Fireproofing, FIRESTOPPING and Fireblocking (Part 3 of 4)

Posted on 12/19/2017 11:25:05 AM By Sharron Halpert

We have all been on a construction project and heard someone talk about fireproofing something when they mean firestop, or firestop when they mean fireblock.  This is the third of a four part series where we look at the difference between Fireproofing, Fire Blocking and Firestop.  We will examine what they do, why they are needed and what materials can be used so that you may better understand the differences.  After this blog series, you won’t confuse the three again.  If you find someone using the wrong phrase, now you can just share this blog link with them.

In our last segment we talked about firestop in rated joints, so you understand about ASTM E119 and the time temperature curve, right?  If not, check out the last blog HERE.


Fire rated joints allow for movement between construction members such as floors or walls.  We talked before about the building being a block that needs to hold a fire in place.  No one wants to live or work in this block without certain comforts such as power, water, heat or air conditioning and what not.  These services punch holes in these precious rated assemblies and firestop is how we regain the integrity of the rating.  This means that penetration firestop is designed to allow trades to run services through the rated floors and walls without interfering with the ability of the rated assembly to perform as expected, which means that a 1 hour wall will still be expected to not allow the passage of fire for an hour, even after you punch a hole in it to run your various services.  


If there are any anticipated changes to the penetrating item, during a fire, then it will likely require an intumescent firestop.  Intumescent materials are going to expand in a fire scenario.  This expansion, when installed properly, will accommodate movement of metal penetrating items that expand and contract or twist during a fire scenario.  It can also fill the voids created when various construction materials are consumed during a fire. A few common examples include elements such as various types of insulation installed around ducts or pipes or possibly plastic pipes or conduits.   Clearly the more space consumed during a fire, the more intumescent material is needed.  This can be achieved either through installing more sealant or with the use of other technology such as wrap strips and collars to name but a few.

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All firestopthrough penetrations tested in the US, are heldto the same standards, ASTM E814 or UL 1479 regardless of the manufacturer and regardless of which test lab is used to.  Requirements in Canada are slightly different.  Requirements in other countries are much more different still.  This discussion only approaches the US market requirements. If you recall the last blog post, we discussed these requirements. If you would like to review please click HERE.

If you recall the discussion of the time temperature curve, this is the temperature that must be reached inside the furnace during the test, these temperatures are the same, but the results will not be.

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As you can see, the temperature inside the furnace at the 5 minute mark must reach 1000F.  Wherever you are, look around you? Identify the various materials in the room.  How long do you thinkthese things would last in this furnace?  Let’s look at obviously combustible materials like plastics.  They will begin to melt around 300-500F. The temperature needs to reach 1500F at the 30 minute mark.  What materials around you will sustain these temperatures?  Did you know that fiberglass insulation will begin to degrade before reaching 1200F and aluminum is going to fail around this temperature as well.  The need for intumescent materials becomes clear relatively fast.   As we said before, this is not to say that the temperature during an actual fire will be reached at these times.  This is just a way to test all materials to the same standard in hopes of being able to guess how they might function in a real fire scenario.


Any through penetration fire stop or a membrane penetration fire stop material with a tested and listed assembly can be used as firestop material.  This could be a basic caulking material or a complex pre-made device that is placed in the rated assemblies allowing for the passage of pipes, cables.  Ultimately, anything shown in a tested and listed third party detail is an appropriate firestop material.  Keep in mind, the material needs to be approved by the AHJ, the Authority Having Jurisdiction; which is the building official.  Also keep in mind that the material needs to be installed in conformance with the actual tested and listed detail. There is a lot more to this topic than presented in this short blog, but this provides an understanding of the industry.  If you have any questions or other topics you would like us to cover here, please reach out to us and let us know.  If you are a manufacturer or just an inventor entrepreneur creative type, stay tuned for a challenge we will be issuing on a new product development idea. 

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