Item H12BOARD OF COUNTY COMMISSIONERS
AGENDA ITEM SUMMARY
Meeting Date: September 16, 2015 Department: Building
Bulk Item: Yes X No Staff Contact Person/Phone #: Christine Hurley, 289-2517
Ed Koconis, 453-8727
AGENDA ITEM WORDING: Approval of a resolution of the Monroe County Board of County
Commissioners adopting FEMA Technical Bulletin 11 "Crawlspace Construction" dated November
2001 as required pursuant to Monroe County Code Section 122-2(c).
ITEM BACKGROUND: Chapter 122 of the Monroe County Code "Floodplain Management"
includes rules for interpreting flood hazard issues. The building official shall be guided by the current
edition of FEMA's 44 CFR, and FEMA's interpretive letters, policy statements and technical bulletins
as adopted from time to time by the board of county commissioners. FEMA's Technical Bulletins
("bulletins") provide guidance concerning the building performance standards of the National Flood
Insurance Program (NFIP), which are contained in Title 44 of the U.S. Code of Federal Regulations.
The bulletins are intended for use primarily by State and local officials responsible for interpreting and
enforcing NFIP regulations and by members of the development community, such as design
professionals and builders. New bulletins, as well as updates to existing bulletins, are issued
periodically as needed. The bulletins do not create regulations; rather they provide specific guidance
for complying with the minimum requirements of existing NFIP regulations. Adopting these
documents as well as internal County policies would serve to allow the County to not only remain in
the NFIP as stated in Section 122-1(b), but also to move forward with the intent of becoming eligible
to enter FEMA's Community Rating System (CRS). The proposed resolution would adopt FEMA
Technical Bulletin 11 "Crawlspace Construction" dated November 2001 as required pursuant to
Monroe County Code Section 122-2(c),
PREVIOUS RELEVANT BOCC ACTION:
January 18, 1994 — BOCC approved Ordinance No. 002-1994 adding the language "as adopted by
resolution from time to time by the Board of County Commissioners" to the rules for interpreting flood
hazard issues.
July 15, 2015 — BOCC rejected proposed ordinance amending Section 122-2(c) and directed staff to
continue proposing resolutions for adoption of both new and amended documents to be used by the
building official for guidance on floodplain management.
CONTRACT/AGREEMENT CHANGES: N/A
STAFF RECOMMENDATION: Approval
TOTAL COST: NIA INDIRECT COST: N/A BUDGETED: Yes No N/A
DIFFERENTIAL OF LOCAL PREFERENCE: N/A
COST TO COUNTY: N/A SOURCE OF FUNDS: N/A
REVENUE PRODUCING: Yes _ No N/A AMOUNT PER MONTH NIA Year
APPROVED BY: County Atty X OMB/Purchasing Risk Management
DOCUMENTATION: Included X Not Required_
DISPOSITION: AGENDA ITEM #
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MONROE COUNTY, FLORIDA
MONROE COUNTY BOARD OF COUNTY COMMISSIONERS
RESOLUTION NO. - 2015
A RESOLUTION OF THE MONROE COUNTY BOARD OF
COUNTY COMMISSIONERS ADOPTING FEMA TECHNICAL
BULLETIN 11 "CRAWLSPACE CONSTRUCTION" DATED
NOVEMBER 2001 AS REQUIRED PURSUANT TO MONROE
COUNTY CODE SECTION 122-2(C)
WHEREAS, Monroe County is currently a participating community in the National
Flood Insurance Program (NFIP) and is working on internal County policies to improve upon its
interpretation of NFIP regulations; and
WHEREAS, Monroe County desires to become eligible to enter FEMA's Community
Rating System (CRS); and
WHEREAS, Monroe County Code Section 122-2(c), in part, requires that in interpreting
other provisions of this chapter, the building official shall be guided by the current edition of
FEMA's 44 CFR, and FEMA's interpretive letters, policy statements and technical bulletins as
adopted by resolution from time to time by the board of county commissioners;
NOW, THEREFORE, BE IT RESOLVED BY THE BOARD OF COUNTY
COMMISSIONERS OF MONROE COUNTY, FLORIDA:
Section 1. Pursuant to Monroe County Code Section 122-2(c), the Board hereby adopts
FEMA Technical Bulletin I l "Crawlspace Construction" dated November 2001, a copy of which
is attached hereto.
