How to Build a Freestanding Deck
A freestanding deck is a self-supporting deck structure built independently from a house wall ledger board attachment. Some freestanding decks stand alone in an open area. Above-ground pool decks are often built freestanding in this fashion.
Some decks can't be attached directly to the house using ledger boards because of a house cantilever or a brick veneer. In other cases, such as stuccoed houses, many builders prefer to build a freestanding deck to avoid the mess and difficulty of cutting and flashing stucco. Some older houses may be built with uncertain wall construction that may not be strong enough to support a deck addition. These decks can be built freestanding using an additional beam and posts situated next to the house wall. It is important that these frost footings are installed on top of compacted soil to prevent them from sinking. Many new houses have unsettled soil surrounding the house foundation that was backfilled during construction. You may be required to install these footings below the house foundation.
Freestanding decks greater than 2 feet above grade must be able to resist lateral and horizontal movement by providing diagonal bracing. Because there isn't a house to anchor one end of the deck, uplift and racking forces are greater issues that must be addressed in the structural design. Diagonal bracing in the form of 4x4s bolted between the support posts and the beams at 45-degree angles can help resist movement on the deck parallel to the house. Diagonal decking and sway bracing installed under the joists can reduce racking forces. Buried support posts can help brace the deck and resist uplift from strong winds that could tip a freestanding deck over.