Ord 1849 - Amending Articles I through IX of Chapter 7 of the Town Code Relating to Building Reguations and to Adopt the 1988 Building Standard Regulations with 1989 State of California AmendmentsORDINANCE 1849
ORDINANCE OF THE TOWN OF LOS GATOS AMENDING ARTICLES I
THROUGH IX OF CHAPTER 7 OF THE TOWN OF LOS GATOS
TOWN CODE RELATING TO BUILDING REGULATIONS AND TO
ADOPT THE 1988 BUILDING STANDARD REGULATIONS WITH 1989
STATE OF CALIFORNIA AMENDMENTS
THE TOWN COUNCIL OF THE TOWN OF LOS GATOS DOES HEREBY
SECTION I
Article I of Chapter 7 of the Town Code is hereby repealed in its entirety.
SECTION II
Article I of Chapter 7 of the Town Code is enacted to read as follows:
ARTICLE I
ADMINISTRATION OF CODES
Section 7.01.010 - Adoption of 1988 Building Standard Regulations
The Uniform Administrative Code, 1988 Edition, including the 1989 State of
California amendments Chapter 14 contained in State Building Standard Regulations
(Title 24) are hereby adopted by reference with the modifications and omissions as
provided in Section 7.01.015 through 7.01.035.
Section 7.01.015 - Board of Appeals
In order to determine the suitability of alternate materials and methods of
construction and to provide for reasonable interpretation and application of the
provisions of this code, the Town Council is a board of appeals. When the Town
Council is acting as the Board of Appeals, the building official shall attend its
sessions. The Town Council, as Board of Appeals, may adopt reasonable rules and
regulations for limiting the time for appeals and concerning procedures, for
conducting its investigations and shall render all decisions and findings in writing to
the building official with a duplicate copy to the appellant.
Section 7.01.020 - Appeal Notice
Any interested person may appeal to the Board of Appeals from any decision
of the building official. The appellant must file a written notice of appeal with the
town clerk not more than thirty (30) days after the decision is rendered. The notice
shall state clearly the decision or matter being appealed.
Section 7.01.025 - Hearing
The appeal shall be heard by the Council within forty -five (45) days after the
filing of the appeal. The board of appeals may continue from time to time any
hearing held. The town clerk shall set the hearing date for the appeal and shall give
notice such hearing to the appellant and the permittee and publish a notice in a
newspaper of general circulation for ten (10) days.
Section 7.01.030 - Building Official's Report
The Building Official shall, four (4) days prior the public hearing, submit to
the board of appeals a report describing the decision or matter being appealed and
basis for his action.
Section 7.01.030 - Conduct of Hearing, Findings
When hearing the appeal the board of appeals shall consider the building
official's report, the applicable codes, regulations and standards involved and such
additional evidence or testimony given at the hearing and may affirm, modify or
reverse, in whole or part, the action being appealed. The decision of the council
upon the appeal shall be expressed by a written resolution, a copy of which shall be
transmitted to the original permittee, the appellant and the building official. If the
decision of the board is adverse to that of the building official, the resolution shall
contain findings used in making their decision.
Section 7.01.035 - Violations
Any person who does any work or causes any work to be done, or who
occupies, or maintains any building or structure, or who causes the same to be done,
contrary to or in violation of the provisions of this code, is guilty of an infraction.
Such person is guilty of a separate offense for each day during any part of which a
violation of any provision of this code is committed, continued, or permitted by such
person and is punishable accordingly.
SECTION III
Article II of Chapter 7 of the Town Code is hereby repealed in its entirety.
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SECTION IV
Article II of Chapter 7 of the Town Code is enacted to read as follows:
ARTICLE II
BUILDING CODE
Section 7.02.010 - Adoption of 1988 Uniform Building Code
The Uniform Building Code, 1988 Edition, as amended in 1989 by the State
of California in the State Building Standard Regulations (Title 24), with Appendix
Chapters 11, 32, 35 and 49 with modifications and omissions provided in Sections
7.02.015 through 7.20.040 of this Article, is adopted by reference.
Section 7.02.015 - Sections Deleted
Each of the following sections of code adopted by this article is hereby
deleted: 101, 102, 103, 104, 105, 106, 107, 201, 202, 203, 204, 205, 301, 302, 303,
304, 305, 306 and 307, respectively.
Section 7.02.020 - Reference to Section Numbers
Any reference in the code adopted by this article, commencing with Chapter
4, to any of the sections deleted by section 7.02.020 now refers to the successor
section in Article II of this chapter.
Section 7.02.025 - Table 29 -A, Relative to Reinforcing Foundations
Table 29 -A of the code adopted by this article is amended by adding the
following footnote:
"Bearing foundation walls shall be provided with a minimum of two (2)
one - half -inch diameter reinforcing steel rods. Placement shall be one (1) rod
three (3) inches from the bottom and one (1) rod three (3) inches from the
top of the foundation. Two (2) additional lower rods, each embedded in the
foundation at least fifteen (15) feet of its length, shall be extended above
grade to provide access for electrical ground connections."
Section 7.02.030 - Section 3207(e) Roof Drainage
Subsection 3207(e) of the code adopted by this article is amended to add
additional exceptions to read as follows:
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"Other occupancies where the drainage plan and method of drainage have
been approved by the town engineer."
Section 7.02.035 - Section 3205, Standpipes
Subsection 3805(f) is added to the code adopted by this article to read:
"(f) Limited omission. Separate standpipe may be omitted in buildings
equipped throughout with an approved automatic sprinkler system; however,
hose connections for fire department use, as specified in section 3073,
National Fire Protection Association Pamphlet No. 13, shall be provided in
all required stair enclosures. The static pressure at hose connections shall not
exceed one hundred fifty pounds per square inch."
SECTION V
Article IV of Chapter 7 of the Town Code is hereby repealed in its entirety.
SECTION VI
Article IV of Chapter 7 of the Town code is enacted to read as follows:
ARTICLE IV
PLUMBING CODE
Section 7.04.010 - Adopted
The Uniform Plumbing Code, 1988 Edition, with appendix chapters A, B, C,
D, E, H and I with modification and omissions provided in sections 7.30.015 through
7.30.025 of this article is adopted by reference.
