The document discusses various types of cracks that can occur in buildings, their causes, and preventative measures. It describes cracks such as shrinkage cracks, hairline cracks, settlement cracks, vertical cracks, diagonal cracks, horizontal cracks, and structural cracks. Major causes of cracks outlined include initial shrinkage of materials, thermal movement, elastic deformation, creep movement, chemical reactions, foundation movement and soil settlement, cracking due to vegetation, permeability of concrete, structural design flaws, poor workmanship, lack of maintenance, and natural forces. The document provides detailed explanations of different crack types, patterns, and underlying causes.

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Contents
1. Abstract..............................................................................................................................................................................2
2. Crack ..................................................................................................................................................................................2
3. Types of Cracks in Buildings.............................................................................................................................................2
3.1 Shrinkage:..................................................................................................................................................................2
3.2 Hairline:.....................................................................................................................................................................3
3.3 Settlement:..................................................................................................................................................................3
3.5 Vertical:......................................................................................................................................................................4
3.6 Diagonal:....................................................................................................................................................................5
3.7 Horizontal:.................................................................................................................................................................5
3.8 Structural:..................................................................................................................................................................5
3.9 Floor cracks:..............................................................................................................................................................6
3.10 Cracks in Roof Slab:...............................................................................................................................................6
3.11 Cracks in Brick Mortar Joints:.............................................................................................................................6
3.12 Crack Formation below the Load Bearing Walls:............................................................................................7
3.13 Main Wall and Cross Walls Joint Cracks:.........................................................................................................7
3.14 Cracks Found in R.C.C Columns and Masonry:...............................................................................................8
3.15 The Horizontal cracks between R.C.C slab and the brick parapet:...............................................................8
3.16 Vertical Cracks at Junction of R.C.C. Column and Wall Masonry: ..............................................................8
3.17 Horizontal Crack at the Junction of Roof Slab and Masonry Wall Support:...............................................8
3.18 Cracks in Foundation:...........................................................................................................................................9
3.19 Extension of Existing Building:............................................................................................................................9
4. Major Causes of Cracks in Buildings:--....................................................................................................................10
4.1 Initial Shrinkage:....................................................................................................................................................10
4.2 Thermal Movement:...............................................................................................................................................11
4.3 Elastic Deformation: .............................................................................................................................................11
4.4 Creep Movement:...................................................................................................................................................11
4.5 Chemical Reaction:................................................................................................................................................11
4.6 Foundation Movement and Settlement of Soil:.................................................................................................11
4.7 Cracking Due To Vegetation:..............................................................................................................................12
4.8 Permeability of Concrete:.....................................................................................................................................12
4.9 Structural Design:..................................................................................................................................................12
4.10 Poor Workmanship:.............................................................................................................................................12
4.11 Lack of Maintenance:..........................................................................................................................................13
4.12 Natural Forces:....................................................................................................................................................13

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1. Abstract
Building cracks are most common problem found in any type of building. We all love to have
a house which structurally safe and beautiful but it is not so easy, one has to overcome
natural calamity, soil failure, construction faults, improper design, and inadequate joints
causing to develop cracks on the building. Though the cracks in concrete cannot be prevented
entirely but they can be controlled by using adequate material and technique of construction
and specific design criteria. On timely identification of such cracks and adopting preventive
measure are essential. Active cracks causes seriously problem and they need special attention
as they are structurally hazardous. So, it is important to understand the types of cracks, crack
patterns and their causes and the preventive measures to be taken to control the cracks.
2. Crack
A crack is a complete or incomplete separation of concrete into two or more parts produced
by breaking or fracturing. Cracks are one kind of universal problems of concrete construction
as it affects the building artistic and it also destroys the wall’s integrity, affects the structure
safety and even reduce the durability of structure.
3. Types of Cracks in Buildings
The cracks appear in the structure, at a certain period of time. Most commonly caused cracks
with their respective causes and precaution, are explained below
The cracks appear in the structure, at a certain period of time. Most commonly caused cracks
with their respective causes and precaution, are explained below
3.1 Shrinkage:
Shrinkage cracks in a poured concrete foundation can be diagonal or vertical and are usually
uniform in width. Sometimes these cracks have a V-shape (less frequent), with the top of the
crack looking larger and the crack getting smaller as it travels towards to floor and diminishing or
stopping before reaching the bottom of the foundation wall. If the crack reaches the bottom, the
crack might damage the building's footings, and the crack might have a significant impact on the
foundation structure.
Shrinkage cracks should not be ongoing nor of structural significance, though they may invite
water entry through the wall. In poured concrete foundations, shrinkage cracks are usually
due to conditions at original construction: poor concrete mix, rapid curing or possibly other
states. In any case, concrete shrinkage causes the concrete to develop internal stresses.
Unless control joints were included in the wall or floor slab design, these stresses would
cause the wall or floor is likely to crack in a classic "concrete shrinkage pattern" as the
concrete cure.

