Fire-resistant sealing: trends and innovation

Fireproofing is a critical component of a building’s construction and safety. Although no building material or product can be considered completely fireproof, using a combination of high-quality fire-resistant products when building or renovating a structure enhances its safety and resilience against the impact of fire.

Due to ever-evolving fire safety regulations and the complexity of modern structures, the demand for effective fireproofing products has seen substantial growth in recent years. The Penosil Fireproofing category offers a diverse range of passive fire protection products such as PU foams, sealants and backer rods, each designed to address specific needs and applications.

Some fireproofing products contain chemicals that raise environmental and health concerns. At Penosil, we have invested heavily in research and development to create new fire-resistant sealing products that meet rigorous environmental standards without compromising on performance. These low-VOC products are safe to use in both residential and commercial applications. As part of our Fireproofing solution, we are introducing three new sealants:

Penosil FireStop Intumescent Acrylic 681

An acrylic-based intumescent sealant specially designed for fireproofing interior joints and penetrations with moderate movement capability (±12.5%). This bright-white acrylic is suitable for a wide range of applications including sealing and filling joints in slabs, window- and door frames, and partition walls. When exposed to flames and temperatures from 200°C to 220°C, the FireStop Intumescent Acrylic 681 expands, effectively sealing gaps and preventing the spread of smoke, hot gases, and flames.

Penosil FireStop Intumescent Graphite Acrylic 682

An acrylic-based intumescent sealant with added graphite flakes offers superior protection for interior penetrations and joints with moderate movement capability (±12.5%). FireStop Intumescent Graphite Acrylic 682 expands when exposed to heat above 200°C – during the expansion process, the graphite flakes form a horn-like shape insulation layer that prevents the spread of fire, smoke and gases to the building’s structure. Due to its extra-high expansion, this product is especially suited for sealing and protecting gaps around pipes, cables, ducts, services and small openings which penetrate firewalls and floors.

Main advantages of intumescent sealants 681 and 682:

• Tested according to EN 1366-3 and EN 1366-4
• Fire resistance rating of up to EI240: withstands fire up to 4 h in a penetration and linear joint (this rating is given based on the duration it would take for the fire to impact this sealant’s structural abilities)
• Reaction to fire C-s1, d0 in accordance with EN ISO 11925-2
• Suitable for vertical and horizontal joints

Penosil FireStop Hybrid 720

This hybrid polymer-based sealant is an ideal choice for sealing and filling moveable interior joints (±25%) such as window and door joints, expansion and connection joints, concrete wall units and passive fire safety walls. Amongst other advantages it is worth to point out that FireStop Hybrid 720 is non-corrosive to metal, fast curing and can be used even on damp surfaces. Due to its high elasticity, it provides a flexible fire-resistant barrier, preventing cracking and ensuring long-term durability and passive fire protection.

Main advantages of hybrid sealant 720:

• Tested according to EN 1366-4
• Fire resistance rating of up to EI240: withstands fire up to 4 h in a linear joint
• Reaction to fire E in accordance with EN ISO 11925-2
• Suitable for vertical and horizontal joints – easy tooling

Fireproofing sealants application instructions:

• Before starting to work, make sure that surfaces to be sealed are clean, dry and free from any dust, loose particles, oil and old sealant residues.
• For clean finish, cover the adjacent surfaces with masking tape.
• In joints over 6 mm width, we recommend using a backer rod to ensure the joints correct thickness and shape.
• To guarantee the fire-resistant properties, the sealant layers thickness needs to be at least the minimum depth recommended at the product’s Technical Data Sheet. The sealant layer’s thickness is a critical factor in determining the effectiveness of the passive fire protection.
• Apply the sealant by keeping an even pressure at the gun trigger and smoothly dragging the nozzle along the joint. Then, remove the excess sealant and smoothen the surface with a suitable tool.
• Remove the masking tape immediately after tooling.
• During the curing process, make sure that the sealed surfaces stay clean and are not under mechanical stress.
• Due to the wide variety of construction materials, we always recommend doing preliminary compatibility test.
• Application temperature between +5°C and +40°C.
• Ensure records of all installations are kept.

Examples of intumescent and hybrid sealant’s fireproofing properties:

Filling PVC pipe penetrations:

1. Fill the opening around pipe penetration with Penosil Fire Rated Gunfoam B1 187 or mineral wool.
2. Cover the cured foam or mineral wool surface with Penosil FireStop Intumescent Acrylic 681.
3. Fire resistance of the sealed penetration: EI240 (tested with PVC pipe Ø 32mm, total penetration width 60 mm, sealant’s depth 25 mm).

Fireproofing bundled cable penetrations:

1. Fill the opening around pipe penetration either with Penosil Fire Rated Gunfoam B1 187 (EI180) or mineral wool (EI240).
2. Cover the cured foam or mineral wool surface with Penosil FireStop Intumescent Acrylic 682.
3. Fire resistance of the sealed penetration: EI180, E240 (tested with 14 cables in a bundle, total penetration width 60 mm, sealant’s depth 30 mm).

Filling vertical joints:

1. Fill the joint with Penosil Fire Rated Gunfoam B1 187.
2. Cover the cured foam on both joint edges with Penosil FireStop Intumescent Acrylic 681, Penosil FireStop Intumescent Graphite Acrylic 682 or Penosil FireStop Hybrid 720.
3. Fire resistance of the sealed joint with FireStop Intumescent Acrylic 681 or FireStop Intumescent Graphite Acrylic 682: EI240 (tested with joint width 20 mm, sealant’s depth 30 mm).
4. Fire resistance of the sealed joint with FireStop Hybrid 720: EI240 (tested with joint width 60 mm, sealant’s depth 30 mm).

While there are various fireproofing products available, Penosil new intumescent and hybrid fireproofing sealants stand out due to their numerous advantages: they are practically odourless and can be easily concealed beneath paint or other finishing materials without compromising their fire protection capabilities. These products are also safe to use, provide good thermal insulation and have excellent adhesion on many materials such as concrete, brick, tile, ceramics, different metals, wood, glass, PVC.

All Penosil fireproofing sealants have undergone third-party testing and certification for fire resistance performance. In addition, depending on the projects scale, these sealants are all available in a handy 300ml cartridge as well as economical 400 ml and 600ml foil packages.

To conclude, the final choice of fireproofing sealant depends on various factors such as the type of structure, exposure conditions, and fire resistance requirements of the specific application. To find out more about our advanced fireproofing products and solutions visit our website at penosil.com.