In this post, you’re going to learn everything about RCC Lintels. You’ll also learn about:
- Various types of lintel
- Their advantages & disadvantages, and
- The construction process of an RCC lintel.
So, if you:
- Are working in the building construction sector,
- Want to learn about various technical things for constructing lintels, and
- Need to get a step-by-step construction process…
Then this guide is for you.
So let’s dive right in without further ado.
What Is A Lintel?
A lintel is a minor structural member that is built on the top of a wall opening.
This opening can be a door opening.
Or, a window opening.
Or any opening in a masonry wall.
What Is The Purpose Of Constructing A Lintel?
To carry loads above the opening.
And transfer them to walls.
So, we can say that a lintel works like a simply supported beam.
Types Of Lintel
Lintels can be categorized based on two criteria:
- Span, and
- Materials used to construct lintels.
Types Of Lintel Based On “Spans”
Based on the span, it can be two types:
- Isolated lintel, and
- Continuous lintel.
Let’s discuss a little about these two types…
This type of lintel is commonly used in framed structures.
They are made individually on the top of openings.
And both sides of the lintel are extended into the walls. This extension is called bearing.
The question is, what should be the length of the bearing?
It should be a minimum of the following:
- 4 inches;
- The thickness of the lintel;
- 1/10 to 1/12th of the span of the lintel.
This type of lintel is like another tie beam. It runs through the top of all masonry walls and connects all the columns.
Normally, this lintel is made with reinforced cement concrete.
And they are commonly used in:
- Load-bearing structures;
- Areas prone to earthquakes, and
- Building with expansive soils.
Now, let’s see the…
Types Of Lintel Based On “Materials”:
This classification is done based on the materials used to make lintels.
And they are the following types:
- Reinforced cement concrete (RCC) lintel
- Plain cement concrete lintel
- Steel lintel
- Stone lintel
- Brick lintel
- Timber lintel
- Flitched lintel
Let’s discuss these lintels in detail.
So that you can choose the right type of materials for lintels.
Reinforced Cement Concrete (RCC) Lintel:
Nowadays, this type of lintel is commonly used in buildings.
It’s made with cement concrete with reinforcement inside it.
So, you can say this is similar to an RCC beam.
RCC lintel can be made in two ways:
- Precast, and
And, RCC lintels can be used as individual or continuous types of lintel.
One of the crucial advantages of RCC lintels is that you can build sunshades along with them.
Besides this, there are some other…
Advantages Of RCC Lintels:
- These are the best of all the other types. Because they are resistant to tension, compression, shear, and deflection;
- It is easy to construct;
- It’s relatively cheap;
- This lintel is most suitable for long-span; and
- Using precast RCC lintels can speed up the construction process.
Along with these advantages, RCC lintel also has some…
- They need formwork to construct;
- It takes time to cure the RCC lintel. And you need extra manpower for that.
Plain Cement Concrete (PCC) Lintel:
Unlike the RCC lintel, PCC lintels are just made with concrete without reinforcement.
That’s why it is good in compression but weak in tension.
Advantages Of PCC Lintels:
- It’s economical for short spans;
- Easy to construct, and
- Relatively cheap.
Disadvantages Of PCC Lintel:
- It can’t be used for long spans;
- It’s weak in tension;
- Requires formwork for casting;
- It’s weak in earthquakes; and
- It’s required to allow a good amount of time for curing. Thus it increases project completion time.
This lintel is made with prefabricated GI sheets, rolled I sections, or angle sections.
This lintel is embedded into concrete or painted with anti-corrosive paint to increase the capability to fire resistance and corrosion.
Advantages Of Steel Lintel:
- It can be used for long spans;
- It doesn’t require formwork and curing. So it’s time-saving;
- Steel lintels can be fabricated to any shape; and
- They are easy to handle and transport.
Disadvantages Of Steel Lintel:
This type of lintel has the following disadvantages –
- These are vulnerable to corrosion, and
- They are also susceptible to fire.
These lintels are made of stone.
Generally, a single stone is preferred to avoid joints as the joint makes the lintel weak.
Normally, 6 inches height of the stone is used for lintels.
Now, let’s see some…
Advantages Of Stone Lintel:
- It provides an aesthetic look and elegant appearance;
- This type of lintel doesn’t require any formwork to construct;
- It also doesn’t need to be cured;
- If the stones are locally available then they can be cost-saving, and
- This lintel can be ideal to use on short spans.
There are also some…
Disadvantages Of Stone Lintel:
- This lintel doesn’t perform well in earthquakes, vibration, and shock waves;
- These lintels are costly when stones are not available locally;
- The stone lintel isn’t suitable for long spans.
Now, we’ll talk about brick lintels.
You may have seen this type of lintel in ancient buildings.
They are still used in some buildings for decorating purposes.
The height of the brick lintel ranges from 4 inches to 8 inches depending on the length of the span.
Advantages Of Brick Lintels:
- This is the cheapest type of lintel;
- This lintel is ideal for short spans;
- In this type of lintel, cracks can be avoided as both lintel and wall materials are the same.
- This is not suitable for long spans;
- Bricks are weak in tension;
- Bricks are weak and can take light loads only;
- A minimum curing period of 2-3 weeks is necessary. Thus it can hamper work progress.
This is the oldest type of lintel.
This lintel is made of well-seasoned natural wood.
It’s better to use a single plank of wood for this type of lintel.
But, you can join two or more strips of wood together with bolts.
The thickness of these lintels should be 1/12th of the span of the lintel.
There are some…
Advantages Of Timber Lintel:
Such as –
- It’s easy to construct;
- They don’t need any formwork to build, and
- No curing period is required.
