Saving Lives and Property
Through Fire and Smoke Containment ©2004 IFC
Perimeter Curtain
Wall Fire Protection
Saving Lives and Property
Through Fire and Smoke Containment ©2004 IFC
• Brief history
• Dynamics of fire
• What do the codes say?
• How are they tested?
• How testing is affecting design
Topics for Discussion
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Through Fire and Smoke Containment ©2004 IFC
Curtain Walls
&
the Perimeter Joint
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A Brief History of Fires -Where Curtain Wall or
Safing Issues Have Been Cited…
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• Summerland, Isle of Man, British Isles. Fire spread
through safing slot. 50 people killed.
• Hilton Hotel, Las Vegas, NV. Fire spread from 8th to 13th
floor in 25 minutes. 8 fatalities.
• First Interstate Bank, Los Angeles, CA. Flames spread
from 13th to 16th floor via perimeter joint. One death.
• One Meridian Plaza, Philadelphia, PA. Fire spread from
22nd to 30th floor through unprotected openings including
slab edge.
Unsealed or Improperly sealed
perimeter joints cost lives and huge
liability losses…
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What are the dynamics of
vertical spread in a high-rise building?
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Rated Floor Assembly and
non-rated Curtain Wall SystemVision Glass
Fire begins on a lower floor,
products of combustion
accumulate at ceiling level,
and positive pressure builds
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The fire follows the flow of
air currents…
Vision Glass Rated Floor Assembly and
non-rated Curtain Wall System
If the void between
the floor and curtain
wall is not properly
sealed, flames will
spread vertically…
and
compartmentation
is breached!
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Vision Glass
Rated Floor Assembly and
non-rated Curtain Wall System
Elevated temp. and pressure
breaks lower vision glassFlames may erupt through
the windows. Oxygen fuels
the fire.
Fire attacks the curtain wall
structure from both sides
causing a premature failure of
the wall structure and potentially
the vision glass above!
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Firestop Coating or Sealant
over mineral wool safing
Rated Floor Assembly and
non-rated Curtain Wall System
A properly designed & tested
Perimeter Fire Barrier System
not only protects the perimeter
joint but critical wall framing and
support elements as well!
Properly installed &
supported mineral wool
spandrel insulation
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How do the codes address the
protection at the perimeter?
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• All Model Codes call for the rating of the floor to
extend to the exterior wall
• All Model Codes require minimum spandrel height
• All Model Codes allow spandrel height exceptions
in certain sprinklered conditions
What do the codes say?
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Extending the Rated Floor to
the Wall...
In rated construction,
all floors are rated
The perimeter joint must be sealed with an
approved material or system that extends
this rating to the exterior wall surface
MANDATORY!
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Code Compliance
Firestopping the perimeter joint is mandatory.
Meeting the Letter of the Law...
1. Designing the wall to keep the firestop
system in place for the rated period of
the floor is an obvious necessity.
PROTECTING THE PERIMETER JOINT:
2. Designing and installing the firestop
correctly is the final step!
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The Leap Frog Effect…
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Fire may break out of a
window and leap back to
the floor above!
That being the case…
Why bother to protect the
perimeter???
The Leap Frog effect…
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Sprinklers are an exception
to window separation
requirements…
But not to requirements for
protection of safing slot!
The Leap Frog effect…
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Sprinkler advocates are
lobbying to reduce these
requirements…
After all… The fire may
jump around the protection!
The Leap Frog effect…
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The Leap Frog affect…
The fact is, depending on
window spacing and other
factors, the fire may jump!
So what exactly does a
Perimeter Fire Barrier
System do?
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Slows the process down. Of course it
depends on window spacing and
other construction factors…
As well as the nature and severity of
the fire…
The Perimeter Fire Barrier
System…
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Along with sealing the slot area, a
well engineered system provides
structural protection and maximizes
the integrity of the wall system…
Keeping the wall and window system
above intact longer!
