Recommended Residential Construction for the Gulf Coast 
Building on Strong and Safe Foundations
FEMA 550 / July 2006

Appendix F. Referenced Fact Sheets from FEMA 499

Fact Sheet Number and Title 
1 Coastal Building Successes and Failures
2 Summary of Coastal Construction Requirements and Recommendations
4 Lowest Floor Elevation
5 V-Zone Design and Construction Certification
6 How Do Siting and Design Decisions Affect the Owner's Costs?
7 Selecting a Lot and Siting the Building
8 Coastal Building Materials
9 Moisture Barrier Systems
11 Foundations in Coastal Areas
12 Pile Installation 
13 Wood-Pile-to-Beam Connections
14 Reinforced Masonry Pier Construction
15 Foundation Walls
16 Masonry Details
26 Shutter Alternatives
27 Enclosures and Breakaway Walls
29 Protecting Utilities



Technical Fact Sheet No. 1
Coastal Building Successes and Failures
Home Builders Guide to Coastal Construction

Purpose: To discuss how coastal construction requirements are different from 
those for inland construction. To discuss the characteristics that make for a 
successful coastal building.

Is Coastal Construction That Different From Inland Construction?
The short answer is yes, building in a coastal environment is different from 
building in an inland area:
--Flood levels, velocities, and wave action in coastal areas tend to make 
coastal flooding more damaging than inland flooding.
--Coastal erosion can undermine buildings and destroy land, roads, utilities, 
and infrastructure.
--Wind speeds are typically higher in coastal areas and require stronger 
engineered building connections and more closely spaced nailing of building 
sheathing, siding, and roof shingles.
--Wind-driven rain, corrosion, and decay are frequent concerns in coastal areas.

In general, homes in coastal areas must be designed and built to withstand 
higher loads and more extreme conditions. Homes in coastal areas will require 
more maintenance and upkeep. Because of their exposure to higher loads and 
extreme conditions, homes in coastal areas will cost more to design, construct, 
maintain, repair, and insure.

Building Success
In order for a coastal building to be considered a success, four things must 
occur:
--The building must be designed to withstand coastal forces and conditions.
--The building must be constructed as designed.
--The building must be sited so that erosion does not undermine the building or 
render it uninhabitable.
--The building must be maintained/repaired.

A well-built but poorly sited building can be undermined and will not be a 
success (see Figure 1). Even if a building is set back or situated farther from 
the coastline, it will not perform well (i.e., will not be a success) if it is 
incapable of resisting high winds and other hazards that occur at the site (see 
Figure 2).

Figure 1. Well-built but poorly sited building.

Figure 2. Well-sited building that still sustained damage.

What Should Owners and Home Builders Expect From a Successful Coastal 
Building?
In coastal areas, a building can be considered a success only if it is capable 
of resisting damage from coastal hazards and coastal processes over a period of 
decades. This statement does not imply that a coastal residential building will 
remain undamaged over its intended lifetime. It means that the impacts of a 
design-level flood, storm, wind, or erosion event (or series of lesser events 
with combined impacts equivalent to a design event) will be limited to the 
following:
--The building foundation must remain intact and functional.
--The envelope (walls, openings, roof, and lowest floor) must remain 
structurally sound and capable of minimizing penetration by wind, rain, and 
debris.
--The lowest floor elevation must be sufficient to prevent floodwaters from 
entering the elevated building envelope during the design event.
--The utility connections (e.g., electricity, water, sewer, natural gas) must 
remain intact or be restored easily.
--The building must be accessible and usable following a design-level event.
--Any damage to enclosures below the Design Flood Elevation (DFE)* must not 
result in damage to the foundation, the utility connections, or the elevated 
portion of the building.

Recommended Practice
--Siting  Site buildings away from eroding shorelines and high-hazard areas.
Building Form  Flat or low-sloped porch roofs, overhangs, and gable ends are 
subject to increased uplift in high winds. Buildings that are both tall and 
narrow are subject to overturning. Each of these problems can be overcome 
through the design process, but each must receive special attention. In the 
design process, chose moderate-sloped hip roofs (4/12 to 6/12) if possible.

--Lowest Floor Elevation  Elevate above the DFE the bottom of the lowest 
horizontal structural member supporting the lowest floor. Add freeboard to 
reduce damage and lower flood insurance premiums.

--Free of Obstructions  Use an open foundation. Do not obstruct the area below 
the elevated portion of the building.  Avoid or minimize the use of breakaway 
walls. Do not install utilities or finish enclosed areas below the DFE (owners 
tend to convert these areas to habitable uses, which is prohibited under the 
National Flood Insurance Program and will lead to additional flood damage and 
economic loss).

--Foundation  Make sure the foundation is deep enough to resist the effects of 
scour and erosion; strong enough to resist wave, current, flood, and debris 
forces; and capable of transferring wind and seismic forces on upper stories to 
the ground.

--Connections  Key connections include roof sheathing, roof-to-wall, wall-to-
wall, and walls-to-foundation. Be sure these connections are constructed 
according to the design. Bolts, screws, and ring-shanked nails are common 
requirements. Standard connection details and nailing should be identified on 
the plans.

--Exterior Walls  Use structural sheathing in high-wind areas for increased 
wall strength. Use tighter nailing schedules for attaching sheathing. Care 
should be taken not to over-drive pneumatically driven nails. This can result in 
loss of shear capacity in shearwalls.

--Windows and Glass Doors  In high-wind areas, use windows and doors capable of 
withstanding increased wind pressures. In windborne debris areas, use impact-
resistant glazing or shutters.

--Flashing and Weather Barriers  Use stronger connections and improved flashing 
for roofs, walls, doors, and windows and other openings. Properly installed 
secondary moisture barriers, such as housewrap or building paper, can reduce 
water intrusion from wind-driven rain.

--Roof  In high-wind areas, select appropriate roof coverings and pay close 
attention to detailing. Avoid roof tiles in hurricane-prone areas.

--Porch Roofs and Roof Overhangs  Design and tie down porch roofs and roof 
overhangs to resist uplift forces.

--Building Materials  Use flood-resistant materials below the DFE. All exposed 
materials should be moisture- and decay-resistant. Metals should have enhanced 
corrosion protection.

--Mechanical and Utilities  Electrical boxes, HVAC equipment, and other 
equipment should be elevated to avoid flood damage and strategically located to 
avoid wind damage. Utility lines and runs should be installed to minimize 
potential flood damage.

--Quality Control  Construction inspections and quality control are essential 
for building success. Even minor construction errors and defects can lead to 
major damage during high-wind or flood events. Keep this in mind when inspecting 
construction or assessing yearly maintenance needs.

*The DFE is the locally mandated flood elevation, which will be equal to or 
higher than the Base Flood Elevation (BFE). The BFE is the expected elevation of 
flood waters and wave effects during the 100-year flood (also known as the Base 
Flood).

Recommended practice and guidance concerning the topics listed above can be 
found in the documents referenced in these fact sheets and in many trade 
publications (e.g., the Journal of Light Construction, 
http://www.jlconline.com).

Will the Likelihood of Success (Building Performance) Be Improved by Exceeding 
Minimum Requirements?
States and communities enforce regulatory requirements that determine where and 
how buildings may be sited, designed, and constructed. There are often economic 
benefits to exceeding the enforced requirements (see box). Designers and home 
builders can help owners evaluate their options and make informed decisions 
about whether to exceed these requirements.

[Textbox]
Benefits of Exceeding Minimum Requirements
--Reduced building damage during coastal storm events
--Reduced building maintenance
--Longer building lifetime
--Reduced insurance premiums*
--Increased reputation of builder
[End of Textbox]

*Note: Flood insurance premiums can be reduced up to 60 percent by exceeding 
minimum siting, design, and construction practices. See the V-Zone Risk Factor 
Rating Form in FEMAs Flood Insurance Manual 
(http://www.fema.gov/nfip/manual.shtm).

[End of Fact Sheet No. 1]




Technical Fact Sheet No. 2
Summary of Coastal Construction Requirements and Recommendations
Home Builders Guide to Coastal Construction
FEMA 499/August 2005

Purpose: To summarize National Flood Insurance Program (NFIP) regulatory 
requirements concerning coastal construction and provide recommendations for 
exceeding those requirements in some instances.

Key Issues
--New construction* in coastal flood hazard areas (V zones and A zones) must 
meet minimum NFIP and community requirements. Repairs, remodeling, and additions 
must meet community requirements and may also be subject to NFIP requirements.
--NFIP design and construction requirements are more stringent in V zones than 
in A zones, in keeping with the increased flood, wave, floodborne debris and 
erosion hazards in V zones.	
--Some coastal areas mapped as A zones may be subject to damaging waves and 
erosion (these areas are often referred to as Coastal A Zones). Buildings in 
these areas constructed to minimum NFIP A-zone requirements may sustain major 
damage or be destroyed during the Base Flood. It is strongly recommended that 
buildings in A zones subject to breaking waves and erosion be designed and 
constructed to V-zone standards.
--Buildings constructed to minimum NFIP A-zone standards and subject solely to 
shallow flooding without the threat from breaking waves and erosion will 
generally sustain only minor damage during the Base Flood.
--Following the recommendations in the table below will result in lower damage 
to the building and reduced flood insurance premiums (see the V-Zone Risk Factor 
Rating Form in FEMA's Flood Insurance Manual 
(http://www.fema.gov/nfip/manual.shtm).

* For floodplain management purposes, new construction means structures for 
which the start of construction began on or after the effective date of a 
floodplain management regulation adopted by a community. Substantial 
improvements, repairs of substantial damage, and some enclosures must meet most 
of the same requirements as new construction.

The following tables summarize NFIP regulatory requirements and recommendations 
for exceeding those requirements for both (1) new construction and (2) repairs, 
remodeling, and additions.

Requirements and Recommendations for New Construction (Note a)

General Requirements

Design (Also see Certification)
--V Zone: Requirement: building and its foundation must be designed, 
constructed, and anchored to prevent flotation, collapse, and lateral movement 
due to simultaneous wind and water loads (see Fact Sheet No. 5)
--Coastal A Zone (note b): Requirement: building must be designed, constructed, 
and anchored to prevent flotation, collapse, and lateral movement resulting from 
hydrodynamic and hydrostatic loads, including the effects of buoyancy. 
Recommendation: follow v-zone requirement.
--A Zone (note c): Requirement: building must be designed, constructed, and 
anchored to prevent flotation, collapse, and lateral movement resulting from 
hydrodynamic and hydrostatic loads, including the effects of buoyancy. 

Free of Obstructions
--V Zone: Requirement: the space below the lowest floor must be free of 
obstructions (e.g., free of any building element, equipment, or other fixed 
objects that can transfer flood loads to the foundation, or that can cause 
floodwaters or waves to be deflected into the building), or must be constructed 
with non-supporting breakaway walls, open lattice, or insect screening. (see 
Fact Sheet Nos. 5, 27)
--Coastal A Zone: Requirement: none. Recommendation: follow v-zone requirement.
--A Zone: Requirement: none

Materials (see Fact Sheet Nos. 1, 8)
--V Zone: Requirement: structural and nonstructural building materials at or 
below BFE must be flood-resistant.
--Coastal A Zone: Requirement: structural and nonstructural building materials 
at or below BFE must be flood-resistant.
--A Zone: Requirement: structural and nonstructural building materials at or 
below BFE must be flood-resistant.

Construction (See Fact Sheet No. 1) (Also see Certification)
--V Zone: Requirement: building must be constructed with methods and practices 
that minimize flood damage
--Coastal A Zone: Requirement: building must be constructed with methods and 
practices that minimize flood damage
--A Zone: Requirement: building must be constructed with methods and practices 
that minimize flood damage 

Siting (see Fact Sheet Nos. 6, 7)
--V Zone: Requirement: all new construction shall be landward of mean high tide; 
alteration of sand dunes and mangrove stands that increases potential flood 
damage is prohibited. Recommendation: site new construction landward of long-
term erosion setback and landward of area subject to erosion during 100-year 
coastal flood event.
--Coastal A Zone: Requirement: encroachments into floodways designated along 
rivers and streams are prohibited unless they will cause no increase in flood 
stage; where floodways have not been designated, encroachments into the SFHA 
cannot increase the BFE by more than 1 foot. Recommendation: follow v-zone 
requirement.
--A Zone: Requirement: encroachments into floodways designated along rivers and 
streams are prohibited unless they will cause no increase in flood stage; where 
floodways have not been designated, encroachments into the SFHA cannot increase 
the BFE by more than 1 foot.

