Have You Fallen for These 5 Fireproof Coating Pitfalls?

Have You Fallen for These 5 Fireproof Coating Pitfalls?

In steel structure fireproofing engineering, the quality of fireproof coating application is directly related to a building's fire resistance. However, several common issues often occur in practice:

1. The Coating is Too Thin

The fire resistance duration of a steel structure is closely related to the coating thickness. If the application does not meet design specifications and the layer is too thin, the steel's fire resistance will fail to meet fire safety requirements.

2. An Uneven Coating Surface

An "orange peel" or bumpy surface from poor application affects the coating's uniformity and overall fire protection performance.

3. Incorrect Coating Type Selected

Using thin-film, especially ultra-thin-film, coatings on structures requiring a 2.5-hour or higher fire resistance rating, or using indoor intumescent coatings for outdoor applications, significantly compromises their protective function.

4. Material Substitution

Inspections have revealed instances where standard topcoat paint was wrongly used instead of certified fireproof coating, severely undermining fire safety.

5. Unprofessional Application

To cut costs, some contractors hire non-specialists (e.g., general painters) for application. Lack of expertise leads to coatings that are non-compliant, visually poor, and ultimately ineffective.

6. Post-Application Damage

Subsequent work, such as welding or installing equipment on coated steel beams/columns, can char or dislodge the coating at connection points, creating localized failures.

I. Case Analysis: Root Causes

1. Sagging

Applying the next coat before the previous one is fully dry causes sagging. This is especially critical in small spaces with short cycle times, each coat must be thoroughly dry before proceeding.

2. Orange Peel & Granulation

Incorrect ratios of coating, binder, and water, or inadequate mixing, can result in bumps and large particles. High humidity or rainy conditions can cause delamination and peeling.

3. Surface Cracking

Insufficient mixing or excessive troweling brings cement paste to the surface, leading to cracks upon drying.

4. Cracking in Internal Corners

Over-application in internal corners due to poor spray technique can cause cracks as the thick coating dries and shrinks unevenly.

5. Adhesive Failure

If the underlying rust-proof paint is too hard (e.g., fluorocarbon paint) and its compatibility with the fireproof coating is not verified beforehand, large-scale delamination can occur.

II. Preventive Measures

1. Surface Preparation

The steel substrate must be thoroughly cleaned and inspected by a dedicated specialist.

2. Primer Compatibility

Ensure the primer is compatible with the fireproof coating. Test this by creating a sample panel before full-scale application.

3. Curing Control & Layering

Ensure each coat is completely dry before applying the next. Application thickness per layer should not exceed 2mm for thin-film coatings and should be kept to approximately 6mm for thick-film coatings. Protect indoor surfaces from moisture, especially during rainy seasons.

4. Material & Environmental Control

Mix the fireproof coating thoroughly before application. Avoid working in damp or rainy conditions.

5. Managing Pot Life

Discard any mixed coating that has been sitting for over 3 hours due to weather or work stoppages, as it may have begun to set.

6. Spray Technique

Maintain a consistent nozzle-to-steel distance, typically between 80-110 cm, to ensure a uniform and even coat.

Beyond proper application techniques, selecting high-quality, suitable flame-retardant materials is fundamental to ensuring safety. Yinsu Flame Retardant Company specializes in providing professional, customized flame-retardant solutions. Our flagship products, such as YS-MF201 (Equivalent to Exolit AP 462) , YS-201 and so on,  are eco-friendly, high-efficiency, halogen-free flame retardants suitable for various applications, including adhesives and coated fabrics, offering reliable fire protection for your materials and projects.

Please feel free to contact us to learn more about our products or customized solutions.