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3.2 Hairline:
Hairline cracks may develop in concrete foundations as the concrete cures. Hairline cracks do
not cause problems with the stability of the foundation but do cause leakage problems. If the
cracks appear shortly after pouring the concrete foundation, concrete may have been mixed
poorly or poured too quickly. In poured concrete foundations, hairline crack frequently
appear in the center of the walls because the wall corners have greater stability
3.3 Settlement:
Settlement cracks may appear when the underlying ground has not been compacted or
appropriately prepared or if the subsoil was not of the proper consistency. A settlement crack
may also appear as a random crack above areas where the soil of the subgrade was uneven
after the concrete was poured. Settlement cracks are usually more extensive at the top of the
crack than the bottom as the foundation "bends" over a single point, allowing differential
settlement. This type of crack is usually continuous and may occur multiple times in a wall.

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3.4 Temperature & Shrinkage:
Horizontal cracks found in the center of the wall are most likely caused by an applied load
such as backfill around foundation compacted improperly or too soon, earth compacting as it
settles, hydrostatic pressure against foundation due to high water table and poor drainage
against the foundation wall, or heavy equipment operated too soon or too close to the
foundation wall. Horizontal cracks found high up on the wall are most likely caused by frost
damage. Sometimes these fine cracks are not noticed for years. In a case like this, a structural
engineer should be consulted.
3.5 Vertical:
Vertical cracks often appear in multiples (multiple cracks in one or more area). Vertical
foundation cracks in poured concrete foundations that tend to appear nearly straight or
wandering, generally even in width, intermittent, or more often straight is caused by
shrinkage/thermal and are usually low risk. If there is significant vertical dislocation or signs of
ongoing movement, you should consult a structural engineer. If the cause is shrinkage, it is
probably less of a concern than if due to settlement.
A vertical foundation crack due to earth loading or frost would be unusual. A more massive
vertical crack can occur when the construction contractors incorrectly prepare the concrete
footings and when the wall had poor steel reinforcement as the workers poured the concrete
for the wall. Cracks can also occur during the footing settlement.

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3.6 Diagonal:
Settlement usually causes diagonal cracks that are almost the full height of the foundation wall.
When there's a settlement problem with footing on one side of the wall, this settlement can also
cause a diagonal crack. In a case like this, a structural engineer should be consulted. If the
diagonal crack is wider at the top than at the bottom, then it may be caused by expansion clay
soil or frost damage. If the crack is wider at the bottom than the top, there is likely a problem
with the settlement beneath.
3.7 Horizontal:
Horizontal cracks found in the center of the wall are most likely caused by an applied load such
as backfill around foundation compacted improperly or too soon, earth compacting as it settles,
hydrostatic pressure against foundation due to high water table and poor drainage against the
foundation wall, or heavy equipment operated too soon or too close to the foundation wall.
Horizontal cracks found high up on the wall are most likely caused by frost damage. Sometimes
these fine cracks are not noticed for years. In a case like this, a structural engineer should be
consulted.
3.8 Structural:
Structural cracks in residential foundations usually result from horizontal loading or settlement.
Most (but not all) structural cracks resulting from an applied load (hydrostatic pressure or heavy
equipment around foundation wall) are nearly horizontal and appear 16" to 48" from the top of
the wall. They are more common in block foundation walls.

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3.9 Floor cracks:
Floor cracks in concrete slabs are relatively common and usually not worrisome on a structural
level. They should be repaired to prevent common issues like moisture, insects, and damage
from seeping through. When floor cracks leak, it is usually caused by hydrostatic pressure or a
high water table. Therefore, sealing the crack will redirect those issues elsewhere, so fixing the
source of those problems beforehand is recommended.
3.10 Cracks in Roof Slab:
The exposure of roof slab to higher temperature variation cause cracks numerously. This can be
reduced by providing a weather proof course. New treatment methods and compounds are
available as weather course that is applied over the terrace.
3.11 Cracks in Brick Mortar Joints:
Vertical or horizontal cracks are seen at the brick mortar joints. One of the main reason is the sulfate
attack that weakens the mortar.
These cracks mainly appear after 2 to 3 years of construction. These cracks can be avoided by:
1-Checking the sulfate content of bricks used in construction.
2-The damping of brick wall has to avoided, as these are more prone to sulfate attack when it is damp.