Foundation

Structural Fill
--V Zone: prohibited (see Fact Sheet No. 11)
--Coastal A Zone: Allowed, but not recommended; compaction required where used; 
protect against scour and erosion (note d) (See Fact Sheet No. 11)
--A Zone: Allowed; compaction required where used; protect against scour and 
erosion (note d)

Solid Foundation (See Fact Sheet Nos. 11, 15)
--V Zone: prohibited
--Coastal A Zone: allowed, but not recommended (note d)
--A Zone: allowed (note d)

Open Foundation (see Fact Sheet No. 11)
--V Zone: required.
--Coastal A Zone: recommended (note d)
--A Zone: allowed (note d)

Lowest Floor Elevation (see Fact Sheet No. 4) (Also see Certification)
--V Zone: See Bottom of Lowest Horizontal Structural Member (see Fact Sheet No. 
5)
--Coastal A Zone: Requirement: top of floor must be at or above BFE (note e). 
Recommendation: elevate bottom of lowest horizontal structural member to or 
above BFE (note e)
--A Zone: Requirement: top of floor must be at or above BFE (note e). 
Recommendation: elevate bottom of lowest horizontal structural member to or 
above BFE (note e).

Bottom of Lowest Horizontal Structural Member (see Fact Sheet No. 4)
--V Zone: must be at or above BFE (note e) (see Fact Sheet No. 5) 
--Coastal A Zone: allowed below BFE (note e), but not recommended (note d). 
Recommendation: follow v-zone requirement.
--A Zone: allowed below BFE (note e), but not recommended (note d). 
Recommendation: follow v-zone requirement.

Orientation of Lowest Horizontal Structural Member
--V Zone: Requirement: none. Recommendation: orient perpendicular to wave crest.
--Coastal A Zone: Requirement: none. Recommendation: follow v-zone requirement.
--A Zone: Requirement: none.

Freeboard (see Fact Sheet Nos. 1, 4)
--V Zone: Not required (note e), but recommended
--Coastal A Zone: Not required (note e), but recommended
--A Zone: Not required (note e), but recommended

Enclosures Below BFE (also see Certification) (see Fact Sheet No. 27)
--V Zone: Prohibited, except for breakaway walls, open lattice, and screening 
(note f). Recommendation: if constructed, use open lattice or screening instead 
of breakaway walls.
--Coastal A Zone: Allowed but not recommended. Requirement: if area is fully 
enclosed, enclosure walls must be equipped with openings to equalize hydrostatic 
pressure; size, location, and covering of openings governed by regulatory 
requirements. Recommendation: elevate on open foundation; if enclosure is 
constructed, use breakaway walls (with flood openings), open lattice, or 
screening, as required in V zone (notes f, g).
--A Zone: Allowed. Requirement: if area is fully enclosed, enclosure walls must 
be equipped with openings to equalize hydrostatic pressure; size, location, and 
covering of openings governed by regulatory requirements (notes f, g).

Nonstructural Fill
--V Zone: Allowed for minor landscaping and site drainage as long as fill dies 
not interfere with free passage of floodwaters and debris beneath building, or 
cause changes in flow direction during coastal storms that could result in 
damage to buildings. 
--Coastal A Zone: allowed (note h). Recommendation: follow v-zone requirement.
--A Zone: Allowed. Recommendation: follow v-zone requirement.

Use of Space Below BFE (note i) (see Fact Sheet No. 27)
--V Zone: Allowed only for parking, building access, and storage.
--Coastal A Zone: Allowed only for parking, building access, and storage.
--A Zone: Allowed only for parking, building access, and storage.

Utilities (note i)
--V Zone: Requirement: utilities, including ductwork and equipment, must be 
designed, located, and elevated to prevent floodwaters from entering and 
accumulating in components during flooding; utility lines must not be installed 
or stubbed out in enclosures below BFE.
--Coastal A Zone: Requirement: utilities, including ductwork and equipment, must 
be designed, located, and elevated to prevent floodwaters from entering and 
accumulating in components during flooding; utility lines must not be installed 
or stubbed out in enclosures below BFE.
--A Zone: Requirement: utilities, including ductwork and equipment, must be 
designed, located, and elevated to prevent floodwaters from entering and 
accumulating in components during flooding; utility lines must not be installed 
or stubbed out in enclosures below BFE.

Certification

Elevation
--V Zone: Requirement: bottom of lowest horizontal structural member must be at 
or above BFE (note e); electrical, heating, ventilation, plumbing, and air 
conditioning equipment and other service facilities (including ductwork) must be 
designed and/or located so as to prevent water from entering or accumulating 
within the components during flooding (see Fact Sheet Nos. 4, 5, 29)
--Coastal A Zone: Requirement: top of lowest floor must be at or above BFE (note 
e); electrical, heating, ventilation, plumbing, and air conditioning equipment 
and other service facilities (including ductwork) must be designed and/or 
located so as to prevent water from entering or accumulating within the 
components during flooding (see Fact Sheet Nos. 4, 29). Recommendation: follow 
v-zone requirement
--A Zone: Requirement: Requirement: top of lowest floor must be at or above BFE 
(note e); electrical, heating, ventilation, plumbing, and air conditioning 
equipment and other service facilities (including ductwork) must be designed 
and/or located so as to prevent water from entering or accumulating within the 
components during flooding (see Fact Sheet Nos. 4, 29). Recommendation: follow 
v-zone requirement

Structure
--V Zone: Requirement: registered engineer or architect must certify that design 
and methods of construction are in accordance with accepted standards of 
practice for meeting design requirements described under General Requirements 
(see Fact Sheet No. 5)
--Coastal A Zone: Requirement: none. Recommendation: follow v-zone requirement. 
--A Zone: Requirement: none. Recommendation: follow v-zone requirement.

Breakaway Walls (see Fact Sheet Nos. 5, 27) (Also see Enclosures Below BFE)
--V Zone: Requirement: walls must be designed to break free under larger of (1) 
design wind load, (2) design seismic load, or (3) 10 psf, acting perpendicular 
to the plane of the wall; if loading at which breakaway wall is intended to 
collapse exceeds 20 psf, breakaway wall design shall be certified; when 
certification is required, registered engineer or architect must certify that 
walls will collapse under a water load associated with the Base Flood and that 
elevated portion of building and its foundation will not subject to collapse, 
displacement, or lateral movement under simultaneous wind and water loads (note 
f). 
--Coastal A Zone: Requirement: not required, but recommended (note f, g) with 
open foundation in lieu of solid walls; if breakaway walls are used and enclose 
an area, flood openings are required. (see Fact Sheet Nos. 11, 15)
--A Zone: Requirement: none (note f, g)

Openings in Below BFE-Walls (see Fact Sheet Nos. 11, 15) (also see Enclosures 
Below BFE)
--V Zone: not applicable (note i)
--Coastal A Zone: Requirement: unless number and size of openings meet 
regulatory requirements, registered engineer or architect must certify that 
openings are designed to automatically equalize hydrostatic forces on walls by 
allowing automatic entry and exit of floodwaters.
--A Zone: Requirement: unless number and size of openings meet regulatory 
requirements, registered engineer or architect must certify that openings are 
designed to automatically equalize hydrostatic forces on walls by allowing 
automatic entry and exit of floodwaters.

Repairs, Remodeling, and Additions (see Fact Sheet No. 30 and consult AHJ (note 
k) for building code requirements)

Substantial Improvements and Repairs of Substantial Damage
--V Zone: Requirement: must meet current NFIP requirements concerning new 
construction in V zones (note k, l) except for siting landward of mean high tide 
[see Fact Sheet Nos. 4, 5, 7, 11, 15, 27, 29]
--Coastal A Zone: Requirement: must meet current NFIP requirements concerning 
new construction in A zones (note k, m) [see Fact Sheet Nos. 4, 11, 15, 27, 29]. 
Recommendation: follow v-zone requirement
--A Zone: Requirement: must meet current NFIP requirements concerning new 
construction in A zones (note k, m) [see Fact Sheet Nos. 4, 11, 15, 27, 29]. 
Recommendation: elevate bottom of lowest horizontal structural member to or 
above BFE.

Lateral Additions That Constitute Substantial Improvement
--V Zone: Requirement: both addition and existing building must meet current 
NFIP requirements concerning new construction in V zones (note k, l, n) [see 
Fact Sheet Nos. 4, 5, 7, 11, 15, 27, 29].
--Coastal A Zone: Requirement: only addition must meet current NFIP requirements 
concerning new construction in A zones (note k, m, o) (See Fact Sheet Nos. 4, 7, 
11, 15, 27, 29), provided existing building is not subject to any work other 
than cutting entrance in common wall and connecting existing building to 
addition; if any other work is done to existing building, it too must meet 
current NFIP requirements for new construction in A zones. Recommendation: 
follow v-zone requirement
--A Zone: Requirement: only addition must meet current NFIP requirements 
concerning new construction in A zones (note k, m, o) (See Fact Sheet Nos. 4, 7, 
11, 15, 27, 29), provided the existing building is not subject to any work other 
than cutting an entrance in a common wall and connecting the existing building 
to the addition; if any other work is done to existing building, it too must 
meet current NFIP requirements for new construction in A zones. Recommendation: 
elevate bottom of lowest horizontal structural member of addition to or above 
BFE (same for existing building if it is elevated).

Lateral Additions That Do Not Constitute Substantial Improvement
--V Zone: Requirement: post-Flood Insurance Rate Map (FIRM) existing building -- 
addition must meet NFIP requirements in effect at time building was originally 
constructed (note k, l, n). Pre-FIRM existing building -- NFIP requirements 
concerning new construction not triggered (note k) [see Fact Sheet Nos. 4, 5, 7, 
11, 15, 27, 29]. Recommendation: make addition compliant with current NFIP 
requirements for V-zone construction.
--Coastal A Zone: Requirement: post-FIRM existing building -- addition must meet 
NFIP requirements in effect at time building was originally constructed (note k, 
m, o) [see Fact Sheet Nos. 4, 7, 11, 15, 27, 29]. Pre-FIRM existing building  
NFIP requirements concerning new construction not triggered (note k). 
Recommendation: follow V-zone requirement.
--A Zone: Requirement: post-FIRM existing building -- addition must meet NFIP 
requirements in effect at time building was originally constructed (note k, m, 
o) [see Fact Sheet Nos. 4, 7, 11, 15, 27, 29]. Pre-FIRM existing building  NFIP 
requirements concerning new construction not triggered (note k). Recommendation:
elevate bottom of lowest horizontal structural member of addition to or above 
BFE (same for existing building if it is elevated) [see Fact Sheet No. 4].

Vertical Additions That Constitute Substantial Improvement 
--V Zone: Requirement: entire building must meet current NFIP requirements 
concerning new construction in V zones (note k, l, n) [see Fact Sheet Nos. 4, 5, 
7, 11, 15, 27, 29]. 
--Coastal A Zone: Requirement: entire building must meet current NFIP 
requirements concerning new construction in A zones (note k, m, o)[see Fact 
Sheet Nos. 4, 7, 11, 15, 27, 29]. Recommendation: follow V-zone requirement.
--A Zone: Requirement: entire building must meet current NFIP requirements 
concerning new construction in A zones (note k, m, o)[see Fact Sheet Nos. 4, 7, 
11, 15, 27, 29]. Recommendation: elevate bottom of lowest horizontal structural 
member to or above BFE [see Fact Sheet No. 4].

Vertical Additions That Do Not Constitute Substantial Improvement 
--V Zone: Requirement: post-FIRM existing building -- addition must meet NFIP 
requirements in effect at time building was originally constructed (note k, l, 
n) Pre-FIRM existing building -- NFIP requirements concerning new construction 
not triggered (note k) [see Fact Sheet Nos. 4, 5, 7, 11, 15, 27, 29]. 
Recommendation: make addition compliant with current NFIP requirements for V-
zone construction. 
--Coastal A Zone: Requirement: post-FIRM existing building -- addition must meet 
NFIP requirements in effect at time building was originally constructed (note k, 
m, o) Pre-FIRM existing building -- NFIP requirements concerning new 
construction not triggered (note k) [see Fact Sheet Nos. 4, 5, 7, 11, 15, 27, 
29]. Recommendation: follow V-zone requirement.
--A Zone: Requirement: post-FIRM existing building -- addition must meet NFIP 
requirements in effect at time building was originally constructed (note k, m, 
o) Pre-FIRM existing building -- NFIP requirements concerning new construction 
not triggered (note k) [see Fact Sheet Nos. 4, 5, 7, 11, 15, 27, 29]. 
Recommendation: elevate bottom of lowest horizontal structural member to or 
above BFE [see Fact Sheet No. 4].

Elevating on New Foundation
--V Zone: Requirement: new foundation must meet current NFIP requirements 
concerning new construction in V zones (note k, l); building must be properly 
connected and anchored to new foundation
--Coastal A Zone: Requirement: new foundation must meet current NFIP 
requirements concerning new construction in A zones (note k, m); building must 
be properly connected and anchored to new foundation. Recommendation: follow V-
zone requirement.
--A Zone: Requirement: new foundation must meet  current NFIP requirements 
concerning new construction in A zones (note k, m); building must be properly 
connected and anchored to new foundation. Recommendation: elevate bottom of 
lowest horizontal structural member to or above BFE  [see Fact Sheet No. 4].


