Span Table FAQs

A deck span table or span chart shows the maximum allowable span for a joist, bearer or beam under stated loading, spacing, support and use conditions. SpanFinder helps compare those source-table results, but the original manufacturer table remains the final reference.

Joist span is the distance a joist spans between supports. Bearer span is the distance a bearer or beam spans between posts, piers, walls or other supports.

FLW means floor load width. It is the width of deck or floor area that loads onto a bearer or beam. A larger FLW usually means a heavier loaded bearer and a shorter allowable span.

For preliminary checks, use the tributary joist length feeding into the bearer. Edge bearers usually carry load from one side, while internal bearers may carry load from both sides.

Yes. Closer joist spacing usually reduces the load carried by each joist, but the allowable span still needs to be checked against the relevant product span table.

Usually, if posts directly support a bearer, the distance between posts is the bearer span. Complex layouts, cantilevers and offsets may need a more detailed review.

Dead load is the permanent weight of materials such as decking, framing and sheeting. Live load is the imposed load from people, furniture and use of the deck or floor area.

Single span usually means one clear span between two supports. Continuous span usually means the member runs over one or more intermediate supports, which can change the allowable span in the source table.

NS commonly means no suitable span or not suitable for that exact table condition. Always check the source table notes because abbreviations can vary by manufacturer.

No. SpanFinder is a preliminary comparison tool. Final selections should be checked against current source tables, project conditions, NCC requirements, Australian Standards and engineering advice where required.

It compares preliminary steel, LVL and timber options for Australian residential floor joists, floor bearers and single-storey wall/roof bearer cases using published source span tables.

Floor joist span is the distance a floor joist spans between supports such as bearers, walls or beams. The allowable span depends on joist size, spacing, dead load, live load and span type.

Floor bearer span is the distance a bearer spans between posts, piers, walls or supports. Bearer span tables often use floor load width to account for the floor area carried by the bearer.

The first floor calculator release is built around a 1.5 kPa residential floor live-load basis, with source rows matched by scenario, dead load, spacing, floor load width and span type.

A heavier floor dead load generally reduces the allowable span. SpanFinder only shows products where the source table dead-load allowance satisfies the selected floor condition.

Floor load width is the width of floor area carried by the bearer. For simple layouts it is related to the supported joist span or tributary floor width feeding into the bearer.

Roof load width is used for bearer checks where a floor bearer also supports a single-storey load-bearing wall and roof load. It helps match the selected condition to wall/roof-bearing source tables.

Some bearer tables separate sheet roof and tiled roof cases because the roof mass changes the load carried by the wall and bearer below.

A result bubble only appears when that material group has a source-backed product row matching the selected scenario and load conditions. If a source does not support the case, it is not displayed.

Not yet. Double-storey wall-bearing bearer checks are held as a coming soon feature so the first release can focus on floor-only and single-storey wall/roof-bearing cases.