Section 2. The Clerk of the Board is hereby directed to forward one (1) certified copy of
this Resolution to the Building Department.
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PASSED AND ADOPTED by the Board of County Commissioners of Monroe County,
Florida, at a regular meeting held on the 16th of September, 2015.
Mayor Danny L. Kolhage
Mayor pro tem Heather Carruthers
Commissioner Sylvia Murphy
Commissioner George Neugent
Commissioner David Rice
BOARD OF COUNTY COMMISSIONERS
OF MONROE COUNTY, FLORIDA
(SEAL)
ATTEST: AMY HEAVILIN, CLERK
Deputy Clerk
Mayor Danny L. Kolhage
MONROE COUNTY ATTORNEY
PPROVED �pO FORM:
.n
STEVEN T. WILLIAMS
ASSISTANT COUNTY ATTORNEY
Date ��
Technical Bulletin
Crawlspace Construction
for Buildings Located in Special Flood Hazard Areas
National Flood Insurance Program Interim Guidance
FEMA TB-- I I / November 200 I
x ti FEMA
�f zq N D 54-C,
Key Word/Subject Index
This index allows the user to locate key words and subjects in this Technical Bulletin. The
Technical Bulletin User's Guide (printed separately) provides references to key words and
subjects throughout the Technical Bulletins. For definitions of selected terms, refer to the
Glossary at the end of this bulletin.
Key Word/Subject Index
Page
Best practices for crawlspace foundations in the SFHA 6
Drainage considerations 8
NFIP requirements for all crawlspace construction 3
Flood forces on buildings 5
Flood insurance implications 6
Flood -resistant materials 8
Pre-engineered below -grade crawlspace foundation guidance 7
Requirements, additional for below -grade crawlspaces 4
Utilities, access, and ventilation openings 9
Any comments on the Technical Bulletins should be directed to:
Federal Emergency Management Agency
Federal Insurance and Mitigation Administration
500 C Street, SW.
Washington, DC 20472
Wave design on cover based on the Japanese print The Great Wave Off Kanagawa, by Katsuchika Hokussai
(1760-1849), Asiatic Museum of Fine Arts, Boston.
TECHNICAL BULLETIN 11-01
Crawlspace Construction for Buildings Located in Special Flood Hazard Areas
National Flood Insurance Program Interim Guidance
Introduction
Crawlspace foundations are commonly used to elevate the lowest floors of residential buildings
located in Special Flood Hazard Areas (SFHAs) above the Base Flood Elevation (BFE). This
Technical Bulletin provides guidance on crawlspace construction and supports a recent policy decision
to allow construction of crawlspaces with interior grades up to 2 feet below the lowest adjacent
exterior grade (LAG), referred to as below -grade crawlspaces, provided that other requirements are
met. Prior to that decision, below -grade crawlspaces were considered basements under the National
Flood Insurance Program (NFIP) Floodplain Management Regulation definitions at 44 CFR 59.1 and
were not permitted below the BFE. This requirement had been established because below -grade
crawlspace foundation walls are exposed to increased forces during flood conditions, such as
hydrostatic and saturated soil forces.
In many parts of the country, a common practice is to construct crawlspaces with the interior floor 1 or
2 feet below -grade by either (1) backfilling against the exterior of the foundation wall or (2)
excavating the crawlspace area to construct footings that result in a below -grade crawlspace floor.
Because FEMA wishes to recognize common construction practices that do not increase flood
damage, FEMA recently completed a review of the policy for residential crawlspace construction. In
this review, the construction practices for below -grade crawlspaces were examined to determine
whether a crawlspace that was 1 or 2 feet below grade would increase the flood damage potential to
the foundation walls or result in additional damages to the building.
The review included (1) an engineering analysis that assessed the damage potential of floodwaters
acting upon below -grade crawlspace foundation walls, (2) a review of available NFIP claims history
for crawlspaces, and (3) input from FEMA Regional staff and NFIP General Adjusters of any
firsthand knowledge of crawlspace damage during flood events. A review of NFIP claims history and
staff input did not reveal evidence of structural damage or failure of crawlspace foundation walls
during flood events. The engineering analysis indicates that below -grade foundation walls, when
constructed according to common practice, have sufficient capacity to resist flood -related forces from
standing and low -velocity floodwaters, subject to the requirements outlined in this bulletin.
