Here I am highlighting one glaring incident that took place due to not marking “LAYOUT” of building properly before starting construction work. It is an important aspect of construction work. The slackness made in layout causes extensively damage to the work and heavy loss to the owner.
All this happened due to ignorance, negligence and desire to save money by not marking centre line, base line and not constructing marking pillars or BURJI indicating prominent axes of the building’s walls and columns. These BURJIS act as reference points for laying out any parts of building in later. This episode is being cited to caution owners of the building, contractor, supervisor of contractor and architect responsible for supervision.
In November, 2007 I visited a site of hospital building with my friend; which was under construction at Sonepat. I was stunned to see that some laborers were dismantling RCC columns by mechanical means and rectifying M.S. steel bars of columns. These columns were constructed up to 2 to 4 feet high from plinth level. I enquired of dismantling work from the owner of hospital. The owner told us that he has let out the work on labor rate to contractor and has hired a local architect for supervision of work also.
Ignorant Owner & No Technical Help
The owner also told that he doesn’t know about construction work and totally depends on the contractor. He told us that one day my relative who is engineer came here and after visiting the site he told me that the alignment of columns were incorrect and with incorrect alignment it is not possible to construct a building. The owner said that he called contractor, architect and his relative engineer to show them all irregularities by using tools like SUTTA, plumb bob, try square and straight edge etc. Both the contractor and architect showed their inability to correct the alignment and left the work.
Mistakes got punished gravely
It is certain that nature does not spare anyone if the things are not done properly. It doesn’t matter if the person committing the fault is ignorant or negligent nor does it matter about the honesty, integrity and knowledge of the people involved.
The contractor started the work in unplanned manner. He did not construct marking pillars, BURJIS, not fixed base line and centre line. He started excavation work of columns, walls one by one without checking their distances and alignments and laid the lean concrete. After that he erected M.S. steel bars of columns without taking any respective distances and centre line references from either front row or middle row or back row of columns. By doing the work in hazardous manner some R.C.C. columns constructed out of line and resulted into heavy loss.
The owner further told that he arranged another contractor for construction work. The new contractor started the work after rectifying the defects but rectification of steel bars by buckling reduced the strength of R.C.C. columns.
The owner told that he faced the loss in many counts i.e. cost of dismantling, material and labor cost for re-construction and wastage of time and the project took 3 months more time for completion. This delay also caused him loss due to late functioning of the hospital.
How it happened?
The hospital building had nearly 10,000 sq. feet area and the contractor and his mason did some mistakes either knowingly to save money or due to ignorance. The architect deployed a local man who knew only job of making drawings but had no experience of construction work in the field. He did not measure or check any thing himself but left all this for contractor.
1. In fact the contractor constructed small houses and had no experience of making frame structure building.
2. He started the work in unplanned manner i.e. he did not construct marking pillars, BURJIS and did not fix base line and centre line.
3. He started excavation work of columns, walls one by one without checking their distances and alignments and laid lean concrete.
4. After that he erected M.S. steel bars of columns without taking any respective distances and centre line references from either front row or middle row or back row of columns.
5. After erecting M.S. steel bars of columns, the contractor started laying cement concrete in footings of columns and filled columns up to 2 to 4 feet from plinth level.
6. When error came to notice, the contractor filled many columns 2 to 4 feet from plinth level.
Why it happened?
The incident happened due to ignorance of layout and not following demarcation procedure.
1. Construction work started without doing layout/demarcation.
2. Unskilled and inexperienced masons who did not know the job well were employed to do work.
3. Due to carelessness from owner, the contractor, masons and supervisor thought that nothing would happen as it was routine work.
What precautions should have taken?
The episode happened due to not adopting LAYOUT procedure and precautions for laying foundation.
1. For layout of a building baseline is marked on the ground either from centre line of the road or from any permanent building nearby. This line helps to mark out the front of a building. Side baseline is also marked with the help of side structure or road or it can be marked with the help of first baseline or boundary of the plot.
2. Fix temporary pegs at centre line of walls/columns on both sides of walls and columns in front and backside.
3. Fix pegs at the centre line of walls/columns on both sides of wall and columns in left and right side at the front of building.
4. Check diagonals of the square or rectangle formed after fixing pegs.
5. Construct BURJI or marking pillars with pegs at a distance of 1.5 meter to 2 meters and their top surface should be plastered.
6. Mark centre line on the top of BURJIS with the help of thread (Soot) or with the THEDOLITE in big projects and diagonal and other dimension should be checked.
7. Construct level BURJI on all corners of the building and fix proposed plinth level on the top of BURJI.
8. Mark the foundation of walls/columns according to drawing on the ground with the help of centerline marked on BURJI.
9. Mark foundation trenches on the ground with chalk powder.
10. Excavate the foundation of walls /columns up to required level and the excavation must be checked with the help of centre line and level BURJI to avoid any complication in later.
11. After erecting M.S. steel bars, centre line should be checked again.
12. It is also necessary to check outer lines of columns at the time of filling cement concrete in formwork.