Section 7.04.015 - Installation standards adopted
The IAMPO Installation Standards, as set out in the 1988 Uniform Plumbing
Code, are adopted by reference.
Section 7.04.020 - Amendments- Sections deleted
Part I of the 1988 Plumbing Code is deleted.
Section 7.04.025 - Same - References to section numbers
Any reference in the code adopted by this article commencing with Chapter
1 to any of the sections deleted by section 6.50.020 now refers to the successor
section in Article II of this Chapter.
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SECTION VII
Article V of Chapter 7 of the Town Code is hereby repealed in its entirety.
SECTION VIII
Article V of Chapter 7 of the Town Code is enacted to read as follows:
ARTICLE V
ELECTRICAL CODE
Section 7.05.010 - Adopted
The National Electrical Code, 1990 Edition, with modifications provided in
sections 7.05.015 through 7.05.025 is adopted by reference.
Section 7.05.015 - Same - Section 250 -81, grounding electrode
Section 250 -81, Grounding Electrode System of the code adopted by this
article, is amended by adding subsection (e) to read as follows:
"(e) Where a concrete encased grounding electrode is installed as
required by section 7.02.030, a supplementary grounding conductor shall be
installed."
Section 7.05.020 - Same- Section 300 -1, scope
Section 300 -1, Scope, of the code adopted by this article, is amended by
adding subsection (c) to read as follows:
"(d) Buildings other than residential shall be wired in approved raceway. For
the purpose of this section, hotels and motels are considered commercial buildings."
Section 7.05.025 - Same - Section 336 -3, was permitted
Section 336 -3, Uses Permitted, of the code adopted by the article, is revised
to read as follows:
"336 -3. Uses Permitted or Not Permitted"
"Type NM and Type NMC cables shall be permitted to be used in one
and two - family dwellings, or multifamily dwellings not exceeding three floors
above grade. For the purpose of this article, the first floor of a building shall
be that floor designed for human habitation which is level with or above
finished grade of the exterior wall line of fifty (50) percent or more of its
perimeter."
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SECTION IX
Article VII of Chapter 7 of the Town Code is hereby repealed in its entirety.
SECTION X
Article VII of Chapter 7 of the Town Code is enacted to read:
ARTICLE VII
UNIFORM CODE FOR THE ABATEMENT OF
DANGEROUS BUILDINGS
Section 7.07.010 - Adopted
The Uniform Code for the Abatement of Dangerous Buildings, 1988 Edition,
with modifications and omissions provided in sections 7.06.015 and 7.06.020 of this
article is adopted by reference.
Section 7.07.015 - Amendments- Sections deleted
Each of the following sections of the code adopted by this article is deleted:
101, 102, 103, 201, 202, 203, 204 and 205.
Section 7.07.020 - Same - References to section numbers
Any reference in the code adopted by this article to any of the sections
deleted in Section 7.06.015 shall be deemed to refer to the appropriate section of
Article II of this Chapter.
SECTION XII
Article VIII of Chapter 7 of the Town Code is enacted to read:
ARTICLE VIII
UNIFORM MECHANICAL CODE
Section 7.08.010 - Adoption
The Uniform Mechanical Code, 1988 Edition, with Appendix Chapters A, B
and C with modifications and omissions provided in sections 7.07.015 and 7.07.020
of this Article, is adopted by reference.
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Section 7.08.015 - Sections deleted
Each of the following sections of the Code is adopted by this Article is hereby
deleted: 101, 102, 103, 104, 105 106, 107, 201, 202, 203, 204, 301, 302, 303, 304, 305
and 306.
Section 7.08.020 - Reference to section numbers
Any reference in the Code adopted by this Article, commencing with Chapter
4 to any of the sections deleted by section 7.08.015 now refers to the successor
sections in Article 1 of this Chapter.
SECTION XIII
Article IX of Chapter 7 of the Town Code is hereby repealed in its entirety.
SECTION XIV
Article IX of Chapter 7 of the Town Code is enacted to read as follows:
ARTICLE IX
UNIFORM CODE OF BUILDING
CONSERVATION
Section 7.09.010 - Adoption of Uniform Code for Building Conservation
The Uniform Code for Building Conservation, including appendices, is hereby
adopted for the regulation of buildings, identified as unreinforced masonry buildings
as defined by Section 8875 et seq. of the California Government Code and listed by
the Town of Los Gatos as "unreinforced masonry buildings." Such list shall be
maintained by the Building Official who may add or delete buildings based on his
inspection and /or engineering analysis. This code shall pertain to altering,
renovating and remodeling of buildings and structures, the issuance of permits
therefor and enforcement thereof, which building code is as follows:
All of the provisions of the Uniform Code for Building Conservation of 1985
of the International Conference of Building Officials, hereinafter termed the:
"Conservation Code ", and each and all of the regulations, appendices, provisions,
penalties, conditions and terms of such building code (one copy of which code has
been filed for use and examination by the public in the Office of the Town Clerk)
are referred to and are adopted and made a part hereof, the same as if fully set
forth in this chapter, and are adopted as sections of this chapter bearing the same
numerical sections, designations, titles as appear in the Conservation Code except
as set forth in Section 7.08.010 through and including Section 7.08.020.
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Section 7.09.015 - Sections Deleted
Chapters 1 and 2 of the Conservation Code are hereby deleted.
Section 7.09.020 - Modifications to Appendix - Chapter 1
The Appendix of Chapter 1 of the Conservation Code is hereby adopted as
amended:
APPENDIX CHAPTER 1
EARTHQUAKE HAZARD REDUCTION IN EXISTING
UNREINFORCED MASONRY BUILDINGS
PURPOSE
Sec. A101. The purpose of this chapter is to promote public safety and welfare by
reducing the risk of death or injury that may result from the effects of earthquakes on
buildings of unreinforced masonry bearing wall construction. Such buildings have been
widely recognized for their sustaining of life hazardous damage as a result of partial or
complete collapse during past moderate to strong earthquakes.
