The Importance of Structural Audit

Structural Audit

Did you know that it is now mandatory for all co-operative housing societies, whose buildings are more than 15 years old to have a mandatory STRUCTURAL AUDIT carried out every 5th year to determine the existing life of the building's structure & the balance life of the structure?

The general health and performance of a building depends on its quality of maintenance. As a building grows old, ageing, use (or misuse) and exposure to the environment can affect the health of the building significantly.

Therefore, it is advisable to monitor it periodically by taking a professional opinion.

Structural Audit is a preliminary technical survey of a building to assess its general health as a civil engineering structure. It is usually initiated as the first step for repair. This is similar to the periodic health checkup recommended for older people.

When to do Structural Audit???

Model byelaw no. 77 specifies Structural Audit as a mandatory (necessary and binding) requirement. It stipulates that if the age of a building is 15 to 30 years, Structural Audit must be carried out once in 5 years and for buildings older than 30 years it should be carried out once in 3 years. You may, however, go for it even earlier if you suspect the condition of your building to be bad.

How is it carried out???

Structural Audit is commissioned by appointing a Consulting Structural Engineer registered with the Municipal Corporation of Greater Mumbai (MCGM or BMC) or in our case, TMC.

The Consultant carries out as a visual survey of the building covering its faces, stilts, staircase, terrace, flats, and ancillary structures such as pump room, compound wall, etc.

Repair history of the building and specific observations/ experiences of the members are also noted. Critical observations, probable causes of distress, remarks on structural health and recommendations for further action are given in the Structural Audit Report.

Why Structural Audit / Status Report???

· Exact details of distress at columns/beams/slabs (cover or core) 25%-50%-75% are known.

· Additional proof of sound structure before purchase or sale flat

· Members can understand the exact status/condition of their individual flat

· Easier to convince, to get co-operation and fund from members

· To produce if required by registrar or TMC or any other Govt. Dept

· Helps contractors to understand the exact nature of distress before touching the structure for repairs, so chances of increasing the work/cost is minimum.

· Even members can visualize the extent of repairs during work and can experience

· The condition of water distribution and water protection system also forms part of structural status report.

· Cost effective solutions and remedial measures will give full justice to your contributed amount. (Every single rupee of yours should be put to good use)

On the strength of authentic reports even after some years if problem arises you can contact consultants or contractor for rectifications.

Consultant’s involvement in repairs (proper planning-systematic/methodical repairs) improves the work –effectiveness by 95% .

STRUCTURAL AUDIT is a means of determining the existing defects present in the building's structure, the ways and means of rectifying these defects & the optimum cost required to rectify these defects.

The existing defects will determine the further life span of the building, and the STRUCTURAL AUDIT will also determine the further addition to the existing life span of the building after the defects pointed out in the structural audit have been rectified.

Sample Structural Audit

The buildings are visited and inspection carried out for:

A] STRUCTURAL DEFECTS & FAILURES.

B] SEEPAGE & LEAKAGE DEFECTS.

C] PLASTER DEFECTS.

D] PLUMBING DEFECTS & LEAKAGES

The entire report is subdivided into the following headings:

BRIEF SUMMARY.

IMPORTANT OBSERVATIONS & INFERENCES.

OTHER OBSERVATIONS & INFERENCES.

PROPOSED METHODS OF REPAIRS.

INTERNAL REPAIRS.

DEFECTS ON DRAWINGS.

DEFECTS IN TABULAR FORM.

GIVING OF FINAL SUMMATION WITH COST.

SUBMITTING BILL OF QUANTITIES

There are 2 distinct ways of conducting a STRUCTURAL AUDIT:

1. Simple visual survey + light hammer tapping to check the soundness of the structural members like columns & beams.

2. Complex visual survey + N.D.T. (Non Destructive Testing) using machines like the Rebound Hammer & the Ultrasonic Pulse Velocity test meter.

The entire building structure, right from the topmost point like the overhead water storage tank top, down to the underground water storage tank is checked internally as well as externally. Each and every flat is examined internally as well as externally to check for the following:

• STRUCTURAL DEFECTS
• WATERPROOFING DEFECTS
• PLASTER DEFECTS
• PLUMBING DEFECTS
• PAINTING DEFECTS

All the defects are noted in the form of a comparative chart & are also saved in the form of notations on the floor plan drawings of the building, Proper digital photographs of all the defects are also taken & preserved.

Based on these tools of observation, all the defects are then compiled into a proper B.O.Q. (Bill of Quantities) using a perfectly scientific methodology of selection in the preparation of the B.O.Q.

After the Structural Audit Report is received, it is decided what quantum of Repairs are required for any building.

Repairs to reinforced concrete structural members like columns, beams and slabs are becoming increasingly necessary, on account of the corrosion of reinforcement steel.

Corrosion leads to several other distressing aspects like cracking, spalling, delamination etc.

Repairs to these damages calls for special techniques and materials. Proper identification of the extent of repair is the first step. Removal of damaged plaster, concrete or mortar follows. At same time it is also essential to support or prop various elements, so that during repairs there is no possibility of unforeseen yielding of any structural elements.

REPAIR TYPES

(a) Minor
Minor repairs can generally be looked upon as those that do not require attending to the structural skeleton. Such repairs as water proofing, replastering, filling up non-structural cracks can be minor jobs.

(b) Major
Major repairs would need to tackle with the structural skeleton - at least attend to some of its members. This calls for an evaluation of the likely extent of repairs and strengthening measures required.

Based on the report received from the Structural Audit, depending on the amount of corrosion of reinforcement steel, it is determined whether the building will require major repairs.