LINEAR VS: PENETRATION SEALS: CHOOSING THE RIGHT FIRE-STOPPING STRATEGY
Whether it’s a commercial or residential building, when fire-stopping the primary goal is to contain fire and smoke and prevent the spread through a building. A critical aspect of achieving this involves sealing gaps and joints in fire-rated walls and floors to maintain a fire compartmentation.
There are two primary types of seals used for this purpose: linear seals and penetration seals. While they share the same ultimate goal—containing fire—each serves a distinct function, uses specialised products, and requires specific installation techniques. Understanding the differences between these two types of seals is essential to choosing the right fire-stopping strategy for your project.
WHAT ARE LINEAR SEALS?
Linear seals are designed to close the gaps in linear joints where two fire-rated compartments meet.These gaps, also known as expansion joints, control joints, or movement joints, are common in construction to allow for building movement caused by temperature changes, shrinkage.
Typical Applications:
• Wall-to-wall joints: Found between adjacent fire-rated walls.
• Wall-to-floor joints: Gaps between fire-rated walls and floors.
• Floor-to-floor joints: Seals used between adjoining floor slabs.
Linear joints are vulnerable to fire and smoke passage if not properly sealed. Because buildings are dynamic structures, the materials used in linear seals must allow for movement while maintaining fire resistance. Flexible fire-resistant sealants like Protecta FR Acrylic and Protecta FR IPT, intumescent strips, or fire-rated foams are commonly used in these applications to ensure both flexibility and fire containment.
Key Products for Linear Seals:
• Fire-rated sealants and foams: These materials expand under heat to seal gaps tightly and resist the spread of fire.
• Intumescent strips: These materials swell when exposed to heat, effectively closing the joint as temperatures rise.
WHAT ARE PENETRATION SEALS?
Penetration seals, on the other hand, are designed to close gaps created by the passage of building services such as pipes, cables, conduits, and ducts through fire-rated walls and floors. These seals prevent the spread of fire, smoke and gases from one compartment to another by ensuring that these service penetrations do not compromise the integrity of the fire-rated elements.
Typical Mechanical and Electrical Applications:
• Pipe penetrations: Gaps left by pipes passing through walls or floors.
• Cable penetrations: Openings for electrical or communication cables.
• HVAC ducts: Fire-resistant barriers used where heating, ventilation, and air conditioning ducts pass through fire-rated partitions.
Since plastic pipes and some cables can be combustible, conduct heat or leave gaps once melted in fire conditions, penetration seals often include materials that react to heat. For example Protecta FR Acrylic, FR Collars, FR Pipe Wraps and Protecta FR Service Transit. These materials expand and close off the penetration in the event of a fire, providing an effective barrier against the spread of flames and smoke.
Key Products for Penetration Seals:
• Intumescent sealants, pipe collars and wraps: These products encapsulate or wrap around pipes and expand in a fire, sealing off the penetration.
• Firestop sleeves: Used to seal cable bundles passing through fire-rated walls or floors.
• Firestop mortar and putty: Applied around penetrations to create a solid, fire-resistant barrier.
KEY DIFFERENCES BETWEEN LINEAR AND PENETRATION SEALS
Purpose:
Linear seals are used to close expansion or movement joints between two fire-rated elements, such as walls or floors.
Penetration seals are designed to seal around services (pipes, cables, ducts) that pass through fire-rated walls or floors.
Firestopping Materials:
Linear seals typically use flexible fire-resistant sealants, foams, or intumescent strips that allow for movement.
Penetration seals often use intumescent collars, wraps, sleeves, and firestop putty or mortar to create a solid barrier around pipes and cables.
CHOOSING THE RIGHT FIRE-STOPPING STRATEGY
To choose the most effective fire-stopping strategy for your project, it’s important to assess the types of gaps or openings you need to seal and select the appropriate products. Here are some key considerations:
1. Determine the Type of Joint or Penetration:
Is it a linear joint that will require flexibility, or is it a penetration seal for pipes, cables, or ducts? Understanding the nature of the gap will guide your product choice.
2. Consider Movement Needs:
If the joint is subject to movement (thermal expansion, building settling, or seismic activity), opt for flexible linear sealants or intumescent strips designed to maintain fire resistance while accommodating movement.
3. Assess Fire Resistance Requirements:
Both linear and penetration seals must meet fire resistance standards to ensure they effectively prevent fire and smoke spread. Always choose fire-stopping products that are tested and certified for their specific applications.
4. Choose the Right Products:
For linear seals, consider Protecta FR Acrylic, Protecta FR IPT or Protecta FR Foam.
For penetration seals, opt for Protecta FR Collar, Protecta FR Pipe Wrap, Protecta FR Board, Protecta EX Mortar or Protecta FR Putty Cord firestop to ensure complete fire containment around service penetrations.
Both linear and penetration seals play critical roles in ensuring fire safety in buildings. Linear seals are essential for closing gaps between fire-rated elements, allowing for movement while maintaining fire resistance. Penetration seals, on the other hand, protect service penetrations such as pipes and cables from compromising the integrity of fire-rated walls and floors.
By selecting the right fire-stopping products and strategies, you can ensure your project meets the highest standards of safety and compliance, keeping occupants safe and reducing the risk of fire spread. At Protecta, we offer a comprehensive range of fire-stopping solutions tailored to both linear and penetration seals, each with supporting ETA’s, UKTA’s and other technical documents
For more information, visit our website or contact our technical team for advice on selecting the best fire-stopping products for your needs.