This Technical Bulletin presents NFIP minimum requirements for crawlspace construction in the
SFHA, including (1) requirements for all crawlspace construction and (2) requirements for below -
grade crawlspace construction that may extend 1 or 2 feet below grade in the SFHA. This Technical
Bulletin also provides a best practices approach for preferred and below -grade crawlspace
construction, illustrated in Figures 1 and 2, including design limitations, water accumulation and
drainage considerations, and use of flood -resistant materials. While communities may now allow
below -grade crawlspace construction in the SFHA, this type of construction is not the recommended
construction method, because of the increased likelihood of problems with water accumulation,
moisture damage, and drainage. The use of crawlspace construction with the interior grade at or above
the LAG minimizes the occurrence of these problems. This interim guidance on residential crawlspace
construction is based on conclusions from the recently completed review and analyses.
Floor Joist
BFE
Wall Height Foundation Wall
Flood Vent
crawlspace
Interior Grade Lowest Adjacent
Exterior Grade (LAG)
Rib"
Figure 1 Preferred crawlspace construction.
Floor Joist
BFE
Wall Height---,.,r Foundation Wall
Flood Vent
Lowest Adjacent
Exterior Grade (LAG)
Crawispace�—
Interior Grade
i
Ff
�tietin f
Figure 2 Below -grade crawlspace construction.
2
This Technical Bulletin provides interim guidance. The decision whether or not to allow below -grade
crawlspace construction will be left to each community. Communities should review applicable state
laws, regulations, and building codes, and consult with their State NFIP Coordinator to determine
whether below -grade crawlspace construction is permitted in their state. Communities that choose to
allow below -grade crawlspace construction will be required to amend their floodplain management
ordinance to include the provisions outlined in the following sections on below parade crawlspace
construction. PIease note that communities that choose to amend their ordinance to allow for below -
grade crawlspaces in response to this interim guidance may also be required at some later date to
amend their ordinance if FEMA adopts revised regulations that differ from the interim guidance.
Note
Any building utility systems within the crawlspace must be elevated above the BFE or designed
so that floodwaters cannot enter or accumulate within system components during flood
conditions. Ductwork, in particular, must either be placed above the BFE or sealed to prevent the
entry of floodwaters. FEMA 348, Protecting Building Utilities from Flood Damage, provides
detailed guidance on designing and constructing flood -resistant utility systems.
NAP Requirements
NFIP requirements that apply to crawlspace construction are found in sections 44 CFR 60.3(a)(3) and
60.3(c)(2) and (c)(5) of the NFIP regulations. NFIP requirements that apply to all crawlspaces are
discussed in the first section below. The second section lists additional requirements that must be
applied to crawlspaces that have interior grades below the LAG. The additional requirements are
intended to ensure that these crawlspaces are not subject to flood -related loads that would exceed the
strength of the crawlspace wall and lead to failure and significant damage to the building or to other
damage related to poor drainage in the below -grade crawlspace.
NFIP Requirements for All Crawlspace Construction
Crawlspaces are commonly used as a method of elevating buildings in SFHAs to or above the BFE.
General NFIP requirements that apply to all crawlspaces that have enclosed areas or floors below the
BFE include the following:
• The building must be designed and adequately anchored to resist flotation, collapse, and lateral
movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects
of buoyancy. Hydrostatic loads and the effects of buoyancy can usually be addressed though the
required openings discussed in the next bullet. Because of hydrodynamic loads, crawlspace
construction is not recommended in areas with flood velocities greater than 5 feet per second unless
the design is reviewed by a qualified design professional, such as a registered architect or
professional engineer. Other types of foundations are recommended for these areas.
• The crawlspace is an enclosed area below the BFE and, as such, must have openings that equalize
hydrostatic pressures by allowing for the automatic entry and exit of floodwaters. The bottom of
each flood vent opening can be no more than I foot above the lowest adjacent exterior grade. For
guidance on flood openings, see Technical Bulletin 1-93, Openings in Foundation Wills.
