Continuous Load Path Provided with Connections from the Roof through the Wall to the Foundation

The Compliance tab contains both program and code information. Code language is excerpted and summarized below. For exact code language, refer to the applicable code, which may require purchase from the publisher.

2018 and 2021 International Residential Code (IRC)

Table R602.3(3) specifies minimum fastening (nailing) requirements for various components of wood frame construction, including: roof rafter or roof truss to wall top plate; wall bottom plate to floor framing; floor framing to sill or top plate below; wood structural panels for subfloors, walls, and roofs.

R602.3 Design and construction.

R602.3.5 Braced wall panel uplift load path.

R602.10.1.3 Spacing of braced wall lines.

R602.10.2.1 Braced wall panel uplift load paths.

Retrofit:  2009, 2012, 2015, 2018,  and 2021 IRC

Section R102.7.1 Additions, alterations, or repairs. Additions, alterations, renovations, or repairs shall conform to the provisions of this code, without requiring the unaltered portions of the existing building to comply with the requirements of this code, unless otherwise stated. (See code for additional requirements and exceptions.)

Appendix J regulates the repair, renovation, alteration, and reconstruction of existing buildings and is intended to encourage their continued safe use.

2018 International Building Code 

Section 2304.10 Connectors and fasteners requirements

Section 2304.10.6 Load paths

IBHS FORTIFIED Home Hurricane Standard

FORTIFIED Gold Designation Requirements Section

Appendix D has provisions for corrosion protection retrofit requirements.

IBHS FORTIFIED Home High Wind Standard

FORTIFIED Gold Designation Requirements Section

The prescriptive measures required by the FORTIFIED Home High Wind standard for new homes in high wind areas are shown below. These measures are in addition to the normal fastening schedules of the IRC:

IBHS Fortified Home New Home High Wind Standard: Prescriptive Requirements

Prescriptive Measures for one-story or two-story buildings where the distance between shear walls is less than or equal to 2.5 times the building width.

In addition to the normal fastening schedules specified in Table R602.3(1) of the 2006 or later edition of the International Residential Code (IRC)—except for roof and wall sheathing nailing patterns which are replaced by the following minimum requirements when they are more stringent than local code requirements—the following minimum fastening and reinforcing requirements are provided as a prescriptive method for providing a qualified FORTIFIED Home High Wind Continuous Load Path (CLP).

