SpanFinder.com.au
A plain-English guide to dead load, live load and why heavier decking or finishes can change joist and bearer span-table results.
Dead load is the permanent weight of the deck structure and finishes. In a span table, heavier dead load generally means the member has less spare capacity for span.
Live load is the imposed load from people, furniture and use. Some deck span tables use different live-load assumptions depending on deck height, use and source document rules.
SpanFinder separates dead-load selection from deck height so the user can understand why span results change.
Deck dead load is the permanent weight of decking boards, framing and fixed materials carried by the joists and bearers.
Generally yes. Higher dead load can reduce the allowable span in published tables.
No. Dead load is permanent weight. Live load is imposed loading from people, furniture and use.
Many span tables list dead-load bands or assume a nominated dead load. Always check the notes in the source table.
If unsure, choosing a heavier dead-load band may be conservative for preliminary comparison, but final design must follow the source table.