Description

Main Features:

KD-NSF-Fp-STI-A Interior Non-Expanding Steel Structure Fireproof Coating is a water-based non-expanding steel structure fireproof coating developed by our company. Its fire resistance and physical and chemical properties exceed the requirements specified for interior non-expanding steel structure fireproof coatings in GB14907-2018 standards. It is environmentally friendly and suitable for a wide range of applications in fire protection for interior steel structures.

Substrate Treatment and Application Methods:

1. Substrate Treatment:(1) Surface treatment of steel structures is essential for ensuring the durability of the fireproof coating. Depending on the type of substrate, surface treatment for steel structures should include the following:
   • New General Steel Structures: The steel structure surface should undergo sandblasting and rust removal before applying a matching anti-rust and anti-corrosion coating. We recommend using an epoxy-rich zinc primer with an epoxy cloud iron intermediate coating system.
   • Galvanized Steel Structures: To ensure good adhesion with the fireproof coating, an epoxy coating transition paint must be applied before construction.
   • Old Steel Structures or Old Primers: If the primer is undamaged and the surface is clean, check the compatibility of the fireproof coating and the primer. In cases where there is no primer or severe primer damage, rust removal and reapplication of an anti-corrosion coating are necessary before construction.

   (2) Before construction, thoroughly inspect the steel components for rust, dust, oil stains, or signs of cracks and inadequate welding. Construction can commence after verifying that there are no issues.

   (3) Steel components that have not undergone rust protection treatment must be treated for rust (this process is typically the user’s responsibility).

2. Base Layer Construction:The coating requires base layer reinforcement treatment, which can be accomplished using the following methods:
   • Welded Mesh: Weld steel reinforcing bars (rebar) with an “L” shape, approximately 4 cm high and spaced approximately 40 cm apart vertically and horizontally. These bars should be welded to the steel components. Special attention should be paid to welding at inner and outer corners.
   • Hanging Mesh: Cut steel plate mesh to suitable lengths based on the specific site conditions. Ensure proper pressing at inner and outer corners, with a typical spacing of 8 to 15 mm. Pay attention to the overlapping of mesh sections, with a typical overlap of 30 mm or more.
3. Fireproof Coating Application:(1) First Coat Application:
   • Mix Ratio: STI-A powder: Adhesive = 1:1. Accurately measure the components and add the appropriate amount of water, stirring thoroughly. The amount of water added during mixing can be adjusted as needed for the specific on-site conditions.
   • Application Method: Apply using a spray method with a coating thickness of 3-4 mm, resulting in a textured surface. The coating should be cured for 24 hours before proceeding to the next step.

   (2) Subsequent Coating:

   • Mix Ratio: STI-A powder: Adhesive = 4-5:1. Measure the fireproof coating powder, adhesive, and water, and mix them in a suitable ratio based on on-site conditions (the water amount can be adjusted as needed for ease of application). Thoroughly mix for 5-8 minutes before application.
   • Application of Fireproof Coating: The fireproof coating can be applied using extrusion mortar pumps, gravity-fed spray guns, or manual application methods.
   • Spray Application Guidelines:
     • Apply the fireproof coating in layers, with a thickness of 6-8 mm for each layer in general. Wait until the previous layer is partially dry before spraying the next, repeating this process until the required thickness is achieved.
     • When the fireproof coating thickness reaches 12-15 mm, apply a layer of high-strength steel wire mesh. Overlap the mesh sections by 5-10 cm and press them in one direction using a trowel. Secure the wire mesh by welding, using insulation nails, or attaching with lead wire, as necessary.
     • When the fireproof coating reaches a thickness of 27-30 mm, apply a layer of high-strength fiberglass cloth. Overlap the cloth sections by 5-10 cm and press them in one direction using a trowel.
     • When spraying, hold the spray gun vertically to the steel components at a distance of 0.5-0.6 meters. Maintain an air pressure of 0.6-0.8 MPa, with a spray gun nozzle diameter of 8-12 mm (or 6-8 mm when using a gravity-fed spray gun).
     • While applying the fireproof coating, control the spray distance and angle to minimize rebound. Clean any fallen coating promptly, and it can be re-mixed and reused if done within 30 minutes. After this time, it is not advisable to reuse the material.

   (4) Trowel Application Guidelines:

   1. Typically, apply in four layers according to the design thickness. The first layer should be thin, generally ≤5mm. Wait until the surface is about 70-80% dry before applying the second layer, and similarly, wait for the surface to reach the same level of dryness before applying the third layer. Once the surface is about 70-80% dry, apply the fourth layer, ensuring it reaches the designed thickness.
   2. While applying, attention should be paid to compacting the layers, and the coating surface should not be excessively smoothed but rather textured. A textured surface is advantageous for enhancing adhesion between layers.
   3. Place iron plates on the ground within the application area to catch any coating material that falls to the ground. This material can be collected and reused after remixing. However, any coating material that remains on the ground for more than 30 minutes should not be reused.
   4. The use of reinforcement methods is the same as the requirements for sprayed application, involving the attachment of mesh.

4. Construction Precautions:

   1. Store the fireproof coating to protect it from moisture during transportation and storage. Do not use the fireproof coating if it has solidified or formed lumps.
   2. It is advisable to use the prepared coating within 30 minutes. If it thickens during use, add a small amount of water and mix it thoroughly.
   3. Areas not requiring construction should be shielded, and the applied coating should be protected from exposure to rainwater.
   4. After completing the construction, thoroughly clean the equipment and tools with water.
   5. The coating should be used at a temperature of at least 5°C.
   6. Within one week after the coating has been applied, take precautions to prevent strong vibrations and collisions with beams and columns.
   7. Prioritize safety and ensure proper safety precautions are in place.