Repairs and Renovation of Buildings
August 22,2015
Dear Saketians,
You all will agree that the condition of
our society buildings is in bad shape and needs immediate attention, repairs
and renovation.
Our society had first conducted a
Structural Audit in 2011. The report then was bad.
We conducted another Structural Audit
last year in December 2014. The report is enclosed herewith for your perusal.
The report clearly mentions that
immediate structural repairs of buildings are required.
On assuming office in April 2015, your
committee was seized with the subject of repairs and we have been having
extensive deliberations with Architects and Engineers on the subject.
Our buildings are over 20 years old. The
last Repair and Renovation was conducted in 2001-2003. It is almost 12 years
since then and now time has come to pay immediate attention to the buildings.
Your committee has organized this Open Forum meeting on
Repairs and Renovation to give members a platform to air their views and
suggestions in a free manner. The meeting will be held in Club House on Sunday,
August 30, 2015 at 11.00 am.
Based on the consensus that may be built
in this meeting, your committee will decide on future course of action.
Friends, we have to understand one
thing. Today, if one has to renovate his bathroom, it costs you around Rs.
70,000/-. Renovation of the entire flat costs one over Rs. 2 lakhs. And we
spend that amount readily.
When we decide to repair our buildings,
it is going to cost us money. But remember, we are going to spend it on our own
buildings. Repairs will strengthen our buildings and enhance their life, apart
from giving them a beautiful look.
So come to the meeting with an open
mind. Saket is our complex – our property. Lets make it beautiful and a better
place to live.
Regards,
Dayanand Nene Bipin
Kulkarni Jayesh
Khakkar
Chairman Secretary Treasurer
FAQs on Structural Repairs
Given below are solutions for some of
the frequently asked questions pertaining to building repairs, corrosion
problems, restoration of buildings and structural
rehabilitation of buildings. These can provide useful guidance for customers who
want to undertake maintenance or repair work of their buildings.
Why do buildings show cracks after a few years?
Buildings show cracks because of two main reasons and hence there are two types of cracks.
First, multi storied buildings are more of dynamic structures rather than static. They go through the normal phenomenon of settlement, deflections, vibrations and movement because of the movements of loads and wind. With time, this dynamism causes some stresses, which show up in the form of cracks in the walls ceiling etc. This type of cracks are only plaster deep. These cracks are treated by, chasing them out into ‘V’ shaped groves and filling them up with good quality crack filler.
Second, in the reinforced concrete, water/moisture reaches the steel by leakage or because of the porosity of concrete. This water in the presence of carbon dioxide oxidises the steel and causes rusting or corrosion. The volume of corroded steel is many times more than that of the original steel. This expanded steel puts lot of pressure on the neighbouring concrete and the concrete develops cracks. The cracks due to corrosion appear on the columns and beams. These cracks are larger and generally associated with brown colour stains.
Are cracks dangerous and how to treat them?
Surface cracks in the plaster, and those, at the junction of the soffit of the beam and the top of brick work in a wall or those, at the junction of column and the brick work, are only plaster cracks and can be treated by the use of crack fillers.
Cracks due to corrosion which are seen on the column and beams, need to be inspected by taking out the concrete to expose the reinforcement. If the reinforcing steel is corroded more than 50% of its original volume, then it will have to be treated by replacing the lost steel and corrosion inhibition treatment done to entire steel. Then re-concreting is done, by jacketing method, using Super Fluid Micro Concretes, after removing the old concrete. If the damage to steel is less than 50% of its original volume then the lost steel is substituted with new steel to make up the lost volume of steel, corrosion inhibition treatment is done and the broken concrete is made good by polymer modified mortar.
How to identify that the building has a structural problem?
Cracks in the columns and beams, cracks associated brown stains and large chunks of concrete falling off from the RCC members and cracks being very big are all signs of corrosion to indicate that the building has structural problems. Physical examination of the steel by a competent structural repair consultant, after removal of the cover concrete establishes the degree of the problem.
How do we know whether reinforcement is corroded?
Brown marks associated with the cracks indicate corrosion. Bigger cracks on the beams and columns also indicate corrosion. A physical inspection after removing the cover concrete will show the corrosion if it is there. Corroded reinforcements can be separated, by picking from the fingers, as they are very weak.
What causes corrosion of reinforcement?
Corrosion is caused by the oxidation of steel. Reinforcing steel when comes in contact with atmospheric carbon dioxide in the presence of moisture the corrosion process starts and spreads fast like a cancer. Ground water containing chlorides sulphates etc, rising in the capillaries of the concrete when comes in contact with the reinforcing steel the reaction between the two oxidises the steel and the corrosion process starts.
Do leakages cause corrosion?
Yes leakages are the main cause of corrosion of steel. Hence, a good waterproofing treatment always ensures a protective atmosphere around the steel for a long time and contributes to the longevity of the structure.
