Science 7 - LAND and SEA BREEZE and its Characteristics
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Defects in construction
1. DEPT. OF ARCH
GBU
GREATER NOIDA
DEFECTS IN CONSTRUCTION
BUILDING CONSTRUCTION - VII
SHIVANGI SAINI
13/AR/010
B.ARCH, IV YR, VII SEM
SHEET NO.
1
CONSTRUCTION DEFECTS: DEFINITION
Construction defects usually include any deficiency in the performing or furnishing of the design, planning, supervision, inspection,
construction or observation of construction to any new home or building.
REASONS FOR DEFECTS IN CONSTRUCTION
Design Deficiencies Material Deficiencies Construction Deficiencies Subsurface Deficiencies
⢠Problems are typically encountered
with roof systems, which due to their
design complexity, pitched or flat, are
prone to leaks.
⢠A majority of roofing problems are a
direct result of the improper
specification of building materials,
which can result in water
penetration, intrusion or other
problems,
⢠The inadequacy of structural
members, which can result in cracks
and deterioration of roofing
components and materials.
ROOFING
PROBLEMS
Common manufacturer
problems with building materials
can include
⢠deteriorating flashing,
⢠building paper,
⢠waterproofing membranes,
⢠asphalt roofing shingles,
⢠particle board,
⢠inferior drywall
⢠other wall products used in
wet and/or damp areas, such
as bathrooms and laundry
rooms.
⢠A typical example is
water infiltration
through some portion of
the building structure,
which may create an
environment for the
growth of mold.
⢠Other problems include
cracks in foundations or
walls, dry rotting of
wood, electrical and
mechanical problems,
plumbing leaks, or pest
infestation.
⢠A lack of a solid foundation may
result in cracked foundations or
floor slabs and other damage to
the building.
⢠If subsurface conditions are not
properly compacted and
prepared for adequate drainage,
it is likely the property will
experience problems such as
improperly settling to the
ground (subsidence), the
structure moving or shifting,
flooding and in many cases
more severe problems such as
landslides.
2. DEPT. OF ARCH
GBU
GREATER NOIDA
DEFECTS IN CONSTRUCTION
BUILDING CONSTRUCTION - VII
SHIVANGI SAINI
13/AR/010
B.ARCH, IV YR, VII SEM
SHEET NO.
2
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PROBLEM-1
DIAGONAL CRACKS IN BRICK WALLS
WIDE AT BOTTOM & NARROW AT THE TOP
CAUSES
1. Differential settlement of
foundation due to
expansion of clayey soil by
absorption of moisture.
This may happen when the rain water finds entry in soil or if a tree is
cut suddenly in the vicinity of structure so that the soil which was
earlier dehydrated by the tree again absorbs moisture and swells.
REMEDIES/PRECAUTIONS
1. In clayey soil, foundation should be taken as
much as deep so as to minimize the effect of
moisture
Entry as much as possible.
1. Adequate plinth protection and drainage
arrangement should be made around the
building to minimize water entry in the
foundation.
2. If from any site intended for new construction,
some vegetation is removed, donât commence
construction activity immediately specially if soil
is clay. allow the soil to absorb moisture , swells
& stabilize
PROBLEM-2
HORIZONTAL CRACKS IN BRICK MORTAR JOINTS
CAUSES
ďą Weakening of mortar due to
sulphate attack. these cracks
normally occur after 2-3yrs of
construction as the reaction is slow.
REMEDIES/PRECAUTIONS
1. Sulphate contents of the bricks should be checked
before allowing their use.
2. Brick walls should not be allowed to be damp because
3. Sulphate attack happens only in presence of moisture.
4. The correct remedy is to reconstruct the affected areas
3. DEPT. OF ARCH
GBU
GREATER NOIDA
DEFECTS IN CONSTRUCTION
BUILDING CONSTRUCTION - VII
SHIVANGI SAINI
13/AR/010
B.ARCH, IV YR, VII SEM
SHEET NO.
