A finished deck is a connected system. Surface boards transfer load to joists, beams, posts and footings. Connections and lateral support help those parts work together.
Footings and posts
Footing size and depth depend on the site, soil, loads and applicable requirements. Foundations should not be chosen from a photo or a generic rule.
Ledger and flashing
Where a deck connects to a house, the supporting structure and water protection matter. Some walls and claddings are not suitable for a standard ledger attachment. An alternative support design may be needed.
Beams, joists and spans
Span tables rely on assumptions such as lumber species, grade, spacing and loads. Values cannot be transferred blindly between projects. A non-ledger deck in DCA6 is not automatically a fully freestanding deck.
Lateral support
Vertical supports alone do not describe the complete load path. Bracing, ties and their connections require coordinated details.
Stairs and guards
Geometry, landings, lighting, handrails and guard attachments are planned together. Product instructions and the approved local details govern the finished work.
Materials and special conditions
Composite surfaces need product-specific support and fastening. Pools, hot tubs, multi-level layouts and unusual loads require additional evaluation.
Reference and scope
This overview draws on the American Wood Council DCA6 guide based on the 2015 IRC. It is educational background, not a construction plan or a statement of current local code. DCA6’s stated scope excludes hot tubs and certain snow-load conditions. Check current state and local requirements, approved plans and manufacturer instructions for your project.