The Perimeter Fire Barrier
System…
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• Extends the rating of the floor to the wall.
• Forces the fire to exit the building in order to
propagate to upper floors.
• Protects structural elements and helps prevent
catastrophic failure of the spandrel system.
• Maximizes fire protection afforded by the
non-rated wall.
The Perimeter Fire Barrier
System…
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• Prevents the migration of flame, hot gases
and smoke through to floors above.
• Buys time for occupants to escape.
• Buys time for first responders to secure the
building
• Provides additional protection in the event of
a sprinkler or detection failure.
The Perimeter Fire Barrier
System…
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The Perimeter Fire Barrier
System…
Provides energy savings through
increased thermal efficiencies
throughout the life of the building…
When considered this way, the
life safety benefits are free!
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How Are Perimeter Fire
Barrier Systems Tested?
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ASTM E2307
Standard Test Method for
Determining Fire
Resistance of Perimeter
Fire Barriers Using
Intermediate-Scale,
Multi-Story Test
Apparatus
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How Are Perimeter Fire Barrier
Systems Tested?
Only two labs presently perform testing in
accordance with newly developed test methods:
• Underwriters Laboratories Inc. – Northbrook, IL
• Omega Point Laboratories – Elmendorf, Texas
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UL & OPL Testing
• Perimeter joint curtain wall test is
performed in accordance with ASTM E2307
• Other labs, testing per UL 2079 alone, do
not adequately capture the dynamics
between a rated floor and a non-rated
curtain wall assembly, the structural nature
of curtain walls, and fire attacking at two planes
• Intermediate-Scale, Multi-Story Test Apparatus
(ISMA) was developed for this application
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• Two ratings are provided per the ASTM E2307 test:
- “F”-rating, in hours (resistance to fire spread)
- “T”-rating, in hours (temperature on non-fire side)
• UL provide two additional ratings using same test apparatus
- “integrity rating” & “insulation rating”
Question: What Test is used to Evaluate
Perimeter Fire Barrier Systems?
Testing Questions…
Answer: ASTM E2307 using the Intermediate-
Scale, Multi-Story Test Apparatus (ISMA)
is used to determine…
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Question: How can this be representative of real life?
Answer: It can’t! The test method indicates whether…
1. The safing method can last as long
as the floor.
2. The protection scheme can adequately
protect wall framing and attachments.
Testing Questions…
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Question: Then how representative is this test?
Answer: It should be considered broadly representative.
Spandrel width, height, and window spacing
are limited because the test is not full scale.
Story height is approximately 7 feet.
Wall framing methods, support, and the safing
slot itself are well represented and provide
excellent engineering data.
Testing Questions…
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Curtain
Wall Test
Assembly
Pre-Burn
Transom above floor
Transom below floor
Mechanical attachments
supporting insulation
Mineral wool insulation at
spandrel area
Mullions
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Assembly
Interior
View
Pre-Burn
Thermocouples measuring
temperature rise
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Interior Burner Lit - Time: 0:00
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Exterior Burner Lit - Time: 0:05
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Flames
Climbing
Exterior
Time: 0:15
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Melting of
Mullions
&
Transoms
Time: 0:45
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Vision
Glass
Breaks
Time:
2:00
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Burner Off at 2 hours
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Post Test:
Close up Detail of
Mullion and Transom
Damage
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Post Test – Interior View
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ASTM E2307 Testing has Improved
Perimeter Joint Evaluation…
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Vertical Mullions
Transoms
Mechanical
Attachment
Mullion Covers
Firestop Coating
Vision
Glass
Spandrel
Panel
Mineral Wool Safing
Stiffback
Angle
Spandrel
Insulation
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Perimeter Fire Containment - Basic Design Criteria
1. Mechanically Attached Curtain Wall Insulation
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1
Mechanically
Attached
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1. Mechanically Attached Curtain Wall Insulation