• Crawlspace construction is not permitted in V zones. Open pile or column foundations that
withstand storm surge and wave forces are required in V zones.
Portions of the building below the BFE must be constructed with materials resistant to flood
damage. This includes not only the foundation walls of the crawlspace used to elevate the building,
but also any joists, insulation, or other materials that extend below the BFE. The recommended
construction practice is to elevate the bottom of joists and all insulation above BFE. Insulation is not
a flood -resistant material. When insulation becomes saturated with floodwater, the additional weight
often pulls it away from the joists and flooring. Ductwork or other utility systems located below the
insulation may also pull away from their supports. See the section Flood -Resistant Materials, on
page 8 this bulletin. For more detailed guidance on flood -resistant materials see Technical Bulletin
2-93, F lood-Resistant Materials Requirements.
• Any building utility systems within the crawlspace must be elevated above BFE or designed so that
floodwaters cannot enter or accumulate within the system components during flood conditions.
Ductwork, in particular, must either be placed above the BFE or sealed from floodwaters. For
further guidance on the placement of building utility systems in crawlspaces, see FEMA 348,
Protecting Building Utilities From Flood Damage.
Flood -resistant materials and utilities, access, and ventilation openings in crawlspaces are further
addressed in this bulletin.
Additional Requirements for Below -Grade Crawlspaces
If a community chooses to amend its floodplain management ordinance to allow for the construction
of below -grade crawlspaces, the ordinance must include the following provisions in addition to the
above requirements:
• The interior grade of a crawlspace below the BFE must not be more than 2 feet below the lowest
adjacent exterior grade (LAG), shown as D in Figure 3.
• The height of the below -grade crawlspace, measured from the interior grade of the crawlspace to the
tap of the crawlspace foundation wall must not exceed 4 feet (shown as L in Figure 3) at any point.
The height limitation is the maximum allowable unsupported wall height according to the
engineering analyses and building code requirements for flood hazard areas (see the section
Guidance for Pre -Engineered Crawlspaces, on page 7 of this bulletin). This limitation will also
prevent these crawlspaces from being converted into habitable spaces.
• There must be an adequate drainage system that removes floodwaters from the interior area of the
crawlspace. The enclosed area should be drained within a reasonable time after a flood event. The
type of drainage system will vary because of the site gradient and other drainage characteristics,
such as soil types. Possible options include natural drainage through porous, well -drained soils and
drainage systems such as perforated pipes, drainage tiles, or gravel or crushed stone drainage by
gravity or mechanical means.
• The velocity of floodwaters at the site should not exceed 5 feet per second for any crawlspace. For
velocities in excess of 5 feet per second, other foundation types should be used.
4
• Below -grade crawlspace construction in accordance with the requirements listed above will not be
considered basements.
Floor Joist
BFE
Foundation Wall
L = 4 ft Maximum Flood Vent
Lowest Adjacent
v Exterior Grade (LAG)
D = 2 ft Maximum
Crawlspace
Interior Grade
Figure 3 Requirements regarding below -grade crawlspace construction.
Drainage considerations for below -grade crawlspaces are further addressed in this bulletin. For
additional information regarding this interim guidance, please contact the FEMA Regional Office or
State NFIP Coordinator. Local FEMA regional offices are listed in the separately printed User's Guide
to Technical Bulletins and may be found at the www.fema.gov website.
Flood Forces on Buildings
Buildings in flood hazard areas may be subjected to a variety of flood -induced forces. During inundation
by standing or low -velocity floodwaters, a building must primarily resist hydrostatic pressures from
saturated soils and floodwaters. This situation is typical of broad, flat floodplains and floodways along
lower -gradient rivers and streams. During inundation by high -velocity floodwaters, a building must
also resist hydrodynamic forces and impact loads. High -velocity floodwaters are found in floodways
along steeper -gradient rivers, sheet flow down slopes, or coastal areas with storm surge and waves.
