Study: Construction Process at Plot 22, Shivaji Nagar, Govandi, Mumbai

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1 -Work in Progress- Study: Construction Process at Plot 22, Shivaji Nagar, Govandi, Mumbai Date: July-August 2012 Researcher: Masoom Moitra Contractor: Wasim Khan Updates: Web: /

2 CONSTRUCTION DOCUMENT FOR PLOT 22 Introduction: Shivaji Nagar falls within the M-ward of the Brihan Mumbai Municipal area and started off as a resettlement area for people displaced from development projects around the city in the 1980s and before. The construction industry is a dynamic one, the burgeoning business opportunity of which has been sensed by a large number of people here. Homes, shops and homes with shops are constantly being built, demolished and rebuilt. Aspirations grow quickly, as does the desire for personal home improvement (with improvement of financial conditions and growing families). The state s lack of involvement in collective improvement of the area, in spite of regular election-toelection promises of doing so, adds to the family-centric initiative to build bigger and better. The promising construction industry has hence, been percolated by contractors local to Shivaji Nagar. Each one has a team of workers trained by them, occasionally shared with another contractor or two. Each time an existing home owner decides to build a house here, the family contacts one of the 300 or more local contractors operating within the area. Usually the one with the closest familial or friendly ties clinches the project. Better the reputation, greater the trust within the neighbourhood and its people and more booming is the business. Trust, is therefore the consistent key factor for maintenance of high quality construction practices here. Plots can be of 3 basic types. Prices and differences in building design differ accordingly. In all plots, the first floor can extend by 2 ft and the existing height restriction is 14 ft. Rent paid to the BMC for residential plots is Rs 100 and for commercial plots, Rs 400 per month. 1. The corner plots (18 x 10 ft) that are the most expensive because the shop is open to 2 streets and also the most challenging to build due to greater limitations in space due to inability to extend the entrance platform into the main street 2. The inner street facing plots (18 x 10 ft) where the 18 ft edge faces the road for greater visibility for shop and easy access. 3. The internal plots (10 x 18 ft) with the 10 ft edge facing the narrow lane. The house is narrow and deep. This is entirely residential. A month of following the construction of one house in Shivaji Nagar, would make the typical process of execution more clear. The house studied here, lies in Plot no.22 of the Lotus Colony in Shivaji Nagar (Type 3 plot) and is being built by a local contractor named Wasim Khan. He is the young partner of contractor and entrepreneur, Pankaj Gupta and only recently made his entry into the lucrative building scene here. He runs an advertising company alongside, as well as helps his father run a popular restaurant in the same area. Apart from this he takes time out to pass on some valuable lessons in building construction, that have been handed down over years from one contractor to another, to curious onlookers (us). Most of the information here is derived from interactions during his regular presence on site. Design and execution here is all through the word of mouth. There is neither any paperwork, nor drawings, nor

3 technical visual tools involved. There is sharp focus on the final form which is seamlessly (sometimes even wordlessly) communicated from the client to the contractor to the head masons to the labour and hired workers. As per challenges that come up during construction- from fluctuating site conditions, to stray BMC officials- the design is tweaked, and inventive ad-hoc solutions proposed. The ultimate resultant would be an amalgamation of ideas thrown in during the process, by all the aforementioned actors, as well as a pre conceived formal form that has already been established as a typology best suited to the 3 typical plot conditions here. Affordability and maximum efficiency from minimum space are most often, the basic design brief for any given project. (A similar detailed study has been conducted by students of JJ College of Architecture during the JJAH workshop which is in the process of compilation) Name of Client : Ali Address : Plot no. 22, G-Block, Lotus Colony, M Ward, Govandi Project Brief : Plot size 15ft x 10ft No. Of users people Context - Houses on either side, narrow lanes at front and back Budget Restricted No. Of floors- G+1.5+terrace Contractor : Wasim Khan, Pankaj Gupta Workforce : The contractors have a regular team of 35, but hire from the neighbouring labour naka as and when required. On an average 4-6 labourers work in a day and the work is usually completed within 45 days. Concrete masons team - 4 Shuttering team - 3 Brick masons - 4 Carpenter - 1 Electrician (with employees) -3 Plumber (with employees) - 2 Tiling 3 The shuttering is done by a specialized team that accompanies the team that does the casting of the concrete columns and beams. The shutters belong to the shuttering team. The rest of the concrete mixing equipment belongs to the carpenter himself. (ref : JJAH study)

4 Location plan : Materials used : Cement + Sand + Aggregate Bricks

5 Shahbad Stone (ladi) Koba Steel reinforcements Steel channels Granite

6 Steps : 1. Demolition This is the first stage of construction when walls of the previous house are demolished. Some walls remain to be used as debris to fill up plinth at a later stage. Most projects given to contractors in SN are improvement of existing homes. Another day goes in site clearing. 2. Excavation

3. Foundation and Sump Pit - 3ft deep trenches are dug for the foundation. An RCC cage of 3 ft X 3ft is inserted into the trench, for footing, above the rubble soiling (fine and coarse aggregate).