The provisions of this chapter are minimum standards for structural seismic
resistance established primarily to reduce the risk of life loss or injury and will not
necessarily prevent loss of life or injury or prevent earthquake damage to an existing
building which complies with this chapter.
SCOPE
Sec. A102. The requirements of this chapter shall apply to all buildings containing
unreinforced masonry bearing walls.
Exception: This chapter shall not apply to a detached Group R, Division 3
Occupancy nor to a detached Group R, Division 1 Occupancy containing less than five
dwelling units used solely for residential purposes.
ALTERNATE MATERIALS
Sec. A103. Alternate materials, designs and methods of construction may be
approved by the Director of Building Services in accordance with the Building Code.
DEFINITIONS
Sec. A104. For the purpose of this chapter, certain terms are defined as follows:
CROSS WALLS are interior walls of masonry or wood frame construction with
surface finish of wood lath and plaster, minimum 1 /2- inch -thick gypsum wallboard or
solid horizontal wood sheathing. In order to be considered as a cross wall within the
intent of this chapter, the cross walls shall be spaced at not more than 40 feet apart in
each story, and shall be full story height with a minimum length of one and one -half
times the story height.
UNREINFORCED MASONRY BEARING WALLS are masonry walls having all
of the following characteristics:
1. Provide the vertical support for a floor or roof.
2. Have a total superimposed load over 100 pounds per linear foot.
3. Have an area of reinforcing steel less than 50 percent of that
required by the Building Code.
HISTORIC BUILDINGS
Sec. A105. (a) General. A historic building may comply with the special provisions
set forth in this chapter and the provisions of the State Historical Building Code.
(b) Unburned Clay Masonry or Adobe. Existing or re- erected walls of adobe
construction shall conform to the following:
1. Exterior bearing walls of unreinforced adobe masonry shall not exceed a
height- or length -to- thickness ratio of 5:1. Such walls shall be provided with a reinforced
bond beam at the top which interconnects all walls. The bond beam shall have a
minimum depth of 6 inches. The bond beam may have a width equal to the width of
the wall less 8 inches, provided the resulting width is not less than 8 inches. Minimum
wall thickness shall be 18 inches for exterior bearing walls and 10 inches for adobe
partitions. No adobe structure shall exceed one story in height unless the historic
evidence satisfactory to the Director of Building Services indicates a two story height. In
such cases the height -to- thickness ratio shall be the same as above for the first story
based on the total two story wall height, and the second floor wall thickness shall not
exceed the ratio of 5:1 by more than 20 percent. Bond beams shall be provided at the
roof and second floor levels.
2. Foundations footings shall be reinforced concrete under newly reconstructed
walls and shall be 50 percent wider than the wall above, soil conditions permitting,
except that the foundation wall may be 4 inches less in width than the wall if rock,
burned brick or stabilized adobe facing is necessary to provide authenticity.
3. New or existing unstabilized brick and adobe brick masonry shall test to 75
percent of the compressive strength required by the Building Code for new material.
Unstabilized brick may be used where existing bricks are unstabilized and where the
building is not susceptible to flooding or direct exposure to the weather. Adobe may be
allowed a maximum value of 3 pounds per square inch for shear with no increase for
lateral forces.
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4. Mortar may be of the same soil composition and stabilization as the brick in
lieu of cement mortar.
5. Nominal tension stresses due to seismic forces normal to the wall may be
neglected if the wall meets the thickness requirements and shear values allowed by this
subsection.
(c) Archaic Materials. Allowable stresses for archaic materials not specified in
this code shall be based on substantiating research data or engineering judgement with
the approval of the Director of Building Services.
ANALYSIS AND DESIGN
Sec. A106.(a) General. Every structure within the scope of this chapter shall be
analyzed and constructed to resist minimum total lateral seismic forces assumed to act
nonconcurrently in the direction of each of the main axes of the structure in accordance
with the following equation:
V = ZIKCSW ........................ (Al -1)
The value of KCS need not exceed but shall not be less than .100 for one story buildings
with less than 100 occupants; and need not exceed but must not be less than .133 for
one story buildings containing 100 or more occupants and buildings over one story above
grade. The value of Z and I shall equal 1.0. The value of W shall be as defined in
Chapter 23 of the 1985 Uniform Building Code.
(b) Lateral Forces on Elements of Structures. Parts or portions of buildings shall
be analyzed and designed for lateral loads in accordance with Chapter 23 of the 1985
Uniform Building Code but not less than the value from the following equation:
Fp = ICpSWp ...................... (Al -2)
For the provisions of this section, the product of IS shall equal 1.0. The value of
Cp shall be in accordance with Table 23 -J of the 1985 Uniform Building Code. The
value of Wp shall be as defined in Chapter 23 of the 1985 Uniform Building Code.
Exception: Unreinforced masonry walls may be designed in accordance with
Section A107.
(c) Regulated Elements of Buildings. The elements of buildings required to be
analyzed by this chapter include: 1) Height -to- thickness ratio of masonry walls; (2)
Tension bolts in bending; (3) in -plane shear stress; (4) Parapets; (5) Diaphragm stresses
and diaphragm chords in floors and roof.
(d) Anchorage and Interconnection. Anchorage and interconnection of all parts,
portions and elements of the structure shall be analyzed and designed for lateral forces
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in accordance with the 1985 Uniform Building Code and the Formula (Al -2) of this
code. Masonry walls shall be anchored to all floors and roof to resist a minimum force
of 200 pounds per linear foot acting normal to the wall at the level of the floor or roof.
(e) Level of Required Repair. Alterations and repairs required to meet the
provisions of this chapter shall comply with all other applicable requirements of the
Building Code unless specifically provided for in this chapter.
(f) Required Analysis. 1. General. Except as modified herein, the analysis and
design relating to the structural alteration of existing buildings within the scope of this
chapter shall be in accordance with the analysis specified in the 1985 Uniform Building
Code. In addition the compatibility of the roof diaphragm stiffness with the out -of -plane
stability of the unreinforced masonry walls of the story immediately below the roof shall
be verified in accordance with the provisions of Section A109.
Exception: Buildings with rigid concrete or steel and concrete roof diaphragms
shall use the h/t values for all other buildings in Table Al -F.