There are also some…
Disadvantage Of Timber Lintel:
- Timber lintel can deteriorate if not maintained properly;
- These lintels are very costly;
- This type of lintel can’t be used in permanent structures;
- Wood is very weak to bear tension, compression, and shear forces;
- They are very vulnerable to fire.
This is actually a timber lintel.
In this timber lintel, steel plates are provided at the top and bottom of the lintel.
Thus, it acts as a composite structure.
Let’s see some…
Advantages Of Flitched Lintel:
- This lintel is easy to construct;
- It’s stronger than timber lintels;
- Does not require curing, and
- No formwork is required.
Disadvantages Of Flitched Lintel:
- This type of lintel is very costly, and
- The materials of this lintel are very vulnerable to fire.
So, These are various types of lintels we used in building construction.
At a glance, here they are:
As you’ve learned about various types of lintel.
And, their advantages and disadvantages.
You can now choose which type of lintel you should use in your project.
But, you’ll find that RCC lintels are mostly used in modern building construction.
So, here, I’ll share the…
Construction Process Of RCC Lintels
Because this is a widely used lintel.
In this process, you’ll learn:
- The step-by-step tutorial to construct an RCC lintel;
- Various technical things that’ll help you to overcome future difficulties;
- To build a lintel with quality.
So, let’s start with…
Step-1: Build Walls Up To Lintel Level
As you know, lintels are built on masonry walls.
So, the first thing is, you’ll build all the walls of an apartment up to lintels bottom level.
But what is the lintel’s bottom level?
It’s 7′-2″ from the unfinished floor.
Because, we know, the height of a door (including the frame) is 7 feet.
But that is from the finished floor.
The finished floor means after completing tiles on the floor.
And, we know that floor tiles somehow take almost 1½” thickness including mortar.
But we need a ½” gap between the door frame and the lintel.
That’s why we keep the lintel’s bottom level at 7′-2″.
[Note: Sometimes floor finishing takes different thicknesses due to the different types of floor finishing materials. You should keep that in consideration too.]
Here I want to talk a little bit about the wall height below the lintels.
See the image below:
In the image above, the wall didn’t reach up to 7′-2″.
It happens because of the different thicknesses of bricks or blocks.
If you put one more layer of bricks, it’ll exceed our desired level.
So, what should you do?
It’s not a big thing.
Keep the wall below the lintel level.
And, increase the thickness of the lintel in that portion.
Step-2: Allow Curing Period
After completing brick walls up to the lintel level, leave them there.
Don’t allow any other work.
And, wait for the curing period to end.
Because walls are weak in that period.
Once the walls gain sufficient strength…
Step-3: Make Formwork
RCC lintels can be haulage in two ways.
- Precast, and
Precast RCC lintels can save you time and speed up the work progress.
Cast-in-situ lintels have the privilege to make strong bonds with walls.
The casting process is the same for both methods.
For precast lintels, you’ll make the formwork somewhere on the floor.
And, for cast-in-place lintels, you’ll make the formwork on walls.
To make the formwork:
First, Get The Size Of The Lintel.
A lintel has three dimensions – Length, width, and thickness.
The length of a lintel is the clear span and bearings.
The width of a lintel is the thickness of the masonry wall that the lintel will build on.
But, the thickness of a lintel depends mostly on the length of the lintel’s span.
So, thickness varies for different lengths of openings.
But, in a building, the commonly used thickness of lintels is six inches.
However, you’ll have a structural drawing of lintels for your project.
Follow that drawing to get the size of the lintels.
Next, Choose the Formwork Materials.
Most of the time, we use wooden shutters for lintels.
Sometimes steel shutters are also used if available in the project.
You can use whatever materials you have. It’s not a big factor.
In my opinion, wooden shuttering materials are the best to use as they are easy to handle.
After That, Make Reference Levels On Walls
This is crucial.
And, you need to understand this very well.
Because all the lintels should be made at the same level.
For that, make a reference mark for the floor somewhere.
Normally, this reference mark is made on the lift core.
Not only for lintel making, but you also need this reference mark for installing door frames.
Now that you have a fixed reference mark for the floor, carry that to the opening where you’ll make the lintel.
It’s done by using a water-level pipe.
Do this for all the lintels.
Finally, Make Forms
You have the size of lintels!
You’ve chosen the shuttering materials!
You’ve taken the reference level.
You can now make forms.
Step-4: Complete The Reinforcement Work
You’ll have a structural drawing for lintels.
That somehow looks like the image below:
If you don’t have a drawing like this, ask the structural engineer to provide one.
Normally, the same drawing is used in all the projects as long as no exceptional lintel is available.
Complete the reinforcement work as specified in the drawing.
Step-5: Pour Concrete
Normally, hand-mix concrete is used for lintels.
And, the proportion of concrete ingredients is 1:2:4.
That means one part cement, two parts sand, and 4 parts coarse aggregates.
With that, prepare concrete and pour it into the lintel.
Step-6: Start To Cure Lintel
Any cementitious materials need to be cured for 28 days.
But, as lintels are the minor structural members, you can cure them for 7 days only to keep up the work progress.
Step-7: Remove Forms
Like any other RCC member, once the lintel gains sufficient strength you can remove forms.
You can reuse these forms for other lintels.
So, while removing them, take care of them.
I hope this post helped you to understand different types of lintel.
And, the construction process of RCC lintels
Now I Would Like To Hear From You:
How long do you cure RCC lintels?
When do you strip lintel forms?
Let me know by leaving a comment below…