1. Roof framing system with roof sheathing and sheathing attachment constructed to meet or exceed the following minimum requirements:
   1. Minimum 7 ⁄16-in.-thick wood structural panels
   2. Sheathing attached in accordance with one of the following fastening schedules:
      1. 8d common nails or 10d box nails at 4 in. o.c. on all roof framing members
      2. 8d ring-shank nails at 6 in. o.c. on all roof framing members
   3. Roof structure
      1. If trusses–Engineered trusses designed for minimum Vasd= 110 mph 3- second gust (ASD) design wind loads for terrain Exposure B.
      2. If rafter system: 
         1. Collar ties on all rafter pairs
         2. Rafters sized for span and Vasd= 110 mph 3-second gust (ASD) design wind loads for terrain Exposure B
         3. Install strap, with the minimum capacity listed in Table 9, over top of ridge board connecting tops of rafter pairs.
2. Anchor roof structure to exterior wall below using metal straps following the requirements listed below:
   1. Metal straps connecting roof structure to exterior wall system at all wall-to-roof framing connections (trusses and rafters) sized to meet the load requirements of Table 8.
   2. If wall sheathing is used to transfer loads from top plate in wood frame walls to studs, metal straps connecting the trusses/rafters to the top plate of the wall must be on the same side as the sheathing or additional metal connectors are required to transfer loads from the wall top plate to the wall studs and they must be located on the same side of the top plate as the metal straps connecting the trusses or rafters to the top plate.
   3. Metal straps from trusses/rafters with the minimum capacity listed in Table 8 can be used to connect directly to wall studs in wood frame walls below if they align vertically within 1½ in.
   4. Wood frame roof structures on masonry walls must be connected to reinforced bond beam at the top of the wall using embedded metal straps that meet the load requirements of Table 8.
3. Interior shear walls (wood frame walls sheathed with wood structural panels on either side, reinforced masonry walls, or other shear walls, depending on the type of construction) are required when the building length is more than 2.5 times its width. Shear walls must be located at intermediate locations between the end walls so that the distance between shear walls (end or interior shear walls) is never greater than 2.5 times the building’s width.
4. Exterior wall and interior shear wall (if needed) construction:
   1. Wood frame exterior walls must be fully sheathed including areas above or below wall openings with minimum 7 ⁄16-in. wood structural panels. Interior shear walls must be fully sheathed including areas above or below wall openings with minimum 7 ⁄16-in. wood structural panels on both wall faces. Wall sheathing shall be attached to the wall framing using the following:
      1. For one-story building or top story of two-story building, wood structural panels shall be fastened to the wall studs with 8d common nails, 10d box nails or 8d ring-shank nails at a minimum of 6 in. o.c. along all edges and 12 in. o.c. to framing members in the field of the panels.
      2. For bottom story of two-story building, wood structural panels shall be fastened to the wall studs with 8d common nails, 10d box nails or 8d ringshank nails at a minimum of 3 in. o.c. along all edges and 12 in. o.c. to framing members in the field of the panels.
   2. Masonry exterior walls and interior shear walls must have bond beams with two (2) #5 bars continuous or lapped at least 25 in. Bond beams must be tied together at corners and at the intersection of interior shear walls with the exterior walls with a minimum 25-in. lap on either side of the corner. The bond beam on interior shear walls shall be continuous across the width of the building. Vertical wall reinforcing shall be tied into the bond beam with a minimum 7½-in. hook. All vertical reinforcing shall be continuous or be lapped at least 25 in. to provide adequate development length. Vertical reinforcing (minimum #5 bars) in masonry walls shall be at all corners, on both sides of openings more than 6 ft wide and not more than 8 ft apart along wall segments without openings. Alternatively, reinforcing may be designed using masonry design standards for Vasd= 110 mph 3-second gust ASD design wind loads for terrain Exposure B.
   3. Other wall systems must be built following minimum design requirements for Vasd= 110 mph 3-second gust (ASD) design wind loads for terrain Exposure B and the roof structural system must be adequately anchored to the wall system using connectors with the minimum capacities provided in Table 9.
5. For multi-story wood frame buildings, load bearing exterior wall systems above and below each floor system shall be connected so that loads pass from the wall system above the floor to the wall system below the floor using one of the following methods to achieve the uplift capacities outlined in Table 9.
   1. Install metal straps that connect wall studs from the wall above to wall studs in the wall below or from wall studs above to the rim board and from the rim board to the wall studs below. Straps can be installed on each stud or at some other convenient spacing not to exceed 8 ft. For example, a 24-ft roof span with straps installed at 4-ft spacing, the required capacity of the strap would be 680 lb (170 lb multiplied by 4-ft spacing).