Is it safe to stay in buildings that have corrosion problems?
Since the process of corrosion progresses very fast and could cause the collapse of the structure it is advisable that the repairs are carried out faster. If the sound steel is reduced to less half its original volume, then it is not safe to stay in such buildings. It could be a great risk to life and valuables stored in such buildings.
When to take up repairs?
Repairs need to be taken up immediately after the first signs of the corrosion to steel are detected so that the minimum damage can be repaired economically. Any season is suitable for repairs except the rainy season.
During the rainy season difficulty will be faced by the workers on the scaffoldings to reach the area of repair and hence inefficiency. Rains cause delays and non-continuity of works with the possibility of the repairs being washed away or becoming weak with the contamination with rain water. During summer holidays many tenants have a tendency to go out on holidays giving fair accessibility to the workers and less botheration to the tenants.
How do I go about repairing such buildings?
You need to contact a Structural Repair Consultant to assess your building, conduct preliminary surveys and give you an initial report for which he may not charge anything. If the problem is serious the consultant highlights it in his preliminary report and suggests detailed investigation and repair or else if it is simple he will suggest ordinary means to solve it economically and may suggest economical applicators for the job. This part is generally done free of cost by the consultants.
Is it expensive to hire a repair consultant in cases of repairs?
No, it is not at all expensive to hire a repair consultant. Their consultancy charges vary from 3% to 6% of the value of the whole work for the indispensable value and quality of services they provide.
Can I trust the rates specification and the contractor suggested by the repair consultant?
Yes, you need to trust your repair consultant as you would trust your doctor or lawyer. After all repair consultants are highly qualified engineers with vast experience with various structures. They ensure that the building gets the best treatment from the contractors and the best materials are utilised on the job.
How do I compare the rates in relation to the materials used on my buildings?
Your repair consultant submits to you the comparison of the various products available their merit and demerits and his own reasons for selecting a particular brand or a method of treatment.
How long does it take to repair say a seven storied building?
Generally it takes nine months to a year from the time the consultant is given the green signal to go ahead.
IMPORTANT DECISIONS TAKEN AT THE OPEN FORUM MEETING HELD IN SAKET CLUB HOUSE ON AUGUST 30, 2015,
1) The Chairman Shri Dayanand Nene welcomed the members.
2) The Chairman and Secretary, Shri Bipin Kulkarni then made a pictoral presentation of the Saket Complex - buildings, ducts, surroundings, exterior facade to all members.
3) The pictoral depiction stirred the members and gave them a serious picture of the state of the complex and the need for repairs.
4) The Secretary informed that Staircases of all buildings were badly battered and damaged and the committee is making immediate arrangements to have them repaired.
5)The condition of the Overhead Water tanks - especially building no. B5/ A1/ A6 were in very bad shape and the committee was in process of repairing them too.
6) The condition of all the lifts was pitiable and needed modernization.
7) The Meter rooms of all the buildings needed reoairs - but urgent work was required in A10 and B4.
8) The exterior facade of the buildings was also looking very shabby and badly needed painting and plastering.
9) The House authorised the Managing Committee to study all the details of conducting a repair and renovation programme, work out logistics and them call an SGM and present the concrete proposal to all members of the society.
10) Meeting ended with chanting of the National Anthem.
________________________________________________________________________________
Why do buildings show cracks after a few years?
Buildings show cracks because of two main reasons and hence there are two types of cracks.
First, multi storied buildings are more of dynamic structures rather than static. They go through the normal phenomenon of settlement, deflections, vibrations and movement because of the movements of loads and wind. With time, this dynamism causes some stresses, which show up in the form of cracks in the walls ceiling etc. This type of cracks are only plaster deep. These cracks are treated by, chasing them out into ‘V’ shaped groves and filling them up with good quality crack filler.
Second, in the reinforced concrete, water/moisture reaches the steel by leakage or because of the porosity of concrete. This water in the presence of carbon dioxide oxidises the steel and causes rusting or corrosion. The volume of corroded steel is many times more than that of the original steel. This expanded steel puts lot of pressure on the neighbouring concrete and the concrete develops cracks. The cracks due to corrosion appear on the columns and beams. These cracks are larger and generally associated with brown colour stains.
Are cracks dangerous and how to treat them?
Surface cracks in the plaster, and those, at the junction of the soffit of the beam and the top of brick work in a wall or those, at the junction of column and the brick work, are only plaster cracks and can be treated by the use of crack fillers.