3
PROBLEM-3
RANDOM CRACK IN FLOORING
CAUSES
⢠Flooring has been cast continuously
without making panels.
⢠Cracks occur due to development of
tensile stresses on account of shrinkage
and thermal contraction of concrete &
occur mostly in the first dry spell.
PRECAUTIONS
⢠Cast flooring in panels do adequate curing in the intial period of
hardening of concrete.
PROBLEM-4
CRACKS IN LOAD BEARING MASONRY WALL BELOW R.C.C.
SLAB
CAUSES
⢠Due to absence of slip joint between RCC
slab and wall which doesnât allow RCC
slab to move freely over wall leads to
cracking in the wall.
⢠Sometimes the movements of the slab may also cause cracking
in the wall.
⢠Sometimes the movement of the slab may also cause cracking
in masonry at lintel and window sill level because here the
masonry is weak.
⢠These cracks are observed mainly on top most storey of the
bldg, because roof is more exposed to temperature variation.
REMEDIES
⢠Before casting RCC slab
over bricks wall, smooth
bearing plaster should
be done over brick walls
coupled with white
wash/bitumen coating
over it.
⢠It allows slab to move
freely over wall
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4. DEPT. OF ARCH
GBU
GREATER NOIDA
DEFECTS IN CONSTRUCTION
BUILDING CONSTRUCTION - VII
SHIVANGI SAINI
13/AR/010
B.ARCH, IV YR, VII SEM
SHEET NO.
4
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PROBLEM -5
VERTICAL CRACKS AT JUNCTION OF R.C.C. COLUMN AND
MASONRY
REMEDIES
CAUSES
â˘Differential movement between R.C.C.
column and masonry due to thermal
expansion/contraction shrinkage.
â˘Differential settlement of R.C.C. column
because of its different foundation.
â˘A groove in plaster should be made at
the junction of R.C.C. column and brick
wall so that crack remains hidden in the
groove and doesnât look unsightly.
â˘Alternatively, chicken wire mesh should
be provided in plaster at the junction of
R.C.C. column and brick walls.
PROBLEM -6
DIAGONAL CRACKS IN WALL OVER R.C.C. LINTELS.
CAUSES
Due to drying shrinkage of lintels and
sudden deflection of lintels after
removal of shuttering.
REMEDIES
â˘Use precast lintels as far as possible for small openings.
â˘Construct brick wall over lintel after it has undergone
considerable shrinkage.
â˘Construct brick wall over lintel after
shuttering below it is removed so that
it doesn't undergo sudden deflection
with the construction of brick wall
over it.
5. DEPT. OF ARCH
GBU
GREATER NOIDA
DEFECTS IN CONSTRUCTION
BUILDING CONSTRUCTION - VII
SHIVANGI SAINI
13/AR/010
B.ARCH, IV YR, VII SEM
SHEET NO.
5
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PROBLEM -7
VERTICAL AND HORIZONTAL CRACK IN PANEL WALL IN R.C.C
FRAMED STRUCTURE
CAUSES
Panels wall too lightly built to the R.C.C.
beams so that the beams are not free to
deflect ,load is transmitted the wall and
vertical and horizontal cracks are
produced in the depending upon the direct in which wall is more slender
(i.e height and length
REMEDIES
â˘Some gap should be left between top of panel wall
and soffit beam /slab so that beam can deflect
freely.
â˘This gap can be fill by weak mortar .
â˘If lateral support is required to be given to wall beam then some special
lateral connections can be made in such a way free deflection of beam is
not hindered in vertical direction.
PROBLEM -8
HORIZONTAL CRACKS BETWEEN BRICK PARAPET
WALL AND ROOF SLAB
CAUSES
differential thermal expansion
and contraction and
differential drying shrinkage of
R.C.C. slab &brick wall.
Due to thermal expansion and arching of slab ,it is not
free to expand .this situation mainly occurs in case of
non projecting slab.