Enclosures Below Buildings-when enclosure constitutes a substantial improvement
--V Zone: Requirement: both enclosure and existing building must meet current 
NFIP requirements for new construction in V zones (note k, l, n) [see Fact Sheet 
Nos. 4, 5, 7, 11, 27, 29].
--Coastal A Zone: Requirement: both enclosure and existing building must meet 
current NFIP requirements for new construction in A zones (note k, m, o) [see 
Fact Sheet Nos. 4, 7, 11, 15, 27, 29]. Recommendation: follow V-zone 
requirement.
--A Zone: Requirement: both enclosure and existing building must meet current 
NFIP requirements for new construction in A zones (note k, m, o) [see Fact Sheet 
Nos. 4, 7, 11, 15, 27, 29]. Recommendation: elevate bottom of lowest horizontal 
structural member to or above BFE [see Fact Sheet No. 4].

Enclosures Below Buildings-when enclosure does not constitutes a substantial 
improvement
--V Zone: Requirement: post-FIRM existing building -- enclosure must meet NFIP 
requirements in effect at time building was originally constructed (note k, l, 
n) Pre-FIRM existing building -- NFIP requirements concerning new construction 
not triggered (note k) [see Fact Sheet No. 27]. Recommendation: make enclosure 
compliant with current NFIP requirements for new V-zone construction.
--Coastal A Zone: Requirement: post-FIRM existing building -- enclosure must 
meet NFIP requirements in effect at time building was originally constructed 
(note k, m, o) Pre-FIRM existing building -- NFIP requirements concerning new 
construction not triggered (note k) [see Fact Sheet Nos. 15, 27]. 
Recommendation: construct only breakaway enclosures; install flood openings in 
enclosure; do not convert enclosed space to habitable use.
--A Zone: Requirement: post-FIRM existing building -- enclosure must meet NFIP 
requirements in effect at time building was originally constructed (note k, m, 
o) Pre-FIRM existing building -- NFIP requirements concerning new construction 
not triggered (note k)[see Fact Sheet Nos. 15, 27]. Recommendation: install 
flood openings in enclosure; do not convert enclosed space to habitable use.

Reconstruction of Destroyed or Razed Building
--V Zone: Requirement: where entire building is destroyed, damaged, or 
purposefully demolished or razed, replacement building must meet current NFIP 
requirements concerning new construction in V zones (note k, l), even if built 
on foundation from original building [see Fact Sheet Nos. 4, 5, 30].
--Coastal A Zone: Requirement: where entire building is destroyed, damaged, or 
purposefully demolished or razed, replacement building must meet current NFIP 
requirements concerning new construction in A zones (note k, m), even if built 
on foundation from original building [see Fact Sheet Nos. 4, 30]. 
Recommendation: follow V-zone requirement.
--A Zone: Requirement: where entire building is destroyed, damaged, or 
purposefully demolished or razed, replacement building must meet current NFIP 
requirements concerning new construction in A zones (note k, m), even if built 
on foundation from original building [see Fact Sheet Nos. 4, 30].

Moving Existing Building
--V Zone: Requirement: where existing building is moved to new location or site, 
relocated building must meet current NFIP requirements concerning new 
construction in V zones (note k, l) [see Fact Sheet Nos. 4, 5, 30].
--Coastal A Zone: Requirement: where existing building is moved to new location 
or site, relocated building must meet current NFIP requirements concerning new 
construction in A zones (note k, m) [see Fact Sheet Nos. 4, 30]. Recommendation:
follow V-zone requirement.
--A Zone: Requirement: where existing building is moved to new location or site, 
relocated building must meet current NFIP requirements concerning new 
construction in A zones (note k, m) [see Fact Sheet Nos. 4, 30]. 
Recommendation: elevate bottom of lowest horizontal structural member to or 
above BFE [see Fact Sheet No. 4]. 

Notes
a	Prohibited and Allowed refer to the minimum NFIP regulatory 
requirements; individual states and communities may enforce more stringent 
requirements that supersede those summarized here. Exceeding minimum NFIP 
requirements will provide increased flood protection and may result in lower 
flood insurance premiums.
b	In these areas, buildings are subject to flooding conditions similar to, 
but less severe than, those in V zones. These areas can be subject to breaking 
waves greater than or equal to 1.5 feet high (which can destroy conventional 
wood-frame and unreinforced masonry wall construction) and erosion (which can 
undermine shallow foundations).
c	In these areas, buildings are subject to flooding conditions similar to 
those in riverine A zones.
d	Some coastal communities require open foundations in A zones.
e	State or community may require freeboard or regulate to a higher elevation 
(e.g., Design Flood Elevation (DFE)).
f	Some coastal communities prohibit breakaway walls and allow only open 
lattice or screening.
g	If an area below the BFE in an A-zone building is fully enclosed by 
breakaway walls, the walls must meet the requirement for openings that allow 
equalization of hydrostatic pressure.
h	Placement of nonstructural fill adjacent to buildings in coastal AO zones 
is not recommended.
i	There are some differences between what is permitted under floodplain 
management regulations and what is covered by NFIP flood insurance. Building 
designers should be guided by floodplain management requirements, not by flood 
insurance policy provisions. For more information, see Section 9.3.1.1 in 
Chapter 9 of FEMAs Coastal Construction Manual (FEMA 55).
j	Walls below BFE must be designed and constructed as breakaway walls that 
meet the minimum requirements of the NFIP regulations. For more information, see 
Section 6.4.3.3 in Chapter 6 of FEMAs Coastal Construction Manual (FEMA 55).
k	Consult with authority having jurisdiction (AHJ) regarding more 
restrictive requirements for repairs, remodeling, and additions.
l 	NFIP requirements for new construction in V zones include those pertaining 
to Design and Construction, Flood-Resistant Materials, Siting, Foundations, 
Lowest Floor Elevation, Enclosures Below the BFE, Free of Obstructions, 
Utilities, and Certifications.
m 	NFIP requirements for new construction in A zones include those pertaining 
to Design and Construction, Flood-Resistant Materials, Siting, Foundations, 
Foundation Openings, Lowest Floor Elevation, Enclosures Below the BFE, 
Utilities, and Certifications.
n 	An addition in the form of an attached garage would not have to be 
elevated to or above the BFE, because its use (parking) would be allowed below 
the BFE; however, it would have to meet other NFIP requirements for new 
construction in V zones.
o 	An addition in the form of an attached garage would not have to be 
elevated to or above the BFE, because its use (parking) would be allowed below 
the BFE; however, it would have to meet other NFIP requirements for new 
construction in A zones.

[End of Fact Sheet No. 2]





Technical Fact Sheet No. 4
Lowest Floor Elevation
Home Builders Guide to Coastal Construction
FEMA 499/August 2005

Purpose: To discuss benefits of exceeding the National Flood Insurance Program 
(NFIP) minimum elevation requirements, to point out common construction 
practices that are violations of NFIP regulations and result in significantly 
higher flood insurance premiums, and to discuss the NFIP Elevation Certificate. 

Why Is the Lowest Floor Elevation Important?
In inland areas, experience has shown that floods damage areas of buildings not 
elevated above the flood level and destroy contents of those areas. In coastal 
areas, wave action causes even more damage, often destroying enclosed building 
areas below the flood level (and any building areas above the flood level that 
depend on the lower area for structural support). Once waves rise above the 
lowest structural member in a V zone or coastal A zone, the elevated portion of 
the building is likely to be severely damaged or destroyed.

Recommended Lowest Floor Elevations*
Because of the additional hazard associated with wave action in V zones and in A 
zones in coastal areas, it is recommended that the minimum elevation 
requirements 
of the NFIP be exceeded in these areas:
--It is recommended that the bottom of the lowest horizontal structural member 
of V-zone buildings be elevated 1 foot or more above the Base Flood Elevation 
(BFE), i.e., add freeboard. 
--It is recommended that the lowest horizontal structural member of A-zone 
buildings in coastal areas be elevated 1 foot or more above the BFE (i.e., add 
freeboard).

Note: NFIP minimum elevation requirements: A zone  elevate top of lowest floor 
to or above BFE; V zone  elevate bottom of lowest horizontal structural member 
to or above BFE. In both V and A zones, many people have decided to elevate a 
full story for below-building parking, far exceeding the elevation requirement. 
See Fact Sheet No. 2 for more information about NFIP minimum requirements in A 
and V zones.

What Does FEMA Consider the Lowest Floor?
--The lowest floor means the lowest floor of the lowest enclosed area, except 
for unfinished or flood-resistant enclosures used solely for parking of 
vehicles, building access, or storage.
--If the lowest enclosed area is used for anything other than parking of 
vehicles, building access, or storage, the floor of that area is considered the 
lowest floor. This will violate NFIP requirements and drastically increase flood 
insurance premiums.
--Note that any below-BFE finished areas, including foyers, will violate NFIP 
requirements, sustain unreimbursable flood damage, and increase flood insurance 
premiums. 
--The floor of a basement (where basement means the floor is below grade on 
all sides) will always be the lowest floor, regardless of how the space is used.
--Walls of enclosed areas below the BFE must meet special requirements in 
coastal areas (see Fact Sheet No. 27). 

Construction Practices and the Lowest Floor
Setting the lowest floor at the correct elevation is critical. Failure to do so 
can result in a building being constructed below the BFE. As a result, work can 
be stopped, certificates of occupancy can be withheld, and correcting the 
problem can be expensive and time-consuming.
--After piles have been installed, the intended elevation of the lowest floor 
should be checked before the piles are cut off.
--Alternatively, after piers or columns have been constructed, the intended 
elevation of the lowest floor should be checked before the lowest horizontal 
structural supporting members are installed.
--After the lowest horizontal structural supporting members have been installed, 
the elevation should be checked again, before any further vertical construction 
is carried out.

Do not modify building plans to create habitable space below the intended lowest 
floor. Doing so will put the building in violation of flood regulations and 
building codes.

FEMA Elevation Certificate
The NFIP requires participating communities to adopt a floodplain management 
ordinance that specifies minimum requirements for reducing flood losses. One 
such requirement is that communities obtain, and maintain a record of, the 
lowest floor elevations for all new and substantially improved buildings. The 
Elevation Certificate (see following pages) provides a way for a community to 
comply with this requirement and for insurers to determine flood insurance 
premiums.

Most communities require permit applicants to retain a surveyor, engineer, or 
architect to complete and submit the elevation certificate. Note that multiple 
elevation certificates may need to be submitted for the same building: a 
certificate may be required when the lowest floor level is set (and before 
additional vertical construction is carried out); a certificate will be required 
upon completion of all construction.

The Elevation Certificate requires that the following information be certified 
and signed by the surveyor/engineer/architect and signed by the building owner:
--elevations of certain floors in the building
--lowest elevation of utility equipment/machinery
--floor slab elevation for attached garage
--adjacent grade elevations
--flood opening information (A zones)

The Elevation Certificate is available on FEMAs web site: 
http://www.fema.gov/nfip/elvinst.shtm
[two pages of the elevation certificate are attached]

[End of Fact Sheet No. 4]




Technical Fact Sheet No. 5
V-Zone Design and Construction Certification
Home Builders Guide to Coastal Construction

Purpose: To explain the certification requirements for structural design and 
construction in V zones. 

Structural Design and Methods of Construction Certification
As part of the agreement for making flood insurance available in a community, 
the National Flood Insurance Program (NFIP) requires the community to adopt a 
floodplain management ordinance that specifies minimum design and construction 
requirements. Those requirements include a certification of the structural 
design and the methods of construction.

Specifically, NFIP regulations and local floodplain management ordinances 
require that:
1.  a registered professional engineer or architect shall develop or review the 
structural design, specifications, and plans for the construction, and 
2.  a registered professional engineer or architect shall certify that the 
design and methods of construction to be used are in accordance with accepted 
standards of practice for meeting the following criteria:
--the bottom of the lowest horizontal structural member of the lowest floor 
(excluding the pilings or columns) is elevated to or above the Base Flood 
Elevation (BFE); and 
--the pile or column foundation and structure attached thereto is anchored to 
resist flotation, collapse, and lateral movement due to the effects of wind and 
water loads acting simultaneously on all building components. Water loading 
values used shall be those associated with the Base Flood. Wind loading values 
used shall be those required by applicable state or local building standards.

The community, through its inspection procedures, will verify that the building 
is built in accordance with the certified design.

[Textbox]
Other Certifications Required in V Zones
--Lowest Floor Elevation, by a surveyor, engineer, or architect (see Fact Sheet 
No. 4)
--Breakaway Wall Collapse, by a registered professional engineer or architect  
(see Fact Sheet No. 27)
[End of Textbox]

[Textbox]
The Design and Methods of Construction certification should take into 
consideration 
the NFIP Free-of-Obstruction requirement for V zones: the space below the lowest 
floor must be free of obstructions (e.g., free of any building element, 
equipment, 
or other fixed objects that can transfer flood loads to the foundation, or that 
can 
cause floodwaters or waves to be deflected into the building), or must be 
constructed with non-supporting breakaway walls, open lattice, or insect 
screening. 
(See NFIP Technical Bulletin 5-93 and Fact Sheet No. 27.)
[End of Textbox]

Completing the V-Zone Certification
There is no single V-zone certificate used on a nationwide basis. Instead, local 
communities and/or states have developed their own certification procedures and 
documents.