2. Continuous load path. A complete, continuous load path from every part or
portion of the structure to the ground shall be provided for the required horizontal
forces.
3. Positive connections. All parts, portions or elements of the structure shall be
interconnected by positive means.
(g) Analysis Procedure 1. General. Stresses in materials and existing construction
utilized to transfer seismic forces from the ground to parts or portions of the structure
shall conform to the those permitted by the Building Code and those materials and types
of construction specified in Section A107.
2. Connections. Materials and connectors used for the interconnection of parts
and portions of the structure shall conform to the Building Code. Nails may be used as a
part of an approved connector.
3. Unreinforced masonry walls. In addition to the seismic forces required by this
chapter, unreinforced masonry walls shall be analyzed as specified in the 1985 Uniform
Building Code to withstand all vertical loads as specified in the Building Code. Such
walls shall meet the minimum requirements set forth in the Building Code.
Exception: When calculating shear or diagonal tension stresses due to seismic
forces, existing masonry shear walls may be designed to resist 1.0 times the required
forces in lieu of the 1.5 factor required by the Building Code.
No allowable tension stress will be permitted in unreinforced masonry walls.
Walls not capable of resisting the required design forces specified in this chapter shall
be strengthened or shall be removed and replaced.
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Exceptions: 1. Unreinforced masonry walls may be analyzed in accordance with
Section A107.
2. Unreinforced masonry walls which carry no design loads other than their own
weight may be considered veneer if they are adequately anchored to new supporting
elements.
Substantial changes in wall thickness or stiffness shall be considered in the
analysis for out -of -plane and in -plane wall stability, and the wall shall be restrained
against out -of -plane instability by anchorage and bracing to the roof or floor diaphragm
in accordance with Section A106(d).
Exception: Variations in wall stiffness caused by nominal openings such as
windows and doors need not be considered.
(h) Combination of Vertical and Seismic Forces. 1. New materials. All new
materials introduced into the structure to meet the requirements of this section which
are subject to combined vertical and horizontal forces shall comply with the Building
Code.
2. Existing materials. When stress in existing lateral force resisting elements are
due to a combination of dead loads plus live loads plus seismic loads, the allowable
working stress specified in the Building Code may be increased 100 percent. However,
no increase will be permitted in the stresses allowed in Section A107. The stresses in
members due to only seismic and dead loads shall not exceed the values permitted by
the Building Code.
3. Allowable reduction of bending stress by vertical load. Calculated tensile
fiber stress may be reduced by the full direct stress due to vertical dead loads.
MATERIALS OF CONSTRUCTION
Sec. A107. (a) General. All materials permitted by this code, including their
appropriate allowable stresses and those existing configurations of materials specified
herein, may be utilized to meet the requirements of this chapter.
(b) Existing Materials. 1. Unreinforced masonry walls. Unreinforced masonry
walls analyzed in accordance with this chapter may provide vertical support for roof and
floor construction and resistance to lateral loads.
All units of both bearing and non - bearing walls shall be laid with full shoved
mortar joints; all head, bed and wall (collar) joints shall be solidly filled with mortar;
and the bonding of adjacent wythes of multi -wythe walls shall be as follows:
The facing and backing shall be bonded so that no less than 4 percent of the wall
surface of each face is composed of headers extending not less than four inches into the
backing. The distance between adjacent full - length headers shall not exceed 24 inches
IN
either vertically or horizontally. In walls where a single header does not extend through
the wall, headers from the opposite sides shall overlap at least four inches, or headers
from opposite sides shall be covered with another header course overlapping the header
below at least four inches.
Wythes of walls not bonded as described above shall be considered as veneer.
The veneer wythe shall not be included in the effective thickness used to calculate the
height -to- thickness ratio and the shear capacity of the wall.
Tension stresses due to seismic forces normal to the wall may be neglected if the
wall does not exceed the height -to- thickness ratio set forth in Table Al -F and the
in -plane shear stresses due to seismic loads set forth in Table AM. If the wall height -to-
thickness ratio exceeds the specified limit, the wall may be supported by vertical bracing
members designed to satisfy the requirements of the 1985 Uniform Building Code. The
deflection of such bracing members at design loads shall not exceed one -tenth of the
wall thickness.
Exception: The wall may be supported by flexible bracing members designed in
accordance with Section A106(b) of this chapter if the deflection at design loads is not
less than one - quarter nor more than one -third of the wall thickness at the level under
consideration.
All vertical bracing members shall be attached to floor and roof construction for
their design loads independently of required wall anchors. Horizontal spacing of vertical
bracing members shall not exceed one -half the unsupported height of the wall nor ten feet,
whichever is less.
The wall height may be measured vertically to bracing elements other than a
floor or roof. Spacing of elements and wall anchors shall not exceed six feet. Bracing
elements shall be detailed to minimize the horizontal displacement of the wall
components of vertical displacements of the floor or roof.
2. Veneer. Veneer shall be anchored with approved anchor ties conforming to the
required design capacity specified in Section 3304(c) of the 1985 Uniform Building
Code, and placed at a maximum spacing of 24 inches.
Exception: Existing veneer anchor ties may be acceptable provided the ties are
in good condition and conform to the minimum size, maximum spacing and material
requirements as indicated below. The veneer anchor ties shall be corrugated galvanized
iron strips not less than one inch in width, eight inches in length and one - sixteenth of an
inch in thickness and shall be located and laid in every alternate course in the vertical
height of the wall at a spacing not to exceed 17 inches on center horizontally. As an
alternate, the spacing may be every fourth course vertically at a spacing not to exceed
nine inches on center horizontally.
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The existence and condition of existing veneer anchor ties shall be verified as
follows:
(a) An approved testing laboratory shall verify the location and spacing of the
ties and shall submit a report to the Director of Inspection Services for approval
as a part of the structural analysis.
(b) The veneer in a selected area shall be removed to expose a representative
sample of ties (not less than four) for inspection by the Director of Building
Services.
3. Existing roof, floors, walls, footings, and wood framing. Existing materials,
including wood shear walls, may be used as a part of the lateral load resisting system,
provided that stresses in these materials do not exceed the values shown in Table No. Al -G.
