Sequence of activities in Building Construction

Construction of a building involves a lot of repetitive activities which needs to be scheduled step by step in a most likely manner. The one who is intending to construct a building needs to have a brief knowledge about the sequence of these activities in order to keep a tab on the contractor. The sequence of activities to be followed is the utmost important procedure of construction. Some of the activities may happen simultaneously and few others happen one after the other. Managing these activities involves managing time, cost and quality of work.

In this article, I would like to through light on the following activities which are basic in construction of a house:

Planning: Construction of building involves a detailed paper works of the project. This activity involves, approval drawings, architectural drawings, working drawings, structural drawings, MEP drawings, preparing bill of quantities, rate analysis of materials and labour, activities scheduling etc.

Marking of layout on site: After planning, site is cleaned for any weeds and plants grown or debris present. Later the working centreline layout is marked on the ground with accurate dimensions and orientation. At this stage, orientation of the proposed building need to be properly fixed parallel to the orientation of the road and all layout needs to be made right angle to each other.

Excavation: The earth is excavated in the layout marked for column footing and wall foundation works. The depth of excavation need to be decided based on the type of soil, strength of soil, scope of the structure that is proposed, risk of earthquakes, wind load etc. After excavation, the footing side earth needs to be dressed for any loose particles and to achieve desired size and shape.

Foundation work: Column foundation comprises of a series of sub activities. These activities usually repeat for every concreting activity. The following are the sub activities for foundation work.

Earth compacting: Once the earth is excavated and the pits are dressed for the desired shape and size, the base of the earth is evenly compacted to have a firm base for the foundation.

PCC: After earth compaction, a layer of about 4inches to 6inches of plain cement concrete is poured to the foundation pit. This proceedure is done to prepare a firm ground for column position markings and to place the reinforcements in place with proper levels. 

Footing & Column reinforcement: The steel reinforcements for the column and the footing are tied and placed into the foundation pits with proper levels and positioning. Along with this, cover blocks are also provided to give proper cover to the reinforcement.

Shuttering: Shuttering for footing is not always necessary as the shape of the foundation pit will be according to the size and shape of the footing, hence the earth walls of the pits will act as the shuttering to the footing. Where as in raft footings and other excavations where excess earth is excavated and the shuttering is necessary, the shuttering moulds are prepared with either metal sheets or plywood boards.

Footing concrete: Once the above activities are finished, concrete of the designed grade is batched, mixed and poured into the foundation pit from not more than 1m depth. The concrete poured is to be properly compacted with needle vibrator to achieve higher strength, avoid honeycombing and to achieve smooth finish.

Column casting: After final setting time or one day after the footing concrete, its time to remark the column upon the footing and column is casted for 2inches which is termed as column starter. This starter is casted to ensure the position of the coulmn and its reinforcements, and to give proper grip to the column metal/wooden box which is used as shuttering to the columns. Later, after the started is set the column boxes are fixed in place and the concrete of the designed grade is batched, mixed and poured. This is also properly compacted with needle vibrator to achieve higher strength, avoid honeycombing and to achieve smooth finish. Once the column has finished final setting time, the column can be deshuttered and wrapped with gunny bags or earth is backfilled for further curing purposes. 

Plinth casting: All the columns are inter-connected with each other by tie-beams called plinth at ground level. These beams have dual functionality; one is to tie all the beams together and second is to act as wall foundation. For casting plinth beam shuttering needs to be provided and plinth reinforcement have to be tied and then concrete of designed grade needs to be placed and compacted.

Damp Proof Course (DPC): DPC layer is usually provided at the plinth level to restrict the movement of moisture through walls and floors. There are various impervious materials that can be used, out of which concrete mix (1:2:4) is generally adopted in the construction of residential projects. 

Construction of walls: Walls are constructed with various materials like burnt bricks, concrete blocks, fly-ash blocks, porotherm blocks, light AAC blocks and many others in thickness of 4inches, 6inches, 8inches and 9inches. The materials and sizes are decided based on the clients requirements, size of the plot and budget available. A wise decision here helps the best usage of space available on the site.

Lintle: Beams that are provided above openings such as doors, windows, path ways and other passages to support the above wall is called lintle. These beams can be provided continuous through out the wall length or restricted to the openings with minimum bearing length. Lintles when provided through the walls also acts as a tie beam in the wall.

Roofing: Concrete roofing includes varioussub activities such as - centering/shuttering, steel barbending, providing cover blocks, electrical conduiting, concrete batching, pouring, compacting and curing. All these activities are same as explained earlier but at different levels. These activities are repetative for each floor.

Fixing of doors & windows: After completion of the structural works such as construction of walls and roofing, and before plastering, doors and windows are fixed into the wall. Now a days, many contractors tend to place them during construction stage which may be not technically correct as the plastering levels wouldn't have been fixed at this stage. All doors and windows are provided with clamps for support and concreted into the wall. 

Fixing of Electrical and Plumbing pipes: All the necessary electrical conduiting and concealed plumbing works need to be completed before the satrt of the finishing works like plastering etc., to avoid the damages. These conduits and pipes are placed into the walls by groove cutting in the wall and inserting the necessary pipes and locking it with nails and binding wires.

Plastering work: The finishing works of the building construction starts from this stage, where the walls are plastered with cement mortor and achieved for the necessary finish . The finish varies with the location of plastering, like it is different for external wall plastering and internal wall plastering and so on. All damages and pipes and conduits are covered up at this atage of work.

Tiles/Granite/Marble laying: Based on the required floor finishes, the material to be used is decided. It is also majorly decided on the budget available for the project. Marble being the costliest, next is the granite and the cheapest option is the tiles. Although, selection of natural materials is a task, which I will be discussing in detail in further blogs. Other than flooring, bathroom floors and wall dado, kitchen wall dado, pooja floor and wall dado, elevation cladding etc. will also be finished with the above materials.

 

Interior woodworks & False ceiling: Interior works of the building includes fabrication of wardrobes, shilves, modular kitchen, T.V units, POP false ceilings and other storage boxes. These are done for creating storage spaces as well as for improving the appearance of the interiors of the building. Please go through the other blog post for further details.

Painting: After the walls are plastered, they have to be made colourful to look appealing. This stage includes applying two coats of putty for interior walls (this is not required for external walls) which provides level and smooth surface for the paint to be applied. Later, one coat of primer is apllied to create a bonding surface for the paint, and then two coats of the required paint is applied.

Miscellaneous works: Various activities like grill works, hand railings, cloth hangers, cloth washing platform, gas pipelines, security systems, access controls etc., are not to be forgotten.

Terrace, bathrooms and toilets waterproofing: Waterproofing is a preventive activity to prevent the moisture absorption and seepage into the flooring. These are done to places which is exposed to continuos water usages in the upper floors. Waterproofing is a must, as water leekages and seepages after construction is highly difficult to inspect the source and arrest the problem.

Landscaping works: This includes installation of indoor plants and planting lawn, plants and trees surrounding the building. This is done to enhance aesthetics, interior atmosphere, improve healthy air and local climate of the building. Maintainance of the plants are quite difficult, but the benefits of having the same is enormous.

Installation of Furniture: Final stage is installation of furnitures such as sofa, cot, teapoy, dining tables, chairs, curtains etc. Appealing fabrics need to be selected for the furnitures as they contribute majorly for the interior looks of the house.

Conclusion: Everyone who have an idea of constructing their dream home in their lifetime need to understand the activities that are involved in the construction of buildings. This knowledge help people in various way, like to understand their own requirements, practical feasibility, to discuss with architects and engineers, to have discussions, negotiations with contractor and to avoid misguidances and misconceptions about construction.