REMEDIES
â˘Make parapet wall a little inside
of the edge of slab so that crack
wont be visible.
â˘Providing a groove in plaster at the junction of parapet
wall and slab so that crack forms in the groove and
doesnât look unsightly
â˘put chicken wire mesh in the plaster at the junction of
parapet wall and slab .
â˘Provide adequate
insulation cover over roof
slab so that its thermal
movements are
minimized.
6. DEPT. OF ARCH
GBU
GREATER NOIDA
DEFECTS IN CONSTRUCTION
BUILDING CONSTRUCTION - VII
SHIVANGI SAINI
13/AR/010
B.ARCH, IV YR, VII SEM
SHEET NO.
6
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PROBLEM -9
VERTICAL CRACK BELOW OPENING IN LINE WITH WINDOW
JAMBS
CAUSES
These cracks are caused due to vertical shear
cause by differential strain in lightly loaded
masonry below the opening and heavily
loaded portion of wall having no opening
REMEDIES
â˘Too much difference in stress in different
walls or parts of a wall should be avoided.
â˘Portions of wall acting as pillars and having
too much concentric loads should be replaced
by RCC pillars if possible .
PROBLEM - 10
VERTICAL CRACKS IN THE SIDE WALLS AT THE
CORNERS OF A LONG BUILDING.
CAUSES
1) The cracks are due to thermal
expansion sometimes aggravated
by moisture of long brick wall and
would be noticed in hot weather.
2) There will be more chances of such
cracks occurring in building
constructed in cold weather.
REMEDIES
1) As far as possible long stretches of walls should be
intercepted by cross walls and expansion joint should be
given at suitable intervals.
2) Bricks should be allowed to undergo initial moisture
expansion before use.
PROBLEM -11
CRACKING DUE TO ARCHING AND UPHEAVING OF A FLOOR.
CAUSES
1) Due to sulphate action in base
concrete.
2) Due to expansion of clayey soil
below by absorbing moisture.
REMEDIES
1) TAKE ALL MEASURES TO PREVENT CONTACT OF SULPHATES WITH
CEMENT OR USE SULPHATE RESISTENT CEMENT.
7. DEPT. OF ARCH
GBU
GREATER NOIDA
DEFECTS IN CONSTRUCTION
BUILDING CONSTRUCTION - VII
SHIVANGI SAINI
13/AR/010
B.ARCH, IV YR, VII SEM
SHEET NO.
7
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PROBLEM - 1
DAMPNESS IN THE CEILING BELOW ROOF SLAB/TERRACES/BALCONIES.
CAUSES
1. Roof slopes not proper. water stagnates at some
points.
2. Rain water pipe choked. So water collects
around that location and gradually seeps below
in the roof.
3. Overhead tank not water proofed so water seeps from it
through its pillars to the roof slab.
4. Area around overhead water tank at roof not properly cleaned.
so some vegetation starts growing due to dampness and makes
its way through the roofing from where water also seeps.
5. Water proofing of roof not properly carried up to the pillars of
overhead water tank because of which water can seep through
this junction of pillars to the roof slabs.
6. Water proofing treatment done over roof not carried up to
specified height over parapet wall.
REMEDIES
1. Correct the roof slopes
wherever required by putting
screed concrete and put
adequate number of rain water
pipes.
2. Water proofing should be done
inside the overhead water tank
on roof.
3. Roof area around and below the water tank should be properly
cleaned and no vegetation should be allowed to grow due to
dampness.
4. Overflow pipe provided in the O.H.T. at roof should be carried
up to the nearest rainwater pipe..
5. Roof topping concrete should
not be cast continuously but
rather laid in panels and the
grooves between panels should
be filled with a sealant or
polymer mixed cement.
PROBLEM -2
SEEPAGE IN THE CEILING BELOW ROOF SLAB IN THE
CORNERS ALONG JUNCTION OF WALL AND SLAB.
1. Since the parapet load is low, the roof slab bends
to lift at its corners due to deflection causing crack..
