HomeMy WebLinkAboutBuilding Board of Appeals 1986-8-1
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APPLICANT
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William H. Neel, Architect
LOCATION
3400 Main Street, Springfield, Oregon
Map #17023131 Tax Lot 2200 - 2300
REQUEST
The applicant is
method' of construction
existing building.
requesting a variance for approval of an alternat~u~
for a one-hour fire resistive wall to retrofit an
PERTINENT INFORMATION
The
feet to
structure
1.
2.
3.
applicant i~Rroposing to construct an additional 8650
an existingK~ehouse structure. The total enclosed area
when completed will amount to 23,050 square feet.
Occupancy: The purpose for which a building is used is
reterreo to as its occupancy. The occupancy classification
relates to the kind and degree of hazard housed within the
building. The occupancy classification of a structure
where combustible materials are stored and/or warehoused is
designated as a B-2 occupancy.
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Type of Construction:-1 The occupancy of a building is
consl0ereO bY(\hazard; the building itself, housing the
occupancy, is considered by its capacity to resist the
potential hazard from the outside or ,within. I lhe.rate of
fire resistance of various parts of the building^as~a whole
is referred to as the type of construction. The proposed
type of construction is Type III-N.
square
of the
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Location on property: (See attached drawing, Exhibit AIL
Tne eXlstlng structure and the pro~addition w++}-b~~
provided with yard separationS of, . fppt or more on
three sides except for the west wall. The build;ng'_se,~,ck. .
from the adj acent west property 1 i ne is ten _fee't. fI Sect; o~
2003.(a) of the State Structural Specialty Code and Fire
and Life Safety Regulations (S.S.C.) provides in,part:
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2. IS- On other than Group H and..\.~cupancies,
exterior walls may be non-combustible one-hour
fire resistive where unprotected openings are
permitted.
Table 5-A of the S.S.C. requires openings in exterior walls
to be protected if located 1 ess than 10 feet.
Subsequently, the west wall of the structure is required to
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be a minimum of one-hour fire resistive construction.
4. Allowable floor areas: The basic allowable area for a B-2
occupancy, Type III-N construction is 12,000 square feet.
Section 506.(a) 3, of the S.S.C. providesi>:> ?~'(""\'"
2. Separation on three sides. Where public ways
or yards more than 20 feet in width extend
along and adjoin three sides of the building,
floor areas may be increased at a rate of 2
1/2 percent for each foot by which the minimum
width exceeds 20 feet, but the increase shall
not exceed 100 percent.
~~~, the total allowable area is as follows:
Base Allowable Area
100% increase for separation, 3 sides
Total Allowable Area - unsprinkled
12,000 sq. ft.
12,000 SQ. ft.
'24,000 sq. ft.
BACKGROUND
One of the principal reasons for establishing building codes is to
provide construction regulations that reduce the hazard of fire spread
and/or damage form building to building or adjacent property. The farther
apart buildings are located from each other or to adjacent property lines,
the less likely there is that a fire in one building or property could be
transferred horizontally. When buildings are located in close proximity,
the odds of fire movement from property to property increase. Exterior
building walls should be able to contain fire outside or within the
building, ftir be located so that there is enough horizontal separation to
prevent fire spread between bUildingsx and/or ad)acent property.
Therefore, when certain clearances between buildings ~open spaces) are
provided, the fire protection of exterior walls is permitted to decrease.
The bui 1 di ng code today functi ons as a pr~scri pti on for provi di ng ~
safety and public protection. Several decades ago, those who formulated
building regulations tended to base fire-protection requirements upon a
description or listing of materials and construction which, in their
opinion, afforded satisfactory fire protection. These earlier code
requirements were based upon descriptive specifications involving the
kind, thickness, composition, weight, etc., of certain materials. These
older specifications, as written,often placed severe restrictions on the
introduction of new and different materials and construction methods. Many---
new materials and installations, capable of equal or sometimes better___
performance than covered by the descriptive code requirements, were---
prohibited from use. To overcome this discriminatory effect,
performance(emphasis added) requirements were written to replace the
earlier, specification-type requirements.
Instead of prescribing, for example, the specific kind or thickness
of fire-protective materials that must be used, code requirements
now prescribe the minimum degree of fire protection needed. The
acceptability of materials proposed for use can now be directly related to
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the fundamental service which the materials must perform rather than to
specific material characteristics. As new materials are manufactured or
new methods appear, it is now possible to meet certain performance
standards without making major changes in the fire-protection requirements.
Fire resistance is generally defined as that property of a material
or assembly which enables it to withstand fire or which provides
protection from fire. As applied to individual elements of buildings, it
is characterized by the ability to confine a fire or to continue to
perform a function during a fire. Fire endurance, or the time period
during which a material or assembly continues to exhibit fire resistance,
is usually measured by the methods specified and according to the criteria
defined in the American Society For Testing and Materials publication
(ASTM E 119), titled "Standard Methods of Fire Tests of Building
Construction and Materi al s." Simil ar test procedures have been adopted by
other groups such as the National Fire Protection Association,
Underwriters Laboratories and is also recognized as a standard by the
American hBtional Standards Institute. (ANSI)
Fire testing has been refined over the years. Today, the primary
objective is to determine the length of time a controlled fire can be
contained by a wall, floor or roof assembly. In each case tests are made
under conditions that closely simulate an actual building installation.
