3. Joists must bear at least 3 inches nominal onto beams, unless joist hangers are used in accordance with section 7.
4. Joists may overhang past the center of the beam up to one-fourth of the actual joist span.
5. Provide full-depth 2x blocking or bridging for 2”x10” or deeper joists at intervals not exceeding 8 feet – except the blocking can be reduced to 60% of the height if placed above a beam, for drainage purposes. Attach the blocking or bridging with (3)10d toe-nails at each end.
6. Attach a continuous rim joist as shown in Figures 5 and 7 unless blocking or bridging is provided for each joist at the beam where a joist overhang begins. Attach the rim joist to the end of each joist with (3)10d nails or (3)#10 by 3-inch wood screws.
Figure 5
JOISTS WITH DROPPED BEAM – DECK ATTACHED AT HOUSE
Figure 6
JOISTS WITH FLUSH BEAM – DECK ATTACHED AT HOUSE
Figure 7
(See section 10 for more information.)
Table 4
SECTION 6: JOIST - TO - BEAM CONNECTIONS
Joists must be attached to beams in accordance with Figure 8 and all of the following:
1.
Use Options 1 or 2 if joists bear on a dropped beam.
2. Use Option 3 if joists bear at a flush beam; see section 7 for hanger requirements.
3. Mechanical fasteners or hurricane clips must have a minimum capacity of 100 pounds in both uplift and lateral directions. Installation must be in accordance with the manufacturer's instructions.
Figure 8
JOIST-TO-BEAM CONNECTIONS
SECTION 7: JOIST HANGERS
Joist hangers must comply with all of the following:
1.
The joist-hanger depth (d, as shown in Figure 9) must be at least 60 percent of the joist depth.
2. The manufactured width of the joist hanger must accommodate the number of plies being carried.
3. Do not bend hanger flanges to accommodate field conditions.
4.
For joist hangers that are fastened to a ledger board, screws which are recommended by the manufacturer must be used. All other fasteners are permitted to be nails. The number of fasteners and the manner in which they are used must be as specified by the manufacturer.
5. Use joist hangers with inside flanges if clearances to the edge of the beam or ledger board dictate.
6. Clip-angles or brackets used to support framing members in lieu of joist hangers are prohibited.
7. Joists must not frame in from both sides of the same beam. Engineering analysis is needed if more beams are needed than are shown in Figures 5 to 7.
8.
Each joist hanger must have the minimum capacity listed in Table 5.
Figure 9
JOIST HANGERS
Table 5
JOIST HANGER DOWNLOAD
SECTION 8: LEDGER ATTACHMENTS
General requirements. Ledger boards must be attached to the existing house in accordance with all of the following and section 9. Compliance is critical to ensure the safety and structural stability of your deck.
1.
The ledger-board depth must be greater than or equal to the depth of the deck joists, but not less than a 2”x8”.
2.
The ledger board must be attached in accordance with one of the conditions shown in Figures 11 through 13 – except if metal-plate-connected wood floor trusses were used in the house, see the text below for manufactured wood trusses.
3.
The existing band board on the house must be capable of supporting the deck. If this cannot be verified or if existing conditions differ from the details here, then a free-standing deck or an engineered design is required.
4.
The top of the ledger board and the top of the deck joists must be at the same elevation.
Wood I-joists. Many homes are constructed with wood I-joists, as shown in Figure 10. Rather than utilize a 2x band board, these systems are often constructed with a minimum 1-inch-thick engineered wood product
(EWP) band board capable of supporting a deck. If a minimum 1-inch EWP or 2x band board is not present, then a free-standing deck is required, as addressed in section 10.
Manufactured wood trusses. A metal-plate-connected wood truss (MPCWT) is an engineered, prefabricated structural component that is designed for each specific application. MPCWT systems that are used in residential floors are often installed - See PDF for diagram 
with a 2”x4” lumber “ribbon” board at the ends of the trusses to tie the ends of the trusses together (see Detail 1 in Appendix C.). The ribbon board, by itself, is not intended to support the deck ledger and deck. Installing a residential deck where the floor for the house uses a MPCWT system must be in accordance with a standard detail provided by the truss designer, a corresponding detail in section 7 of Appendix C, or a full plan submission – unless the deck is free-standing as addressed in section 10.
Siding and flashing.
Flashing must be installed in accordance with all of the following:
1.
The exterior finish, such as house siding, must be removed in the area for the ledger board prior to the installation of the ledger board.
2. Continuous flashing with a drip edge, as shown in Figure 11, is required at a ledger board that is attached to wood-framed construction. Caulking is needed with the flashing at a threshold to prevent water intrusion due to splash from the deck or due to melting snow and ice.
3.
Flashing must be a corrosion-resistant metal having a minimum nominal 0.019-inch thickness – such as galvanized steel coated with 1.85 ounces of zinc per square foot (G-185 coating), copper (attached using copper nails only), or stainless steel – or must be a UV-resistant plastic recommended by its manufacturer for this use. Do not use aluminum in direct contact with lumber treated with preservatives that contain copper, such as ACQ, copper azole, or ACZA.
Figure 11
ATTACHMENT OF LEDGER BOARD TO BAND BOARD OR BAND JOIST
Figure 12
ATTACHMENT OF LEDGER BOARD TO SOLID FOUNDATION
Figure 13
ATTACHMENT OF LEDGER BOARD TO HOLLOW FOUNDATION
Prohibited ledger attachments. Attaching a ledger board to or through an exterior veneer such as brick or stone, or to or through a masonry chimney, or to a house overhang – as shown below – are prohibited. In such cases, the deck must be free-standing, as addressed in section 10. Attaching a ledger board to a house overhang is allowed if supported by engineering.
Figure 14
PROHIBITED LEDGER ATTACHMENTS
SECTION 9: LEDGER-BOARD FASTENERS
General requirements. Ledger board fasteners must be installed in accordance with this section. Placement and spacing must be in accordance with Figure 15 and Table 6. Only the fastener types listed here are approved for use; lead anchors are prohibited. Adequacy of connections may be verified by local inspectors.
Figure 15
LEDGER BOARD FASTENER SPACING AND CLEARANCES
Table 6
1These values are valid for deck ledgers consisting of douglas fir/larch, hem/fir, or southern pine; and for band boards consisting of douglas fir-larch, hem-fir, spruce-pine-fir, southern pine, or engineered wood product (EWP).