(c) Strengthening of Existing Materials. New materials, including wood shear walls
may be utilized to strengthen portions of the existing seismic resisting system provided that
stresses do not exceed the values shown in Table No. Al -H.
(d) Minimum Acceptable Quality of Existing Unreinforced Masonry Walls. 1.
General provisions. All unreinforced masonry walls utilized to carry vertical loads and
seismic forces parallel and perpendicular to the wall plane shall be tested as specified in
this subsection. All masonry quality shall equal or exceed the minimum standards
established herein or shall be removed and replaced by new materials. The quality of
mortar in all masonry walls shall be determined by performing in -place shear tests.
Alternate testing methods may be approved by the Director of Building Services upon
submission of adequate evidence to indicate its equivalence. The vertical wall joint between
wythes (collar joint) shall be inspected at each test location after the in -place shear tests,
and an estimate of the percentage of wythe to wythe mortar coverage shall be reported
along with the results of the in -place shear tests. Where the exterior face is veneer, the type
of veneer its thickness and its bonding and /or ties to the structural wall masonry shall also
be reported. Nothing shall prevent the pointing with mortar of all the masonry wall joints
before the tests are first made. Prior to any pointing, the mortar joints must be raked and
cleaned to remove loose and deteriorated mortar. Mortar for pointing shall be Type S or
N, except masonry cements shall not be used. All preparation and mortar pointing shall be
done under the continuous inspection of a special inspector. At the conclusion of the
inspection, the inspector shall submit a written report to the person responsible for the
seismic analysis of the building setting forth the results of the work inspected. Such report
shall be submitted to the Director of Building Services for approval as part of the structural
analysis. All testing shall be performed in accordance with the requirements specified in this
section by an approved agency. An accurate record of all such tests and their location in
the building shall be recorded and these results shall be submitted to the Director of
Building Services for approval as part of the structural analysis.
2. Number and location of tests. The minimum number of tests shall be as follows.
At each of both the first and top stories, not less than two per wall line or line of wall
elements providing a common line of resistance to lateral forces. At each of all other
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stories, not less than one per wall elements providing a common line of resistance to lateral
forces. In any case, not less than one per 1500 square feet of wall surface and a total of
eight. The shear tests shall be taken at locations representative of the mortar conditions
throughout the entire building, taking into account variations in workmanship at different
building height levels, variations in weathering of the exterior surfaces, and variations in the
condition of the interior surfaces due to deterioration caused by leaks and condensation of
water and /or by the deleterious effects of other substances contained within the building.
Where the higher h/t ratios allowed in footnotes 4 and 5 of Table Al -F are to be utilized,
all the in -place shear tests taken at the top story shall be included in the 80 percent of the
shear tests used to determine the minimum mortar shear strength. The exact test locations
shall be determined at the building site by the person responsible for the seismic analysis
of the subject building.
3. In -place shear tests. The bed joint of the outer wythe of the masonry wall shall
be tested in shear by laterally displacing a single brick relative to the adjacent bricks in the
wythe. The opposite head joint of the brick to be tested shall be removed and cleaned prior
to testing. The minimum quality mortar in 80 percent of the shear tests shall not be less
than the total of 30 psi plus the axial stress in the wall at the point of the test. The shear
stress shall be based on the gross area of both bed joints and shall be that at which
movement of the brick is first observed.
(e) Testing Shear Bolts. One - fourth of all new shear bolts and dowels embedded in
unreinforced masonry walls shall be tested by a special inspector using a torque calibrated
wrench to the following minimum torques:
1/2 -inch diameter bolts or dowels
= 40 foot - pounds
5/8 -inch diameter bolts or dowels
= 50 foot- pounds
3/4 -inch diameter bolts or dowels
= 60 foot - pounds
No bolts exceeding 3/4 -inch diameter shall be used. All nuts shall be installed over
malleable iron or plate washers when bearing on wood and heavy cut washers when bearing
on steel.
(f) Determination of Allowable Stresses for Design Methods Based on Test Results.
1. Design shear values. Design seismic in -plane shear stresses shall be substantiated
by tests performed as specified in Item No. 3 of Subsection (d).
Design stresses shall be related to test results obtained in accordance with Table No.
Al -I. Intermediate values between 5 and 10 psi may be interpolated.
2. Design compression and tension values. Compression stresses for unreinforced
masonry having a minimum design shear value of 3 psi shall not exceed 100 psi. Design
tension values for unreinforced masonry shall not be permitted.
(g) Existing Wall Anchors. Five percent of the existing wall anchors utilized as all
or part of the required wall anchors shall be tested in pullout by an approved testing
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agency. The minimum number tested shall be four per floor, with two tests at walls with
joist parallel to the wall. The test apparatus shall be supported on the masonry wall at a
minimum distance equal to the wall thickness from the anchor tested. The rod anchor shall
be given a preload of 300 pounds prior to establishing a datum for recording elongation.
The tension test load reported shall be recorded at 1/8 -inch relative movement of the
anchor and the adjacent masonry surface. Results of all tests shall be reported. The report
shall include the test results as related to the wall thickness and joist orientation. The
allowable resistance value of the existing anchors shall be forty percent of the average of
those tested anchors having the same wall thickness and joist orientation.
(h) Qualification Tests. Qualifications tests for new devices used for wall anchorage
shall be tested with the entire tension load carried on the enlarged head at the exterior face
of the wall. Bond on the part of the device between enlarged head and the interior wall
face shall be eliminated for the qualification tests. The resistance value assigned the device
shall be twenty percent of the average of the ultimate loads.
INFORMATION REQUIRED ON PLANS
Sec. A108. (a) General. In addition to the seismic analysis required in this chapter
the person responsible for the seismic analysis of the building shall determine and record
the information required by this section on the approved plans.
(b) Construction Details. The following requirements with appropriate construction
details shall be made a part of the approved plans.
1. All unreinforced masonry walls shall be anchored at the roof and ceiling levels by
tension bolts through the wall as specified in Table Al -H, or by an approved equivalent at
a maximum anchor spacing of six feet.