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3.12 Crack Formation below the Load Bearing Walls:
Cracks are observed below the load bearing walls, mainly those that supports R.C.C slabs. Now
the temperature variation makes the reinforced concrete slab to expand or contract, but both in
the horizontal direction. These are observed in the Top most story that is more exposed to the
temperature changes. There no smooth contact between the wall and the slab. Hence the
frictional forces are developed at the contact place of the wall and the slab. This creates cracking
in the walls.
The precaution that can be suggested is to provide a bearing plaster over the brick wall, which
helps in having a smooth contact with the floor over it. If required a bituminous coating can be
applied over the plaster applied
3.13 Main Wall and Cross Walls Joint Cracks:
Improper bonding between the cross wall and the main wall creates cracks between the joints.
This suggests us to have proper and quality bonding between the two walls. These are properly
done by tooting.

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3.14 Cracks Found in R.C.C Columns and Masonry:
One of the main reason behind this is the differential movement of the columns and the masonry
because of temperature variation. This variation can be either expansion or contraction
depending upon the temperature.
These cracks can be hidden by making a groove in the reinforced concrete column and masonry
junction. The provision of chicken wire alternatively at the plaster between the junction of
columns and masonry can also help in this variation.
3.15 The Horizontal cracks between R.C.C slab and the brick parapet:
The non-projecting slab is mainly subjected to such cracks. This too is due to the temperature
variation and the drying shrinkage. Small micro cracks formed he propagated with the increase
in expansion or contraction.
These cracks can be hidden by making a groove at the masonry junction will help in hiding the
cracks. The provision of chicken wire alternatively at the plaster junction can also help.
3.16 Vertical Cracks at Junction of R.C.C. Column and Wall Masonry:
The cracks occur a few months after construction not only due to differential strain between
R.C.C. and masonry because of elastic deformation, shrinkage and creep in R.C.C. column also
act upon.
As a preventive measure butterfly ties may be provided at the junctions.
3.17 Horizontal Crack at the Junction of Roof Slab and Masonry Wall Support:
In case of framed structure roof slab, beams, and columns move jointly, causing diagonal cracks
in walls which are generally parallel to the movement and horizontal cracks are located below
the beams. Extent of movement in a framed structure is comparatively less as columns on
account of their stiffness and ability to withstand bending stresses are able to resist and contain
the movement to some extent. Both in load-bearing and framed structures, provision of adequate
or protective cover on the roof is very important in order to avoid cracks in walls.

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3.18 Cracks in Foundation:
Plinth protection around the building helps in preventing seepage of rain and surface water into
the foundation; possibility of settlement cracks may thus be avoided.
3.19 Extension of Existing Building:
When extension of existing building is desired, new construction should not be bonded with the
old. Two parts should be separated by a step or expansion joint right from the foundation to top.
Care should be taken while excavating below the foundation of existing building. When the
existing structure is 20 – 25 m long, the old and the new work should be separated by an
expansion joint with a gap of about 25 to 40 mm to allow room for unhindered expansion of the
two portions.
In case of extension of framed structure, twin columns should be provided with combined
footing. Combined footing shall be provided during original construction.

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4. Major Causes of Cracks in Buildings:--
Aging and natural deterioration of the building can result in many types of defects. While most
of the defects are localized and non-structural in nature, there are few which are severe and can
affect the structural safety of the buildings. Home or building owners should always be aware of
the condition of their buildings. One of the best ways to avoid unnecessary panic is by
identifying the defects early on and carry out timely repair and maintenance works to keep the
building in sound structural condition. One of the most important defects to monitor are the
cracks in buildings.
Cracks can occur due to various reasons chemical reactions in construction materials, foundation
movements and settling of buildings, changes in temperature and climate, environmental stresses
like the nearby movement of trains, earthquakes etc. Faulty and defective design, poor quality
materials, incorrect methods of construction, weather, and loads of wear and tear can create
cracks.
Most of the buildings develop cracks at some point in time during their lifetime, following are
the top reasons that cause them.
4.1 Initial Shrinkage:
Building materials like brickwork, concrete, etc. shrink in the beginning. This shrinkage is
partially irretrievable. Shrinkage cracks in buildings wall can be reduced by using less rich
cement mortar in the masonry and by suspending application of plaster on the brickwork surface,
basically when the masonry has experienced most of its early shrinkage and has dried well after
proper curing.
Shrinkage cracks in rendering/plastering can be minimized by using mortar for the plaster which
is less rich and perfect for providing resistance to durability and abrasion.

