CHAPTER 45 COASTAL AND FLOOD PLAIN …

1 CHAPTER 45 COASTAL AND FLOOD PLAIN construction STANDARDSSECTION 4501 PURPOSE, APPLICATION AND SCOPEThe requirements set forth in this CHAPTER shall apply to all con-struction located within areas identified by governmental agen-cies (state and federal) as COASTAL high hazard areas, oceanhazard areas, the regulatory FLOOD PLAIN areas, and all areas des-ignated as 130 mph (57 m/s) wind zone [see Table (1)].SECTION Sea Level as defined by National Geodetic Verti-cal FLOOD peak water elevation inrelation to MSL expected to be reached during a FLOOD having aone percent chance of being equaled or exceeded in any HIGH HAZARD area, as identifiedby the North Carolina COASTAL Resources Commission, near theshoreline of the Atlantic Ocean which are subject to at least oneof the following hazards: (A) Historical or predicted futuretrends of long term erosion, (B) erosion expected to occur dur-ing a COASTAL storm reaching the base FLOOD elevation, or (C)shoreline fluctuations due to tidal below base FLOOD elevation, which hasin the past been flooded by storm water-surface runoffs or tidalinflux, as defined by the Corps of Engineers maps, the FederalEmergency Management Agency maps or as determined by theBuilding Code lowest floor of the lowest enclosedarea (including basement).

2 An unfinished or FLOOD resistant en-closure, usable solely for parking of vehicles, building accessor storage in an area other than a basement area is not consid-ered a building s lowest floor; the walls are substantially impermeable to the pas-sage of water and the structural components have the ca-pability of resisting hydrostatic and hydrodynamic loadsand effects of buoyancy, shall be designed to automatically equalizehydrostatic FLOOD forces on exterior walls by allowing theentry and exit of FLOOD 4503 PILING one- and two- family dwellings in areas identified ascoastal high hazard areas or ocean hazard areas shall be con-structed on a pile foundation of wood or Concrete piles may be used if madeand installed in accordance with North Carolina State BuildingCode, General construction , CHAPTER Size of wood timber piles shall not be lessthan 8 inches (203 mm)in diameter at building level and have aminimum tip diameter of 6 inches (152 mm).

3 Square timberpiles shall not be less than 8 inches square, ( m2) supporting uncovered stairs, uncovered stairs, uncoveredwalkways and uncovered decks shall be 6-inch by 6-inch (152mm by 152 mm) minimum, or if round, have a minimum tip di-ameter of 6 inches (152 mm). Piles supporting uncoveredstairs, uncovered walkways and uncovered decks less than 5feet (1524 mm) above grade may be 4-inch by 4-inch (102 mmby 102 mm) Required depth of tip shall extend to adepth of not less than 8 feet below the natural grade or finishedgrade of the lot whichever is lower. All pilings within theOcean Hazard Area shall have a tip penetration of at least below mean sea level or 16 feet (406 mm) below averageoriginal grade whichever is least. Structures within OceanHazard Areas which are placed upon the site behind a line 60times the annual erosion rate, as determined by the Division ofCoastal Management, away from the most seaward line of sta-ble natural vegetation area are exempt from this additional tippenetration Spacing of wood maximum center-to-cen-ter spacing of wood piles shall not be more than 8 feet on centerunder load bearing sills, beams, or girders.

4 However, fordwellings having more than two stories above piles or wherethe piling spacing exceeds 8 feet (2438 mm) , the pile foun-dation shall be designed by a registered design spacing in the nonload bearing direction may be 12 feet(3658 mm). Tieing and bracing and wood sills, beams, orgirders are attached to the piling, a minimum of two5/8-inchgalvanized steel bolts per beam member shall be throughbolted at each piling connection. Piling shall not be notched sothat the cross-section is reduced below 50 percent. Sills,beams, or girders may be attached using3/16-inch by 4-inch by18 inch hot dip galvanized straps, each side, bolted with two1/2-inch galvanized through bolts (see Figure ). Bracingof pile foundations is required where the clear height fromground to sill, beam, or girder exceeds 10 feet or the dwelling ismore than one story above piles. A line of X-bracing is definedas a row of piles with X-bracing provided in at least 2 bays.

5 Aline of X-bracing shall be provided at all exterior pile the perimeter lines of X-bracing exceed 40 feet, an addi-tional line of X-bracing shall be provided near the center of thebuilding (see Figure ). X-bracing shall be with 2 10'sthrough bolted with two3/4-inch bolts at each end. The buildinginspector may accept bracing designs if they bear the seal of aregistered design minimum net retention of preservatives shall be inaccordance with Section may be placed by auger, jetting, or drop shall receive a final set by drop hammer or other ap-2006 NORTH CAROLINA residential CODE3073082006 NORTH CAROLINA residential CODECOASTAL AND FLOOD PLAIN construction STANDARDSFor SI: 1 inch = mm, 1 foot = (SHOWING POSSIBLE ARRANGEMENT OF X BRACING IN LINE) (G AND H SIMILAR)proved methods, determined by the Building Inspector to in-sure compaction of material at end 4504 ELEVATION lowest structural member excluding pilings andbracing supporting the lowest habitable floor in the coastalhigh hazard area and ocean hazard area, shall be elevated abovethe base FLOOD elevation of the first habitable floor of all structuresin the Regulatory FLOOD PLAIN except in the COASTAL high hazardareas shall be above the base FLOOD .

