What’s the difference between a fire partition, a fire barrier and a fire wall?
In our last segment we talked about what fire-rating is.
Here we’re going to talk about the difference between three key terms for fire resistive construction for walls.
WHAT IS A FIRE PARTITION, FIRE BARRIER, AND FIRE WALL?
The terms Fire Partition, Fire Barrier, and Fire Wall are three distinct definitions that refer to types of fire-rated assemblies. They each carry different meanings.
Of the three, a Fire Partition carries the least requirements, and a Fire Wall is the most-intensive. They each serve a similar purpose.
Fire walls, fire barriers, and fire partitions all prevent the passage of fire. Each could be constructed of the same materials – Type “X” Gypsum Board on both sides of a steel stud.
They all have a fire resistance rating in terms of hours – the time duration for which fire must be contained.
So what is the difference?
One difference is continuity.
Does the wall have to go all the way to the roof or can it stop at the ceiling?
Another difference is duct penetrations – is a fire damper always required, sometimes required or hardly ever?
Of the three, the fire wall is the most robust – it has the most stringent requirements. The fire partition is the least robust, it has the more lenient requirements and the fire barrier is in between.
SAYING “FIRE WALL”, MEANING “FIRE BARRIER”
Many people, even well-seasoned architects with decades of experience will use the term “fire wall” when they don’t mean it.
They may also use the term “fire rated wall” which is a little ambiguous.
More than likely, they are referring to a Fire Barrier.
Fire Barriers are the most common type of fire rated construction in buildings.
Shafts for HVAC, stairways, or elevators are typically constructed as Fire Barriers.
When mechanical rooms, fire pump rooms, or storage rooms are fire rated, they are constructed as Fire Barriers.
Occupancy separations are constructed as Fire Barriers.
Again, these are by far the most common type of fire rated construction in buildings. If you see something that has a fire rating, it’s more than likely a fire barrier.
So what is a fire wall?
SO WHAT IS A FIRE WALL?
A fire wall is a substantial assembly of fire resistance rated construction that is used to separate buildings. It must be continuous from foundation through roof, from exterior wall to exterior wall.
One example of a Fire Wall may be a masonry wall which separates townhomes. You’ve probably seen these before. Those odd-looking walls that go all the way up through the roof? Those are Fire Walls.
Fire Walls are the most-substantial of the three terms we’re talking about today. They also carry the most-intensive requirements. Why? Well, separating buildings is a pretty big deal. The general intent is that a fire on one side will not collapse the building on the other side.
That in itself is a challenge. Fire Walls must be structurally isolated, so that the wall will remain standing if the building on the adjacent side collapses.
So not only does a Fire Wall have to be continuous, (again) extended from exterior wall all the way to the opposite exterior wall, and from the foundation all the way through the roof, but they also must be structurally isolated so that either side can collapse without impacting the opposite side.
Hopefully it’s pretty obvious that a true “Fire Wall” is not what most people are talking about when the casually talk about an interior 1-hour rated wall. That’s more than likely a “Fire Barrier”.
Except in cases where two buildings are being separated, it is uncommon to see a Fire Wall.
WHAT IS A FIRE PARTITION?
So then; a Fire Barrier is the most common type of fire-rated construction in buildings. They make up shafts, stairways, elevators, and occupancy separations.
Fire Walls are used to separate buildings and are the most-intensive separation.
What then is a Fire Partition?
A Fire Partition is like a fire barrier, but with distinctions that make it less robust than a Fire Barrier.
One is that fire partitions are permitted to terminate at fire-rated ceilings, whereas a Fire Barrier must terminate at the floor or roof above. Fire Partitions have a few limited uses, and also far less common than a Fire Barrier.
It’s helpful to think that the Fire Wall is most robust, followed by Fire Barrier, then Fire Partition which is least robust.
In terms of how commonly these are used in buildings, Fire Barriers are by far the most common, followed by Fire Partitions, then finally Fire Walls.
We’ll get into a lot more detail in the subsequent videos. In our next segment, we’ll kickoff the most-common: Fire Barriers.
I’m Steven Barrett, this is MeyerFire University.
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