2. Since the parapet load is low, slab is also able to
move due to thermal contractions/expansion &
shrinkage.
Remedies
1) By making brick or concrete cornice at the bottom of parapet
wall and making drip mould in it.
2) By extending roof slab itself by 2â to 3â beyond the load bearing
wall and making a drip mould at the bottom .
3) By taking precautions that minimum water drips through roof
and parapet wall to the outside wall.
8. DEPT. OF ARCH
GBU
GREATER NOIDA
DEFECTS IN CONSTRUCTION
BUILDING CONSTRUCTION - VII
SHIVANGI SAINI
13/AR/010
B.ARCH, IV YR, VII SEM
SHEET NO.
8
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PROBLEM - 3
SEEPAGE IN THE WALLS OF TOILET ABOVE TOILET FLOOR LEVEL
CAUSES
Leakage in water supply lines which
are concealed in the walls.
REMEDIES
1) Make a chase in the wall along the route of water
lines in the toilet/bathroom and expose these lines
at the location+ of dampness . then examine them for
leakage.
2. In extreme cases some pipe piece can also be found cracked rusted
(specially when pipes have become quite old) which should be
replaced.
2. As a preventive measures, during the time
of new construction , all the water lines
must be pressure tested before concealing
them and before accepting the work. this
will save much of future maintenance
problem.
PROBLEM- 4
ROOF /TERRACE CONCRETE SLAB POROUS IN GENERAL
AND LOT OF FINE HAIR LINE CRACKS BECAUSE OF
WHICH WATER SEEPS
CAUSES
Concrete not cast properly and mixing
and compacting not done uniformaly and
properly.
REMEDY
Apply water profing coating over the
concrete slab.
PROBLEM-5
WATER ENTERING THROUGH DOORS AND WINDOWS
OF THE BUILDING AND CAUSING DAMPNESS INSIDE
THE BUILDING
3. Floor not sloping away from external door
4. There is gap between door /window frames and jambs
5. Glazed windows are opened inside the room instead of
outside
1. Chajjas not provided over doors and
windows
2. Stilts not provided at the bottom of door
on the outside
CAUSES
REMEDIES
1. Provide chajjas over doors and windows
2. Gaps between doors/windows frame and jambs should be properly
sealed through sealant.
3. Rubber gasket/beading should be provided on edge of door/ window
shutters if you want a perfect leak proof door/ window.
4. Glazed windows should always open outside and not inside the room.
9. DEPT. OF ARCH
GBU
GREATER NOIDA
DEFECTS IN CONSTRUCTION
BUILDING CONSTRUCTION - VII
SHIVANGI SAINI
13/AR/010
B.ARCH, IV YR, VII SEM
SHEET NO.
9
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PROBLEM -1
CRACKS TO BRICKWORK
CAUSES
1. This is the lack of tying in
of brickwork.
2. Wall has been
constructed and not tied
into the adjoining
brickwork
REMEDY
By construction of the two brick walls at the
same time with the brickwork being
interlocked
PROBLEM â 2
DEFECTIVE FLASHINGS
1. Flashings to the base of the cavity have
been installed.
2. These flashings are designed to collect any
water entry to the
3. Building and discharge it to the outside
4. In this case the end of the flashing has not
been turned up at the
5. Ends and would allow any water trapped within the cavity to
6. Form a water leakage
REMEDY
The flashing in this case should have been turned up at the ends
to prevent the leaks at the door sill.
3. Case a half brick has been cut and abuts the joining wall
4. There is no form of tying in of the brickwork, nor fixing
PROBLEM - 3
SPALLING OF CONCRETE (CONCRETE CANCER)
Spalling of concrete is commonly called
concrete cancer . This occurs when the steel
reinforcing rods within the concrete are
affected by moisture, or a salt environment,
which causes the steel to rust which then
expands and pushes off the surface
CAUSES
⢠The problem occurs because the
steel reinforcing has insufficient
âcoverâ which allows either
moisture or salt laden air to
affect the steel reinforcing.
