Where to use FIRECOAT Exterior
FIRECOAT Exterior is suitable for both interior and exterior surfaces, including natural and composite timber, brick, concrete, plasterboard, masonry and structural steel. It can be used with or without compatible topcoats. Please note that the final finish will have a slightly textured finish due to the intumescent properties of the product.
FIRECOAT Exterior is not suitable for use on trafficable surfaces such as deck floors and stairways.
Surface preparation
Before application, ensure that all surfaces are thoroughly clean, dry and free of oil, grease, loose or flaking paint, and any other contaminants that could hinder adhesion. Any existing coatings with poor adhesion must be completely removed.
For timber surfaces, ensure they are completely dry before application.
For steel surfaces, adhere to the specifications for metal finishing as outlined in AS 1627 Part 1: Removal of oil, grease and related contamination and Part 4: Abrasive blast cleaning of steel
Please note that FIRECOAT Exterior does not provide corrosion protection for steel surfaces (as per AS/NZS 2312.1:2014 Category C2). We recommend using Carboline 635 primer beforehand to improve both adhesion and corrosion protection.
Mixing
Stir the contents thoroughly before use, either with a paint paddle or power mixer, ensuring the paint is mixed evenly from the bottom to the top of the tin.
Application information
Application conditions
Only apply and cure FIRECOAT Exterior at temperatures between 10 °C and 35 °C, ensuring good air circulation and a relative humidity no greater than 75%. Avoid extremely hot or cold conditions for optimal results. Protect the coating from the elements and contamination during application to achieve the best performance and finish. We recommend maintaining a complete record of the application by filling out the Application Quality Control form (see below).
Application method
FIRECOAT Exterior can be applied with a brush, roller, or airless spray.
- Brush: Use a top-quality polyester/nylon blend brush or similar.
- Roller: Use a roller with a 20 mm or greater nap. A shorter nap (closer to 20 mm) will give a smoother finish.
- Airless spray: Use equipment with a minimum 1 GPM rating at 3000 psi, such as a Graco 795, Graco 1095 or similar model. Use a tip size of 531 or greater, with a pressure of 2100 psi or higher. Due to the unique properties of FIRECOAT, it’s important to use an airless spray gun with the correct specifications to avoid clogging.
Compatible water-based acrylic paints can be applied as a topcoat over FIRECOAT Exterior for aesthetic purposes. We recommend testing the chosen topcoat on a small area to check for compatibility. Allow FIRECOAT to fully dry before applying the topcoat – refer to the Recoat and drying time section for details.
Important: Do not thin FIRECOAT Exterior. The use of a thinner is strictly prohibited.
Coating thickness and coverage
To ensure the desired level of fire protection, it’s essential that the fully dried coating achieves the minimum dry film thickness (DFT). The easiest way to do this is by measuring the wet film thickness (WFT) immediately after application. You can then estimate the corresponding minimum DFT for the level of fire protection that you want, as shown in the following table.

Each coat should achieve a coverage of 1.43 square metres per litre. However, actual spreading rates may vary due to factors such as roughness and porosity of the substrate, overspraying, choice of application method, and environmental conditions such as wind, temperature and humidity. Adjust application techniques or apply additional coats as necessary to achieve the specified DFT.
Remember that conforming to the specifications requires meeting the DFT targets, not simply applying a certain number of coats.
How to use a wet film gauge for measuring paint thickness
A wet film gauge is a simple tool used to measure the thickness of applied paint while it’s still wet. This helps ensure the correct application thickness, which is critical for achieving the desired protection and finish.
Here is a step-by-step guide to help you accurately measure the WFT and ensure your coating is applied according to specifications, to provide optimal performance and durability.
- Apply the paint or coating: Begin by applying the paint to the surface, ensuring it is evenly distributed.
- Choose the appropriate gauge: Select a wet film gauge that covers the range of thickness you expect for your application. The gauge has notches or teeth that correspond to different thickness measurements (usually in microns or mils).
- Position the gauge: Hold the wet film gauge perpendicular (at a 90° angle) to the coated surface.
- Place the gauge in the wet paint: Immediately after applying the paint, gently press the gauge into the wet paint so that it touches the surface underneath. Be careful not to drag the gauge, as this could alter the paint film.