Registered engineers and architects involved in V-zone construction projects 
should check with the authority having jurisdiction regarding the exact nature 
and timing of required certifications.

Page 2 shows a sample certification form developed by one state. It is intended 
to show one of many possible ways by which a jurisdiction may require that the 
certification and supporting information be provided. In this instance, three 
certifications are included on the form (Lowest Floor Elevation, Design and 
Methods of Construction, Breakaway Wall Collapse).

Note: The V-zone certificate is not a substitute for and cannot be used without 
the NFIP Elevation Certificate (see Fact Sheet No. 4), which is required for 
flood insurance rating.

[End of Fact Sheet No. 5]




Technical Fact Sheet No. 6
How Do Siting and Design Decisions Affect the Owners Costs?
Home Builders Guide to Coastal Construction
FEMA 499/June 2005

Purpose: To show the effects of planning, siting, and design decisions on 
coastal home costs.  

Key Issues
--When building a coastal home, initial, operating, and long-term costs (i.e., 
life cycle costs) must be considered.
--Coastal (especially oceanfront) homes cost more to design, construct, 
maintain, repair, and insure than inland homes. 
--Determining the risks associated with a particular building site or design is 
important.
--Siting, designing, and constructing to minimum regulatory requirements do not 
necessarily result in the lowest cost to the owner over a long period of time. 
Exceeding minimum design requirements costs slightly more initially, but can 
save the owner money in the long run.

Costs
A variety of costs should be considered when planning a coastal home, not just 
the construction cost. Owners should be aware of each of the following, and 
consider how siting and design decisions will affect these costs:  
--Initial costs include property evaluation and acquisition costs and the costs 
of permitting, design, and construction.
--Operating costs include costs associated with the use of the building, such as 
the costs of utilities and insurance*.
--Long-term costs include costs for preventive maintenance and for repair and 
replacement of deteriorated or damaged building components.

Note: Flood insurance premiums can be reduced up to 60 percent by exceeding 
minimum siting, design, and construction practices. See the V-Zone Risk Factor 
Rating Form in FEMAs Flood Insurance Manual 
(http://www.fema.gov/nfip/manual.shtm).

Risk
One of the most important building costs to be considered is that resulting from 
storm and/or erosion damage. But how can an owner decide what level of risk is 
associated with a particular building site or design? One way is to consider the 
probability of a storm or erosion occurring and the potential building damage 
that results (see matrix).

Building sites or designs resulting in extreme or high risk should be avoided  
the likelihood of building loss is great, and the long-term costs to the owner 
will be very high. Building sites or designs resulting in medium or low risk 
should be given preference.

[Graphic Description] Costs, Hazards, and Damage Vary With Location: Homes 
located farther landward may be less appealing to some owners, but will be less 
prone to damage and will cost less to build, insure, and maintain. Homes located 
closer to the shore may have spectacular views, but are subject to greater 
risks, more frequent and more severe damage, and higher construction, 
maintenance, and insurance costs. 
[End of graphic description]

Siting
Note that over a long period, poor siting decisions are rarely overcome by 
building design.

Design
--How much more expensive is it to build near the coast as opposed to inland 
areas? The table below suggests approximately 10 - 30 percent more.
--What about exceeding minimum design requirements in coastal areas? The table 
suggests that the added construction costs for meeting the practices recommended 
in the Home Builders Guide to Coastal Construction (beyond typical minimum 
requirements) are nominal.

[Graphic Description] Table that shows the effects of selected design items on 
costs.. 
[End of graphic description]

[End of Fact Sheet No. 6]





Technical Fact Sheet No. 7
Selecting a Lot and Siting the Building
Home Builders Guide to Coastal Construction
FEMA 499/June 2005 

Purpose: To provide guidance on lot selection and siting considerations for 
coastal residential buildings.

Key Issues
--Purchase and siting decisions should be long-term decisions, not based on 
present-day shoreline and conditions.
--Parcel characteristics, infrastructure, regulations, environmental factors, 
and owner desires constrain siting options.
--Conformance with local/state shoreline setback lines does not mean buildings 
will be safe.
--Information about site conditions and history is available from several 
sources.

[Textbox]
Siting, design, and construction should be considered together (see Fact Sheet 
No. 6), but know that poor lot selection and siting decisions can rarely be 
overcome by improved design and construction. Building failures (see Fact Sheet 
No. 1) are often the result of poor siting.
[End of Texbox]

The Importance of Property Purchase and Siting Decisions
The single most common and costly siting mistake made by designers, builders, 
and owners is failing to consider future erosion and slope stability when an 
existing coastal home is purchased or when land is purchased and a new home is 
built. Purchase decisions  or siting, design, and construction decisions  
based on present-day shoreline conditions often lead to future building 
failures.

Over a long period of time, owners of poorly sited coastal buildings may spend 
more money on erosion control and erosion-related building repairs than they 
spent on the building itself.

What Factors Constrain Siting Decisions?
Many factors affect and limit a home builders or owners ability to site 
coastal residential buildings, but the most influential is probably parcel size, 
followed by topography, location of roads and other infrastructure, regulatory 
constraints, and environmental constraints.  

Given the cost of coastal property, parcel sizes are often small and owners 
often build the largest building that will fit within the permissible 
development footprint. Buyers frequently fail to recognize that siting decisions 
in these cases have effectively been made at the time the land was platted or 
subdivided, and that shoreline erosion can render these parcels unsuitable for 
long-term occupation. 

In some instances, however, parcel size may be large enough to allow a hazard-
resistant coastal building to be sited and constructed, but an owners desire to 
push the building as close to the shoreline as possible increases the likelihood 
that the building will be damaged or destroyed in the future. 

Coastal Setback Lines  What Protection Do They Provide?
Many states require new buildings to be sited at or landward of coastal 
construction setback lines, which are usually based on long-term, average annual 
erosion rates. For example, a typical minimum 50-year setback line with an 
erosion rate of 2.5 feet/year would require a setback of 125 feet, typically 
measured from a reference feature such as the dune crest, vegetation line, or 
high-water line.

Building at the 125-foot setback (in this case) does not mean that a building 
will be safe from erosion for 50 years.  
--Storms can cause short-term erosion that far exceeds setbacks based on long-
term averages.  
--Erosion rates vary over time, and erosion could surpass the setback distance 
in just a few years time. The rate variability must also be known to determine 
the probability of undermining over a given time period.

What Should Builders, Designers, and Owners Do?
--Consult local and state agencies, universities, and consultants for detailed, 
site-specific erosion and hazard information.
--Look for historical information on erosion and storm effects. How have older 
buildings in the area fared over time? Use the experience of others to guide 
siting decisions.
--Determine the owners risk tolerance, and reject parcels or building siting 
decisions that exceed the acceptable level of risk.

[Textbox]
Common Siting Problems
--Building on a small lot between a road and an eroding shoreline is a recipe 
for trouble.
--Odd-shaped lots that force buildings close to the shoreline increase the 
vulnerability of the buildings.
--Siting a building near the edge of a bluff increases the likelihood of 
building loss, because of both bluff erosion and changes in bluff stability 
resulting from development activities (e.g., clearing vegetation, building 
construction, landscaping, changes in surface drainage and groundwater flow 
patterns).
--Siting near a tidal inlet with a dynamic shoreline can result in the building 
being exposed to increasing flood and erosion hazards over time. 
--Siting a building immediately behind an erosion control structure may lead to 
building damage from wave overtopping and may limit the owners ability to 
repair or maintain the erosion control structure. 
--Siting a new building within the footprint of a pre-existing building does not 
guarantee that the location is a good one.
[End of Textbox]

Siting should consider both long-term erosion and storm impacts. Siting should 
consider site-specific experience, wherever available.

[End of Fact Sheet No. 7]





Technical Fact Sheet No. 8
Coastal Building Materials
Home Builders Guide to Coastal Construction
FEMA 499/June 2005 

Purpose: To provide guidance on the selection of building materials used for 
coastal construction. 

Key Issues
--The durability of a coastal home relies on the types of materials used to 
construct it. For more details, see the U.S. Department of Housing and Urban 
Development (HUD) report Durability by Design, A Guide for Residential Builders 
and Designers, available on the HUD User website at 
http://www.huduser.org/publications/destech/durdesign.html.
--Materials and construction methods should be resistant to flood and wind 
damage, driving rain, corrosion, moisture, and decay.
--All coastal buildings will require maintenance and repairs (more so than 
inland construction)  use proper materials and methods for repairs, additions, 
and other work following initial construction (see Fact Sheet No. 30).

[Textbox]
Section 60.3(a)(ii) of the National Flood Insurance Program (NFIP) regulations 
requires 
that all new construction and substantial improvements in floodprone areas be 
constructed with materials below the Base Flood Elevation (BFE) that are 
resistant to 
flood damage. (See Fact Sheet No. 30 for a definition of substantial 
improvement.)
[End of Textbox]

Flood-Resistant Materials
Flooding accounts for a large percentage of the damage caused by a coastal 
storm. Building materials exposed to flooding must be resilient enough to 
sustain a certain amount of water exposure in order to avoid the need for 
complete replacement after the flood.

FEMA defines a flood-resistant material as any building material capable of 
withstanding direct and prolonged contact (i.e., at least 72 hours) with 
floodwaters without sustaining significant damage (i.e., requires more than 
cosmetic repair).

The following are examples of flood-resistant materials:
--Lumber: pressure-treated or naturally decay-resistant, including redwood, 
cedar, some oaks, and bald cypress
--Concrete: a sound, durable mix, and when exposed to saltwater or salt spray, 
made with a sulfate-resisting cement, with a 28-day compressive strength of 
5,000 psi minimum and a water-cement ratio not higher than 0.40  consult ACI 
318-02, Building Code Requirements for Structural Concrete and Commentary, by 
the American Concrete Institute International
--Masonry: reinforced and fully grouted
--Structural Steel: coated to resist corrosion
--Insulation: plastics, synthetics, and closed-cell foam, or other types 
approved by local building officials

This table lists examples of flood-resistant materials used in coastal homes.
Table description: two columns: Location of Material Use and Name of Material

--Piles and Posts: Round, tapered wood piles preservative-treated for ground 
contact, at a minimum; square-section piles or wood posts preservative-treated 
for marine use.
--Piers: reinforced concrete or concrete masonry units (CMU) (see Flood-
Resistant Materials above and Fact Sheet No. 14)
--Foundation walls: reinforced concrete or CMU, or wood that is preservative-
treated for foundation or marine use (see Fact sheet No. 15)
--Beams: solid sawn timbers and glue-laminated products, either naturally decay-
resistant or preservative-treated for aboveground exposure; built-up members 
preservative-treated for ground contact
--Decking: preservative-treated or naturally decay-resistant wood, or composite 
wood members (e.g., manufactured of recycled sawdust and plastic)
--Framing: sawn wood or manufactured lumber (preservative-treated or naturally 
resistant to decay if in close proximity to the ground)
--Exterior sheathing: high-capacity shearwall sheathing rated exterior
--Subflooring: plywood or oriented strand board (OSB) rated Exposure 1, or 
rated exterior if left permanently exposed (e.g., exposed underside of 
elevated house on open foundation)
--Siding: vinyl or naturally decay-resistant wood (see Fact Sheet No. 25)
--Flooring: latex or bituminous cement formed-in-place, clay, concrete tile, 
pre-cast concrete, epoxy formed-in-place, mastic flooring, polyurethane formed
in-place, rubber sheets, rubber tiles with chemical-set adhesives, silicone 
floor formed in-place, terrazzo, vinyl sheet-goods, vinyl tile with chemical-
set adhesives, pressure-treated lumber or naturally decay-resistant lumber.
--Walls and Ceilings: cement board, brick, metal, cast stone in waterproof 
mortar, slate, porcelain, glass, glass block, clay tile, concrete, CMU, 
pressure-treated wood, naturally decay-resistant wood, marine grad plywood or 
pressure-treated plywood.
--Doors: hollow metal
--Insulation: foam or closed-cell
--Trim: natural or artificial stone, steel, or rubber

Many coastal jurisdictions make available a list of approved materials that can 
be used in coastal environments. Check for locally approved flood-resistant 
materials. Include all proposed construction and materials in approved plans. 
For guidance on testing specific materials, refer to NES Evaluation Protocol for 
Determination of Flood-Resistant Properties of Building Elements (NES, Inc.  
http://www.nateval.org).

Wind-Resistant Materials
Homes in many coastal areas are often exposed to winds in excess of 90 mph (3-
second peak gust). Choose building materials (e.g., roof shingles, siding, 
windows, doors, fasteners, and framing members) that are designed for use in 
high-wind areas.

