Common Mistakes in Using CNP Iron in Construction

CNP (Channel) steel is a steel profile widely used in construction projects, particularly for roof frames, canopies, and secondary building structures. However, in practice, errors in the use of CNP steel are still common, which can impact the strength, safety, and even lifespan of a building.

To ensure construction projects run optimally and meet standards, here's a discussion of common mistakes in the use of CNP steel that should be avoided.

Understanding the Function of CNP Steel in Construction
CNP steel has a C-shaped cross-section, making it strong enough to withstand certain loads when used properly. Generally, CNP steel is used for:

• Roof trusses
• Roof purlins
• Canopy and carport frames
• Non-main support structures

CNP steel is not a primary structural element like columns or main beams in high-rise buildings.

Common Mistakes in Using CNP Steel
1. Using CNP Steel for Main Structures
The most fatal mistake is using CNP steel as columns or main beams. CNP steel is not designed to withstand heavy loads and significant structural forces.

Impact:

• Structure bends easily
• Risk of structural failure
• Does not meet building safety standards

2. Wrong Size and Thickness Selection
CNP steel is often chosen with too thin a thickness to reduce costs.

Impact:

• Roof trusses sag easily
• Inability to withstand wind and roof loads
• Shortened building lifespan

3. Not Calculating Loads Correctly
CNP steel must be adjusted to:

• Roof load (tile, spandek, metal)
• Wind load
• Frame span distance

Without proper calculations, CNP steel will work beyond its capacity.

4. Inaccurate Installation
Installation errors such as misaligned joints, inconsistent spacing between CNP steel members, or improper welding often occur in the field.

Impact:

• Loads are not evenly distributed
• Structures become unstable

Vibration and noise occur when exposed to wind

5. Ignoring Anti-Rust Protection
CNP steel used in open areas without anti-rust protection is highly susceptible to corrosion.

Impact:

• Decreased material strength
• Porosity over time
• Higher maintenance and replacement costs

6. Using Low-Quality CNP Steel
CNP steel that does not meet standards often has inconsistent thickness and low steel strength.

Impact:

• Easily bent during installation
• Lack of precision
• Lack of durability

How to Avoid Mistakes in Using CNP Steel
To ensure optimal performance of CNP steel:

• Use CNP according to its function (secondary structure)
• Choose a size and thickness appropriate to the project load
• Ensure neat and precise installation
• Use an anti-rust coating for outdoor areas

Choose CNP steel with guaranteed quality and meets standards

Conclusion
CNP steel is a highly effective material when used correctly. Mistakes in the selection, calculation, and installation of CNP steel can seriously impact the safety and durability of a building. Therefore, understanding the function and specifications of CNP steel is key to the success of a construction project.

Get Quality CNP Steel at ISBS
PT Intisumber Bajasakti (ISBS) supplies high-quality CNP steel in a full range of sizes, guaranteed quality, and is ready to meet the needs of your various construction projects.

📞 Phone: 021-66675999
🌐 Website: intisumberbajasakti.com
✉️ Email: info@intisumberbajasakti.com

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