A plinth level forms the foundation of a house. It is a rectangular block of stone on which a column and pillar of a building stands. It is a wall between the ground level and the ground floor level. Column bears the weight of the building’s structure but all this weight presses down on the column. The main function of a plinth in construction is to distribute the load of the columns over the foundation evenly. There are also many other uses of plinth which we will discuss in this blog. Let’s take a look.
Uses of Plinth in the Construction Industry
Here is a quick rundown on some of the most important advantages of plinth when constructing a house.
- It evenly distributes and disperses the load of the columns to the foundation evenly
- It acts a barrier or a retaining wall that keeps the concrete filled ground floor below the raised floor of the building
- The plinth doesn’t allow the dampness and moisture of the ground floor to reach the building’s top structure
- In framed structure houses and buildings plinth beams are used as a barrier for protection from water seepage. Plinth protects the rest of the house from dampness, mold and mildew. It is a kind of waterproofing sheet laid above the ground floor level to protect the house from any damage because of added moisture
- Gives strength and durability to the residential unit
- Provides a better aesthetic appeal to the building
- It also prevents cracks in the building when the foundation suffers from settlement
- Houses are normally constructed around 150-300 mm over the adjoining road level. The plinth functions as a retaining structure for the compacted soil which is applied to fill the empty space from foundation level to the top of the plinth.
Let us now go through the structure of a plinth beam.
Basic Structure of a Plinth Beam
In order to find out how a plinth beam is constructed, let us take a look at all the elements involved in it.
- Steel bars used for plinth beam
- The strength of the concrete structure
- Minimum dimension of a plinth beam
- Shuttering or formwork of plinth beam
Let us discuss how the structure of a plinth is formed.
Steel bars used for plinth beam
The basic structure of a plinth beam involves two bars with a minimum diameter of 12mm at the bottom of the beam. Similarly, two bars with a minimum diameter of 10mm must be provided at the top of the plinth beam.
It is important to cover the reinforcement bars with a 25mm concrete cover. As long as stirrups are concerned, the stirrup diameter should be at least 6mm with a spacing of 15cm.
The plinth level of the building should be above the adjoining road level The height of the plinth level should be around 2ft high as compared to the road level so that the water doesn’t enter your house during a heavy downpour.
Strength of the concrete structure
The concrete mixture of a plinth beam should have a suitable strength. It is recommended that the strength of the concrete used in the plinth beam should not be more than 20 MPa. The concrete mixture should be in a perfect ratio of 3 parts sand, 2 parts gravel and 1 part cement. If you are making the concrete mixture manually then an additional 20% cement needs to be added.
Minimum dimension of a plinth beam
The minimum depth of the plinth beam should be 20 cm while its width should be in line with the foundation of the house. Pillars and the plinth beam depends on the size of your building, whether it is a single story unit or a multi-story apartment.
Shuttering or formwork of plinth beam
All the columns are bound by steel bars and filled with concrete mixture to make it durable. The ground beams should be properly leveled and in a perfect line. The ground beams should be at a minimum 150 mm in natural ground so that the earth filled within walls is compact and makes the column durable and sturdy.
Shuttering should be dry and a mold release agent must be applied on it. Make sure all the joints are tight and there is no leakage of cement. Make sure that the junction of the beam column is tight and there is no bulge during concreting.
Difference Between Plinth Level, Sill and Lintel Level
There are three basic structural levels when constructing a residential unit. The plinth, sill and the lintel levels. For your convenience, we will explain the differences between these three for better understanding.
|Plinth Level||Sill Level||Lintel Level|
|Part of the structure between the ground and the raised floor of the house||It is between the base of the window and the portion above the ground floor||The level between the top portion of the window and the top slab is called the lintel level|
|It is part of the flooring of the house and forms the basic foundation of a building||It is part of the window and is provided between the bottom of the window frame and the wall below||The frame of the window or door can not bear the weight of the wall and therefore a structural element is introduced to disperse the weight of the wall evenly which is known as lintel|
So, this was all there was to know about the purpose of plinth when constructing a building. You can also check out the different types of bricks, types of parapet walls and how to build stable boundary walls if you are building a basic understanding of the construction process. Make sure to check out the construction cost of building a 5 marla, 10 marla and 1 kanal house in Pakistan. Don’t forget to write to us at firstname.lastname@example.org and we will surely get back to you. Subscribe to the Zameen Newsletter appearing on the right hand side of the page. Stay tuned to the Zameen Blog, the best real estate blog in Pakistan.