3M Fire Barrier Sealant CP 25WB+ Installation Guide for Firestop Applications

3M Fire Barrier Sealant CP 25WB+ is a high-performance, latex-based intumescent sealant used in firestop applications to help maintain structural integrity and control the spread of fire, smoke, and noxious gases in fire-rated construction assemblies. Designed to expand significantly when exposed to high temperatures, it provides a flexible and durable firestop solution for both new construction and retrofit projects. This guide outlines the key steps for proper installation, based on official documentation and technical specifications provided by 3M and its partners.

Overview of 3M Fire Barrier Sealant CP 25WB+

3M Fire Barrier Sealant CP 25WB+ is a one-component, water-based sealant that cures to form a monolithic firestop seal. It is compatible with a wide range of construction substrates and is suitable for sealing penetrations in fire-rated walls, floors, and ceilings. When exposed to fire, the intumescent properties of the sealant allow it to expand up to four times its dried volume, forming a barrier that helps maintain the firestop seal for up to four hours in accordance with fire test standards.

The product is halogen-free, sag-resistant, and paintable, making it a versatile option for both commercial and residential applications. It is also re-enterable and repairable, allowing for adjustments or maintenance without compromising fire protection.

Pre-Installation Considerations

Before beginning installation, it is essential to review the specific requirements of the project and ensure compliance with local building codes and fire safety regulations. The sealant is tested and approved for use in firestop systems that meet the criteria of ASTM E 814 (UL 1479) and CAN/ULC S115, and it has demonstrated fire resistance in static construction joint systems under ASTM E 1966 (UL 2079).

Tools and Materials

The following tools and materials are required for proper installation:

3M Fire Barrier Sealant CP 25WB+ (cartridge, sausage pack, or pail)
Applicator (cartridge applicator, sausage pack applicator, or bulk loading applicator)
Mineral wool (if specified by system requirements)
Utility knife or scissors
Trowel (for pail application)
Follower plate (for pail application)
Safety equipment (gloves, safety glasses, etc.)

Surface Preparation

Prior to applying the sealant, ensure that the surface is clean, dry, and free of dust, grease, or other contaminants that may interfere with adhesion. The annular space around the penetration or joint should be inspected to confirm that it meets the required depth and dimensions specified in the system design.

If mineral wool is part of the firestop system, it should be installed to the required depth according to the system specifications before applying the sealant.

Step-by-Step Installation Instructions

Step 1: Prepare the Sealant for Application

The sealant is available in three formats: cartridge, sausage pack, and pail. Each format requires a specific preparation method:

Cartridge: Cut off the tip of the nozzle to the desired size. Insert the cartridge into a cartridge applicator.
Sausage Pack: Cut off the tip of the nozzle to the desired size. Remove the foil crimp on one end of the sausage pack. Insert the sausage pack into a sausage pack applicator and secure the nozzle on the end of the applicator tube with a screw-on collar.
Pail: Remove the lid and install the appropriate follower plate. Use a bulk loading applicator or apply the sealant directly with a trowel.

Step 2: Apply the Sealant

Apply the sealant to the annular space around the penetration or in the joint as specified by the system design. The sealant should be applied to the required depth and completely fill the annular space.

For penetrations, ensure that the sealant fully surrounds the penetrant and fills the annular space without gaps.
For joints, apply the sealant along the length of the joint to create a continuous barrier.

Use the applicator or trowel to work the sealant into the space, ensuring full coverage and even distribution.

Step 3: Tool the Sealant

After application, the sealant should be tooled to be flush with the substrate. This ensures a smooth, finished appearance and helps maintain the integrity of the seal. A trowel or other tooling device can be used to shape the sealant surface.

Step 4: Allow to Cure

Once applied and tooled, the sealant requires time to cure. Curing times may vary depending on environmental conditions such as temperature and humidity. It is important to follow the manufacturer's recommended curing times before subjecting the seal to mechanical stress or painting.

