➢Different membranes are used depending on the type of deck or balcony construction
 SINKING AND SAGGING OF BALCONIES AND DECKS

Deck or Balcony Membrane

1. Liquid-applied urethane
➢Installed on concrete balconies to protect the reinforcing steel within the concrete from water
penetrating at cracks and causing corrosion (rusting) of the steel, or on wood balconies to similarly protect
the wood structure below

➢Expected service life is usually ten years, however, with lower traffic and less exposure to the elements
these membranes could last longer if regularly maintained

https://www.youtube.com/watch?v=umTmrRy3-60
 SINKING AND SAGGING OF BALCONIES AND DECKS

Deck or Balcony Membrane

2. Sheet applied vinyl

➢Typically used on wood-frame balconies

➢Expected service life is usually ten to fifteen years, depending on degree of exposure to sun, wetting, and
wear and tear

https://www.youtube.com/watch?v=NwuqGsnQQVw
 SINKING AND SAGGING OF BALCONIES AND DECKS

➢Why Must Deck and Balcony Membranes be Maintained?

➢Without proper maintenance, water may get in through holes and cracks in the membrane and joints that
have separated and produce leaks to the interior, damage to the wall assembly and rotting of the deck or
balcony structure

➢Residents in newly constructed wood-frame buildings should be aware that their building may be more
susceptible to some structural movement over the first eighteen months of operation, as moisture from the
wood dries out and the wood shrinks

➢During this time, the balcony or deck membrane may move or pull away from the wall, causing seams to
fail and allowing water ingress at the edge of the membrane

➢Shrinkage of the building frame can also cause the balcony slope to change, and ponding (standing water)
at the wall to occur
 SINKING AND SAGGING OF BALCONIES AND DECKS

➢While these matters are often taken into account during the building’s design and construction, some
movement can still occur, potentially affecting the membrane

➢Balconies and decks on wood-frame buildings are sensitive to water damage

➢If the membrane or other balcony or deck component fail, water can
penetrate to the wood structure, where wood decay may occur
 SINKING AND SAGGING OF BALCONIES AND DECKS

Other Deck and Balcony Maintenance Items

Guardrails and guard walls
➢Guardrails and guard walls are important safety features designed to prevent falls from balconies and
decks
➢Guardrails can be constructed of a combination of wood, metal and glass
➢One location where guardrails require special attention is at the bottom, where the guardrail may be
fastened directly through the membrane to the horizontal surface of the balcony or deck

➢Water can leak through this vulnerable connection to the structure below. (Guardrails are best secured
to a vertical face of the parapet or edge of the balcony, deck or walkway where the connection to the wall
is not as vulnerable to water ingress.)
 SINKING AND SAGGING OF BALCONIES AND DECKS

Other Deck and Balcony Maintenance Items

Guardrails and guard walls
➢Attention also needs to be paid to
locations where the guardrail connects to
the wall

➢All guardrail connections, either through

the membrane or to the wall, should be
regularly inspected and maintained to
reduce the likelihood of water penetration
into the wall assembly or building
structure
 SINKING AND SAGGING OF BALCONIES AND DECKS

Other Deck and Balcony Maintenance Items

Guardrails and guard walls

➢Guard walls are typically half-height walls that wrap around the perimeter of the balcony or deck

➢Depending on the type of construction, guard walls are particularly susceptible to leaks at corners and
intersections with the exterior wall
 JACK ARCH ROOFING SYSTEM

➢Jack arch Roof construction can be done in brick or concrete

➢The arch of the Jack arch roof is either made of brick or of concrete

➢The arch is supported on the lower flange on rolled steel joists (RSJs)

➢The rolled steel joists are supported at their ends on the walls or on the longitudinal girders

➢They are spaced at a distance of 1m to 1.5m centre to centre

https://www.youtube.com/w
atch?v=2I_n5VoBpJc&t=114
s
JACK ARCH ROOFING SYSTEM
 JACK ARCH ROOFING SYSTEM

➢The rise of the arch is kept equal to 1/12th of the span

➢Layer of concrete is then poured over the roof to straighten the roof

➢The concrete layer thickness over the crown of the arch is not less than 15cm
 JACK ARCH ROOFING SYSTEM

➢Due to the super-imposed load on the arch, tension develops at the ends of the arch

➢Steel tie rods are placed at the ends of an arch with a suitable spacing of 1.8m to 2.4m

➢The two main causes of Jack-arch roof leakage are:

➢Poor quality of cement
➢Inappropriate grade of sand

Repair of the roof

➢The Jack Arch roof leakage problem has to be fixed and should be so done so as to avoid future recurring
water leakage problem. This can be achieved by waterproofing the roof
 JACK ARCH ROOFING SYSTEM

➢Here are the four simple steps to repairing and waterproofing

the Jack Arch Roof:
➢Step one:
➢The old cement mortar and tiles are to be removed so that the new
cement mortar settles and becomes firm over the rough roof surface.
➢Step two:
➢After scraping of the cement mortar, fresh cement mortar is laid
and left to dry.
➢Step three:
➢After the drying of cement mortar, waterproofing is done to avoid
any kind of further leakage. Waterproofing material is mixed in a
drum of water and splashed over the cement mortar layer. We must
make sure that every corner of the roof is to be covered with this
waterproofing material.
➢Step four:
➢After the process of waterproofing, tiling is done with the help of a
suitable adhesive
 JACK ARCH ROOFING SYSTEM

