Building a Freestanding Deck
Q: When building a deck, is it necessary to fasten the deck ledger board to the house, or can I build a freestanding deck?
A: Check with your local building codes. In many cases, a freestanding deck is acceptable if they meet certain requirements. Freestanding decks do not utilize the exterior wall of the existing house to support vertical loads. Instead, an additional cantilevered beam with posts located near the house wall provides the support. In some cases, the footings for the deck posts should be placed at the same elevation as the existing house footing, if located closer than 5 feet to an existing house wall. For houses with basements, a cylindrical footing is recommended to minimize excavation at the basement wall. Additionally, diagonal bracing should be used both parallel and perpendicular to the beam at each post. Furthermore, it may be required that a freestanding deck should be fastened to the existing house exterior wall, usually via the rim joist just like a ledger board, complying with the same lag screw (or thru-bolt) and flashing requirements.