The community Flood Insurance Study contains a Floodway Data Table that includes data on mean
velocities (in feet per second) within the floodway at each cross section along the river or stream. The
mean averages the higher channel velocities with lower velocities in overbank areas that are within the
floodway. Generally, velocities at sites outside of the floodway are lower than the mean floodway
velocities listed in the Floodway Data Table. For example, if the mean floodway velocity at a cross
section is 4 feet per second, the velocities outside the floodway are likely less than that value. If in
doubt about the floodway velocity or in areas where the mean floodway velocity may exceed S feet
per second, contact an engineer knowledgeable in hydraulics and hydrology to determine flood
velocities at the building site.
Buildings located in areas subject to ponding or low -velocity flows must primarily address issues
related to hydrostatic loads on the crawlspace foundation, removal of floodwater and sediment from
the crawlspace area, and other NFIP floodproofing requirements, such as protecting or elevating
utilities and using flood -resistant materials.
Crawlspace construction is not recommended in A zones with high -velocity floodwaters (greater than
5 feet per second). Other types of foundations, such as open pile or column foundations, that allow
floodwaters to flow freely beneath the building are recommended for these areas.
Flood Insurance Implications
In May 1999, the Federal Insurance Administration (now the Federal Insurance and Mitigation
Administration — FIMA) revised the rates being charged for residential buildings with below -grade
crawlspaces. These rates were considerably lower than the full basement rates previously charged for
these buildings. In May 2001, these rates were further reduced based on engineering analyses
performed by FEMA. However, rates for buildings with below -grade crawlspaces will be higher than
rates for buildings that have the interior grade of the crawlspace at or above the adjacent exterior
grade, since the risk of floors damage is greater for the former type of construction. As more
experience is gained on crawlspace losses, FEMA will continue to reassess those rates, factoring in
the cost of pumping out and cleaning these areas, as well as physical damage to the foundation.
Buildings with below -grade crawlspaces currently cannot be rated by an insurance agent using the
NF1P F lood Insurance Manual. They must be submitted for a special rating under the Submit -to -Rate
process by underwriters knowledgeable in this type of construction. FIMA will determine whether the
rating for this type of construction should be standardized and included in the Flood Insurance
Application and the Flood Insurance Manual.
Caution
Buildings that have below -grade crawlspaces will have higher flood insurance premiums than
buildings that have the preferred crawlspace construction, with the interior elevation at or above
the lowest adjacent exterior grade (LAG).
Best Practices for Crawlspace Foundations in SFHA
The NFIP preferred construction practice for excavated crawlspace construction is to backfill the
interior area so that it is level with or higher than the LAG. If trench construction is used to place
footings, the trenches should be backfilled to the level of the adjacent exterior grade, to avoid ponding
of water. A reinforced masonry or concrete foundation wall that is anchored to the footing and lowest
floor with connectors will provide the best performance in flood events. This type of construction will
better resist hydrostatic pressures against the foundation and limit the amount of water that will pond
under the building after a flood.
The 2000 International Residential Code (IRC 2000), Section 327, addresses flood -resistant design
and construction of foundation walls in flood hazard areas and is consistent with NF1P requirements.
The IRC requires that all structural systems in floodplains be designed, connected, and anchored to
resist flotation, collapse, or permanent lateral movement due to structural loads from flooding equal to
the design flood elevation. The IRC limits the unsupported height of plain (unreinforced) 8-inch
hollow masonry walls to 4 feet for flood -resistant construction, where the unsupported height is the
distance from the finished grade of the enclosed crawlspace area to the top of the foundation wall.
A community that chooses to allow the construction of below -grade crawlspaces should develop a
multi -hazard approach that also resists other loads from hazards such as wind and earthquake.
Crawlspace foundation walls must bear or resist all loads that may be experienced during their useful
service He.
Guidance for Pre -Engineered Below -Grade Crawlspace Foundations
FEMA performed an engineering analysis to determine the effect of flood -related forces on
crawlspace foundation walls (see Figure 4), particularly for unreinforced concrete and concrete
masonry construction. The analysis followed design criteria prescribed in the American Concrete
Institute (ACI) Building Code Requirements and Commentary for Reinforced Concrete (ACI 318-92)
and the 1999 Masonry Standards Joint Committee (MSJC) Building Code Requirements and
Specifications. Flood analysis procedures from FEMA 259, Engineering Principles and Practices of
Retrofitting Flood -Prone Residential Structures, were used for calculating hydrostatic and
hydrodynamic forces. A comprehensive analysis of two flood scenarios was conducted:
• Fully saturated soil and I -foot-deep floodwaters, that just reach the bottom of the flood opening, but
have not flooded the enclosed crawlspace area.
