Perimeter Curtain Wall Fire Protection
-
Upload
eolande-orcoran -
Category
Documents
-
view
44 -
download
4
description
Transcript of Perimeter Curtain Wall Fire Protection
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Perimeter Curtain Wall Fire Protection
Saving Lives and PropertyThrough 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
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Curtain Walls &
the Perimeter Joint
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
A Brief History of Fires -Where Curtain Wall or
Safing Issues Have Been Cited…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
• 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…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
What are the dynamics of vertical spread in a high-rise
building?
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Rated Floor Assembly and non-rated Curtain Wall System
Vision Glass
Fire begins on a lower floor, products of combustion
accumulate at ceiling level, and positive pressure builds
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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!
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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!
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Firestop Coating or Sealant over mineral wool safing
Rated Floor Assembly and non-rated Curtain Wall System
A properly designed & tested Perimeter Fire Barrier Systemnot only protects the perimeter
joint but critical wall framing and support elements as well!
Properly installed & supported mineral wool
spandrel insulation
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
How do the codes address the
protection at the perimeter?
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
• 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?
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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!
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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!
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
The Leap Frog Effect…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Sprinklers are an exception to window separation requirements…
But not to requirements for protection of safing slot!
The Leap Frog effect…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Sprinkler advocates are lobbying to reduce these requirements…
After all… The fire may jump around the protection!
The Leap Frog effect…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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?
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
• 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…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
• 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…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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!
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
How Are Perimeter Fire
Barrier Systems Tested?
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
ASTM E2307
Standard Test Method for Determining Fire
Resistance of Perimeter Fire Barriers Using
Intermediate-Scale, Multi-Story Test Apparatus
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
• 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…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Curtain Wall Test Assembly
Pre-Burn
Transom above floor
Transom below floor
Mechanical attachments supporting insulation
Mineral wool insulation at spandrel area
Mullions
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
AssemblyInterior View
Pre-Burn
Thermocouples measuring temperature rise
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Interior Burner Lit - Time: 0:00
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Exterior Burner Lit - Time: 0:05
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Flames Climbing Exterior
Time: 0:15
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Melting of Mullions
& Transoms
Time: 0:45
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Vision Glass
Breaks
Time: 2:00
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Burner Off at 2 hours
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Post Test:
Close up Detail of Mullion and Transom
Damage
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Post Test – Interior View
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
ASTM E2307 Testing has Improved
Perimeter Joint Evaluation…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Vertical Mullions
Transoms
Mechanical Attachment
Mullion Covers
Firestop Coating
Vision Glass
Spandrel Panel
Mineral Wool Safing
StiffbackAngle
SpandrelInsulation
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Perimeter Fire Containment - Basic Design Criteria
1. Mechanically Attached Curtain Wall Insulation
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
1
Mechanically Attached
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
1. Mechanically Attached Curtain Wall Insulation
2. Protect Aluminum Mullions
Perimeter Fire Containment - Basic Design Criteria
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
2Protect Mullions
1
Mechanically Attached
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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 orientation
Vertical fiber orientation
Perimeter Fire Containment - Basic Design Criteria
Saving Lives and PropertyThrough 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)
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Compression Fit Safing (Direction of
Safing as required per tested assembly)
Safing Clips (as required per tested assembly)
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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
Saving Lives and PropertyThrough 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
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
75% of fire related deaths are caused by smoke inhalation
What about smoke?
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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)
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
5Firestop Coating
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
Question: What is the function of the firestop coating in these systems?
Answer: The firestop coating performs several important functions.
Additional Design Questions…
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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:
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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.
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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.
Saving Lives and PropertyThrough Fire and Smoke Containment ©2004 IFC
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