All hardware (e.g., joist hangers, hold-down devise, etc.) shall be galvanized or shall be stainless steel. Hardware to be hot-dipped prior to fabrication shall meet ASTM A653 – Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process, G-185 coating. Hardware to be hot-dipped galvanized after fabrication shall meet ASTM A123 – Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products.
Fasteners and hardware exposed to saltwater or located within 300' of a salt water shoreline shall be stainless steel grade 304 or 316.
Fasteners and hardware shall be of the same corrosion-resistant material.
Other coated or non-ferrous fasteners or hardware shall be as approved by the authority having jurisdiction.
4. Install flashing at top of ledger for water tightness. Flashing shall be corrosion-resistant metal of minimum nominal 0.019” thickness or an approved non-metallic material. Do not use aluminum flashing in direct contact with lumber treated with preservatives containing copper, such as ACQ, Copper Azole or ACZA.
5. Two-ply 2x4 truss end verticals, 4x4 truss vertical webs and key-blocks connected to ledger with lag screws or bolts shall have a specific gravity, G = 0.42 (includes DF, HF, SP and SPF).
Construct key-blocks with minimum 2x4 No. 2 or better lumber.
Install key-blocks at required locations. Cut to fit tight.
Refer to Detail 1 and Detail 2 for additional information concerning key-block construction and attachment.
Detail 1: Attachment of Deck Ledger to Floor System with MPCW Trusses
- See PDF for table 
Table 1: Deck Ledger Connection to Ends of MPCW Floor Trusses Spaced 24” o.c., Max.1,2,3
(Deck Live Load = 40 psf, Deck Dead Load = 10 psf, Snow Load < 40 psf)
- See PDF for table
Table 2: Deck Ledger Connection to Ends of MPCW Floor Trusses Spaced 24” o.c., Max.1,2,3
(Deck Live Load = 60 psf, Deck Dead Load = 10 psf, Snow Load < 60 psf)
Detail 2: Attachment of Deck Ledger to Floor System with MPCW Trusses,
When Ledger is Installed Parallel to Truss Span & Spacing of Screws is Less Than the Spacing of the Verticals
-
See PDF for table
Table 3: Deck Ledger Connection to Side of MPCW Floor Ladder Frame with 4s4 Vertical Webs Spaced at 16” o.c., Max.1,2,3
(Deck Live Load = 40 psf, Deck Dead Load = 10 psf, Snow Load < 40 psf)
- See PDF for table
Table 4: Deck Ledger Connection to Side of MPCW Floor Ladder Frame with 4x4 Vertical Webs Spaced at 16” o.c., Max.
1,2,3
(Deck Live Load = 60 psf, Deck Dead Load = 10 psf, Snow Load < 60 psf)
Detail 3: Deck Lateral Load Connection Capable of Resisting the 1500 lbf Lateral Load Requirement
Specified in 2009 & 2012 IRC Section 507
Findings:
Nailing deck ledgers to metal plate connected wood truss floor systems is not sufficient. The deck ledger must be attached to the truss or key-block with lag screws or bolts. Various options and connection details for achieving the connection of the deck ledger to the metal plate connected wood truss floor system are provided in this report, which may be referred to by the building designer to achieve a code-conforming deck ledger connection.
IBC Section 104.11 and IRC Section R104.11 (IFC Section 104.9 is similar) state:
104.11 Alternative materials, design and methods of construction and equipment. The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. An alternative material, design or method of construction shall be approved where the building official finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, at least the equivalent of that prescribed in this code. … Where the alternative material, design or method of construction is not approved, the building official shall respond in writing, stating the reasons the alternative was not approved. - See PDF for diagram
This research report is subject to periodic review and revision. For the most recent version of this report, visit sbcindustry.com. For information on the current status of this report, contact SBCA.
References and Substantiating Data:
Anderson, C.A., Woeste, F.E. and Loferski, J.R. 2003; Manual for the Inspection of Residential Wood Decks and Balconies; Forest Products Society, 2801 Marshall Ct., Madison, WI 53705.
ANSI/AWC NDS-2012, ASD/LRFD NDS®;
National Design Specification for Wood Construction. 2012; American Wood Council, 222 Catoctin Circle, SE, Suite 201, Leesburg, VA 20175.
Carradine, D.M., Bender, D., Loferski, J.R. and Woeste, F.E. 2005; Residential Deck Ledger Design; Building Safety Journal, December, 2005: (4-7).
Carradine, D.M., Bender, D., Loferski, J.R. and Woeste, F.E. 2006; Residential Deck Ledger Connection Testing and Design; Structure Magazine, May, 2008: (53-56).
Design for Code Acceptance, DCA 6, Prescriptive Residential Wood Deck Construction Guide; 2009; American Wood Council, 222 Catoctin Circle, SE, Suite 201, Leesburg, VA 20175.
Loferski, J.R., Woeste, F.E., Caudill, R., Platt, T. and Smith, Q. 2004; Load-Tested Deck Ledger Connections; Journal of Light Construction. 22(6):71-78.
Woeste, F.E. 2008; Safe and Durable Coastal Decks; Coastal Contractor, March/April, 2008: (1-7).
