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FCIA Standard Answers to Common Questions
UL's New "W" and "L" Ratings December, 2004
Fire Resistance Rated Walls and Floors are the main ingredient to
Effective Compartmentation. Effective Compartmentation provides positive
protection to buildings to contain fire to the room or area of origin,
minimizing damage to buildings when fire occurs. Effective Compartmentation,
Alarms and Detection, Sprinklers and Occupant and Firefighter Personnel,
Procedures & Training complete NFPA's Total Fire Protection Concept.
To maintain the fire resistance rating of Effective Compartmentation,
several test standards have been developed to address the many penetrations
and openings that provide services and structural relief to a building.
UL 555 & UL 555S qualifies Fire Dampers for Ductwork passing
through Fire Barriers. UL 263 provides testing protocol for Fire
Doors. And, there are two tests for Firestopping metal and plastic
pipes, non-fire-dampered ducts, electrical conduit and cables, cable
trays, bus ducts, service items plus gaps and joints.
Developed in 1983, UL 1479 has been used as a testing standard
to qualify Through Penetration Firestop Systems. The UL 2079 qualification
for expansion, walltops and construction joints has been in use
since the mid 1990's. Both standards, plus the fire damper and door
systems, work to maintain continuity to Effective Compartmentation.
Over the past few years, Underwriters Laboratories has developed
optional ratings that are available to manufacturers as suitability
for use of products in specific applications. UL developed standards
that addressed both Smoke Travel in Buildings, the L Rating, as
well as Water Resistance, the W Rating. Below are descriptions of
the two optional ratings
- "L" Rating - The L Rating measures the amount of air
that moves through an opening in cubic feet per minute per square
foot of opening area, at ambient temperatures and 400F. The two
temperature levels simulate cold and hot smoke moving in a building.
Ratings are stated <x cfm/sf, and are stated right below the
F and T Ratings. An acceptable amount of air movement for a complete
wall assembly has been established by NFPA 101 as .75 cfm/sf opening
area. Many firestop systems have L Ratings of less than one.
- "W" Rating - The W Rating quantifiably measures resistance
of a firestop product to water in buildings. Developed to address
concerns by building owners about the ability of a firestop system
to resist the passage of water through floor assemblies, the W
rating development offers a new quantifiable characteristic for
a firestop system. The test protocol simulates water on a firestop
system for 72 hours, under a 3' head of water.
The 3' head of water does not translate into 3' of water ponding
on the entire floor assembly, as the floor might collapse. It simply
simulates water on top of the material, to provide pressure that
may cause water to transfer to the bottom side of the assembly.
There are some key points about the W and L Ratings for Specifiers
and Contractors to know.
- Specification Requirements - Specifications have been appearing
for both L and W Ratings on projects nationwide.
- L Ratings - When specifying firestopping in fire and smoke
resistance rated construction, specify L Rated Systems. The
L Rating is the qualification for fire resistance rated smoke
protection.
- W Ratings - When specifying firestopping in floor systems,
specify a W Rating for areas that may need water resistance.
Specifying a W Rating provides protection against water from
floor to floor.
- Responsibility Requirements - Once specified, who is responsible
for protection in buildings? Currently, the warranty offerred
by most firestopping manufacturers is a material warranty for
one year (1) from date of shipment. There is no warranty from
the manufacturers for labor and material together. Contractors
may provide. FCIA therefore recommends specifiers and owners
consider the Firestopping Quality Process, FCIA Member Specialty
Firestop Contractors, FM 4991 Approved, Inspected to ASTM E 2174/2393
Protocol.
- Code Requirements - There are new code requirements that have
recently passed for L Ratings, and none for W Ratings.
- L Ratings - NFPA's Technical Committee on Fire Protection
Features recently voted positively for have new code language
that quantifies a value for leakage through smoke resistance
rated assemblies based on logic from the fire door and fire
damper industry. Smoke Protection using firestopping in effective
compartmentation is attainable with L Ratings.
- W Ratings - There are no code requirements at this time
for W Ratings in the International Building Code, NFPA 5000
or NFPA 101. Building owners and managers, architects and
engineers have been requesting water resistance for many years.
Effective Compartmentation was originally developed for protection
from fire travel first from building to building, then from area
to area in construction. When properly specified with tested and
listed systems with F, T, L and W Ratings, installed by an FCIA
Member, FM 4991 Approved Contractor, Inspected to ASTM E 2174 Inspection
Standard, and properly maintained, Effective Compartmentation performs
admirably.
Contact FCIA for more information about Effective Compartmentation
and Firestopping.
Firestop Contractors International Association
4415 W. Harrison St.
Hillside, IL 60162
Phone: (708) 202-1108
Fax: (708) 449-0837
http://www.fcia.org ~ Email: info@fcia.org
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