One of the main components in constructing joist-block roofs is the joist itself; these are long and slender elements that are installed in parallel across the roof span and are responsible for transferring the roof load to the main beams. With advancements in construction technology, various methods for producing joists have emerged, with the most important being divided into two categories: traditional joist (handmade) and industrial joist (factory-made).
Each of these two types has its own features, advantages, and disadvantages, and choosing between them directly impacts the project’s quality, execution speed, cost, and safety. In this article, we aim to answer the question—'Is industrial joist better or traditional joist?'—and determine which is the better choice for construction projects by thoroughly comparing both types.
What is a Traditional Joist?
The traditional joist, also known as a handmade or workshop joist, is one of the common and old methods for building joists in joist-block roof systems. In this method, the joist’s components—including tensile rebars, transverse (zigzag or truss) rebars, and reinforcement rebars—are assembled manually in a workshop or even directly on site. These components are then partially or fully concreted (depending on execution method) to form the final joist.
Main components of a traditional joist:
- Tensile rebar: Placed at the lowest part of the joist and bears the tensile stress from roof loads.
- Zigzag (shear, truss) rebar: Positioned diagonally or in a truss form between the tensile rebar and the upper rebar, helps distribute forces and maintain structural integrity between parts.
- Upper rebar: Typically used horizontally at the top of the truss to help withstand compressive forces.
- Reinforcement rebar (if needed): Added for longer spans or higher loads.
- Cover concrete (if present): Sometimes, the bottom of the joist is partially concreted to maintain shape and integrity.
Execution method:
Producing traditional joists is usually done without fully automated equipment and relies on worker skill and the accuracy of rebar placement and welding or tying. Sometimes, traditional joists are constructed and concreted directly on site, known as “cast-in-place joists.”
Applications:
Traditional joists are mainly used in small to medium-size buildings, especially in areas with limited access to industrial factories. They are also advantageous for projects that require high flexibility in joist design (e.g., unique spans or unusual shapes).
What is an Industrial Joist?
An industrial joist is a type of construction joist manufactured in specialized factories with engineering oversight and quality control. Unlike traditional joists, which depend more on individual craftsmanship, industrial joists are produced using automatic and semi-automatic machinery. This manufacturing method ensures uniform quality, higher precision, and greater speed in construction execution.
Main components of an industrial joist:
The general structure is similar to traditional joists, but materials and combinations are made more precisely and in a standardized manner:
- Tensile rebar (bottom wire): Like traditional joists, this bears tension from roof loads.
- Truss rebars (zigzag or mesh): Connected to the tensile rebar by spot or arc welding using machinery.
- Upper rebar: Placed at the top of the truss and embedded in the roof concrete.
- Filler block (during installation): Usually clay, cement, or polystyrene.
- Bottom or end concrete (in some factories): Pre-stressed or semi-prefabricated as part of the joist.
Production process:
For industrial joists, after detailed engineering design, components are assembled and welded using specialized machines. The joists are then cast in molds and cured under controlled conditions (temperature, humidity, and time) to obtain the required strength. This ensures every industrial joist has identical build quality and meets national and international standards.
Main features of industrial joists:
- Mass production and consistency with millimeter precision
- Strict quality control at all production stages
- Ability to custom design for special spans and loads
- Higher load capacity at lower weight compared to handmade joists
- Easy transport and installation, via crane or manual labor
Applications:
Because of their speed, standard quality, and greater strength, industrial joists are widely used in large-scale residential projects, high-rises, commercial complexes, industrial halls, and office buildings. They are the first choice for engineers and contractors in projects where time and construction quality are critical.
General Comparison of Traditional and Industrial Joists
Comparing traditional and industrial joists requires evaluating several key aspects that directly affect structural performance, project cost, execution time, and build quality. Each joist type has features that make it suitable for particular conditions. Below, we review these attributes separately:
· Build Quality
Industrial joists are manufactured in factories under strict supervision, so their quality is uniform, standard, and reliable. In contrast, traditional joists are made by hand in workshop settings, and their quality is highly dependent on worker skill and accuracy. Therefore, errors, weak connections between rebars, or misalignment are more likely in traditional joists.
· Production and Execution Speed
Industrial joists are produced using mechanized equipment, allowing fast and mass production, which is an advantage for large projects. On the other hand, traditional joists take more time to assemble and manufacture and may delay progress in bigger projects.
· Cost and Economic Efficiency
At first glance, traditional joists may seem less expensive, especially for smaller projects or where labor is cheap. However, while industrial joists might have higher initial costs, savings in time, reduced material waste, and better quality can lead to lower overall project costs in the long term.
· Dimensional Accuracy and Design
With industrial joists, length, height, concrete thickness, and rebar amount all precisely follow engineering drawings and calculations. This dimensional accuracy ensures better alignment with structural design and reduces the risk of execution errors. Conversely, the manual process of traditional joists can lead to inconsistencies in size.
· Design Flexibility
Because traditional joists are hand-made, they offer more flexibility to adapt to unique spans, irregular roof shapes, or real-time changes in design. Should changes be needed during construction, traditional joists accommodate adjustments better. Industrial joists, due to mass and planned production, require final design decisions before manufacturing, making later modifications difficult.
· Transportation and Its Limitations
Industrial joists are usually factory-made and transported to the project site. This can be challenging for sites with restricted access or those far from factories. In contrast, traditional joists can be built directly on site, avoiding heavy or bulky transport needs.
· Quality Control and Supervision
A key advantage of industrial joists is the ability to conduct detailed and documented quality control in the factory. Concrete strength, rebar weight, weld inspection, and other technical parameters are tested and recorded. In traditional joists, quality checks are often done by eye or experience, with less documentation.
The choice between traditional and industrial joists depends on several factors:
If your project is small, has a limited budget, and is located far from factories, traditional joists can be a logical option.
But for large-scale, sensitive, or time-and-quality-critical projects, industrial joists—with their technical and operational advantages—are the superior choice.
Conclusion
In today’s construction landscape—with demands for speed, technical accuracy, and quality—choosing between traditional and industrial methods for building components is increasingly important. One of the most crucial of these choices is the selection of joist type for joist-block roofs.
In this article, we’ve examined both common joist types—traditional (handmade) and industrial (factory-made)—from technical, economic, operational, and performance perspectives. Each method has its own benefits and drawbacks that make it suitable for specific scenarios.
Traditional joists, thanks to manual construction, lower initial costs, and greater site flexibility, are a solid choice for small-scale or budget projects, or those with special requirements and execution constraints. However, it’s important to note that this method is highly dependent on worker skill and precision, and carries a higher risk of errors, quality drop, and hidden costs in the long term.
On the other hand, industrial joists—produced via mechanized factory processes—offer uniform quality, higher strength, faster installation, and more precise quality control. These features make them an ideal option for large projects, mass development, or situations where precision and high standards are required. While they may involve higher transportation or initial costs, savings from reduced material waste, fewer human errors, and time efficiencies generally make them economically advantageous in the end.
Therefore, in response to the main question of this article—"Is industrial joist better or traditional joist?"—the answer is:
- If your project prioritizes high quality, quick execution, durability, and compliance with standards, industrial joists are the superior option.
- However, if you’re working on a small-scale project, with limited resources and a need for execution flexibility, traditional joists can be a practical and dependable choice.
Ultimately, the final decision should consider all technical, financial, operational, and timing aspects of the project. Consulting with design and structural engineers and carefully assessing local conditions and available resources can help make a better decision and play a vital role in your project’s success.