7 3. Foundation and Sump Pit - 3ft deep trenches are dug for the foundation. An RCC cage of 3 ft X 3ft is inserted into the trench, for footing, above the rubble soiling (fine and coarse aggregate). Reinforcement rods are 12mm in diameter and 5 to 8 rods are used in one direction. Concrete is poured over it. The sump pit is also built simultaneously. 4. Column Reinforcement The column reinforcement starts side by side with the excavation and foundation. There are 6 columns in total with dimensions of 9" x 12" on one side and 6" x 12" in on the other. 6 reinforcement bars of 12 mm thickness are used, as opposed to 4 bars that are usually used by other contractors to reduce cost. On one side, the columns need to be flushed into the wall more to make space for the door opening. The reinforcements had to be readjusted in the first column at the entrance due to lack of space for staircase, thus resulting in an extra day of work and payment for the shuttering labourers.

Once filled, the next day is spent filling the top layer with brickbat koba as a waterproofing layer. 6.

8 5. Plinth A day is spent after this for filling in the excavated parts and building the plinth up to 3 feet in height. The remaining old walls are broken so as to fall into the pits. Once filled, the next day is spent filling the top layer with brickbat koba as a waterproofing layer. 6. Plinth Beam The plinth beam is a 9" ring beam that ties the entire plinth together so as to bind the 6 columns and transfer load to the foundation. Gaps are left in this beam for the pipe leading out of the sump pit at a slope as well as for the entrance steps.

7. Ground Floor Netting The netting consists of 8mm reinforcement bars set in a mesh that give strength to the plinth and tie into the ring reinforcements of the plinth beam(in which concrete is only

9 7. Ground Floor Netting The netting consists of 8mm reinforcement bars set in a mesh that give strength to the plinth and tie into the ring reinforcements of the plinth beam(in which concrete is only filled to 3/4 of the beam height to allow for space for netting to tie in). This eventually ties in all the structural members on the ground floor. It is then filled with a 3" layer of cement mortar and finished with tiles at the end.

Only ground floor columns take one day to complete. 9.

10 8. Column formwork Column framework (shuttering) is done by a special team called the centring team that goes from one site to another. Only ground floor columns take one day to complete. 9. Column filling Another new specialized set of labour are called in for mixing the concrete and the filling the structural members.

10. Brickwork Ground Floor The brickwork only needs to be done on the front and back elevation. Both the side walls are shared with the neighbouring houses. This reduces cost considerably.

as no plans or drawings are made before starting. The rest of the brickwork is added before the beams are cast. 11.

2 feet is cantilevered from both ends to compensate for space lost for constructing the staircase. There is an intermediate beam to transfer load to the two columns in the center.

11 10. Brickwork Ground Floor The brickwork only needs to be done on the front and back elevation. Both the side walls are shared with the neighbouring houses. This reduces cost considerably. First a portion of the walls are built (at the same time as column filling) to get an idea of the space to be allotted to other openings, stairway etc. as no plans or drawings are made before starting. The rest of the brickwork is added before the beams are cast. 11. Beam and Staircase reinforcements Beams are the next members to be constructed. They are 9"x9" in dimension. 2 feet is cantilevered from both ends to compensate for space lost for constructing the staircase. There is an intermediate beam to transfer load to the two columns in the center. The total floor height is 11 feet, excluding the beams. The staircase starts at midlevel from the floor level as the future access till that level will be with a steel ladder. Intermediate beam reinforcements are to support the mid landing. 12. Beam and Staircase Shuttering The shuttering of the beams and staircase continues alongside the laying out of the channel ladi slab for the flooring of the room above

12 13. Beam and Staircase Filling The beam and staircase are filled at the same time. Both levels of the staircase need to be filled at one go and left to set. 14. Channel Ladi Floor Slab

The Shahbad stones are laid across the joists and then cemented, waterproofed and tiled.