Examples:
--shingles rated for high winds (see Fact Sheet No. 20)
--double-hemmed vinyl siding (see Fact Sheet No. 25)
--deformed-shank nails for sheathing attachments (see Fact Sheet No. 18)
--wind-resistant glazing (see Fact Sheet No. 22)
--reinforced garage doors
--tie-down connectors used throughout structure (from roof framing to 
foundation  see Fact Sheet Nos. 10 and 17)
--wider framing members (2x6 instead of 2x4)

Remember: a wind-resistant material is only as good as its connection. Always 
use recommended fasteners and connection methods.

Corrosion and Decay Resistance
Coastal environments are conducive to metal corrosion and moisture- and termite-
related decay of other building materials. Metal corrosion is most pronounced on 
coastal homes (within 3,000 feet of the ocean), but moisture- and termite-
related decay are prevalent throughout coastal areas.

Corrosion-Resistant Metals
Most jurisdictions require metal building hardware to be hot-dipped galvanized 
or stainless steel. Some local codes require protective coatings that are 
thicker than off-the-shelf products typically have. For example, a G90 zinc 
coating (0.75 mil on each face) may be required, which is thicker than the 
common G60 (0.5 mil on each face) coating.

Recommendations
--Use hot-dipped galvanized or stainless steel hardware. Reinforcing steel 
should be protected from corrosion by sound materials (masonry, mortar, grout, 
concrete) and good workmanship (see Fact Sheet No. 16). Use galvanized or epoxy-
coated reinforcing steel in situations where the potential for corrosion is high 
(see Fact Sheet No. 14).
--Avoid joining dissimilar metals, especially those with high galvanic 
potential (e.g., copper and steel).
--Some wood preservatives should not be used in direct contact with 
galvanized metal. Verify that wood treatment is suitable for use with galvanized 
metal, or use stainless steel.
--Metal-plate-connected trusses should not be exposed to the elements. Truss 
joints near vent openings are more susceptible to corrosion and may require 
increased corrosion protection.

[Textbox]
The term "corrosion-resistant" is widely used but, by itself, is of little help 
to those specifying or evaluating materials for use in a coastal home. Every 
material resists corrosion to some extent, or conversely, every material 
corrodes.

The real issue is how long will a given material serve its intended purpose at a 
given home? The answer depends on the following:
--the material
--where it is used in the home
--whether installation techniques (e.g., drilling, cutting, bending) will 
compromise its resistance
--its degree of exposure to salt air, moisture, and corrosive agents
--whether maintenance required of the homeowner is performed

The bottom line: do not blindly specify or accept a product just because it is 
labeled corrosion-resistant. Evaluate the nature of the material, its coating 
type and thickness (if applicable), and its performance in similar environments 
before determining whether it is suitable for a particular application.

For guidance on the selection of metal hardware for use in coastal environments, 
consult an engineer with experience in corrosion protection. For more 
information about corrosion in coastal environments, see FEMA Technical Bulletin 
8-96, Corrosion Protection for Metal Connectors in Coastal Areas for Structures 
Located in Special Flood Hazard Areas (see the Additional Resources section of 
this fact sheet).
[End of Textbox]

Moisture Resistance
Materials resistant to moisture can greatly reduce maintenance and extend the 
life of a coastal home (however, by themselves, such materials cannot prevent 
all moisture damage. Proper design and installation of moisture barriers (see 
Fact Sheet No. 9) is also required).

Recommendations
--Control wood decay by separating wood from moisture, using preservative-
treated wood, using naturally decay-resistant wood, and applying protective wood 
finishes.
--Use proper detailing of wood joints and construction to eliminate standing 
water and reduce moisture absorption by the wood (e.g., avoid exposure of end 
grain cuts, which absorb moisture up to 30 times faster than the sides of a wood 
member).
--Do not use untreated wood in ground contact or high-moisture situations. 
Do not use untreated wood in direct contact with concrete.
--Field-treat any cuts or drill holes that offer paths for moisture to enter 
wood members.
--For structural uses, employ concrete that is sound, dense, and durable; 
control cracks with welded wire fabric and/or reinforcing, as appropriate.
--Use masonry, mortar, and grout that conform with the latest building 
codes.

Termite Resistance
Termite damage to wood construction occurs in many coastal areas (attack is most 
frequent and severe along the southeastern Atlantic and Gulf of Mexico 
shorelines, in California, and in Hawaii and other tropical areas). Termites can 
be controlled by soil treatment, termite shields, and the use of termite-
resistant materials.

Recommendations
--Incorporate termite control methods into design in conformance with 
requirements of the authority having jurisdiction.
--Where a masonry foundation is used and anchorage to the foundation is 
required for uplift resistance, the upper block cores must usually be completely 
filled with grout, which may eliminate the requirement for termite shields (see 
Fact Sheet No. 14).
--Use preservative-treated wood for foundations, sills, above-foundation 
elements, and floor framing.

Additional Resources
FEMA. NFIP Technical Bulletin 2-93, Flood-Resistant Materials Requirements for 
Buildings Located in Special Flood Hazard Areas. 
(http://www.fema.gov/fima/techbul.shtm)
FEMA. NFIP Technical Bulletin 8-96, Corrosion Protection for Metal Connectors in 
Coastal Areas for Structures Located in Special Flood Hazard Areas. 
(http://www.fema.gov/fima/techbul.shtm)
American Concrete Institute International. (http://www.aci-
int.org/general/home.asp)
American Wood-Preservers Association. (http://www.awpa.com)
International Code Council Evaluation Service, Inc. Protocol for Testing the 
Flood Resistance of Materials. (http://www.icc-es.org/index.shtml)

[End of Fact Sheet No. 8]




Technical Fact Sheet No. 9
Moisture Barrier Systems
Home Builders Guide to Coastal Construction
FEMA 499/June 2005 

Purpose: To describe the moisture barrier system, explain how typical wall 
moisture barriers work, and identify common problems associated with moisture 
barrier systems.

Key Issues
--A successful moisture barrier system will limit water infiltration into 
unwanted areas and allow drainage and drying of wetted building materials. 
--Most moisture barrier systems for walls (e.g., siding and brick veneer) are 
redundant systems, which require at least two drainage planes (see page 2).
--Housewrap or building paper (asphalt-saturated felt) will provide an adequate 
secondary drainage plane.
--Proper flashing and lapping of housewrap and building paper are critical to a 
successful moisture barrier system.
--Sealant should never be substituted for proper layering.

The purpose of the building envelope is to control the movement of water, air, 
thermal energy, and water vapor. The goal is to prevent water infiltration into 
the interior, limit long-term wetting of the building components, and control 
air and vapor movement through the envelope.

Locations and Causes of Common Water Intrusion Problems
--Poor water shedding from roof: use moderate overhangs of 12 to 16 inches, drip 
edges, and a gutter system.
--Roof/wall intersection: install effective kick-out flashing at roof-to-wall 
intersections, diverter flashing around trapped-valleys, and rake flashing.
--Flashing around windows: proper lapping is key to leak prevention. Do not 
depend on sealant for sustained protection. Protect flashings with overlapping 
wrap.
--Door sills: use pan flashing to prevent damage to subfloor.
--Improper flashing over doors: proper lapping is key to leak prevention. Do not 
depend on sealant for sustained protection. Protect flashings with overlapping 
housewrap or building paper. 
--Improper flashing and damaged housewrap or building paper at wall 
penetrations: follow window flashing techniques at every wall penetration.
--Damaged or improperly installed siding: follow manufacturers guidelines. 
Prime all surfaces of wood siding (back-priming) before applying top coats.
--No housewrap or building paper used, or improperly lapped: virtually all 
siding leaks. Use housewrap or building paper to shed water. Properly lap 
material so water flows without bucking seams. Water must be allowed to drain 
out of walls.

The location of water entry is often difficult to see, and the damage to 
substrate and structural members behind the exterior wall cladding frequently 
cannot be detected by visual inspection.

Proper Lapping Is the Key
Proper lapping of moisture barrier materials is the key to preventing water 
intrusion. Most water intrusion problems are related to the improper lapping of 
materials. Usually, flashing details around doors, windows, and penetrations are 
to blame. If the flashing details are right and the housewrap or building paper 
is properly installed, most moisture problems will be prevented. Capillary 
suction is a strong force and will move water in any direction. Even under 
conditions of light or no wind pressure, water can be wicked through seams, 
cracks, and joints upward behind the overlaps of horizontal siding. Proper lap 
distances and sealant help prevent water intrusion caused by wicking action.

How a Redundant Moisture Barrier Works
--Siding: the siding is the first line of defense, but by no means should it be 
the only protection from outside moisture. Sidings shed most of the water, but 
some does get through, especially in coastal areas where high winds can drive 
rain.
--Housewrap or Building Paper: Housewrap or building paper is a dual-purpose 
protection layer. It sheds water that gets through the siding and limits air 
intrusion from the outside. A unique feature of this barrier is that it sheds 
water, but allows water vapor to pass through. This permits water vapor from the 
inside to pass through without condensing on the framing.
--Sheathing: If structural sheathing is used, it should be protected from 
moisture. Prolonged wetting, especially without the ability to drain the 
moisture and dry out, will damage the sheathing.
--Vapor Retarder: In cold regions, a vapor retarder is often used on the warm 
side of the wall cavity to minimize the movement of vapor from the inside of the 
building into the wall cavity, where it will condense on the cool framing 
members. Vapor retarders are typically used only where the predominant vapor 
drive is from the inside to the outside (cold climates).

[End of Fact Sheet No. 9]




Technical Fact Sheet No. 11
Foundations in Coastal Areas
Home Builders Guide to Coastal Construction
FEMA 499/June 2005 

Purpose: To describe foundation types suitable for coastal environments.

Key Issues
--Foundations in coastal areas must elevate buildings above the Base Flood 
Elevation (BFE), while withstanding flood forces, high winds, scour and erosion, 
and floating debris.
--Foundations used for inland construction are generally not suitable for 
coastal construction.
--Deeply embedded pile or column foundations are required for many coastal 
areas; in other coastal areas, they are recommended  instead of solid wall, 
crawlspace, slab, or other shallow foundations that can be undermined easily. 
("Deeply embedded" means sufficient penetration into the ground to accommodate 
storm-induced scour and erosion and to resist all design vertical and lateral 
loads without structural damage.)
--Areas below elevated buildings in V zones must be free of obstructions that 
can transfer flood loads to the foundation and building (see Fact Sheet No. 27).

Graphic: Storm surge and waves overtopping a barrier island during Hurricane 
Frederic.

Foundation Design Criteria
All foundations for buildings in flood hazard areas must be constructed with 
flood-damage-resistant materials (see Fact Sheet No. 8) and must do two things 
in addition to meeting the requirements for conventional construction: (1) 
elevate the building above the BFE, and (2) prevent flotation, collapse, and 
lateral movement of the building, resulting from loads and conditions during the 
design flood event (in coastal areas, these loads and conditions include 
inundation by fast-moving water, breaking waves, floating debris, erosion, and 
high winds).

Because the most hazardous coastal areas are subject to erosion and extreme 
flood loads, the only practical way to perform these two functions is to elevate 
a building on a deeply embedded and open (i.e., pile or column) foundation. 
This approach resists storm-induced erosion and scour, and it minimizes the 
foundation surface area subject to lateral flood loads  it is required by the 
National Flood Insurance Program (NFIP) in V zones (even when the ground 
elevation lies above the BFE) and is recommended for coastal A zones. However, 
even a deeply embedded open pile foundation will not prevent eventual 
undermining and loss due to long-term erosion (see Fact Sheet No. 7).

Performance of Various Foundation Types in Coastal Areas
There are many ways to elevate buildings above the BFE: fill, slab-on-grade, 
crawlspace, stemwall, solid wall, pier (column), and pile. Not all of these are 
suitable for coastal areas. In fact, several of them are prohibited in V zones 
and are not recommended by the Home Builders Guide to Coastal Construction for 
A zones in coastal areas.

Fill  Because fill is susceptible to erosion, it is prohibited as a means of 
providing structural support to buildings in V zones and must not be used as a 
means of elevating buildings in any other coastal area subject to erosion, 
waves, or fast-moving water.

Slab-on-Grade  Slab-on-grade foundations are also susceptible to erosion and 
are therefore prohibited in V zones. They also are not recommended for A zones 
in coastal areas. (Note that parking slabs are often permitted below elevated 
buildings, but are themselves susceptible to undermining and collapse.)

Graphic: Building failure caused by undermining of slab-on-grade foundation 
during Hurricane Fran.

Crawlspace  Crawlspace foundations are prohibited in V zones and are not 
recommended for A zones in coastal areas. They are susceptible to erosion when 
the footing depth is inadequate to prevent undermining. Crawlspace walls are 
also vulnerable to wave attack. Where used, crawlspace foundations must be 
equipped with flood openings; grade elevations should be such that water is not 
trapped in the crawlspace (see Fact Sheet Nos. 15 and 27).

Graphic: Failure of crawlspace foundation undermined by scour.