All unreinforced masonry walls shall be anchored at all floors and ceiling with
tension bolts through the wall or by existing rod anchors at a maximum anchor spacing
of six feet. All existing rod anchors shall be secured to the joists to develop the required
forces. Tests conforming to this chapter will be required to verify the adequacy of the
embedded ends of existing rod anchors.
Exception: Walls need not be anchored to ceiling systems that, because of their
low mass and or relative location with respect to the floor or roof systems, would not
impose significant normal forces on the wall and cause out -of -plane wall failure.
Calculations and drawings to verify this exception must be submitted as part of the
analysis.
At the roof and all floor levels, the anchors nearest the building corners shall be
combination shear and tension anchors located not more than two feet horizontally from
the inside corners of the walls.
16
When access to the exterior face of the masonry wall is prevented by proximity of
an existing building, wall anchors conforming to Items 5 (a) or (b) in Table No. Al -H
may be used.
Alternative devices to be used in lieu of tension bolts for masonry wall anchorage
shall be tested as specified in Section A107(h).
2. Diaphragm chord stresses of horizontal diaphragms shall be developed in
existing materials or by the addition of new materials.
3. Where trusses and beams other than rafters or joists are supported on masonry
independent secondary columns shall be installed to support vertical loads.
4. Parapets and exterior wall appendages not capable of resisting the forces
specified in this chapter shall be removed, stabilized, or braced to ensure that the
parapets and appendages remain in their original position. The maximum height of an
unbraced, unreinforced masonry parapet above the lower of either the level of tension
anchors or roof sheathing, shall not exceed one and one -half times the thickness of the
parapet wall. If the required parapet height exceeds this maximum height a bracing
system designed for the force factors specified in the Table 23 -J of the 1985 Uniform
Building Code shall support the top of the parapet. Parapet corrective work must be
performed in conjunction with the installation of tension roof anchors.
The minimum height of a parapet above the wall anchor shall be 12 inches.
Exception: If a reinforced concrete beam is provided at the top of the wall, the
minimum height above the wall anchor may be six inches.
5. All deteriorated mortar joints in unreinforced masonry walls shall be pointed
with Type S or N mortar. Prior to any pointing, the wall surface must be raked and
cleaned to remove loose and deteriorated mortar. All preparation and pointing shall be
done under the continuous inspection of a special inspector. At the conclusion of the
project, the inspector shall submit a written report to the Director of Building Services
setting forth the portion of work inspected.
6. Repair details for any cracked or damaged unreinforced masonry wall required
to resist forces specified in this chapter.
(c) Existing Construction. The following existing construction information shall be
made part of the approved plans:
1. The type and dimensions of existing walls and the size and spacing of floor and
roof members.
2. The extent and type of existing wall anchorage to floors and roof.
17
3. The extent and type of any parapet bracing or other structural reinforcement to
parts or portions of the building which were previously performed.
4. Accurately dimensioned floor plans and masonry wall elevations showing
dimensioned opening, piers, wall thickness and heights, veneer locations and existing
anchorages.
5. The locations of cracks or other damaged portions of unreinforced masonry
walls requiring repair.
6. The type of interior wall surfaces and ceilings, and if reinstalling or anchoring
of existing plaster is necessary.
7. The general condition of the mortar joints and if the joints need repointing.
8. The location of all in -place shear tests or core tests, shall be shown on the
floor plans and building wall elevations.
Design Check for Compatibility of Roof Diaphragm Stiffness to Unreinforced
Masonry Wall Out -of -Plane Stability.
Sec. A109 (a) General. The requirements of this section are in addition to the
other analysis requirements of this Chapter. The relative stiffness and strength of a
diaphragm governs the amount of amplification of the seismic ground motion by the
diaphragm. and therefore, a diaphragm stiffness and strength related check of the out -of
plane stability of unreinforced masonry walls anchored to wood diaphragms shall be
made. This section contains a procedure for evaluation of the out -of -plane stability of
unreinforced masonry walls anchored to wood diaphragms that are coupled to shear
resisting elements.
(b) Definitions. The following definitions are applicable to this section.
Cross Wall. A wood framed wall having a height to length ratio complying with
Section 4713(d) or table 25 -I of the 1985 Uniform Building Code and sheathed with any
of the materials described in Table Al -J or Table Al -K. The total strength of all cross
walls located within any 40 feet length of diaphragm measured in the direction of the
diaphragm span shall not be less than 30 percent of the strength of the diaphragm in the
direction of consideration.
Demand Capacity Ratio (DCR). A ratio of the following:
1. Demand equals the lateral forces due to 33 percent of the combined weight of
the diaphragm and the tributary weight of the walls and other elements anchored to the
diaphragm.
WO
2. Capacity equals the diaphragm total shear strength in the direction under
consideration as determined using the values in Tables No. Al -J or Table Al -K.
(C) Notations.
D = depth of diaphragm in feet, measured perpendicular to the
diaphragm span.
h/t = height -to- thickness of an unreinforced masonry wall. The height
shall be measured between wall anchorage levels and the thickness
shall be measured through the wall cross section at the level under
consideration.
L = span of diaphragm between masonry shear walls or steel frames.
Vc = total shear capacity of cross walls in the direction of analysis
immediately below the diaphragm level being investigated as
determined by using Tables No. Al -J and Al -K.
VU = maximum shear strength in pounds per foot for a diaphragm
sheathed with any of the materials given in tables No. Al -J and
Al -K.
Wd = total dead load of the diaphragm plus the tributary weight of the
walls anchored to the diaphragm, the tributary ceiling and partitions
and weight of any other permanent building elements at the
diaphragm level under consideration.
(d) Design Check Procedure. 1. General. The demand - capacity ratio (DCR) for
the building shall be calculated using the following equations:
DCR = 0.33 Wd / 2 vu D For building without cross walls or
DCR = 0.33 Wd /2 vu D + Vc for building with cross walls
2. Diaphragm Deflection. The calculated DCR shall be to the left of the curve in
Figure No. Al -L. Where the calculated DCR is outside (to the right of) the curve, the
diaphragm deflection limits are exceeded and cross walls may be used to reduce the
deflection.