• A fully flooded crawlspace area with velocity floodwaters acting on the above -grade portion of the
crawlspace walls.
Foundation Wall Fdyr - Hydrodynamic
Force
f
G
FH - Hydrostatic Force
Fdif - Differential
Moist Soil Soil Force
Figure 4 Flood -related forces on a crawlspace wall.
The first analysis evaluated four parameters: (1) wall construction of unreinforced 8-inch and 12-inch
masonry block with standard M or S mortar type and 6-inch plain concrete foundation walls, (2) depth
of interior crawlspace grade relative to the LAG, (3) flood velocity, and (4) soil types suitable for
construction. The hydrostatic pressures from the saturated soil and 1-foot-deep floodwaters cause the
maximum loads to occur in the lower section of the wall below the exterior grade. This analysis
assumed that the 1-foot-deep floodwaters have a low velocity and are unlikely to cause significant
hydrodynamic or impact loads on the foundation wall.
The second analysis evaluated hydrodynamic forces for varied flood depths and flood velocities on a
foundation wall. The analysis assumed that the crawlspace was provided with proper openings to
equalize hydrostatic pressure. Impact forces were not included in the analysis, as the shallow flood
depths and low -velocity flows are not expected to produce significant debris impact damage. This
decision was further supported by the lack of field evidence concerning wall failures from impact by
debris. However, debris impact should be considered as part of the foundation wall design and
analysis for riverine or other locations with high -velocity flows.
These analyses found that a crawlspace can resist flood -related forces for flood velocities up to 5 feet per
second, if the wall height is limited to 4 feet and the top of the footing is no more than 2 feet below -grade.
As a result of these analyses, FEMA has determined that communities may allow below -grade
residential crawlspace construction provided that the interior grade of the crawlspace does not exceed
2 feet below the LAG, and the height of the crawlspace measured from the interior grade of the
crawlspace at any point to the bottom of the lowest horizontal structural member of the lowest floor
does not exceed 4 feet for the specified wall construction.
Flood -Resistant Materials
All structural and non-structural building materials at or below the BFE must be flood resistant. A
flood -resistant material is defined as any building material capable of withstanding direct and
prolonged contact with floodwaters without sustaining significant damage. Flood -resistant materials
must be used for all building elements subject to exposure to floodwaters, including floor joists,
insulation, and ductwork. If flood -resistant materials are not used for building elements, those
elements must be elevated above the BFE. The term "prolonged contact" means at least 72 hours, and
the term "significant damage" means any damage requiring more than low-cost cosmetic repair (such
as painting). This requirement applies regardless of the expected or historical flood duration. Technical
Bulletin 2-93, Flood Resistant Materials Requirements, further defines NFIP criteria for flood -
resistant materials and material categories.
Drainage Considerations
A significant issue associated with below -grade crawlspaces is drainage of the interior crawlspace area
after normal precipitation and flood events. Moisture damage to a building can be severe when water
remains standing in the crawlspace area after precipitation or a flood event. Standing water also creates
significant health hazards, such as mosquito breeding grounds and growth of bacteria, mold, and fungus.
If crawlspace access doors do not remain secured, standing water also presents a drowning hazard.
The interim guidance for below -grade crawlspace construction requires an adequate drainage system
that allows floodwaters to drain from the interior area of the crawlspace within a reasonable time. A
maximum time of 72 hours is recommended to minimize floodwater contact with crawlspace materials
and related moisture damage. The interim guidance is not prescriptive as to a type of drainage system;
however, it is the community's responsibility to ensure that all buildings with below -grade crawlspaces
have adequate drainage systems to ensure that accumulated waters drain from the crawlspace area.
Communities must include in their ordinances a provision that addresses drainage requirements.
Drainage systems for below -grade crawlspace areas will vary because of site characteristics and soil
types. Possible drainage system options include perforated pipes, drainage tiles, or gravel or crushed
stone drainage by gravity or mechanical means. Fill dirt placed around the outside of the foundation
wall should be adequately graded to slope away from the foundation and aid natural site drainage. If
lots are too small to provide adequate site drainage through grading, other methods, such as swales,
may be used to provide drainage away from the structure. Foundation drainage practices required by
local codes must be met in addition to drainage of the enclosed below -grade crawlspace area.
