Starter bars

Starter bars are reinforcing bars left projecting from a footing or slab so they can lap into the column, wall, or slab cast above, providing structural continuity between two separate concrete pours. They are how the reinforcement carries load across a construction joint that the concrete alone cannot.

Concrete gets poured in stages, footing first, then the column or wall on top, so the steel has to be made continuous across the joint. Starter bars do that: they are cast into the lower pour in the right position and projecting the right length, then the bars of the element above lap over them. Without starters (or with them in the wrong place), the column or wall is just sitting on the footing with no tension connection, which fails the design.

Three things have to be right:

• Position: starters must come up exactly where the column/wall bars will be, set out from the drawings before the lower pour. Bars cast in the wrong spot cannot simply be bent across.
• Projection (lap) length: they must project far enough to develop the required lap with the bars above, per AS 3600.
• Bond and cover: they must stay clean and correctly covered, not bent over and walked on, then straightened (re-bending can crack the bar).

For a builder and steel fixer the practical points are to set the starters out accurately and tie them firmly so they do not move during the pour, to protect the projecting ends (capped for safety, kept clean), and never to relocate or re-bend a mis-set starter without the engineer, because the lap and position are what make the connection work. A column of starters in the wrong place is an engineer’s fix, not a site bend.

Also known as: Starters, dowel bars (loosely), connection bars.

Category: Concrete / Reinforcement.

Related

• Steel fixer
• Lap length

See also

• Footing

References

• AS 3600 Concrete structures, Standards Australia (verified 2026-06-03)

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Last updated: 2026-06-03. Verified: 2026-06-03. Quarterly review for currency.