Firestop Penetrations in Fire-Rated Walls and Smoke Barriers: What You Need to Know

When it comes to passive fire protection, proper firestopping is essential – especially in 1-hour and 2-hour fire-rated walls and smoke barriers. These assemblies are designed to compartmentalize fire and smoke, giving occupants critical time to evacuate and helping to minimize property damage. But even a small penetration can compromise the entire barrier if not properly sealed and maintained.

What Is a Firestop System?

A firestop system is a UL-classified or FM-approved assembly of materials (caulk, collars, wrap strips, etc.) designed to restore the integrity of a fire-rated assembly where it’s been compromised by penetrations like:

  • Electrical conduit

  • Plumbing pipes

  • Cable trays

  • HVAC ductwork

  • Communication wiring

1-Hour vs. 2-Hour Fire-Rated Wall Requirements

1-Hour Fire-Rated Walls:

  • Designed to resist fire for at least 60 minutes

  • Common in commercial interior walls and corridor separations

  • Penetrations must be sealed with a UL-listed firestop system rated for a 1-hour wall

  • Must be installed according to manufacturer’s tested system specifications

  • Must also maintain smoke and air leakage control where applicable (especially in healthcare or IBC/IFC-regulated occupancies)

2-Hour Fire-Rated Walls:

  • Designed to resist fire for at least 120 minutes

  • Common in stairwells, fire barriers, horizontal exits and between building occupancies

  • Requires higher-performing firestop systems, often including wrap strips or firestop collars

  • Larger annular space or combustible penetrants (like plastic pipes) typically require intumescent materials

  • Must match or exceed the wall’s fire rating and be UL-tested for 2-hour penetrations

Smoke Barriers & Smoke Partitions

In facilities like healthcare, educational institutions and high-rise buildings, smoke barriers and partitions are used to limit the movement of smoke throughout the building.

Key Requirements for Smoke Barriers:

  • Penetrations must be sealed to restrict the passage of smoke

  • Must meet air leakage criteria per NFPA 105 and IBC

  • Sealants and materials must be tested for smoke-resistance, not just fire resistance

Relevant Codes and Standards

  • NFPA 101: Life Safety Code – Outlines requirements for fire and smoke barriers and penetration protection

  • NFPA 80 & NFPA 105 – Address installation and maintenance of fire doors, dampers and smoke barriers

  • International Building Code (IBC) – Sections 714 and 717 cover penetration firestopping and duct penetrations

  • UL Fire Resistance Directory – Lists tested and approved firestop systems for various wall ratings and penetrants

Consequences of Non-Compliance

Failure to properly firestop penetrations can result in:

  • Failed inspections from local AHJs, state agencies or third-party assessors

  • Citations from OSHA or the Joint Commission (in healthcare settings)

  • Increased liability in the event of a fire-related injury or death

  • Higher insurance premiums or potential denial of claims

  • Accelerated spread of fire and smoke, endangering lives and property

Even one improperly sealed penetration can allow fire and toxic smoke to spread rapidly through a building – defeating the purpose of a rated barrier.

How Tyger River HVAC & Fire Can Help

Our trained technicians are experienced in:

  • Installing UL-classified firestop systems

  • Inspecting existing penetrations for code compliance

  • Maintaining and documenting firestop conditions per regulatory standards

  • Assisting with firestop for new construction, retrofits and repairs

Whether your facility has 1-hour walls in a commercial office or 2-hour smoke barriers in a healthcare center, we ensure your penetrations are properly sealed and documented to meet code.

Contact Tyger River HVAC & Fire today to schedule a firestop inspection or installation. Let us help you protect your building – and the people in it.