Cracks due to corrosion which are seen on the column and beams, need to be inspected by taking out the concrete to expose the reinforcement. If the reinforcing steel is corroded more than 50% of its original volume, then it will have to be treated by replacing the lost steel and corrosion inhibition treatment done to entire steel. Then re-concreting is done, by jacketing method, using Super Fluid Micro Concretes, after removing the old concrete. If the damage to steel is less than 50% of its original volume then the lost steel is substituted with new steel to make up the lost volume of steel, corrosion inhibition treatment is done and the broken concrete is made good by polymer modified mortar.
How to identify that the building has a structural problem?
Cracks in the columns and beams, cracks associated brown stains and large chunks of concrete falling off from the RCC members and cracks being very big are all signs of corrosion to indicate that the building has structural problems. Physical examination of the steel by a competent structural repair consultant, after removal of the cover concrete establishes the degree of the problem.
How do we know whether reinforcement is corroded?
Brown marks associated with the cracks indicate corrosion. Bigger cracks on the beams and columns also indicate corrosion. A physical inspection after removing the cover concrete will show the corrosion if it is there. Corroded reinforcements can be separated, by picking from the fingers, as they are very weak.
What causes corrosion of reinforcement?
Corrosion is caused by the oxidation of steel. Reinforcing steel when comes in contact with atmospheric carbon dioxide in the presence of moisture the corrosion process starts and spreads fast like a cancer. Ground water containing chlorides sulphates etc, rising in the capillaries of the concrete when comes in contact with the reinforcing steel the reaction between the two oxidises the steel and the corrosion process starts.
Do leakages cause corrosion?
Yes leakages are the main cause of corrosion of steel. Hence, a good waterproofing treatment always ensures a protective atmosphere around the steel for a long time and contributes to the longevity of the structure.
Is it safe to stay in buildings that have corrosion problems?
Since the process of corrosion progresses very fast and could cause the collapse of the structure it is advisable that the repairs are carried out faster. If the sound steel is reduced to less half its original volume, then it is not safe to stay in such buildings. It could be a great risk to life and valuables stored in such buildings.
When to take up repairs?
Repairs need to be taken up immediately after the first signs of the corrosion to steel are detected so that the minimum damage can be repaired economically. Any season is suitable for repairs except the rainy season.
During the rainy season difficulty will be faced by the workers on the scaffoldings to reach the area of repair and hence inefficiency. Rains cause delays and non-continuity of works with the possibility of the repairs being washed away or becoming weak with the contamination with rain water. During summer holidays many tenants have a tendency to go out on holidays giving fair accessibility to the workers and less botheration to the tenants.
How do I go about repairing such buildings?
You need to contact a Structural Repair Consultant to assess your building, conduct preliminary surveys and give you an initial report for which he may not charge anything. If the problem is serious the consultant highlights it in his preliminary report and suggests detailed investigation and repair or else if it is simple he will suggest ordinary means to solve it economically and may suggest economical applicators for the job. This part is generally done free of cost by the consultants.
Is it expensive to hire a repair consultant in cases of repairs?
No, it is not at all expensive to hire a repair consultant. Their consultancy charges vary from 3% to 6% of the value of the whole work for the indispensable value and quality of services they provide.
Can I trust the rates specification and the contractor suggested by the repair consultant?
Yes, you need to trust your repair consultant as you would trust your doctor or lawyer. After all repair consultants are highly qualified engineers with vast experience with various structures. They ensure that the building gets the best treatment from the contractors and the best materials are utilised on the job.
How do I compare the rates in relation to the materials used on my buildings?
Your repair consultant submits to you the comparison of the various products available their merit and demerits and his own reasons for selecting a particular brand or a method of treatment.
How long does it take to repair say a seven storied building?
Generally it takes nine months to a year from the time the consultant is given the green signal to go ahead.
IMPORTANT DECISIONS TAKEN AT THE OPEN FORUM MEETING HELD IN SAKET CLUB HOUSE ON AUGUST 30, 2015,
1) The Chairman Shri Dayanand Nene welcomed the members.
2) The Chairman and Secretary, Shri Bipin Kulkarni then made a pictoral presentation of the Saket Complex - buildings, ducts, surroundings, exterior facade to all members.
3) The pictoral depiction stirred the members and gave them a serious picture of the state of the complex and the need for repairs.
4) The Secretary informed that Staircases of all buildings were badly battered and damaged and the committee is making immediate arrangements to have them repaired.
5)The condition of the Overhead Water tanks - especially building no. B5/ A1/ A6 were in very bad shape and the committee was in process of repairing them too.
6) The condition of all the lifts was pitiable and needed modernization.
7) The Meter rooms of all the buildings needed reoairs - but urgent work was required in A10 and B4.
8) The exterior facade of the buildings was also looking very shabby and badly needed painting and plastering.
9) The House authorised the Managing Committee to study all the details of conducting a repair and renovation programme, work out logistics and them call an SGM and present the concrete proposal to all members of the society.
10) Meeting ended with chanting of the National Anthem.
________________________________________________________________________________
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