   2. Use continuous sheathing (minimum 4 ft) that spans across the floor depth to connect the upper wall to the lower wall with the specified number of nails listed in Table 10 in the wall studs above the floor and wall studs below the floor. Nail spacing along the studs shall not be less than 3 in.
6. Strapping is required at ends of openings in wood frame exterior walls when openings are greater than 3 ft wide:
   1. Strap double top plate to king stud using strapping with 840 lb capacity at each end of opening.
   2. Strap double top plate to header at 16 in. o.c. using strapping with 420 lb capacity at each connection.
   3. Strap end of header to jack stud using strapping with 840 lb capacity at each end of header.
   4. Connect king/jack stud to foundation using strapping with capacity of 1,700 lb at each end of opening.
7. Anchor floor system and exterior walls to foundation using 5 ⁄8-in.-diameter anchor bolts with 3-in. x 3-in. x ¼-in.-thick plate washers using the appropriate spacing described below:
   1. For slab-on-grade, 24-in. spacing of anchor bolts and within 12 in. of the end of plate. For raised floor foundation including stem-wall foundations:
      1. 72-in. spacing for a one-story structure along exterior walls in long direction of building
      2. 56-in. spacing for a two-story structure along exterior walls in long direction of building
      3. 36-in. spacing for a one-story structure along exterior walls (and interior shear walls if present) in short direction (across width) of building
   2. 24-in. spacing for a two-story structure along exterior walls (and interior shear walls if present) in short direction (across width) of building.
   3. Note: Alternative connections can be developed using guidance provided in Section 2.2 of the American Forest and Paper Association, American Wood Council “Guide to Wood Construction in High Wind Areas for One- and Two-Family Dwellings 110 MPH Exposure B Guide.” If using an alternate method, a description of the connection size and spacing including appropriate references to the American Forest and Paper Association, American Wood Council “Guide to Wood Construction in High Wind Areas for One- and Two-Family Dwellings 110 MPH Exposure B Guide” must be provided to the FORTIFIED Home Evaluator.
8. Hold-downs connecting exterior walls and interior shear walls to foundation shall be installed as indicated below:
   1. For one-story wood frame construction, hold-downs with a minimum allowable capacity of 3,490 lb (for an 8 ft wall height; 4,360 lb for a 10 ft wall height) must be installed at the exterior corners of the building and at the ends of any interior shear walls where they connect to the exterior walls.
   2. For the top story of two-story wood frame construction, straps or hold-downs with a minimum capacity of 3,490 lb for an 8 ft wall height (4,360 lb for a 10 ft wall height) are required at each exterior corner and each intersection of an interior shear wall with the exterior wall that connect the corner stud system of the wall above to the corner stud system of the wall below.
   3. For the bottom floor of a two-story wood frame building, hold-downs with a minimum allowable capacity of the sum of the required capacity for each story must be installed at the exterior corners of the building and at the ends of any interior shear walls where they connect to the exterior walls. For a second-story wall height of 8 ft and a first-story wall height of 10 ft, the required hold-down capacity for the bottom floor would be 3,490 lb plus 4,360 lb = 7,850 lb.
9. Blocking shall be installed at floor deck edges in the first 2 joist or truss bays from exterior walls for edges where walls are parallel to floor joists or floor trusses. Blocking shall be spaced a maximum of 4 ft o.c. and connected using three (3) 16d nails at each end and two (2) 16d nails through the floor sheathing above. For a second-floor-level floor system, a strap with a minimum capacity of 200 lb shall be installed so that it wraps the outside edge of the double top plate of the wall below and is connected to the bottom of the blocking in the first bay.
10. Gable end bracing is required for systems not using balloon framing or walls with continuous reinforcing to the roof deck level. For wood frame roof structure, install continuous 2x4-in. lateral brace at ceiling from gable end truss to opposite end of attic at 6 ft o.c. Each lateral brace to have a minimum 20 gauge metal strap connected to the lateral brace that also wraps over bottom chord of gable end wall plate/truss, over the top plate of wall below and is connected to stud in wall below or to bond beam if wall is masonry construction. Strap to be fastened with ten (10) 8d nails at each end of strap for wood frame wall below or by masonry screws to bond beam for masonry wall below. Blocking (2- x 4-in.) must be added in bay between gable wall framing and first ceiling joist or truss and attached to bottom of lateral brace with four (4) 10d nails.

Table 7. Required Minimum Capacities for Ridge Straps Connecting Pairs of Rafters Based on Roof Span and 24-in. Spacing between Rafters (Source: IBHS High Wind Standard).

Table 8. Roof-to-Wall Connector Minimum Capacities Based on Roof Span and 24-in. Spacing between Rafters or Trusses. (Source: IBHS High Wind Standard).

Table 9. Floor-to-Floor Connection Loads per Ft of Wall Length Based on Roof Span. (Source: IBHS High Wind Standard).

Table 10. Number of 8d Common, 10d Box or 8d Ring-Shank Nails in Each Stud Required to Transfer Loads from Studs in Wall Above to Studs in Wall below Based on Roof Span Indicated and a Stud Spacing of 16 in. (Source: IBHS High Wind Standard).