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4.2 Thermal Movement:
All building materials expand on heat and contract on cooling. Thermal movement in the
components of building structure creates cracks owing to tensile of shear stresses. But again, the
scale of movement depends on their molecular structure and other properties. Thermal changes
are one of the strongest causes of cracks in buildings and demand attention.
Daily changes in temperature are more rapid and have a higher damaging effect than the seasonal
changes, which are regular. On the other hand, in seasonal changes, the pressure gets relieved to
a large extent on account of creep.
4.3 Elastic Deformation:
Unevenly loaded walls suffer huge variation in stress in different parts which causes cracks in
walls. When two construction materials (masonry, concrete, steel, etc) with wide different elastic
properties under the effect of load are built together, different shear stresses in these materials
result in cracks at the junction. Dead and live loads cause elastic deformation in structural
components of a building.
The amount of deformation is dependent hugely upon the elastic modulus of the material, the
magnitude of loading and dimension of the components.
4.4 Creep Movement:
Gradual and slow time-dependent distortion of the concrete structure under constant loads is
known as creep. It can generate extreme stress and lead to the development of cracks.
Additionally, creep increases with increase in cement and water content, water-cement ratio and
temperature. Added to that, pozzolans and admixtures tend to increase the creep. Also, the
increase of temperature in the steel bars surges creep as well. It decreases with a rise in the
humidity of neighboring atmosphere and age of building material at the time of loading.
The mechanism of creep is still vague and not visibly understood. At low-stress levels, it is
believed to be due to seepage and viscous flow and at high-stress levels, it can be due to micro
cracking and inter-crystalline slip.
4.5 Chemical Reaction:
Chemical reactions in building materials increase their overall volume and internal stress which
results in cracks. The materials involved weaken due to chemical reactions.
Carbonation in cement-based materials, sulphate attack on cement products, alkali-aggregate
reaction, and corrosion of reinforcement in concrete are few of the most common types of
chemical actions on building materials.
4.6 Foundation Movement and Settlement of Soil:
Shear cracks happen due to huge differential settlement in the foundation. Structures constructed
on expansive soils which are vulnerable to swelling on absorbing moisture and shrink on drying
due to change in moisture content of the soil are highly prone to cracking.

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Shear cracks occur due to any of the following causes.
 Unequal bearing pressure under different parts of the structure.
 A low factor of safety in the design of foundations.
 Bearing pressure being in excess of the safe bearing strength of the soil.
 Local distinction in the nature of supporting soil.
 These are serious cracks as they occur due to foundation movement of the corner and end
of the building structure, hence demand special measures to prevent such cracks.
4.7 Cracking Due To Vegetation:
The existence of any form of vegetation can be a reason of cracks in the walls of a building. This
is mainly due to the expansive action of roots growing in the brick masonry or under the
foundation. Simply put, the roots of trees set in the vicinity of a wall can create cracks in walls
due to the growth of roots under foundation. The cracks occur in clay soil due to moisture
contained by roots.
4.8 Permeability of Concrete:
The deterioration process in concrete starts with the penetration of several aggressive agents and
is a major cause of cracks on walls. Essentially, it dictates the capacity of concrete to survive
weathering action, chemical attack, or any other process of deterioration. Hence, low
permeability is the main factor to concrete resilience. There are several factors which control
concrete permeability, water-cement ratio, curing, air voids due to deficient compaction, use of
admixtures, micro-cracks due to loading, cyclic exposure to thermal differences, and oldness of
the concrete.
The permeability of cement mixture is a function of water-cement ratio given great quality
materials, suitable proportioning and good construction practice. The permeability of the
concrete is a straight function of the interconnection and porosity of pores of the cement paste.
4.9 Structural Design:
Poor or bad structural design and specifications are another striking cause of the cracks in
concrete works. The designer needs to consider all the environmental aspects which include soil
investigations; this will enable the designer to come up with a proper robust design of the
foundation.
4.10 Poor Workmanship:
Inferior mixing of construction materials, like sand, cement, and aggregate cause cracks on the
walls, slabs, beams, etc. Poor workmanship is normally a result of a lack of proper supervision,
ignorance, negligence, carelessness, negligence, and many others or a combination of all these.

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4.11 Lack of Maintenance:
It is crucial to always take good care of your house, and this can be done by doing regular
maintenance works. This ensures the building structure is intact and it also adds to its lifespan.
4.12 Natural Forces:
Earthquakes, tremors, winds, rains, flooding like the Kerala Havoc and many others can cause
cracks in the buildings.