13 Instead of using a concrete slab that is usually needed for larger loads, a money saving technique is to use steel channels (T OR I sections). These joists are laid to cover the shorter span, in between the beams. The Shahbad stones are laid across the joists and then cemented, waterproofed and tiled. There is a layer of waste bricks (koba) below as fillers to waterproof the joints of slab to wall. 15. Brickwork and Door Windows for Ground Floor

The rest of the brickwork along with the lintels and openings are added before the beams are cast. Lintels are made of kadappa stone. The framing for the openings are made of granite stone.

14 The rest of the brickwork along with the lintels and openings are added before the beams are cast. Lintels are made of kadappa stone. The framing for the openings are made of granite stone. Since the space between the door and the staircase was not enough for the window, a bigger opening was added in the space between the door and the ceiling. Cement mortar is added to fill in space between the brickwork and granite. 16. Brickwork and Windows for First Floor Once the slabs, beams and staircase are cast, the first floor elevation is quickly constructed. The first floor can then be used for storage of materials instead of keeping them outside, in case of a visit from BMC officials. The first time round, the wall is temporary for BMC demolition so construction can be resumed after this formality, without any problems.

17. Bathroom brickwork and channel ladi mezzanine Around the same time as the brickwork is completed, the internal

The steel channels are laid out at a height of 6 ft (this is why the height of the ceiling is more).

Shahbad stones are laid above and covered with an inch of cement mortar. 18.

15 17. Bathroom brickwork and channel ladi mezzanine Around the same time as the brickwork is completed, the internal brickwork of the bathroom too is finished and the mezzanine started. The steel channels are laid out at a height of 6 ft (this is why the height of the ceiling is more). The construction technique is the same as the slab. Shahbad stones are laid above and covered with an inch of cement mortar. 18. Exterior/Interior Plastering for Ground Floor The interior plaster is applied once the formwork is removed and the old walls from the neighbouring houses are scraped. The plaster of the parts of the wall that need to be tiled are then scraped to provide a good grip for tiles.

concrete on top is levelled and koba added in 2 layers to form the filling between the channels

16 19. Column formwork and filling for first floor 20. Beam and Staircase to Second floor formwork After beam formwork is built and filled in, the concrete on top is levelled and koba added in 2 layers to form the filling between the channels for the slab. The 2 ft cantilever of the beams is used as landing space for the staircase. The staircases are directly on top of each other to save space.

21. Laying of channels for First Floor slab This is the same as the floor below.

netting. The floor can then be finished with tiles, if preferred. 22.

structural members is done on the above floors by specialists, the regular team of workers

17 21. Laying of channels for First Floor slab This is the same as the floor below. First the beam is levelled, then koba lined up on top, then the channels laid between the intermediate beams. Ladi rests on top of this and is coated with cement mortar, with or without the use of netting. The floor can then be finished with tiles, if preferred. 22. Wall and Bathroom tiling and fittings for Ground Floor While the formwork and filling for structural members is done on the above floors by specialists, the regular team of workers begin the tiling and granite kitchen counters for the ground floor. The skirting is left for later. The fittings in the bathroom, in this case an Indian toilet, are installed and the floor and wall tiling completed.

finishing off the plastering of the first floor already.

18 23. Plastering of First floor walls- Since the material for the mezannine floor (steel channels and ladi) haven t come yet, the contractor decides on finishing off the plastering of the first floor already. The staircase too is freed from its formwork and the lower portion plastered. 24. Completion of slab

19 25. Brickwork for final floor

It will be the future bedroom for the husband and wife, with an attached terrace while the ground floor will be rented out.

20 26. Facade for Second floor and openings with lintels The second floor, is different from the first 2 floors as it is not independent with a kitchen and a toilet. It will be the future bedroom for the husband and wife, with an attached terrace while the ground floor will be rented out. The water tank will sit on a slab on top of the roof of the final floor. This floor has completely load bearing walls and the structure is made up of brick piers. Lintels are made of stone and take the load of the brickwork and slab above.

21 27. Laying of kadappa stone slab over staircase and roof detail

Incase the house is vertically expanded, it ll be easy enough to

22 Since the slab over the final flight of staircase will not take any load, it is simply made up of slabs of a stone called kadappa. Incase the house is vertically expanded, it ll be easy enough to remove these and extend the flight of stairs to any future floors.