Stemwall  Stemwall foundations are similar to crawlspace foundations in 
construction, but the interior space that would otherwise form the crawlspace is 
often backfilled with gravel that supports a floor slab. Stemwall foundations 
have been observed to perform better during storms than many crawlspace and pier 
foundations. However, the building code may limit stemwall height to just a few 
feet. Flood openings are not required in a backfilled stemwall foundation. 
Stemwall foundations are prohibited in V zones but are recommended in A zones 
subject to limited wave action, as long as embedment of the wall is sufficient 
to resist erosion and scour.

Solid Foundation Walls  Solid foundation walls are prohibited by the NFIP in V 
zones and are not recommended for A zones subject to breaking waves or other 
large flood forces  the walls act as an obstruction to flood flow. Like 
crawlspace walls, they are susceptible to erosion when the footing depth is 
inadequate to prevent undermining. Solid walls have been used in some regions to 
elevate buildings one story in height. Where used, the walls must allow 
floodwaters to pass between or through the walls (using flood openings). See 
Fact Sheet Nos. 15 and 27.

Pier (column)  Pier foundations are recommended for A zones where erosion 
potential and flood forces are small. This open foundation is commonly 
constructed with reinforced and grouted masonry units atop a concrete footing. 
Shallow pier foundations are extremely vulnerable to erosion and overturning if 
the footing depth and size are inadequate. They are also vulnerable to breakage 
if materials and workmanship are not first rate. Fact Sheet No. 14 provides 
guidance on how to determine whether pier foundations are appropriate, and how 
to design and construct them.

Graphic: Pier (column) failures: footings undermined and columns separated from 
footings.

Pile  Pile foundations are recommended for V zones and many A zones in coastal 
areas. These open foundations are constructed with square or round, wood, 
concrete, or steel piles, driven or jetted into the ground, or set into augered 
holes. Critical aspects of a pile foundation include the pile size, installation 
method and embedment depth, bracing, and the connections to the elevated 
structure (see Fact Sheet Nos. 12 and 13). Pile foundations with inadequate 
embedment will lead to building collapse. Inadequately sized piles are 
vulnerable to breakage by waves and debris.

Graphic: Pile failures led to collapse of floor of elevated building.

Foundations for High-Elevation Coastal Areas
Foundation design is problematic in bluff areas that are vulnerable to coastal 
erosion but outside mapped flood hazard areas. Although NFIP requirements may 
not apply, the threat of undermining is not diminished.
Moreover, both shallow and deep foundations will fail in such situations. Long-
term solutions to the problem may involve better siting (see Fact Sheet No. 7), 
moving the building when it is threatened, or (where permitted and economically 
feasible) controlling erosion through slope stabilization and structural 
protection.

Graphic: Insufficient pile embedment and failure of connections at tops of piles 
allowed elevated building to be floated off its foundation.

Foundations in V Zones With Ground Elevations Above the BFE
In some instances, coastal areas will be mapped on an NFIP Flood Insurance Rate 
Map (FIRM) as V zones, but will have dunes or bluffs with ground elevations 
above the BFE shown on the FIRM. Deeply embedded pile or column foundations are 
still required in these areas, and solid or shallow foundations are still 
prohibited. The presence of a V-zone designation in these instances indicates 
that the dune or bluff is expected to erode during the base flood event and that 
V-zone wave conditions are expected after the erosion occurs. The presence of 
ground elevations above the BFE in a V zone should not be taken to mean that the 
area is free from Base Flood and erosion effects.

Graphic: House undermined by bluff erosion. Photograph by Lesley Ewing. Courtesy 
of California Coastal Commission.

[End of Fact Sheet No. 11]





Technical Fact Sheet No. 12
Pile Installation
Home Builders Guide to Coastal Construction
FEMA 499/June 2005 

Purpose: To provide basic information about pile design and installation.

Key Issues
--Use a pile type that is appropriate for local conditions.
--Have piles designed by a foundation engineer for adequate layout, size, and 
length.
--Use installation methods that are appropriate for the conditions.
--Brace piles properly during construction.
--Make accurate field cuts, and treat all cuts and drilled holes to prevent 
decay.
--Have all pile-to-beam connections engineered, and use corrosion-resistant 
hardware. (See Fact Sheet No. 8.)

Pile Types
Treated wood piles are the most common type of pile used in coastal 
construction. They can be square or round in cross section. Wood piles are 
easily cut and adjusted in the field and are typically the most economical type. 
Concrete and steel can also be used but are less common. Concrete piles are more 
expensive, but they are stronger and more durable. Steel piles are rarely used, 
because of potential corrosion problems. 

Pile Size and Length
Pile size and length are determined by the foundation engineer. Specified 
bearing and penetration requirements must be met. Piles should have no less than 
an 8-inch tip diameter; minimum timber size should be 8x8. The total length of 
the pile is based on code requirements, calculated penetration requirements, 
erosion potential, Design Flood Elevation (DFE), and allowance for cut-off and 
beam width (see figure at right).

Note: Misaligned piles lead to connection problems. See Fact Sheet No. 13 for 
information about making connections t misaligned piles.

Pile Layout
The pile layout is determined by the foundation engineer. Accurate placement and 
correction of misaligned piles is important. Pile placement should not result in 
more than 50 percent of the pile cross-section being cut for girder or other 
connections. Verify proper pile locations on drawings before construction and 
clarify any discrepancies. Layout can be done by a licensed design professional, 
a construction surveyor, the foundation contractor, or the builder. The layout 
process must always include establishing an elevation for the finished first 
floor. Construction of the first-floor platform should not begin until this 
elevation is established (see Fact Sheet No. 4).

Installation Methods
Piles can be driven, augured, or jetted into place. The installation method will 
vary with soil conditions, bearing requirements, equipment available, and local 
practice. One common method is to initially jet the pile to a few feet short of 
required penetration, then complete the installation by driving with a drop 
hammer.

Pile Bracing
Pile bracing is determined by the foundation engineer. Common bracing methods 
include knee and diagonal bracing. Bracing is often oriented perpendicular to 
the shoreline so that it is not struck broadside by waves, debris, and velocity 
flow (see figure at right). Temporary bracing or jacking to align piles and hold 
true during construction is the responsibility of the contractor.

Graphic: 
--Knee Bracing: 3x or 4x treated wood members at 45 degrees to pile and located 
approximately 4 feet below end of pile (see Fact Sheet No. 13)
--Diagonal Bracing: 2x or 3x treated wood members, or steel rods, attached near 
top of pile and near ground

[Textbox]
To avoid costly pile repairs or replacement, measure, locate, and double-check 
the required pile cutoff elevations before cutting off piles.
[End of Textbox]

Field Cutting and Drilling
A chain saw is the common tool of choice for making cuts and notches in wood 
piles. After making cuts, exposed areas should be field-treated to prevent 
decay. 

Connections
The connection of the pile to the structural members is one of the most critical 
connections in the structure. Always follow design specifications and use 
corrosion-resistant hardware (see Fact Sheet Nos. 8 and 13).

Verification of Pile Capacity
Generally, pile capacity for residential construction is not verified in the 
field. If a specified minimum pile penetration is provided, bearing is assumed 
to be acceptable for the local soil conditions. Subsurface soil conditions can 
vary from the typical assumed conditions, so verification of pile capacity may 
be prudent, particularly for expensive coastal homes. Various methods are 
available for predicting pile capacity. Consult a foundation engineer for the 
most appropriate method for the site.

Additional Resources

American Forest and Paper Association (AF&PA). National Design Specification for 
Wood Construction. (www.afandpa.org)

American Society for Standards and Testing (ASTM). Standard Specification for 
Round Timber Piles, ASTM D25. (www.astm.org)

American Wood-Preservers Association (AWPA). All Timber Products  Preservative 
Treatment by Pressure Processes, AWPA C1-00; Lumber, Timber, Bridge Ties and 

Mine Ties  Preservative Treatment by Pressure Processes, AWPA C2-01; Piles  
Preservative Treatment by Pressure Process, AWPA C3-99; and others. 
(www.awpa.com)

Pile Buck, Inc. Coastal Construction. (www.pilebuck.com)

[End of Fact Sheet No. 12]




Technical Fact Sheet No. 13
Wood-Pile-to-Beam Connections
Home Builders Guide to Coastal Construction
FEMA 499/June 2005 

Purpose: To illustrate typical wood-pile-to-beam connections, provide basic 
construction guidelines on various connection methods, and show pile bracing 
connection techniques.

NOTE: The pile-to-beam connection is one of the most critical links in the 
structure. This connection must be designed by an engineer.  See Fact Sheet No. 
10 for load path information. The number of bolts and typical bolt placement 
dimensions shown are for illustrative purposes only. Connection designs are not 
limited to those shown here, and not all of the information to be considered in 
the designs is included in these illustrations. Final designs are the 
responsibility of the engineer. 

Key Issues
--Verify pile alignment and correct, if necessary, before making connections.
--Carefully cut piles to ensure required scarf depths.
--Limit cuts to no more than 50 percent of pile cross-section.
--Use corrosion-resistant hardware, such as hot-dipped galvanized or stainless 
steel (see Fact Sheet No. 8).
--Accurately locate and drill bolt holes.
--Field-treat all cuts and holes to prevent decay.
--Use sufficient pile and beam sizes to allow proper bolt edge distances.

Pile-to-beam connections must:
1.	provide required bearing area for beam to rest on pile
2.	provide required uplift (tension) resistance
3.	maintain beam in an upright position
4.	be capable of resisting lateral loads (wind and seismic)
5.	be constructed with durable connectors and fasteners

Note: Pile-to-beam connections must be designed by an engineer.

[Textbox]
Problem: misaligned pilessome piles are shifted in or out from their intended 
(design) locations.
Option 1 (see page 3): beam cannot be shifted
Option 2 (see page 3): beam can be shifted laterally and remains square to 
building
Option 3 (see page 3): beam can be shifted laterally, but does not remain square 
to building
Option 4 (not shown): beam cannot be shifted, and connections shown in this fact 
sheet cannot be made; install and connect sister piles; an engineer must be 
consulted for this option
Option 5 (not shown): beam cannot be shifted, and connections shown in this fact 
sheet cannot be made; remove and reinstall piles, as necessary
[End of Textbox]

Note: pile-to-beam connections must be designed by an engineer.

[Textbox]
Connections to misaligned piles (see drawings on page 3 and details below) 
1.	The ability to construct the pile-to-beam connections designed by the 
engineer is directly dependent on the accuracy of pile installation and 
alignment.
2.	Misaligned piles will require the contractor to modify pile-to-beam 
connections in the field.
3.	Badly misaligned piles will require removal and reinstallation, sister 
piles, or special connections, all to be determined by the engineer.
[End of Textbox]

[End of Fact Sheet No. 13]





Technical Fact Sheet No. 14
Reinforced Masonry Pier Construction
Home Builders Guide to Coastal Construction
FEMA 499/June 2005 

Purpose: To provide an alternative to piles in V zones and A zones in coastal 
areas where soil properties preclude pile installation, yet the need for an 
open foundation system still exists. Examples of appropriate conditions for 
the use of piers are where rock is at or near the surface or where the potential 
for erosion and scour is low.

Key Issues
--The footing must be designed for the soil conditions present. Pier foundations 
are generally not recommended in V zones or in A zones in coastal areas.
--The connection between the pier and its footing must be properly designed and 
constructed to resist separation of the pier from the footing and rotation to 
due to lateral (flood, wind, debris) forces.
--The top of the footing must be below the anticipated erosion and scour depth.
--The piers must be reinforced with steel and fully grouted.
--There must be a positive connection to the floor beam at the top of the pier.
--Special attention must be given to the application of mortar in order to 
prevent saltwater intrusion into the core, where the steel can be corroded.

Piers vs. Piles
Graphic:
Piers are subject to upward, downward, and horizontal loads. Pier reinforcement 
and footing size are critical to resisting these loads; therefore, pier and 
footing design must be verified by an engineer.

Pier: used only where the potential for erosion and scour is low or where the 
pier can be anchored to underlying bedrock or other stratum that terminates 
erosion and scour.
Pile: used where the potential for erosion and scour is high.

In coastal areas, masonry pier foundations are not recommended in V zones with 
erodible soils, or in A zones subject to waves and erosionuse pile foundations 
in these areas.

Pier foundations are most appropriate in areas where:
--erosion and scour potential are low,
--flood depths and lateral forces are low, and
--soil can help resist overturning of pier.

The combination of high winds and moist (sometimes salt-laden) air can have a 
damaging effect on masonry construction by forcing moisture into even the 
smallest of cracks or openings in the masonry joints. The entry of moisture into 
reinforced masonry construction can lead to corrosion of the reinforcement steel 
and subsequent cracking and spalling of the masonry. Moisture resistance is 
highly influenced by the quality of the materials and the quality of the masonry 
construction at the site.

Graphic: The small footings on the piers in this photograph did not prevent 
these piers from overturning during Hurricane Iniki.

Good Masonry Practice
--Masonry units and packaged mortar and grout materials should be stored off the 
ground and covered.
--Masonry work in progress must be well protected.
--Mortar and grouts must be carefully batched and mixed. The 2003 International 
Building Code (IBC 2003) specifies grout proportions by volume for masonry 
construction.