Step 5: Painting and Finishing

3M Fire Barrier Sealant CP 25WB+ is paintable, allowing it to be finished with the same paint or coating used on the surrounding surfaces. Ensure that the sealant is fully cured before applying paint to avoid compromising the firestop performance.

Troubleshooting and Common Issues

Sagging

Sagging may occur if the sealant is applied too thickly or if environmental conditions are not optimal. To prevent sagging, apply the sealant in thin, even layers and ensure that the surface is properly prepared and free of contaminants that could affect adhesion.

Adhesion Issues

Poor adhesion may result from improper surface preparation or the presence of incompatible materials in the system. Always clean the surface thoroughly before application and verify that the system components are compatible with the sealant.

Incomplete Filling

If the annular space is not completely filled, the firestop performance may be compromised. Ensure that the sealant is applied to the full depth required by the system specification and that no gaps or voids are present.

Re-entry and Repairs

One of the key advantages of 3M Fire Barrier Sealant CP 25WB+ is that it is re-enterable and repairable. If modifications are required after installation, the sealant can be cut or removed without damaging the surrounding structure. Once the adjustments are made, the sealant can be reapplied or repaired as needed.

Compatibility and System Integration

3M Fire Barrier Sealant CP 25WB+ is designed to work with a variety of construction materials and firestop systems. It exhibits excellent adhesion to a wide range of substrates, including metal, concrete, drywall, and plastics. When used in conjunction with other 3M fire protection products, such as the 3M™ Fire Barrier Tuck-In Wrap Strips or 3M™ Electrical Box Insert, it can provide a comprehensive firestop solution.

The 3M™ Fire Barrier Tuck-In Wrap Strips, for example, use 3M™ Hyper-GS Intumescent Technology and can expand up to 100 times in volume when exposed to fire. These strips are ideal for sealing around penetrants in fire-rated walls and ceilings and can be used in both new construction and retrofit applications.

The 3M™ Electrical Box Insert is another complementary product that offers an easy-to-apply solution for fire protection in electrical boxes. It is bendable, requires no tools, and can be applied in three simple steps: peel off the adhesive liner, position the insert, and stick it to the back of the box. This product is particularly useful in applications where access to the exterior back of the box is limited.

Safety and Compliance

3M Fire Barrier Sealant CP 25WB+ is halogen-free, which means it does not release toxic halogen gases when exposed to fire. This is an important safety consideration in firestop applications, as halogen gases can contribute to the spread of smoke and noxious fumes, posing additional risks to occupants.

The product is also compliant with a range of fire test standards and has been tested in various firestop configurations. It is important to verify that the system in which it is used is listed and approved by the relevant certification bodies.

Environmental and Storage Considerations

3M Fire Barrier Sealant CP 25WB+ is a water-based product, which makes it environmentally friendly and suitable for use in applications where VOC emissions are a concern. It should be stored in a cool, dry place, away from direct sunlight and extreme temperatures. Proper storage helps maintain the product's performance and extends its shelf life.

Technical Support and Resources

For technical support regarding 3M fire protection products and systems, users can contact 3M directly at 1-800-328-1687 or visit the 3M Firestop website at www.3M.com/firestop. Additional resources, including product specifications, technical documents, CAD drawings, and BIM files, are also available through the 3M website.

3M offers in-person presentations, live webinars, and on-demand training courses to help users better understand the application and performance of their fire protection products. These resources are valuable for contractors, engineers, and building professionals seeking to ensure the proper use of firestop materials.

Conclusion

3M Fire Barrier Sealant CP 25WB+ is a reliable and versatile firestop solution that offers excellent performance in both new construction and retrofit applications. Its intumescent properties, ease of application, and compatibility with a wide range of substrates make it an ideal choice for sealing penetrations in fire-rated walls, floors, and ceilings. By following the recommended installation procedures and ensuring proper system integration, users can achieve a high level of fire protection and compliance with building codes.

Whether used alone or in combination with other 3M fire protection products, CP 25WB+ provides a durable and effective solution for maintaining firestop integrity in a variety of construction scenarios. With proper preparation, application, and maintenance, it can help ensure the safety and resilience of building structures in the event of a fire.