Fire endurance, expressed in terms of hours, has been established as the
means of comparing test results relative to the amount of time fire
protection is provided. The classifications (one-hour through four-hour)
are the results of fire tests on assemblies composed of specific materials
put together in a specified manner. The assemblies when tested, include
the material, material thickness, wall finishes, attachment methods, wall
cavity thickness, insulation if applicable, etc. These components then
become specific parts of the tested and listed fire protection assembly.
Various building codes which specify fire resistance in terms of fire
test results also include tabulations of construction methods which are
also accepted as meeting code requirements for specific fire resistance
rating. These tables are based upon specific fire test data (See
Attached, Exhibit C).
When a product is tested and listed as an assembly that provides a
certain degree of fire resistance, it is then applied as a assembly, or
more simply, as tested. Substitutions of other materials not meeting
relevant specifications and standards or deviation from the specified
construction method could adversely affect performance of the listed
assembly.
DISCUSSION
For the existing building to qualify as a Type III-N building. the
west wall must be of one-hour fire resistive construction. The applicant
is requesting approval to retrofit this wall with the materials and method
of construction as follows:
*
Leave exterior skin of deformed metal siding and 1 1/2"
vinyl-faced insulation in place.
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* Install 5/8" gypsum sheathing against the exterior skin.
* Install metal studs 24" O.C. between base angle and Z girt
(8'0" O.C.). Metal studs are to hold gypsum tight against
vinyl-faced insulation. No attachment of outside gypsum
sheathing to wall studs is intended.
Install 5/8" type X gypsum to inside of wall studs and
provide attachments and finish in an approved manner(~~~
b..~~~o.. a.~~ ,~\ G...'IM.~~ Co') ,
The applicant is requesting approval under Section 204, lOS, and 106
of the S.S.C., 1986 Edition. The City of Springfield on August IS, 1983,
adopted the Building Safety Code Administrative Code (BSC) to replace the
first three chapters of the State Administrative code. The Applicable
sections for the appellant are 205, 106 and 107. C~ :.,,~~ ~.'5.c._
*
RECOMMENDATIONS
Staff recommends denial of the request based on the following
fi ndi ngs:
Section 106. of the BSC provides in part:
The Building Official may approve any alternate, provided he
finds that the proposed design is satisfactory and complies
with the provisions of the SpeCialty Codes and that the
materi a 1, method or work offered is, for the purpose
intended, at least the equivalent of that prescribed in the
Specialty Codes in suitability, strength, effectiveness,
fire resistance, durability, safety and sanitation. The
Building Official shall require that sufficient evidence or
proof be submitted to substantiate any claims that may be
made regarding its use.
The Code is very clear as to what constitutes one-hour wall
protection. When a product such as wall protection is tested and listed,
the listing of that product also includes the (,Utachment method and
schedule as to how the component is to be secured. In the applicants
proposal, the outside layer of protection is intended to be sandwiched
between the vinyl-faced insulation and the metal stud without direct
mechanical attachment. In a fire situation, it would be extremely
questionable that such a wall assembly would provide the equivalent fire
resistance, durability and effectiveness as that prescribed in the State
Specialty Codes. Alternates may be approved only when providing 'at
least' the equivalent.
Section 107. of the BSC provides in part:
MODIFICATIONS. Whenever there are practical difficulties
involved in carrying out the provisions of the Specialty
Codes, the 8uilding Official may grant modifications for
individual cases, provided he shall first find that a
special individual reason makes the strict letter of the
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Specialty Code impractical and the modification is in
conformity with the intent and purpose of the Specialty
Code, and that such modification does not lessen health,
life and fire safety requirements or any degree of
structural integrity. The details of actions granting
modifications shall be recorded and entered in the files of
, the_Building Safety Division. c;~~
The proposed wall protection without adequate attachment and testing
is not in conformity with the intent and purpose of the Specialty Code.
Subsequently, health, life and fire safety requirements are lessened.
Section 205 of the ~~G regarding Board Authority, provides
in part:
1. Determine the suitability of alternate materials and
methods of construction and to provide for reasonable
interpretations of the Specialty Codes enumerated in
Articles 2 through 6 of these codes. Provided that,
since City Specialty Code standards are required to be
in compliance with State Specialty Code standards, the
Board is not authorized to grant a Variance to Specialty
Codes.
Since the Code is very clear as to what constitutes one-hour wall
protection and is equally clear as to where one-hour construction is
required, there is no authority implied in Section 205 which would allow
the Appeals Board to waive specific code requirements.
#850
WM H NEEL AlA
and associated architects
241 EAST BROADWAY
EUGENE, OREGON 9Plm
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Mr. Dave Puent
City of Springfield
Office of Community & Economic
225 North 5th Street
Springfield, OR 97477
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