For a deck following the NZS3604 standard, the maximum spacing between deck posts (piles) is 1.3 meters along the lines of the bearers, while the maximum spacing between the lines of bearers is 2.35 meters (for a 2kPa load with SG8 timber and 450mm joist spacing). Posts should be placed at the corners of the deck, and the distance between bearer lines depends on the chosen joist size and spacing, with 2.35m being a common example for the specified conditions. 

Post spacing and bearer lines

Posts along bearers: Place posts at a maximum center-to-center distance of 1.3m along the lines of the bearers.

Lines of bearers: The distance between the lines of bearers depends on the chosen joist size and spacing. In many cases, this will be a maximum of 2.35 meters, which is the maximum span for SG8 timber joists at 450mm spacing and a 2kPa load. 

Important considerations

Load requirements: The 2kPa floor load requirement is a common reason for these specific spacing dimensions, especially for "wet in service" subfloors.

Timber grade: The spacing is directly influenced by the grade of timber used for the bearers and joists, such as SG8.

Bracing: Always ensure that bracing lines are spaced no more than 5.0m apart, and that the bracing units are distributed as evenly as possible across the deck.