Fire Inspection Passed Instantly! Practical Guide to the 'Zero-Rework' Construction Method for Intumescent Fireproof Coatings

Ultra-thin and thin types both belong to intumescent fireproof coatings for steel structures, which expand and foam at high temperatures to form a fire-resistant and heat-insulating protective layer on steel structures.

Before construction:

Remove dust, oil stains, and loose rust from steel components, then apply an anti-rust primer to the prepared surface. Proceed to the next step only after confirming full primer coverage with no missed spots on the steel structure.

Application of Fireproof Coatings:

First Layer:

• Method: Spray application

• Thickness: 1–2mm

• Surface Texture: Slightly rough ("orange peel" effect)

• Quality Requirements:

• Uniform thickness, complete coverage

• Adequate adhesion to steel substrate (roughened surface enhances bonding)

• Next Step: Proceed only after full curing (check per product specs).

Second Layer:

• Prerequisite: First layer must be fully cured and firmly bonded (inspect for delamination).

• Mixing: Stir coating thoroughly as per manufacturer’s instructions.

• Application: Spray application (2–3mm per pass).

• Final Requirements:

• Repeat until total design thickness is achieved.

• Maintain uniform "orange peel" texture.

Spray Application Guidelines for Fireproof Coatings

(1) Layered Spraying Technique

• Apply the fireproof coating in layers. The thickness of each layer depends on environmental conditions and temperature.

• First layer: 1–2mm (typical).

• Subsequent layers: 2–3mm per pass after the previous layer has dried.

• Continue until the required thickness is achieved (as per fire safety inspection standards).

(2) Spray Gun Operation

• Hold the spray gun perpendicular to the steel surface.

• Optimal distance: 0.35–0.6 meters.

• Air pressure: 0.4–0.6 MPa.

• Nozzle diameter: 6–10mm.

• Minimize rebound loss by maintaining proper spray angle and distance.

• Clean and reuse fallen coating (if uncontaminated and within 1-hour workability window).

(3) Construction Precautions

1. Storage & Transport: Protect from rain and moisture.

2. Mixing & Usage:

• Use mixed coating within 60 minutes.

• If thickening occurs, add a small amount of water and remix.

3. Surface Protection:

• Mask areas not requiring coating.

• Avoid water exposure for 24 hours after application.

4. Equipment Cleaning: Rinse tools and machinery with water immediately after use.

5. Temperature Control: Apply at **≥5°C**.

6. Curing Protection: Avoid strong vibrations on beams/columns for 7 days post-application.

7. Safety: Wear protective gear (masks, gloves, goggles).