Any enclosed area below the BFE is subject to flood forces and must have exterior wall openings
whose bottom edges are no more than 1-foot above the LAG, in accordance with NFIP regulations.
The wall openings allow the automatic entry and exit of floodwaters and for the floodwaters to reach
equal Ievels on both sides of the foundation wall. The only exception to this requirement is dry
floodproofed non-residential buildings. Further information on NFIP requirements for flood openings
in foundation walls is found in Technical Bulletin 1-93, Openings in Foundation Walls.
Utilities, Access, and Ventilation Openings
NFIP regulations at 44 CFR, Section 60.3(a)(3)(iv) require that "utility systems shall be constructed
with electrical, heating, ventilation, plumbing, and air conditioning equipment and other service
facilities that are designed and/or located to prevent water from entering or accumulating within the
components during conditions of flooding." The utility systems can be either elevated above the BFE
or floodproofed in a manner that prevents floodwaters from infiltrating or accumulating within any
component of the system. Elevation is the recommended method of mitigation for utility systems in
A Zones. FEMA 348, Protecting Building Utilities from Flood Damage, provides detailed guidance
on designing and constructing flood -resistant utility systems.
Access and ventilation openings shall be provided to the crawlspace area according to the local
building codes and regulations. Access and ventilation requirements under the IRC 2000 include the
following:
• An access opening 18 inches by 24 inches shall be provided to the enclosed crawlspace area to
allow access to mechanical equipment or building utilities located in this space.
• The minimum net area of required ventilation openings shall not be less than 1 square foot for each
1.50 square feet of enclosed crawlspace area. One such ventilation opening shall be within 3 feet of
each corner of the building. Ventilation openings shall be covered with an appropriate material.
The NFIP
The NFIP was created by Congress in 1968 to provide federally backed flood insurance coverage,
because flood coverage was generally unavailable from private insurance companies. The NFIP is also
intended to reduce future flood losses by identifying floodprone areas and ensuring that new development
in these areas is adequately protected from flood damage. The NFIP is based on an agreement between
the Federal government and participating communities that have been identified as floodprone. FEMA,
through the Federal Insurance and Mitigation Administration, makes flood insurance available to the
residents of a participating community, provided the community adopts and enforces adequate
floodplain management regulations that meet the minimum NFIP requirements. The NFIP encourages
communities to adopt floodplain management ordinances that exceed the minimum NFIP criteria set
forth in Part 60 of the NFIP Floodplain Management Regulations (44 CFR 60). Included in the NFIP
requirements, found under Title 44 of the U.S. Code of Federal Regulations, are minimum building
design and construction standards for buildings located in SFHAs. Through their floodplain management
ordinances or laws, communities adopt the NFIP performance standards for new, substantially
improved, and substantially damaged buildings in floodprone areas identified on FEMNs Flood
Insurance Rate Maps (FIRMS).
Technical Bulletins
This publication is one of a series of Technical Bulletins that FEMA has produced to provide guidance
concerning the building performance standards of the NFIP. These standards are contained in 44 CFR
60.3. The bulletins are intended for use primarily by state and local officials responsible for
interpreting and enforcing NFIP regulations and by members of the development community, such as
design professionals and builders. New bulletins, as well as updates of existing bulletins, are issued
periodically, as necessary. The bulletins do not create regulations; rather they provide specific
guidance for conforming with the minimum requirements of existing NFIP regulations. Users of the
Technical Bulletins who need additional guidance concerning NFIP regulatory requirements should
contact the Mitigation Division of the appropriate FEMA Regional Office or the local floodplain
administrator. NFIP Technical Bulletin 0, User's Guide to Technical Bulletins, lists the bulletins issued
to date, provides a key word/subject index for the entire series, and lists addresses and telephone
numbers for FEMA's 10 Regional. Offices.
Ordering Information
Copies of FEMA Technical Bulletins can be obtained from the FEMA Regional Office that serves
your area. In addition, Technical Bulletins and other FEMA publications can be ordered from the
FEMA Publications Distribution Facility at 1-800-480-2520. The Technical Bulletins are also
available at the FEMA web site at www.fema.gov.
