§ 8-99. Technical amendment to the Florida Building Code, Residential related to flood-resistant construction.

R322 FLOOD RESISTANT CONSTRUCTION

R322.2.1 Elevation requirements.

1.

Buildings and structures in flood hazard areas not designated as Coastal A Zones shall have the lowest floors elevated to or above the base flood elevation plus 1 foot or the design flood elevation, whichever is higher.

2.

Buildings and structures in flood hazard areas designated as Coastal A Zones shall have the lowest floors elevated to or above the base flood elevation plus 1 foot (305 mm), or to the design flood elevation, whichever is higher.

3.

In areas of shallow flooding (AO Zones), buildings and structures shall have the lowest floor (including basement) elevated at least as high above the highest adjacent grade as the depth number specified in feet on the FIRM plus 1 foot, or at least 3 feet if a depth number is not specified.

4.

Basement floors that are below grade on all sides shall be elevated to or above the base flood elevation plus 1 foot or the design flood elevation, whichever is higher. Exception: Enclosed areas below the design flood elevation, including basements whose floors are not below grade on all sides, shall meet the requirements of Section R322.2.2.

R322.2.2 Enclosed areas below design flood elevation. Enclosed areas, including crawl spaces, that are below the design flood elevation shall:

1.

Be used solely for parking of vehicles, building access or storage. The interior portion of such enclosed area shall not be partitioned or finished into separate rooms except for stairwells, ramps, and elevators. The limitation on partitions does not apply to crawlspace foundations.

R322.3.2 Elevation requirements.

1.

All buildings and structures erected within coastal high-hazard areas shall be elevated so that the lowest portion of all structural members supporting the lowest floor, with the exception of mat or raft foundations, piling, pile caps, columns, grade beams and bracing, is:

1.1 Located at or above the base flood elevation plus 1 foot or the design flood elevation, whichever is higher, if the lowest horizontal structural member is oriented parallel to the direction of wave approach, where parallel shall mean less than or equal to 20 degrees (0.35 rad) from the direction of approach, or

1.2 Located at the base flood elevation plus 2 feet, or the design flood elevation, whichever is higher, if the lowest horizontal structural member is oriented perpendicular to the direction of wave approach, where perpendicular shall mean greater than 20 degrees (0.35 rad) from the direction of approach.

2.

Basement floors that are below grade on all sides are prohibited.

3.

The use of fill for structural support is prohibited.

4.

Minor grading, and the placement of minor quantities of fill, shall be permitted for landscaping and for drainage purposes under and around buildings and for support of parking slabs, pool decks, patios and walkways.

Exception: External walls enclosing areas below the design flood elevation shall meet the requirements of Sections R322.3.4 and R322.3.5.

R322.3.4 Walls below design flood elevation. Walls are permitted below the elevated floor, provided that such walls are not part of the structural support of the building or structure and:

1.

Electrical, mechanical, and plumbing system components are not to be mounted on or penetrate through walls that are designed to break away under flood loads; and

2.

Are constructed with insect screening or open lattice; or

3.

Are designed to break away or collapse without causing collapse, displacement or other structural damage to the elevated portion of the building or supporting foundation system. Such walls, framing and connections shall have a design safe loading resistance of not less than 10 (470 Pa) and no more than 20 pounds per square foot (958 Pa); or

4.

Where wind loading values of this code exceed 20 pounds per square foot (958 Pa), the construction documents shall include documentation prepared and sealed by a registered design professional that:

4.1 The walls below the design flood elevation have been designed to collapse from a water load less than that which would occur during the design flood.

4.2 The elevated portion of the building and supporting foundation system have been designed to withstand the effects of wind and flood loads acting simultaneously on all building components (structural and nonstructural). Water loading values used shall be those associated with the design flood. Wind loading values used shall be those required by this code.

R322.3.5 Enclosed areas below the design flood elevation. Enclosed areas below the design flood elevation shall be used solely for parking of vehicles, building access or storage. The interior portion of such enclosed area shall not be partitioned or finished into separate rooms except for stairwells, ramps, and elevators.

(Ord. No. 2017-41, § 1, 12-12-17)