Recommendations for Masonry Piers in Coastal Regions
--Head and bed joints must be well mortared and tooled to prevent water 
intrusion. Type S mortar for below grade is recommended. Concave joints and v-
joints provide the best moisture resistance.
--Reinforcing bars must be protected from saltwater to prevent corrosion. Good 
grout practice will normally protect reinforcing. Galvanized or epoxy-coated 
bars may enhance pier performance, but holidays and chipped coatings must be 
painted, and lap splice lengths must be increased by 50 percent for epoxy-coated 
bars.
--Grout should be in conformance with the requirements of the IBC 2003. 
Cleanouts should be placed at the bottom of fully grouted cells to ensure that 
the grout completely fills the cells from top to bottom.

[End of Fact Sheet No. 14]





Technical Fact Sheet No. 15
Foundation Walls
Home Builders Guide to Coastal Construction
FEMA 499/June 2005 

Purpose: To discuss the use of foundation walls in coastal buildings.

Key Issues
--Foundation walls include stemwalls, cripple walls, and other solid walls.
--Foundation walls are prohibited by the National Flood Insurance Program (NFIP) 
in V zones. (read note below)
--Use of foundation walls in A zones in coastal areas should be limited to 
locations where only shallow flooding occurs, and where the potential for 
erosion and breaking waves is low.
--Where foundation walls are used, flood-resistant design of foundation walls 
must consider embedment, height, materials and workmanship, lateral support at 
the top of the wall, flood openings and ventilation openings, and interior grade 
elevation.

Note: Note that the use of shearwalls below the design flood elevation (DFE) may 
be permitted in limited circumstances (e.g., lateral wind/seismic loads cannot 
be resisted with a braced, open foundation. In such cases, minimize the length 
of shearwalls and the degree of obstruction to floodwaters and waves, orient 
shearwalls parallel to the direction of flow/waves, do not form enclosures). 
Consult the authority having jurisdiction for guidance concerning shearwalls 
below the DFE.

Foundation Walls  When Are They Appropriate?
Use of foundation walls  such as those in crawlspace and other solid-wall 
foundations  is potentially troublesome in coastal areas for two reasons: (1) 
they present an obstruction to breaking waves and fast-moving flood waters, and 
(2) they are typically constructed on shallow footings, which are vulnerable to 
erosion. For these reasons, their use in coastal areas should be limited to 
sites subject to shallow flooding, where erosion potential is low and where 
breaking waves do not occur during the Base Flood. The NFIP prohibits the use of 
foundation walls in V zones (read note above). This Home Builders Guide to 
Coastal Construction recommends against their use in many A zones in coastal 
areas. Deeply embedded pile or column foundations are recommended because they 
present less of an obstruction to floodwaters and are less vulnerable to 
erosion.

Graphic: Foundation walls: flood-resistant design considerations

Design Considerations for Foundation Walls
The design of foundation walls is covered by building codes and standards (e.g., 
Standard for Hurricane Resistant Residential Construction, SSTD 10, by the 
Southern Building Code Congress International). For flood design purposes, there 
are six additional design considerations: (1) embedment, (2) height, (3) 
materials and workmanship, (4) lateral support at the top of the wall, (5) flood 
openings and ventilation openings, and (6) interior grade elevation.

Embedment  The top of the footing should be no higher than the anticipated 
depth of erosion and scour (this basic requirement is the same as that for 
piers; see figure at right and Fact Sheet No. 14). If the required embedment 
cannot be achieved without extensive excavation, consider a pile foundation 
instead.

Height  The wall should be high enough to elevate the bottom of the floor 
system to or above the DFE (see Fact Sheet No. 4).

Materials and Workmanship  Foundation walls can be constructed from many 
materials, but masonry, concrete, and wood are the most common. Each material 
can be specified and used in a manner to resist damage due to moisture and 
inundation (see Fact Sheet No. 8). Workmanship for flood-resistant foundations 
is crucial. Wood should be preservative-treated for foundation or marine use 
(aboveground or ground-contact treatment will not be sufficient). Cuts and holes 
should be field-treated. Masonry should be reinforced and fully grouted (see 
Fact Sheet No. 16 for masonry details). Concrete should be reinforced and 
composed of a high-strength, low water-to-cement ratio mix. 

Graphic: Floor slab atop backfilled stemwall foundation. Floor joist system and 
crawlspace.

Lateral Support at the Top of the Wall  Foundation walls must be designed and 
constructed to withstand all flood, wind, and seismic forces, as well as any 
unbalanced soil/hydrostatic loads. The walls will typically require lateral 
support from the floor system and diaphragm, and connections to the top of the 
walls must be detailed properly. Cripple walls, where used, should be firmly 
attached and braced.

Flood Openings and Ventilation Openings  Any area below the DFE enclosed by 
foundation walls must be equipped with openings capable of automatically 
equalizing the water levels inside and outside the enclosure. Specific flood 
opening requirements are included in Fact Sheet No. 27. Flood openings are not 
required for backfilled stemwall foundations supporting a slab. Air ventilation 
openings required by building codes do not generally satisfy the flood opening 
requirement; the air vents are typically installed near the top of the wall, the 
flood vents must be installed near the bottom, and opening areas for air flow 
may be insufficient for flood flow.

Interior Grade Elevation  Conventional practice for crawlspace construction 
calls for excavation of the crawlspace and use of the excavated soil to promote 
drainage away from the structure (see left-hand figure on page 3). This approach 
may be acceptable for non-floodplain areas, but in floodplains, this practice 
can result in increased lateral loads (e.g., from saturated soil) against the 
foundation walls and ponding in the crawlspace area. If the interior grade of 
the crawlspace is below the DFE, NFIP requirements can be met by ensuring that 
the interior grade is at or above the lowest exterior grade adjacent to the 
building (see right-hand figure on page 3). When floodwaters recede, the flood 
openings in the foundation walls allow floodwaters to automatically exit the 
crawlspace. FEMA may accept a crawlspace elevation up to 2 feet below the lowest 
adjacent exterior grade; however, the community must adopt specific requirements 
in order for this type of crawlspace to be constructed in a floodplain.

If a stemwall and floor slab system is used, the interior space beneath the slab 
should be backfilled with compacted gravel (or such materials as required by the 
building code). As long as the system can act monolithically, it will resist 
most flood forces. However, if the backfill settles or washes out, the slab will 
collapse and the wall will lose lateral support.

Graphic: crawlspace construction: interior grade elevation for A zones not 
subject to breaking waves and erosion.

[End of Fact Sheet No. 15]





Technical Fact Sheet No. 16
Masonry Details
Home Builders Guide to Coastal Construction
FEMA 499/June 2005 

Purpose: To highlight several important details for masonry construction in 
coastal areas.

Key Issues
--Continuous, properly connected load paths are essential because of the higher 
vertical and lateral loads on coastal structures.
--Building materials must be durable enough to withstand the coastal 
environment.
--Masonry reinforcement requirements are more stringent in coastal areas.

Load Paths
A properly connected load path from roof to foundation is crucial in coastal 
areas (see Fact Sheets Nos. 10 and 17). The following details show important 
connections for a typical masonry home.

Durability  High winds and salt-laden air can damage masonry construction. The 
entry of moisture into large cracks can lead to corrosion of the reinforcement 
and subsequent cracking and spalling. Moisture resistance is highly dependent on 
the materials and quality of construction.

Quality depends on:
--Proper storage of material  Keep stored materials covered and off the ground.
--Proper batching  Mortar and grout must be properly batched to yield the 
required strength.
--Good workmanship  Head and bed joints must be well mortared and well tooled. 
Concave joints and V-joints provide the best moisture protection (see detail 
above). All block walls should be laid with full mortar coverage on horizontal 
and vertical face shells. Block should be laid using a double butter technique 
for spreading mortar head joints. This practice provides for mortar-to-mortar 
contact as two blocks are laid together in the wall and prevents hairline 
cracking in the head joint.
--Protection of work in progress  Keep work in progress protected from rain. 
During inclement weather, the tops of unfinished walls should be covered at the 
end of the workday. The cover should extend 2 feet down both sides of the 
masonry and be securely held in place. Immediately after the completion of the 
walls, the wall cap should be installed to prevent excessive amounts of water 
from directly entering the masonry.

Reinforcement: Masonry must be reinforced according to the building plans. 
Coastal homes will typically require more reinforcing than inland homes. The 
following figure shows typical reinforcement requirements for a coastal home.

Gable Ends: Because of their exposure, gable ends are more prone to damage than 
are hipped roofs unless the joint in conventional construction at the top of the 
endwall and the bottom of the gable is laterally supported for both inward and 
outward forces. The figure at right shows a construction method that uses 
continuous masonry from the floor to the roof diaphragm with a raked cast-in-
place concrete bond beam or a cut masonry bond beam.

[End of Fact Sheet No. 16]






Technical Fact Sheet No. 26
Shutter Alternatives
Home Builders Guide to Coastal Construction
FEMA 499/June 2005 

Purpose: To provide general information about the installation and use of storm 
shutters in coastal areas.

Why Are Storm Shutters Needed?
Shutters are an important part of a hurricane-resistant or storm-resistant home. 
They provide protection for glass doors and windows against windborne debris, 
which is often present in coastal storms. Keeping the building envelope intact 
(i.e., no window or door breakage) during a major windstorm is vital to the 
structural integrity of a home. If the envelope is breached, sudden 
pressurization of the interior can cause major structural damage (e.g., roof 
loss) and will lead to significant interior and contents damage from wind-driven 
rain.

Graphic: plywood panels are a cost-effective means of protection.

Where Are Storm Shutters Required and Recommended?
Model building codes, which incorporate wind provisions from ASCE 7 (1998 
edition and later), require that buildings within the most hazardous portion of 
the hurricane-prone region, called the windborne debris region (see page 4 of 
this fact sheet), either (1) be equipped with shutters or impact-resistant 
glazing and designed as enclosed structures, or (2) be designed as partially 
enclosed structures (as if the windows and doors are broken out). Designing a 
partially enclosed structure typically requires upgrading structural components 
and connections, but will not provide protection to the interior of the 
building. Designers and owners should assume that a total loss of the building 
interior and contents will occur in partially enclosed structures.

Using opening protection (e.g., shutters or laminated glass) is recommended in 
windborne debris regions, as opposed to designing a partially enclosed 
structure. The Home Builders Guide to Coastal Construction also recommends 
giving strong consideration to the use of opening protection in all hurricane-
prone areas where the basic wind speed is 100 mph (3-second peak gust) or 
greater, even though the model building codes do not require it. Designers 
should check with the jurisdiction to determine whether state or local 
requirements for opening protection exceed those of the model code.

Note: Many coastal homes have large and unusually shaped windows, which will 
require expensive, custom shutters. Alternatively, such windows can be 
fabricated with laminated (impact-resistant) glass.

Graphic: Temporary, manufactured metal panel shutter. The shutter is installed 
in a track permanently mounted above and below the window frame. The shutter is 
placed in the track and secured with wing nuts to studs mounted on the track. 
This type of shutter is effective and quickly installed, and the wing nut and 
stud system provides a secure anchoring method.

What Types of Shutters Are Available?
A wide variety of shutter types are available, from the very expensive motor-
driven, roll-up type, to the less expensive temporary plywood panels (see 
photograph on page 1 of this fact sheet). Designers can refer to Miami-Dade 
County, Florida, which has established a product approval mechanism for shutters 
and other building materials to ensure they are rated for particular wind and 
windborne debris loads (see Additional Resources on page 5 of this fact sheet).

[Table]

Shutter Type: Temporary plywood panels
Cost: Low
Advantages: Inexpensive
Disadvantages: Must be installed and taken down every time they are needed; must 
be adequately anchored to prevent blow-off; difficult to install on upper levels

Shutter Type: Temporary manufactured panels
Cost: Low/Medium
Advantages: Easily installed on lower levels
Disadvantages: Must be installed and taken down every time they are needed; 
difficult to install on upper levels

Shutter Type: Permanent, manual-closing
Cost: Medium/High
Advantages: Always in place. Ready to be closed
Disadvantages: Must be closed manually from the outside; difficult to access on 
upper levels

Shutter Type: Permanent, motor-driven
Cost: High
Advantages: Easily opened and closed from the inside
Disadvantages: Expensive 

[End of Table]			

Shutter Styles
Shutter styles include colonial, Bahama, roll-up, and accordion.

Are There Special Requirements for Shutters in Coastal Areas?
ASCE 7 and the International Building Code (IBC) state that shutters (or 
laminated glazing) shall be tested in accordance with the American Society for 
Testing and Materials (ASTM) standards ASTM E 1886 and ASTM E 1996 (or other 
approved test methods). E 1886 specifies the test procedure; E 1996 specifies 
missile loads. The IBC allows the use of wood panels (Table 1609.1.4) and 
prescribes the type and number of fasteners to be used to attach the panels. A 
shutter may look like it is capable of withstanding windborne missiles; unless 
it is tested, however, its missile resistance is unknown.

