Fire Barrier Insights From 3M Experts


A person installing 3M Fire Barrier Duct

Much more goes into fire protection than preventing a fire from starting or putting one out. A core piece of fire safety happens in the middle: firestopping and fire barriers. Accidents happen no matter how protected your building is, but you can minimize the damage and keep people safe. 

Protecting your building from fire damage means following specific best practices. Distribution International recently hosted a webinar with 3M on firestopping and fire barriers, and we are breaking down the highlights here. Read on to learn how to get maximum protection from your fire barrier products.

What is Firestopping?

Firestopping prevents the spread of fire from one room to another, providing a certain level of hourly resistance to fire. Firestopping systems act as a sealant to stop smoke and fire from passing through places where they spread the most, such as:

  • Penetrations
  • Joints
  • Ceiling joists
  • Wall-to-wall connections
  • Weaknesses in fire-rated walls and floors

The primary goal is to provide containment and compartmentation, rather than prevent fire and smoke altogether.

Containment and Compartmentation

Firestopping divides a building into separate compartments via fire-rated walls, floors and smoke barriers. 

All buildings have three types of containment zones you need to focus on to reduce the threat of fire and smoke spread.

  • Penetrations and membrane penetrations: Openings in walls, floors and ceilings that pipes or similar components penetrate
  • Protective wrap systems: Protective insulation that guards ducts and electrical circuitry
  • Construction joints: Openings in or between fire-rated assemblies that allow independent movement of the building

Each compartment needs to be able to confine a fire to its zone of origin for specified time. The F-rating — usually 30 minutes to 4 hours, as specified by ASTM E 814 or UL1479 — dictates how long the area can realistically remain protected from fire, smoke and gasses. Longer F-ratings increase the time occupants have to safely evacuate and avoid injury and minimize the severity of structural damage. To earn an F-rating, a firestop must pass the hose stream test, which verifies that the firestop material will not dislodge at the penetration when sprayed by a firehose. 

Firestop Technologies

Firestops come in all shapes, sizes and types. The best solution may depend on how the technology functions. Common firestop technologies include:

Insulative Intumescent Endothermic Ablative

A firestop product that prevents fire from spreading to combustible materials as the fire worsens, which may include fire wrap, plenum wrap and aerogel blankets  



A firestop product that expands and chars as the fire worsens, which may include caulk, firestop pillows and restraining collars




A firestop product that releases chemically-bound water molecules as the fire worsens, which may include latex sealants, mats and jacketing tapes 



A firestop product that forms a hard char that resists erosion from fire and flames and has thermal insulation characteristics, forming a seal as the fire worsens, which may include silicone sealants and batting



What Are Fire Barriers?

Fire barriers specifically protect the inside of buildings. They are the interior walls that extend from the floor‐to‐floor or floor‐to‐roof, including concealed and interstitial spaces. Fire barriers subdivide areas of the building and restrict heat flow to a fire’s area of origin for 1-4 hours, depending on fire-resistance rating. 

Fire barriers are designed to provide two core benefits:

  • Fire containment
  • Time for occupants to evacuate 

Fire Barrier Codes

Buildings follow codes established by regulatory bodies to prevent the spread of fire and risk of injury to occupants. Fire barrier codes vary depending on the type of building and industry served. 

New Construction Existing Buildings Mechanical Healthcare 

International Building Code, Chapter  7

International Fire Code, Chapter 7 National Building Code NFPA 101 (Life Safety Code), Chapter 8
National Electrical Code, NFPA 70   Uniform Mechanical Code  

International Mechanical Code  
    Standard Building Code  


All codes are verified by testing agencies that determine and enforce standards. UL and Intertek develop the standards for which systems need to pass ASTM standards.

Key Considerations for Choosing and Installing Fire Barriers

When you select firestops and fire barriers for your building, you must keep a few things in mind. Understand the differences between manufacturers and their installation processes, ask the right questions to select a certified system, and be mindful of your annular space.

Variety of Manufacturers 

Each fire barrier manufacturer has its own installation process, so it is essential to install fire barrier products correctly through a professional with proper training. Always follow installation guidelines for your product. 

Can’t find the instructions? Contact the manufacturer. If your product is installed based on another manufacturer’s instructions, it likely will not function at 100%.

Finding a UL-Certified System

Everyone plays a part in making sure your building gets the correct solution. From ownership to architects, contractors and code officials, preventing fire spread is a shared responsibility. 

To select a certified system, ask the important questions, such as:

  • What is the hourly rating? 
  • What is the construction type? 
  • What types of materials are used? 
  • What type of insulation? 
  • What is the thickness of the insulation? 
  • What is the annular space?

Doing necessary research ahead of time will ensure you find the best solution for your needs.

Annular Space Considerations

Annular space is the distance from the inside edge of the opening (e.g., floor or wall) to the outside of the penetrating item. 

When you select and install a fire barrier or firestop, take note of the minimum and maximum amount of annular space allowed to provide adequate protection. The size and shape of the installation opening may impact this. The combination of the right solution, plus proper installation, will prevent smoke or fire from leaking and successfully contain the damage.

Learn About Fire Protections From 3M and Distribution International

A fire in your building can be devastating. Thankfully, firestopping and fire barriers protect your building by minimizing fire, smoke and gas spread, containing them to the point of origin and providing valuable time for people to safely evacuate. 

However, these products are not created equal, and you must do your research to select the best fit solution. What fire barrier codes do you need to follow? How should specific products be installed? Do the work upfront so your building will be better protected. 

Want to know more about how you can prevent the spread of fire? Watch the 3M webinar for more insights, and don’t forget to contact Distribution International for your fire barrier needs.



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