Construction projects are massively incorporated with monetary expenses. If viewed from the bottom line, every single construction material or the resources used in the project are connected with monetary expenses. Every project be it residential, commercial, or industrial, comes up with a specific budget and if this set amount is exceeded, the entities involved in the project could suffer from heavy losses. So, to ensure, a cost-effective construction project, every single process involved has to be measured with its cost incurred. Often the slab height (the plinth beam) and its representation in the monetary value is ignored but that should not be the case if the involved parties want to save money and yet have the best results. The height of the plinth beam is directly and indirectly connected to the structures it is connected which are central to the entire project.
The relation between the plinth beam and other structure(s) of the building
When the ground floor is constructed, the function of the plinth beam is to carry the load of its construction material such as the building blocks which are used to construct it. It is to be noted that the plinth beam supports the ‘dead weight’ of the ground floor.
Due to the difference in the height of the settlement, the size of the plinth beam can vary greatly. In areas with high sea levels, this factor has to be more seriously taken into account. Anyway, in normal cases, the adjacent road level is always maintained to be at least 150-300 mm below the house. This creates a gap between the foundation level to the top of the plinth and can greatly increase if the difference between the adjacent road level and the construction is huge. In these cases, the plinth beam retains the backfilled soil and fills that gap.
The density of the soil below the foundations has to be adequate or else masonry walls are subjected to possible cracks which weaken the construction and can lead to personal risk of its habitants and even the surroundings. This is prevalent in the differential settlement; the plinth beam reduces the differential settlement in the construction project and sustains the respective structures.
The slenderness ratio (it results from the unsupported length of the column to the cross-sectional area of the column) affects the load-carrying capacity of columns. When the foundation is deep, i.e., more than six feet, the plinth beam rightly adjusts the slenderness ratio. It is suggested to mandatorily add an RCC plinth beam in the case of the foundation being more than six feet.
The plinth beam functions as a tie beam when the foundations of the construction are less than or equal to six feet.
Firstly, make sure that the entire project is well-planned, and the planning is inclusive of making the construction cost-effective. Secondly, estimate clearly how the plinth bean would affect various structures and processes involved in the construction project. Thirdly, and most importantly, invest in high-quality building material for constructing the plinth beam.