Different modes of failure of traditional one-way jack

arch slab.
(a) inability to transfer in-plane axial loads;
(b) concentration of stresses in brick arch under out-of-
plane bending;
(c) inability to transfer in-plane shear force;
(d) inability to act as a diaphragm.
 MADRAS TERRACE ROOF REPAIR

➢In a Madras terrace roof, wall plates give support to thick

wooden beams which in turn supports a series of wooden
rafters that run along the shorter side of the rooms
➢Grooves are made along the edges of the beams to enable
them to expand and contract without damaging the roof
➢Then a series of masons sit diagonally across this wooden
framework and using both their hands and feet, they proceed
to use narrow bricks and lime paste to stick the bricks
together to create a sheet of bricks over the frame of rafters
➢A three course diagonal brick course is laid with each course
in alternate direction which forms a 12 inch thick slab
➢This is then covered with a layer of lime mortar

https://www.youtube.com/watch?v=xg0ELsA7rXo
 MADRAS TERRACE ROOF REPAIR

➢Myrobalan is soaked in water and this liquid is poured onto the surface and
then the roof is manually beaten to become firm and weatherproof

➢This process of beating is called the kadukka

➢This surface is then covered with pressed tiles to give it the final finish
MADRAS TERRACE ROOF REPAIR
MADRAS TERRACE ROOF REPAIR
MADRAS TERRACE ROOF REPAIR
 MADRAS TERRACE ROOF REPAIR

Madras Terrace Roof Repair 3)

1) The old roof
covered with
tarp

2)

Exposing original Severe leaks visible

roof to do water
test
 MADRAS TERRACE ROOF REPAIR

4) 5)

Excavating surface to check quality

Manually checking each rafter

6)
Stripping old roof and
providing support from
below
 MADRAS TERRACE ROOF REPAIR

7) 8)

Looking for termite damages & carrying

out repairs and stripping layers of old paint

Handcrafting every beam and rafter

 MADRAS TERRACE ROOF REPAIR

9) 11)

10) The team The Kadukka, (possibly

of expert called that because of the
masons at beating sound that
working the wooden batons make
together) results in an
elephant hide like surface
that is then layered with
pressed clay tiles
MADRAS TERRACE ROOF REPAIR
 MADRAS TERRACE ROOF REPAIR

https://www.youtube.com/watch?v=kEKnsAMo6gI
 PROPPING IN CONSTRUCTION

➢An object placed beneath or against a structure to keep it from

falling or shaking

➢ Props are popular on construction sites, often used as a support

when building is constructed or renovated

➢ Propping can be used in most forms of construction as they support horizontal loads. They can be used as a:
➢1. Temporary support
➢2. Formwork reinforcing support
➢3. Floor support, transferring loads from one level to another
➢4. Slab reinforcement

➢When selecting a prop, two things need to be considered: the height that the prop needs to reach and the
weight it needs to support
 PROPPING IN CONSTRUCTION

Props are made of following material:

1. Wooden Props (Wooden Ballies)

2. Steel Adjustable Props

3. Aluminium Props
1. Wooden Props (Wooden Ballies)

3. Aluminium Props
2. Steel Adjustable Props
 PROPPING IN CONSTRUCTION

➢Adjustable props
Adjustable props consist of four parts:
1. The outer tube (60mm OD) with welded base plate
2. The inner tube (48.3mm OD) with welded top plate
3. The nut and handle.
4. The prop pin

➢Prop sizes range from 1050mm to 4900mm and can

support a safe working load between 8kN (815 kg)
and 42.5kN (4335kg) - 32kN (3265kg) on average
 PROPPING IN CONSTRUCTION

➢Tilt Props

➢Tilt Props supporting pre cast

concrete walls

➢Tilt Props base plate

 SHUTTERING IN CONSTRUCTION

➢ Shuttering or formwork is the term used for

temporary timber, plywood, metal or other material
used to provide support to wet concrete mix till it
gets strength for self support.

➢ It provides supports to horizontal, vertical and

inclined surfaces or also provides support to cast
concrete according to required shape and size.

➢ The formwork also produces a desired finish

concrete surface

➢ New materials such as steel, plastics and fibreglass

are used in formwork.

➢ Greater attention is being given to the design,

fabrication, erection and dismantling of formwork
 SHUTTERING IN CONSTRUCTION

Qualities of Formwork Major objectives considered in formwork:

➢ It should be water tight. • Quality
➢ It should be strong. • Safety
➢ It can be reusable. • Economy
➢ Its contact surface should be uniform.
➢ It should be according to the size of member.

In order to successfully carry out its function, formwork must achieve a balance of following requirements:
• Containment
• Strength
• Resistance To Leakage
• Accuracy Three stages in the process :
• Ease Of Handling a) Assembly and erection .
• Finish And Reuse Potential b) Concrete placement.
• Access For Concrete c) Stripping and dismantling.
• Economy
 SHUTTERING IN CONSTRUCTION

Requirements of formwork:
• 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
SHUTTERING IN CONSTRUCTION
SHUTTERING IN CONSTRUCTION
SHUTTERING IN CONSTRUCTION
 SHUTTERING IN CONSTRUCTION

➢When deep excavations are to be made in the earth

strutting systems are adopted to control the Earth retaining
wall movements or deflections
➢Timbering of trenched can be used for 3 to 4 feet shallow
earth excavations
 SHUTTERING IN CONSTRUCTION

➢In order to excavate to a depth of more than 50 feet then strutting system should be adopted

➢Strutting system is of two types

1. Horizontal strutting system

2. Inclined/ Raker strutting system

2. Inclined/ Raker strutting system

1. Horizontal strutting system