2. Protect Aluminum Mullions
Perimeter Fire Containment - Basic Design Criteria
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2Protect
Mullions
1
Mechanically
Attached
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1. Mechanically Attached Curtain Wall Insulation
2. Protect Aluminum Mullions
3. Compression-Fit Safing Insulation -as required per tested assembly
Install Safing Impaling Clips -as required per tested assembly
Horizontal fiber
orientationVertical fiber
orientation
Perimeter Fire Containment - Basic Design Criteria
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2Protect
Mullions
1
Mechanically
Attached
3
Compression Fit
Safing (Direction of Safing
as required per tested assembly)
Safing Clips (as required per tested assembly)
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Compression Fit Safing (Direction of
Safing as required per tested assembly)
Safing Clips (as required per tested assembly)
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1. Mechanically Attached Curtain Wall Insulation
2. Protect Aluminum Mullions
3. Compression-fit Safing Insulation -as required per tested assembly
Install Safing Impaling Clips -as required per tested assembly
4. Provide Backing/Reinforcement Member at
Safing Line
Perimeter Fire Containment - Basic Design Criteria
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Through Fire and Smoke Containment ©2004 IFC
2Protect
Mullions
1
Mechanically
Attached
3
Compression Fit
Safing (Direction of Safing
as required per tested assembly)
Safing Clips (as required per tested assembly)
4 Reinforcement
Member
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75% of fire related
deaths are caused by
smoke inhalation
What about smoke?
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1. Mechanically Attached Curtain Wall Insulation
2. Protect Aluminum Mullions
3. Compression-fit Safing Insulation -as required per tested assembly
Install Safing Impaling Clips -as required per tested assembly
4. Provide Backing/Reinforcement Member at
Safing Line
5. For “Smoke Containment,” Add Firestop Coating
Perimeter Fire Containment - Basic Design Criteria
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5 Firestop
Coating
4 Reinforcement
Member
2Protect
Mullions
1
Mechanically
Attached
3
Compression Fit
Safing (Direction of Safing
as required per tested assembly)
Safing Clips (as required per tested assembly)
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5Firestop
Coating
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Question: Why aren’t floor-to-wall (FW) systems acceptable for
curtain walls?
Answer: Floor-to-wall systems test fire resistance between a
rated floor and rated wall tested per ASTM E1966.
CW systems are specific perimeter tests between a
rated floor and non-rated curtain wall using the
Intermediate Scale Multi-story Apparatus (ISMA) per
ASTM E2307.
Additional Design
Questions…
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Question: Why are windows spaced so far apart?
My windows are closer together…
Answer: ASTM E2307 evaluates the interior
passage of fire and hot gases
through the perimeter joint only.
Increasing the spandrel height
reduces the likelihood of the leap
frog effect.
Additional Design Questions…
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Question: What is the function of the firestop
coating in these systems?
Answer: The firestop coating performs
several important functions.
Additional Design
Questions…
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Additional Design
Questions…
1. The most obvious role is as a smoke seal.
2. Seals off the path of hot gasses. Makes
the safing more effective.
3. “Glues” everything together.
The Role of the Firestop Coating:
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Additional Design
Questions…
Question: Are curtain wall joints static or dynamic?
Answer: This area is referred to as a slot. The word joint
suggests movement. Experts tend to agree that a
small amount of movement occurs within the slot
area. It is up to the design professional to
determine the level of movement required for the
project.
Some wall designs are subject to a small amount
of vertical shear or horizontal sway and some
systems incorporate these values.
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Additional Design
Questions…
Question: What if our design isn’t a perfect match
for a system?
Answer: We strongly suggest specifying tested
systems. However, real world designs are
seldom a perfect match!
Find a listing that is reasonably close and
contact the manufacturer for an Engineering
Judgment to match the design.
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Benefits of Specifying A Listed
Perimeter Joint System
• Completes the curtain wall package
• Applies pedigreed testing and competent
engineering
• Assists the local AHJ
• Standardizes design and cost
• Limits liability
• Provides energy conservation from insulation value