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Generally, a beam is made of concrete, wood, or metal to give support. It is a load-bearing tool that can vertically transfer all incoming load.
Do you want to know what size beam for 24 foot span? Well using the right size beam is essential to ensure proper support.
So Let’s know how to calculate beam size to avoid a wrong purchase.
What size beam for 24 foot span?
You should use a minimum of a 4-2×18, 18”*24” or 8*8 size beams to span 24 feet. Now the question that pops up in your mind is how this calculation done, right?
So Let’s learn the general thumb rule to find out the exact beam size according to your needs.
Calculate beam size
Typically beam size depends on the span between two supports and the predicted load on the beam.
The beam is made in different sizes to rule the different types of shear forces and stresses.
Beam’s depth is the key to deciding its load-carrying capacity. We use a beam with the top bar that faces compression.
On the other hand, the bottom bar faces tension. As a result, the tention bar experiences a bending moment and stirrup.
So you can always use a standard-size RCC concrete beam if you don’t have expertise.
At least a 9″ ×9″ size beam can give you enough support. The depth of the beam needs to rise or decrease depending on its span and load value.
So according to span value, you need to adjust the size. You can apply different methods to calculate beam size.
Below we will discuss two popular methods to calculate the beam size.
1. IS 456:2000
IS 456:2000 method declared that when you are choosing beam for the RCC column for 2-3 storey building follow the below Standards.
- First of all the cantilever beam span need to maintain a depth ratio minimum of 7
- Besides, the supported beam span’s standard depth ratio is 20
- The continuous beam span depth ratio should be 26
So when you are buying a beam for a 24-foot span the standard depth ratio for the supported beam is 20, span 24 feet so standard depth= 24×12″/20= 15″, the diameter of the beam= 16 mm, cover = 1″ so the ultimate depth= standard depth + cover+ 1/2 of the diameter of beam bar = 15″+1″+0.3″=16.3″
So you can count it as 18″ for ease of calculation or size.
Now the width = D/1.5= 18″/1.5= 12″
According to the formula, you need a 15″ ×18″ beam for a 24-foot span where the width is 12 inches and the depth is 15 inches. It is the calculation for the supported beam.
But if you want to know the beam size for the continuous beam for a 24-foot span then below is the calculation.
The continuous beam size for a 24-foot span is 12″ ×15″ where the depth is 15 inches and the width is 12inch.
You should use a 25mm clear cover and 2nos of 16 mm bar at the top and 2nos of 20 mm bar at the bottom to make the beam secure.
All the above calculation is done using the thumb rule and for a 2-3 storey building.
2. Thumb Rule Method
You can easily calculate beam size using the thumb rule. Here the rule us to calculate beam size and depth.
1 foot (span of the beam) = 1inch (depth of beam)
Suppose the beam span is 24 feet then the depth should b 24 inches, beam width = 24/1.5= 16. You can increase the value a bit to avoid calculation errors. So take the value as 18″.
According to the thumb rule, you need an 18″ ×24″ inches beam for a 24 feet span.
FAQs About Beam For 24 Foot Span
What size of lumber is required to span 20 feet?
You need a 2×8-10 dimensional lumber 16-inch os to span 20 feet.
What size beam can span 24 feet?
According to the thumb rule an 18″ ×24″ beam can span 24 feet.
How to know the beam size?
Use the below formula to calculate beam size.
The total depth of beam= effective depth + diameter of bar/2+ cover size.
Why do we use beam span?
To maintain building code it is essential to use beam span. It provides support for the joists which is important to ensure your safety.
What Is The Maximum Span Of The Beam Without A Column?
If you use an LVL beam then you can maximum span is 20’-30’ without column. For ordinary structures, it can be a maximum of 7.5 m.
We try to give a detailed answer on what size beam for 24-foot span.
Hopefully, now you know how to calculate beam size according to the required foot span. As it is a matter of safety so don’t use the wrong size span.
Follow the above methods to calculate beam size for your needed foot span. It will give you proper support and safety.
Moreover, you can’t cross the maximum span value of the beam with no columns. It is important to ensure structural safety.