- Read the measurement: Remove the gauge and examine the notches. The last notch with paint on it indicates the WFT. For example, if the paint fills the notches up to 150 microns but does not reach the 200-micron notch, the thickness is between 150 and 200 microns.
- Clean the gauge: After use, clean the wet film gauge with an appropriate solvent or water to remove any paint residue. This will keep the gauge in good condition for future use.



Recoat and drying time
Drying time depends on temperature, air movement, humidity, coating thickness and application method. Under ideal drying conditions (24 °C with good air circulation and relative humidity below 50%), the drying time for a single coat is as follows:
- Between coats of FIRECOAT Exterior: 4–6 hours
- Before applying a topcoat: At least 12 hours
Drying times may be longer at lower temperatures and/or higher humidity. Ensure the paint is thoroughly dry to the touch before applying the next coat, to prevent cracking and peeling. Full hardness is achieved after 7 days.
Paint maintenance and repair
- Repair any substrate damage before reapplying FIRECOAT Exterior.
- Periodically inspect the surface for cracks or damage.
- Remove any loose material or paint flakes and sand any rough edges.
- Make sure the surface is clean and dry before reapplying FIRECOAT Exterior to the intended thickness, following the manufacturer’s original application specifications.
- After a fire, remove the char with a high-pressure hose. If no structural damage is found, follow the original surface preparation steps and reapply all paint layers, including the anti-corrosion primer for steel surfaces.
- Protect the paint from contamination, such as dirt and grit, and keep it out of the weather during onsite application.
- Only apply coatings in good weather – poor weather can affect adhesion, curing times, appearance and performance.
- Wash off any airborne salt deposits and dry the surface immediately before painting.
Cleaning equipment
- After painting, promptly clean application tools with clean, cold water. Flush airless spray equipment thoroughly.
- Dispose of wash water according to local regulations.
- Ensure any dried product is removed from tools.
- To minimise waste, use all product completely. If any remains, contact a licensed disposal company for proper disposal.
Disposal
- Avoid releasing product into the environment.
- Do not pour leftover paint down the drain.
- Dispose of contents and containers at an authorised chemical waste collection point in accordance with any local regulations.
Storage
- Store at temperatures between 5–35° C.
- Keep away from direct sunlight and extreme heat.
- Ensure containers are tightly closed when not in use.
- Store out of reach of children and pets.
Limitations
The choice of topcoat applied over FIRECOAT Exterior will affect the durability of the undercoat. Select high-quality water-based topcoats suitable for either interior or exterior use.
Safety recommendations
All users should refer to the Safety Data Sheet for FIRECOAT Exterior for further safety and handling information.
- Eye protection: Wear safety glasses or goggles that meet the requirements of Australian standards AS 1336 and AS 1337.
- Respiratory protection: When spraying, use half or full masks with P2 or P3 ratings to protect against spray mists.
- Skin protection: Wear gloves made of PVC or rubber that meet the requirements of Australian standard AS 2161. Wear covered shoes.
Note: This product has been independently tested and certified as non-irritant to eyes and skin. However, if a skin irritation or rash should occur, wash the affected area with cold water. Seek medical attention if you feel unwell or are concerned.
Testing and results
Refer to the Technical Documents and Certifications for our world-first fire protection products.
Quality control forms
The success of any coating application can be influenced by multiple factors, including:
- ambient conditions during surface preparation, application and curing
- cleanliness and condition of equipment
- suitability of the chosen coating system
- correct application methods for surface preparation and coating
- adherence to specified DFT
- quality of the paint used
- proper site access, lighting, and ventilation.
Thorough inspection and detailed record-keeping are essential for quality assurance, future assessments and possible warranty claims. As the product manufacturer, Flame Security International recommends that users maintain, at a minimum, the following records during the application of FIRECOAT Exterior and related products:
- Table 1 – Coating inspection (PDF)
- Table 2 – Equipment details and conditions (PDF)
- Table 3 – Surface and ambient conditions (PDF)
Disclaimer: While every care is taken in providing these application instructions and users are always directed to follow the application instructions explicitly, Flame Security International Pty Ltd has no direct control over the end application of the product. Neither Flame Security International Pty Ltd nor any of its employees, contractors or agents are responsible or liable for any claim, loss or damage which might arise from the use of FIRECOAT Exterior.