When installing any type of shutter, carefully follow manufacturers 
instructions and guidelines. Be sure to attach shutters to structurally adequate 
framing members (see shutter details on page 3 of this fact sheet). Avoid 
attaching shutters to the window frame or brick veneer face. Always use hardware 
not prone to corrosion when installing shutters.

What Are Hurricane-Prone Regions Windborne Debris Regions?
ASCE 7, the IBC, and the International Residential Code (IRC) define hurricane-
prone regions as:
--the U.S. Atlantic Ocean and Gulf of Mexico coasts where the basic wind speed 
is greater than 90 mph (3-second peak gust), and
--Hawaii, Guam, Puerto Rico, the U.S. Virgin Islands, and American Samoa.
ASCE 7, the IBC, and the IRC define windborne debris regions as areas within 
hurricane-prone regions located:
--within 1 mile of the coast where the basic wind speed is equal to or greater 
than 110 mph (3-second peak gust) and in Hawaii, or
--in all areas where the basic wind speed is equal to or greater than 120 mph 
(3-second peak gust), including Guam, Puerto Rico, the U.S. Virgin Islands, and 
American Samoa.

Additional Resources
American Society of Civil Engineers. Minimum Design Loads for Buildings and 
Other Structures, ASCE 7. (http://www.asce.org)

International Code Council. International Building Code. 2003. 
(http://www.iccsafe.org)

International Code Council. International Residential Code. 2003. 
(http://www.iccsafe.org)

The Engineered Wood Association. Hurricane Shutter Designs Set 5 of 5. Hurricane 
shutter designs for wood-frame and masonry buildings. (http://www.apawood.org)

Miami-Dade County, Florida, product testing and approval process  information 
available at http://www.miamidade.gov/buildingcode/pc_home.asp

[End of Fact Sheet No. 26]







Technical Fact Sheet No. 27
Enclosures and Breakaway Walls
Home Builders Guide to Coastal Construction
FEMA 499/June 2005 

Purpose: To discuss requirements and recommendations for enclosures and 
breakaway walls below the Base Flood Elevation (BFE). 

Key Issues
--Spaces below elevated buildings can be used only for building access, parking, 
and storage.
--Areas enclosed by solid walls below the BFE (enclosures) are subject to 
strict regulation under the National Flood Insurance Program (NFIP). Note that 
some local jurisdictions enforce stricter regulations for enclosures.
--Non-breakaway enclosures are prohibited in V-zone buildings. Breakaway 
enclosures in V zones must meet specific requirements and must be certified by a 
registered design professional
--Enclosures (breakaway and non-breakaway) in A-zone buildings must be built 
with flood-resistant materials and equipped with flood openings that allow water 
levels inside and outside to equalize (see Fact Sheet No. 15). 
--For V zones, enclosures below the elevated building will result in higher 
flood insurance premiums.
--Breakaway enclosure walls should be considered expendable, and the building 
owner will incur substantial costs when the walls are replaced.

WARNING: Home builders and homeowners should consider the long-term effects of 
the 
construction of enclosures below elevated residential buildings and post-
construction conversion of enclosed space to habitable use in A zones and V 
zones. 
Designers and owners should realize that (1) enclosures and items within them 
are likely to be destroyed even during minor flood events, (2) enclosures, and 
most items within them, are not covered by flood insurance and can result in 
significant costs to the building owner, and (3) even the presence of properly 
constructed enclosures will increase flood insurance premiums for the entire 
building (the premium rate will increase as the enclosed area increases). 
Including enclosures in a building design can have significant cost 
implications.

This Home Builders Guide to Coastal Construction recommends the use of insect 
screening or open wood lattice instead of solid enclosures beneath elevated 
residential buildings.
[End of Warning]

Space Below the BFE  What Can it Be Used For?
NFIP regulations state that the area below an elevated building can be used only 
for building access, parking, and storage. These areas must not be finished or 
used for recreational or habitable purposes. No mechanical, electrical, or 
plumbing equipment is to be installed below the BFE. 

What Is an Enclosure?
An enclosure is formed when any space below the BFE is enclosed on all sides 
by walls or partitions. A V-zone building elevated on an open foundation (see 
Fact Sheet No. 11), without an enclosure or other obstructions below the BFE, is 
said to be free-of-obstructions, and enjoys favorable flood insurance premiums 
(a building is still classified free-of-obstructions if insect screening or open 
wood lattice is used to surround space below the BFE). See FEMA Technical 
Bulletin 5-93, Free of Obstruction Requirements for more information.

Graphic: breakaway walls that failed under the flood forces of Hurricane Ivan.
Enclosures can be divided into two types, breakaway and non-breakaway. 
--Breakaway enclosures are designed to fail under Base Flood conditions without 
jeopardizing the elevated building  any below-BFE enclosure in a V zone must be 
breakaway. Breakaway enclosures are permitted in A zones but must be equipped 
with flood openings. 
--Non-breakaway enclosures, under the NFIP, can be used in an A zone (they may 
or may not provide structural support to the elevated building), but they must 
be equipped with flood openings to allow the automatic entry and exit of 
floodwaters. The Home Builders Guide to Coastal Construction recommends their 
use only in A zone areas subject to shallow, slow-moving floodwaters without 
breaking waves.

Graphic: open wood lattice installed beneath an elevated house in a V zone.

Breakaway Walls
Breakaway walls must be designed to break free under the larger of the design 
wind load, the design seismic load, or 10 psf, acting perpendicular to the plane 
of the wall. If the loading at which the breakaway wall is intended to collapse 
exceeds 20 psf, the breakaway wall design must be certified. When certification 
is required, a registered engineer or architect must certify that the walls will 
collapse under a water load associated with the Base Flood and that the elevated 
portion of the building and its foundation will not be subject to collapse, 
displacement, or lateral movement under simultaneous wind and water loads. (See 
the sample certification at the bottom of page 2 of Fact Sheet No. 5.) Utilities 
should not be attached to or pass through breakaway walls.

Graphic: recommended breakaway wall construction. [diagram]

Flood Openings
Where permitted and used in A zones, foundation walls and enclosures must be 
equipped with openings that allow the automatic entry and exit of floodwaters.

Note the following:
--Flood openings must be provided in at least two of the walls forming the 
enclosure.
--The bottom of each flood opening must be no more than 1 foot above the 
adjacent grade outside the wall.
--Louvers, screens, or covers may be installed over flood openings as long as 
they do not interfere with the operation of the openings during a flood.
--Flood openings may be sized according to either a prescriptive method (1 
square inch of flood opening per square foot of enclosed area) or an engineering 
method (which must be certified by a registered engineer or architect).

Details concerning flood openings can be found in FEMA Technical Bulletin 4-93, 
Openings in Foundation Walls.

Other Considerations
Enclosures are strictly regulated because, if not constructed properly, they can 
transfer flood forces to the main structure (possibly leading to structural 
collapse). There are other considerations, as well:
--Owners may be tempted to convert enclosed areas below the BFE into habitable 
space, leading to life-safety concerns and uninsured losses. Construction 
without enclosures should be encouraged. Contractors should not stub out 
utilities in enclosures; utility stub-outs make it easier for owners to finish 
and occupy the space.
--Siding used on non-breakaway portions of a building should not be extended 
over breakaway walls. Instead, a clean separation should be provided so that any 
siding installed on breakaway walls is structurally independent of siding 
elsewhere on the building. Without such a separation, the failure of breakaway 
walls can result in damage to siding elsewhere on the building. 
--Breakaway enclosures in V zones will result in substantially higher flood 
insurance premiums (especially where the enclosed area is 300 square feet or 
greater). Insect screening or lattice is recommended instead. 
--If enclosures are constructed in A zones with the potential for breaking 
waves, open foundations with breakaway enclosures are recommended in lieu of 
foundation walls or crawlspaces. If breakaway walls are used, they must be 
equipped with flood openings that allow flood waters to enter the enclosure 
during smaller storms. Breakaway enclosures in A zones will not lead to higher 
flood insurance premiums.
--Garage doors installed in below-BFE enclosures of V-zone buildings  even 
reinforced and high-wind-resistant doors  must meet the performance requirement 
discussed in the Breakaway Walls section on page 2 of this fact sheet. 
Specifically, the doors must be designed to break free under the larger of the 
design wind load, the design seismic load, or 10 psf, acting perpendicular to 
the plane of the door. If the loading at which the door is intended to collapse 
is greater than 20 psf, the door must be designed and certified to collapse 
under Base Flood conditions. See the Breakaway Walls section of this fact sheet 
for information about certification requirements.

Graphic: Siding on the non-breakaway portions of this elevated building was 
extended over breakaway enclosure walls and was damaged when breakaway walls 
failed under flood forces.

[End of Fact Sheet No. 27]





Technical Fact Sheet No. 29
Protecting Utilities
Home Builders Guide to Coastal Construction
FEMA 499/June 2005 

Purpose: To identify the special considerations that must be made when 
installing utility equipment in a coastal home.

Key Issues: Hazards, requirements, and recommendations
Special considerations must be made when installing utility systems in coastal 
homes. Proper placement and connection of utilities and mechanical equipment can 
significantly reduce the costs of damage caused by coastal storms and will 
enable homeowners to reoccupy their homes soon after electricity, sewer, and 
water are restored to a neighborhood.

Coastal Hazards That Damage Utility Equipment
--Standing or moving floodwaters
--Impact from floating debris in floodwaters
--Erosion and scour from floodwaters
--High winds
--Windborne missiles

Common Utility Damage in Coastal Areas
Floodwaters cause corrosion and contamination, short-circuiting of electronic 
and electrical equipment, and other physical damage.

Electrical  Floodwaters can corrode and short-circuit electrical system 
components, possibly leading to electrical shock. In velocity flow areas, 
electrical panels can be torn from their attachments by the force of breaking 
waves or the impact of floating debris.

Water/Sewage  Water wells can be exposed by erosion and scour caused by 
floodwaters with velocity flow. A sewage backup can occur even without the 
structure flooding.

Fuel  Floodwaters can float and rupture tanks, corrode and short-circuit 
electronic components, and sever pipe connections. In extreme cases, damage to 
fuel systems can lead to fires.

[Textbox]
Elevation of utilities and mechanical equipment is the preferred method of 
protection.
[End of Textbox]

Basic Protection Methods
The primary protection methods are elevation or component protection.

Elevation
Elevation refers to the location of a component and/or utility system above the 
Design Flood Elevation (DFE). 

Component Protection
Component protection refers to the implementation of design techniques that 
protect a component or group of components from flood damage when they are 
located below the DFE.

NFIP Utility Protection Requirements
The NFIP regulations [Section 60.3(a)(3)] state that:
All new construction and substantial improvements shall be constructed with 
electrical, heating, ventilation, plumbing, and air conditioning equipment and 
other service facilities that are designed and/or located so as to prevent water 
from entering or accumulating within the components during conditions of 
flooding.


Utility Protection Recommendations

Electrical
--Limit switches, wiring, and receptacles below the DFE to those items required 
for life safety. Substitute motion detectors above the DFE for below-DFE 
switches whenever possible. Use only ground-fault-protected electrical outlets 
below the DFE.
--Install service connections (e.g., electrical lines, panels, and meters; 
telephone junction boxes; cable junction boxes) above the DFE, on the landward 
side of interior piles or other vertical support members.
--Use drip loops to minimize water entry at penetrations.
--Never attach electrical components to breakaway walls.

Water/Sewage
--Attach plumbing risers on the landward side of interior piles or other 
vertical support members.
--When possible, install plumbing runs inside joists for protection. 
--Never attach plumbing runs to breakaway walls.

Graphic: Recommended installation techniques for electrical and plumbing lines 
and other utility components. [diagram]

HVAC
--Install HVAC components (e.g., condensers, air handlers, ductwork, electrical 
components) above the DFE.
--Mount outdoor units on the leeward side of the building.
--Secure the unit so that it cannot move, vibrate, or be blown off its support.
--Protect the unit from damage by windborne debris.

Graphic: Elevated air conditioning compressors.

Fuel
--Fuel tanks should be installed so as to prevent their loss or damage. This 
will require one of the following techniques: (1) elevation above the DFE and 
anchoring to prevent blowoff, (2) burial and anchoring to prevent exposure and 
flotation during erosion and flooding, (3) anchoring at ground level to prevent 
flotation during flooding and loss during scour and erosion. The first method 
(elevation) is preferred.
--Any anchoring, strapping, or other attachments must be designed and installed 
to resist the effects of corrosion and decay.


Additional Resources
American Society of Civil Engineers. Flood Resistant Design and Construction 
(SEI/ASCE 24-98). (http://www.asce.org)

FEMA. NFIP Technical Bulletin 5-93, Free-Of-Obstruction Requirements for 
Buildings Located in Coastal High Hazard Areas. 
(http://www.fema.gov/fima/techbul.shtm)

FEMA. Protecting Building Utilities From Flood Damage. FEMA 348. November 1999. 
(http://www.fema.gov/hazards/floods/lib06b.shtm)

[End of Fact Sheet No. 29]