The 2009 International Residential Code has new provisions concerning the attachment of decks to homes. Most significant in this is the new hold-down tension device requirement of R502.2.2.3. This device is illustrated below and will certainly add construction costs to deck addition projects due to the invasive nature of the interior tension device attachment.
From the 2009 IRC:
R502.2.2 – Decks.
Where supported by attachment to an exterior wall, decks shall be positively anchored to the
primary structure and designed for both vertical and lateral loads as applicable. Such attachment
shall not be accomplished by the use of toenails or nails subject to withdrawal. Where positive
connection to the primary building structure cannot be verified during inspection, decks shall be
self-supporting. For decks with cantilevered framing members, connections to exterior walls or
other framing members, shall be designed and constructed to resist uplift resulting from the full
live load specified in Table R301.5 acting on the cantilevered portion of the deck.
R502.2.2.1 -Deck ledger connection to band joist.
For decks supporting a total design load of 50 pounds per square foot [40 pounds per square foot
live load plus 10 pounds per square foot dead load], the connection between a deck ledger of
pressure-preservative-treated Southern Pine, incised pressure-preservative-treated Hem-Fir or
approved decay-resistant species, and a 2-inch nominal lumber band joist bearing on a sill plate
or wall plate shall be constructed with 1/2-inch lag screws or bolts with washers in accordance
with Table R502.2.2.1. Lag screws, bolts and washers shall be hot-dipped galvanized or stainless
steel.
R502.2.2.3 – Deck lateral load connection.
The lateral load connection required by Section R502.2.2 shall be permitted to be in accordance
with Figure R502.2.2.3. Hold-down tension devices shall be installed in not less than two
locations per deck, and each device shall have an allowable stress design capacity of not less
than 1500 pounds (6672 N).
