What Size Beam For 24 Foot Span?
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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 is 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 4-2×18, 18”*24” or 8*8 size beams to span 24 feet.
The appropriate size of the beam for a 24-foot span depends on various factors such as the load it will bear, the type of wood or material, and the spacing of the beams.
As a general reference, below is a table of standard lumber sizes and their corresponding maximum span for a uniformly distributed load.
| Lumber Size | Maximum Span |
|---|---|
| 4×6 | 9 feet 11 inches |
| 4×8 | 12 feet 4 inches |
| 4×10 | 14 feet 7 inches |
| 4×12 | 16 feet 10 inches |
| 6×6 | 11 feet 10 inches |
| 6×8 | 15 feet 2 inches |
| 6×10 | 18 feet 2 inches |
| 6×12 | 20 feet 3 inches |
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 tension 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 the 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 a beam for the RCC column for a 2-3 story 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 is 24 feet so the standard depth= is 24×12″/20= 15″, and the diameter of the beam= 16 mm, and the cover = 1″ so the ultimate depth= standard depth + cover+ 1/2 of the diameter of beam bar = 15″+1″+0.3″=16.3″
Thus 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 12 inches.
You should use a 25mm clear cover and 2 nos of 16 mm bar at the top and 2 nos of 20 mm bar at the bottom to make the beam secure.
All the above calculation is done using the thumb rule for a 2-3 story 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.
What are the different types of beams?
There are three main types of beams: wood beams, steel beams, and concrete beams.
Wood Beam:
Wood beams are the most common type of beam used in construction.
They are made from lumber that has been cut to size and then joined together to form a beam.
Wood beams are strong and durable, but they can be susceptible to fire and termite damage.
Steel Beam:
Steel beams are made from rolled steel that has been cut to size and then welded together to form a beam.
Steel beams are very strong and are often used in construction that requires long spans or heavy loads. Steel beams can be susceptible to corrosion.
Concrete Beam:
Concrete beams are made from concrete that has been formed into a beam shape.
Concrete beams are very strong and are often used in construction that requires long spans or heavy loads.
Concrete beams can be susceptible to cracking.
Which type of beam is best for a 24 foot span?
The best type of beam for a 24-foot span depends on various factors such as the load it will bear, the spacing of the beams, and other design considerations.
Below are some commonly used beam types and their advantages:
Wood beams:
Wood is a common material for beams due to its availability, cost-effectiveness, and ease of construction.
Wood beams can be solid or engineered, and they come in different grades and sizes.
The advantage of wood beams is their aesthetic appeal, and they are suitable for many residential applications.
Steel beams:
Steel beams are commonly used in commercial and industrial buildings due to their strength, durability, and fire resistance.
Steel beams are available in various sizes and shapes, and they can span longer distances than wood beams.
The advantage of steel beams is their ability to support heavy loads and resist deflection.
Glulam beams:
Glulam (glue-laminated) beams are engineered wood products that consist of multiple layers of dimensioned lumber bonded together with adhesive.
Glulam beams are strong, durable, and versatile, and they come in various sizes and shapes.
The advantage of glulam beams is their ability to span long distances and resist deformation.
LVL beams:
LVL (laminated veneer lumber) beams are similar to glulam beams but are made of thin layers of wood veneer glued together.
LVL beams are strong, stable, and uniform, and they come in various sizes and lengths.
The advantage of LVL beams is their ability to span long distances and resist sagging.
FAQs About Beam For 24 Foot Span
What size of lumber is required to span 20 feet?
It is not accurate to state that a 2×8-10 dimensional lumber spaced at 16 inches on center can span 20 feet.
The appropriate size of lumber required to span 20 feet depends on various factors such as the load it will bear, the spacing of the lumber, and the type of wood.
What size beam can span 24 feet?
According to the thumb rule an 18″ ×24″ beam can span 24 feet.
The appropriate size of beam required to span 24 feet depends on various factors such as the load it will bear, the spacing of the beam, and the type of beam.
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 a column.
For ordinary structures, it can be a maximum of 7.5 m.
Bottom line
Determining the appropriate size of the beam for a 24-foot span requires consideration of various factors such as the load it will bear, the spacing of the beams, and the type of beam.
While a table of standard lumber sizes can provide a general reference, it is recommended to consult with a structural engineer or a building professional to ensure the safety and structural integrity of the building.