3. Unreinforced Masonry Wall Out -of -Plane Stability. The DCR shall be
calculated discounting any cross wall. If the DCR from this method corresponding to the
diaphragm span is to the right of the curve in Figure No. Al -L, the region within the
curve at and below the intersection of the diaphragm span with the curve may be used
to determine the allowable h/t values per Table No. Al -F.
19
TABLE NO AI -F
ALLOWABLE VALUE OF HEIGHT - THICKNESS (h /t) RATIO
OF UNREINFORCED MASONRY WALLS WITH MINIMUM QUALITY MORTAR
BUILDING WITH ALL OTHER
COMPLYING CROSS WALLS BUILDINGS
One Story Building Walls 13 -16 234 13
First Story of
Multi -Story Buildings 16 15
Walls in the Top Story
of Multi -Story Buildings 9-14 234
9
All Other Walls 16 13
Minimum mortar quality shall be determined by laboratory testing in accordance
with this chapter.
2 The minimum mortar shear strengths required in the following footnotes 4 and 5
shall be that shear strength without the effect of axial stress in the wall at the
point of the test.
3 The larger height -to- thickness ratio may be used where mortar shear tests in
accordance with Section A107(d) establish a minimum mortar shear strength of
not less than 100 psi or where the tested mortar shear strength is not less than 60
psi and a visual examination of the vertical wythe -to -wythe wall joint (collar joint)
indicates not less than 50 percent mortar coverage.
4 Where a visual examination of the collar joint indicates not less than 50 percent
mortar coverage and the minimum mortar shear strength when established in
accordance with Section A107(d) is greater than 30 psi but less than 60 psi, the
allowable height -to- thickness ratio may be determined by linear interpolation
between the larger and smaller ratio values in direct Proportion to the mortar
shear strength.
20
TABLE NO. Al -G
VALUES FOR EXISTING MATERIALS 1
1. Horizontal Diaphragms
a. Roofs with straight sheathing with
the roof covering applied directly to 100 PLF for seismic shear.
the sheathing.
b. Roofs with diagonal sheathing with
the roof covering applied directly to 400 PLF for seismic shear.
the sheathing.
c. Floors with straight tongue and
groove sheathing.
150 PLF for seismic shear.
d. Floors with straight sheathing and
finished wood flooring.
e. Floors with diagonal sheathing and
finished wood flooring.
f. Floors or roofs with straight
sheathing and plaster applied to the
joists or rafters.
300 PLF for seismic shear.
450 PLF for seismic shear.
Add 50 PLF to the allowable values in
items 1a and 1c.
2. Cross Walls
Wood stud walls with lath and plaster.
3. Plain Concrete Footings
100 PLF for each side for seismic shear.
f c = 1500 psi unless a otherwise shown by
tests.
4. Douglas Fir Wood
5. Reinforcing Steel
6. Structural Steel
Same as 1985 UBC values for No. Douglas
Fir 3
f c = 18,000 psi maximum.
f c = 20,000 psi maximum.
-------------------------------------------------------------------------------------------------------------------------
1 Materials must be sound and in good condition.
2 Wood lath and plaster must be reattached to existing joists or rafters in a manner
approved by the Director of Building Services.
3 Stresses given may be increased for combinations of loads as specified in Section
A106.
21
TABLE NO. Al -H
ALLOWABLE VALUES FOR NEW MATERIALS USED
IN CONJUNCTION WITH EXISTING CONSTRUCTION
New Materials or Configuration
of Materials
...........................................................
1. Horizontal Diaphragms
Plywood sheathing applied directly over
existing straight sheathing with ends of
plywood sheets bearing on joists or rafters
and edges of plywood located on center of
individual sheathing boards.
2. Cross Walls
Plywood sheathing applied directly over
existing wood studs. (No value shall be
given to plywood applied over existing
plaster or wood sheathing boards).
Allowable Values
Same as specified in Table 25 -J of the
1985 Uniform Building Code for blocked
diaphragms.
Same as values specified in Table No. 25-
K of the 1985 UBC for shear walls.
b. Dry wall or plaster applied directly over
existing wood studs.
c. Dry wall or plaster applied to plywood
sheathing over wood studs
3. Shear Bolts
Shear bolts and shear dowels embedded a
minimum of 8 inches into unreinforced
masonry walls. Bolt centered in a 2 -1/2
inch diameter hole with dry -pack or non-
shrink grout around the circumference of
the bolt. 13
75 percent of the values specified in Table
No. 47 -I of the 1985 UBC
One -third of the values specified in Table
No. 47 -I of the 1985 UBC
133 percent of the values for plan masonry
specified in Table No. 24 -J of the 1985
UBC. No values larger than those given
for 3/4 inch diameter bolts shall be used.
4. Tension Bolts
Tension bolts and tension dowels extending 1200 pounds per bolt.
entirely through URM walls secured with
bearing plates on far side of wall with at
least 30 square inches of area. 2
5. Combination Shear and Tension Wall
Anchors
(a) Bolts extending to the exterior face of
the wall with a 2 -1/2 inch round plate
under the head. Install as specified for
shear bolts. Spaced not closer than 12
inches on centers. 123
600 lbs. per bolt for tension see Item 3
(Shear Bolts) for shear values.
Fla
[5. Combination Shear and Tension Wall
Anchors Continued]
(b) Bolts or dowels extending to the
exterior face of the wall with a 2 -1/2
inch round plate under the head and
drill at an angle of 22 -1/2 degrees to
the horizontal. Install as specified for
shear bolts. 123
1200 lbs. per bolt or dowel for tension
See Item 3 for shear values
(c) Through bolt with bearing plate for
tension per Item 4. Combined with
minimum 8 inch grouted section for
shear per Item 3.
7. Infilled Walls
Reinforced masonry infilled openings in
existing unreinforced masonry walls with
keys or dowels to match reinforcing.
8. Reinforced Masonry
Masonry piers and walls reinforced as
specified in Chapter 24 of the 1985
Uniform Building Code.
9. Reinforced Concrete
Concrete footings, walls and piers
reinforced as specified in Chapter 26 and
designed for tributary loads.