6 This requirement does not apply to the addition,renovation or reconstruction to any building which was con-structed prior to the Federal Emergency ManagementAgency (FEMA), initial FLOOD Insurance Study for that areaif the addition, renovation or reconstruction does not exceed50 percent of the present market value of the walls are constructed below FLOOD elevation in aCoastal high Hazard Area and Ocean Hazard Area, they shallbe constructed in a manner to eliminate wave forces on the 4505 construction MATERIALS AND requirements of Sections through applicable in the COASTAL High Hazard Area, the OceanHazard Area, and all areas designated as 130 mph (57 m/s)wind rafter or roof truss shall be anchored to the bear-ing wall as required by Section 4408. At the ridges, rafters shallhave a minimum 1 6 or 2 4 collar or wind beam. Every thirdrafter not to exceed 4 feet (1219 mm) shall be anchored ver-tically with a minimum 1 6 or 2 4 from its midpoint to ceil-ing joists Wood frame wall stud spac-ing shall be 16 inches for 2 4s and 24 inches for 2 Section 4405 for wall construction requirements (see Sec-tion 4408 for uplift anchorage requirements).

7 Wood structuralpanel sheathing including endwall sheathing shall extend 12inches (305 mm) beyond construction joints and shall overlapgirders their full depth. Panels may be installed with face graineither parallel or perpendicular to or better methods of tieing structures togetherand to foundations designed for a specific building by a Profes-sional Engineer or Architect shall be accepted by the the COASTAL Hazard Area and the Ocean Hazard Area,all metal connectors and fasteners outside of conditionedspaces shall not be hot dip galvanized steel after fabrication andshall meet ASTM A 153. Exposed metal connectors, such astie-down straps on porches, decks, and areas under the struc-ture shall be a minimum of3/16inch thick, and shall be hot dipgalvanized after fabrication and meet ASTM A 123 or ASTMA 153. Stainless steel light-gage metal connectors shall be per-mitted in exposed or partially exposed locations. Metal con-nectors of approved equivalent corrosion resistant materialshall be accepted (see Table ).

8 Building masonry buildings, the roof structure, including raf-ters and joists shall be securely anchored to the wall perSection All mortar used for masonry wallsshall be Type M or masonry or wood frame buildings, all sills, beams orgirders which resist uplift (including interior sills,beams, girders, and joists where the perimeter is unen-closed) shall be securely anchored to the footing per Sec-tion 4404. Footing dowel bars shall have an 8 inch (203mm) wood partitions and masonry walls join, the studabutting the masonry shall be double and bolted to themasonry with three1/2inch galvanized NORTH CAROLINA residential CODE309 COASTAL AND FLOOD PLAIN construction STANDARDSTABLE RESISTANCE(Applies only to Structure Located in COASTAL High Hazard Areas and Ocean Hazard Areas)Open (exterior, porches,underhouse)Exposure Level Vented/Enclosed (attic, floor trusses,enclosed crawl spaces and stud cavity)Conditioned(heated/cooledliving areas)Nails, staples, screwsHot dip galvanizedHot dip galvanized-Nuts, bolts, washers, tie rodsHot dip galvanizedHot dip galvanized-Steel connection plates &straps (3/16" minimumthickness)

9 Hot dip galvanized afterfabricationHot dip galvanized-Sheet metal connectors, windanchors, joists hangers, steeljoists and beamsStainless steel or hot dippedgalvanized after fabricationHot dip galvanized after plate fabricationHot dipgalvanizedTruss platesStainless steel or hot dippedgalvanized after fabricationHot dip galvanized after fabrication or stainless steelwithin 6'-0" of a gable louver or soffit vent. Otherwisein accordance with TPI-95 of the Truss Plate InstituteStandardgalvanizedFor SI:1 inch = and wooden columns and posts, including porchcolumns shall be anchored with metal ties and bolts totheir foundations to and to the members which they Roof devices shall be hot dip galvanized after fabri-cation or be of other corrosion resistant butts or tabs on roof shingles shall be securely spot-ted or tabbed with plastic fibrous, asphaltic cement, oranchored by clips or locks. The use of seal-o-matic roof-ing may be used as the equivalent of this two or more layers of roll or built-up roofing areapplied, the deck shall be thoroughly mopped before theanchor sheet is nailed to the sheathing with sheet metalcaps and nails not over 12 inches (305 mm) in eachdirection and 6 inches (152 mm)

10 Along edges and additional sheet above the anchor sheet shall bemopped and finished with corrosion resistant cappingaround edges of the roof covering shall be Class A or Class B covering, orClass C asphalt installed in floors in buildingselevated on pilings shall be held in place with plywood with ex-terior glue or other material approved by the building Accessory accessory structuresand out buildings shall be bolted to their foundation or other-wise constructed so as to prevent overturning during NORTH CAROLINA residential CODECOASTAL AND FLOOD PLAIN construction STANDARDS2006 NORTH CAROLINA residential CODE311 COASTAL AND FLOOD PLAIN construction STANDARDSFor SI: 1 inch = (a)TWO-STORY WALL SECTION (TYPICAL)3122006 NORTH CAROLINA residential CODECOASTAL AND FLOOD PLAIN construction STANDARDSFIGURE (b)TWO-STORY WALL SECTION (TYPICAL)