DECAY IN BUILDINGS AND CAUSES OF BUILDING FAILURE

1. Decay in builing

2. introduction
• The ancient Multan City was originally surrounded by the fortress wall or Faseel also called
Alung as other old walled cities of the country with famous gates named as Haram Gate,
Dolat Gate, Pak Gate, Bohar Gate, Lohari Gate & Dehli Gate
• It has been mentioned by all historians that from the beginning there were six gate in the
city proper and four in the fort of Multan. Haram Gate has always been there. inside this
gate was the Haram or women quarters of the Saint Hazrat Musa Pak Shaheed therfore it
was named haram gate. Word Haram is associated with Wife Woman etc
• Architectural style
• The Haram gate in Multan features a blend of Islamic and Hindu
architectural styles, with intricate stonework
• It is a fine example of Mughal architecture
• All the existing gates are of one and the same design. A circular road,
locally known as the "alang" runs right around the old city, but inside the
fortification wall and not outside it as in common on other old cities.

3. Causes of building failure
• In the study by the Building Research Advisory Service, the causes of failures were
also analysed to indicate whether they were due to Fig. 12.1 Analysis of defects.
172 FAILURE PATTERNS AND CONTROL faulty design, to poor execution, to the
use of poor materials or through unexpected user requirements. Faulty design
was taken to include all cases where the failure could reasonably be attributed to
a failure to follow established design criteria: 58% of all failures were found to lie
in this category. Faulty execution, defects attributed to a failure of the builder to
carry out a design satisfactory in itself and properly specified, accounted for 35%.
Only in 12% of cases did the materials or components fail to meet their generally
accepted performance levels. Some 11 % of failures were caused by the users
expecting more from the design than the designer anticipated. (There was some
overlap between these categories.) A more recent analysis within the defect
reporting systems of the PSA already referred to showed that 51% of the causes
of defects were due primarily to shortcomings in design, 28% to inadequate
workmanship and the remainder were due to other causes including the failure
of materials

4. • decay
• detoriation of buidling facade due to acid rain.
• cracks in the facade due to intensive heat and temperature.
• settlement of foundation due to dampness.
• damaging of parapet due to wind pressure and vendalism.

5. Defects in elements: soil and foundation-related
problems
• Subsidence is a downward movement under applied load. It can occur as
a wholesale movement whereby the building progressively settles with the
soil. This may be small, in the order of millimetres.
• It is more common for partial or differential subsidence to occur, however,
and it is this form of movement which is generally more destructive,
especially to building services. This usually results in differential movement
in the foundations, causing profound disruption to the structure and fabric
of the building.
• The cause of subsidence may be as straightforward as poor bearing
capacity or soil erosion.
• Special foundation/structure forms have been devised for such problems
(where foreseen), such as raft foundations

6. Stone wall
• The principal mechanisms of deterioration in stone walls are
material degradation (including pointing) and other structural
failures such as movement cracking. The causes are the
design/construction detailing and use, and/or the
chemical/physical degradation of the material.
• Erosion It is common for this mechanism to cause gradual erosion, such as
in limestones, aided by the washing of rainwater. The sedimentary
deposition of stones can exacerbate such problems, as will details which
expose the stone to run-off. The rainwater run-off on stone buildings may
produce staining as it leads to the transportation of salts to other locations,
leading in turn to secondary attack on other materials
• dislocation of the stone panels due to extreme wheather

7. Movement in parapt wall
• Movement can occur in parapets for a number of reasons. Instability
in parapets is common because of the relative lack of self-weight or
restraint which usually limits movement in walls, coupled with a
relatively high exposure to the environmental agents of thermal and
moisture movement. Parapets are therefore also relatively
susceptible to defects in materials, such as frost attack or sulphate
attack. The main mechanisms of movement are irreversible
movement, usually expansion in clay bricks (but could be contraction
in concrete), and reversible movement such as thermal and/or
moisture movemen

8. roof
• Directly caused defects in the roof may arise from inaccuracy or
inadequacy of falls to the roof, which can lead to ponding and
subsequent sagging of the structure. Movement caused by changes in
temperature (common with uninsulated decks) can cause tearing and
compressive stressing of the felt covering (deckrelated defects). All of
these defects can occur in combination, and lead to secondary
defects such as water leakage