REMEDY
â˘The new mesh which has been fitted is also bolted
and fixed to the affected concrete slab above to
provide adequate fixing.
â˘This confirms the mesh is only fitted
to provide some bonding agent for
the later rendering to the underside of
the slab.
10. DEPT. OF ARCH
GBU
GREATER NOIDA
DEFECTS IN CONSTRUCTION
BUILDING CONSTRUCTION - VII
SHIVANGI SAINI
13/AR/010
B.ARCH, IV YR, VII SEM
SHEET NO.
10
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1. CONCRETE CREEP
It is the property of concrete by which it continues to deform with time
under sustained stress. the total deformation of concrete element can
be divided into two parts:
1. An initial, instantaneous deformation at an application of load.
2. A time dependent deformation due to creep.
REMEDY
1 . Design the structure with a mind to the degree of restraint during
drying or cooling of the concrete.
2 . Pre stress wherever feasible.
3. SHRINKAGE
The moisture loss results in concrete
shortening of length. The shortening
of length of a member or contraction
of the concrete per unit length due to
drying when concrete sets in known as
shrinkage.
this is an irreversible process.
REMEDY
1. Provide competent inspection, and back it up.
2. Use materials known to have a good service record with
regard to cracking, irrespective of shrinkage or other tests on
single contribution causes.
3. Use the minimum cement content consistent with design
requirements.
2. CARBONATION
â˘Carbonation occurs in concrete because the calcium bearing
phases present are attacked by carbon dioxide of the air and
converted to calcium carbonate.
â˘Carbonation may be recognized in the
field by the presence of a dis colour zone in
the surface of the concrete. the colour may
vary from light gray and difficult to
recognize to strong orange and easy to
recognize. carbonation can be visualized by
using phenolphthalein.
REMEDY
1. Use the minimum water content necessary for workability; do
not permit over wet consistencies.
2. Place the concrete uniformly, and take account of early
settlement in the forms, around reinforcement , on slopes,
and elsewhere.
11. DEPT. OF ARCH
GBU
GREATER NOIDA
DEFECTS IN CONSTRUCTION
BUILDING CONSTRUCTION - VII
SHIVANGI SAINI
13/AR/010
B.ARCH, IV YR, VII SEM
SHEET NO.
11
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4. CORROSION OF THE REINFORCEMENT
â˘Corrosion of steel bars is due to oxygen and moisture.
â˘Any common steel will corrode slowly when exposed to the air with
no protection.
â˘when ordinary steel is used to in concrete, it automatically protected
from corrosion by means of:
1. cover of concrete and alkalinity of concrete.
2. steel in corroding expands and can double its volume.
3. layers and lumps can flake off.
4. as most reinforcement is embedded in concrete, this expansion
can push off the surrounding concrete.
INSUFFICIENT STEEL REINFORCEMENT
Due to the insufficient amount of steel
present in the concrete element it will
not perform to the design and if over-
stressed, suffer from carbonation or
other damages and will not have
sufficient factor of safety.
â˘connecting hoops and tie-rods bent over where they did not line up
â˘ties and pre-cast panels not pulled out to make in-situ connections with
in-situ elements.
â˘lack of stitch bars between precast units in
in-situ joints.
â˘continuity re bars not passing through all
connecting hoops.
POOR FIXING OF BETWEEN STRUCTURAL ELEMENTS
REMEDY
â˘Cure the concrete moist or sealed, beginning very early.
â˘Avoid extremes of temperature.
â˘Protect the concrete in service from moisture and temperature
changes wherever feasible, as by backfilling, shading, or coating.
MOISTURE OR
THERMAL EXPANSION
MOVEMENT IN MATERIALS
CHANGE IN SIZE OF MATERIALS
CRACKS
REMEDY
EXPANSION JOINTS
FLOWCHART SUMMARIZING THE DEFECTS DUE
TO CHANGE IN SIZE.