10. Existing Foundation Loads
Foundation loads for structures exhibiting
no evidence of settlement.
See Item 4 (Tension Bolts) for tension
values See Item 3 for shear values.
Same as values specified for unreinforced
masonry walls in this chapter.
Same as values specified in Table No. 24-
B of the 1985 Uniform Building Code.
Same as values specified in Chapter 26 of
the 1985 Uniform Building Code.
Calculated existing foundation loads due to
maximum dead load plus live load may be
increased by 25 percent and may be
increased 50 percent for dead load plus
seismic loads required by this chapter.
--------------------------------------------------------------------------------------------------------------------------
1 Bolts and dowels to be treated as specified in Section A107.
2 Bolts and dowels to be 1/2 -inch diameter minimum.
3 Drilling for bolts and dowels shall be done with an electric rotary drill. Impact tools
shall not be used for drilling holes or tightening anchor and shear bolt nuts.
4 Allowable bolt and dowel values specified are for installations in minimum three
wythe wall. For installations in two wythe walls use 50 percent of the value specified,
except that no value shall be given to tension bolts that do not extend entirely through
the wall and are secured with bearing plates on the far side.
23
TABLE NO. Al -1
ALLOWABLE SHEAR STRESS FOR TESTED
UNREINFORCED MASONRY WALLS
SHEAR TESTS
Eighty percent of
Average test results.
Seismic in-plane
test results in psi
of cores in psi
shear in psi based
not less than:
on gross area*
30 plus axial stress
20
3
40 plus axial stress
27
4
50 plus axial stress
33
5
100 plus axial stress
67 or more
10 (maximum)
or more
4 Allowable shear stress may be increased by addition of 10 percent of the axial
stress due to the weight of the wall directly above.
24
TABLE NO. AW
ALLOWABLE VALUES FOR EXISTING MATERIALS TO BE USED ONLY IN THE
COMPUTATION OF THE DEMAND CAPACITY RATIO DESIGN CHECK
Existing Materials or
Configuration of Materials 1
----------------------------------------
1. Horizontal Diaphragms
Allowable Values
a. Roofs with straight sheathing and
roofing applied directly to the
sheathing.
b. Roofs with diagonal sheathing and
roofing applied directly to the
sheathing.
2. Cross Walls 2
a. Plaster on wood or metal lath.
b. Plaster on gypsum lath.
c. Gypsum wall board unblocked
edges.
d. Gypsum wall board blocked edges
100 lbs. per foot for seismic shear.
250 lbs. per foot for seismic shear.
Per side:
200 lbs. per foot for seismic shear.
175 lbs. per foot for seismic shear.
75 lbs. per foot for seismic shear.
125 lbs. per foot for seismic shear.
-----------------------------------------------------------------------
Materials must be sound and in good condition.
2 For cross walls, values of all materials may be combined, except the total combined
value shall not exceed 300 lbs. per foot for seismic shear.
25
TABLE NO. Al -K
ALLOWABLE VALUES FOR NEW MATERIALS USED IN CONJUNCTION WITH
EXISTING CONSTRUCTION MATERIALS TO BE USED ONLY IN THE
COMPUTATION OF THE DEMAND CAPACITY RATIO DESIGN CHECK
New Materials or Configuration of New
and Existing Materials
Allowable Values
1. Horizontal Diaphragms
a. Plywood sheathing applied directly
over existing straight sheathing with
ends of plywood sheets bearing on
rafters and edges of plywood located
on the center of individual sheathing
boards.
225 lbs. per foot for seismic shear.
2. Cross Walls 2
a. Plywood sheathing applied directly
over existing wood studs. No value 1.33 times the values specified in Table 25-
shall be given to plywood applied K of the 1985 UBC
over existing plaster or wood
sheathing.
b. Drywall or plaster applied directly 100 percent of the values specified in
over existing wood studs. Table 47 -I of the 1985 UBC
----------------------------------------------------------------------------------------------------------------------
Materials must be sound and in good condition.
2 For cross walls, values of all materials may be combined, except the total combined
shear value shall not exceed 300 lbs. per foot for seismic shear.
Section 7.09.025 - Reconstruction of Unreinforced Chimneys
Unreinforced chimneys shall be reconstructed in accordance with the seismic safety
standrds set forth in Chapter 37 of the currently adopted edition of the Uniform Building
Code and be done to the satisfaction of the Director of Building Services.
Section 7.09.030 - Modifications to Reinforced Masonry. Woodframe and Other
Structures
The repair, reconstruction or restoration of reinforced masonry structures, woodframe
structures and other types of structures shall be made in accordance with seventy -five
percent (75 %) of the current Uniform Building Code Value for lateral forces to the
satisfaction of the Planning Director and the Director of Building Services.
26
Section 7.09.035 - Mitigation Measures
Phase 1: Owners of unreinforced masonry buildings shall provide complete plans and
calculations for seismic upgrades by March 1, 1991.
Phase 2: Owners of unreinforced masonry buildings shall complete all work related to
seismic upgrades by May 1, 1993.
SECTION XV
Article IX of Chapter 7 of the Town code is hereby repealed in its entirety.
SECTION XVI
This ordinance takes effect 30 days after it is adopted. Within 15 days after this
ordinance is adopted the Town Clerk shall cause it to be published once in a newspaper
of general circulation published and circulated in the Town.
This ordinance was introduced at a regular meeting of the Town Council of the Town
of Los Gatos on the 6th day of May, 1991 and adopted by the following vote as an
ordinance of the Town of Los Gatos at a regular meeting of the Town Council of the
Town of Los Gatos on the 20th day of May, 1991.
COUNCIL MEMBERS:
AYES: Randy Attaway, Joanne Benjamin
Steven Blanton, Eric D. Carlson,
Mayor Brent N. Ventura
NAYS: None
ABSENT: None
ABSTAIN: None
SIGNED:
MAYOR OF THE TOWN OF LOS GATOS
LOS GATOS, CALIFORNIA
ATTEST:
CLERK OF THE TOWN OI - OS GATOS
LOS GATOS, CALIFORNIA
c1k:d7: \other \b1dgcode
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