U
Further Information
The following publications contain information related to the guidance presented in this bulletin:
American Concrete Institute. 1992. AC1318-92. Building Code Requirements and Commentary for
Reinforced Concrete. Detroit, MI.
American Society of Civil Engineers. 1998. SEI/ASCE 7-98. Minimum Design Loads for Buildings
and Other Structures. Reston, VA.
American Society of Civil Engineers. 1998. SEIIASCE 24-98. Flood Resistant Design and
Construction. Reston, VA.
Federal Emergency Management Agency. 1986. Floodproofing Non -Residential Structures. FEMA
102. Washington, DC.
Federal Emergency Management Agency. 1999. Protecting Building Utility Systems From Flood
Damage. FEMA 348. Washington, DC.
Federal Emergency Management Agency. 2001. Engineering Principles and Practices for Retrofitting
Flood -Prone Residential Structures. FEMA 259. Washington, DC.
International Code Council. 2000. International Building Code. Birmingham, AL.
International Code Council, 2000. International Residential Code. Birmingham, AL.
Masonry Standards Joint Committee. 1999. ACI 530-99/ASCE 5-99/TMS 402-99. Building Code
Requirements for Masonry Structures.
National Association of Home Builders Research Foundation, Inc. 1977. Manual for the Construction
of Residential Basements in Non -Coastal Flood Environs. Upper Marlboro, MD. March.
National Association of Home Builders Research Center, Inc. 2000. Residential Structural Design
Guide: 2000 Edition. Upper Marlboro, MD.
National Concrete Masonry Association. 2000. TR 121. Concrete Masonry Design Tables. Hemdon, VA.
Glossary
Base Flood —The flood that has a 1-percent probability of being equaled or exceeded in any given
year (also referred to as the 100-year flood).
Basement —Any area of a building having its floor subgrade (below ground level) on all sides.
Community — Any state or area or political subdivision thereof, or any Indian tribe or authorized
tribal organization, or Alaska Native village or authorized native organization, which has the authority
to adopt and enforce floodplain management regulations for the areas within its jurisdiction.
Federal Emergency Management Agency (FEMA) — The independent Federal agency that, in
addition to carrying out other activities, administers the NFIP.
Federal Insurance and Mitigation Administration (FIMA) — The component of FEMA directly
responsible for administering the flood hazard identification, floodplain management, and flood
insurance activities of the NFIP
Flood Insurance Rate Map (FIRM) — The insurance and floodplain management map issued by
FEMA that identifies, on the basis of detailed or approximate analysis, areas of 100-year flood hazard
in a community.
Floodprone area —Any land area susceptible to being inundated by flood water from any source.
New construction/structure — For floodplain management purposes, new construction means
structures for which the start of construction commences on or after the effective date of a floodplain
management regulation adopted by a community and includes subsequent improvements to the
structure. For flood insurance purposes, these structures are often referred to as "post -FIRM"
structures.
Special Flood Hazard Area (SFHA) — Area subject to inundation by the base flood, designated Zone
A, At -30, AE, AH, AO, V, V 1-V30, or VE.
12
BOCC AGENDA ROUTING SLIP
/3
BUILDING DEPARTMENT
Agenda Item Subject: Resolution adopting FEMA P-55, Volumes I and II "Coastal
Construction Manual"
Date: August 17, 2015
Prepared By: Ed Koconis, AICP, Permit Manager
Agenda Deadline: August 20, 2015 BOCC meeting date: September 16, 2015
#
Reviewer
***Internal Deadline to Teresa:***
Notes
.Initials
Date
Permit Manager-
It
U
MT �t e� T
Senior Director of Building
&V S
County Attorney
Deadline:
Assistant County Administrator
Deadline:
FINAL review by legal
XBulk Approval
Time Approximate Requested
Type of Proceeding:
Ad (Ad map, if applicable)
Surrounding Property Owner Notice:
Public Hearing
Yes
Legislative
Deadline
Deadline NIA
Discussion
Time
Quasi -Judicial
Publish Date
***Reminder***
Once your item is complete and includes all corrections,
email all final word documents to Teresa Smith.