Rebar Spacing and Cover: The Details That Decide Durability
Wholesale, mill-certified reinforcing steel — export-direct at mill prices.
Why cover matters most
Concrete cover — the distance from the bar to the surface — is the single biggest durability control. Too little and chlorides/carbonation reach the steel early; too much and crack widths grow. Codes set minimum cover by exposure class (e.g. 25 mm internal, 50 mm+ marine). It’s guaranteed on site by correctly sized spacers and chairs.
Bar spacing rules
Spacing has minimums (so concrete and aggregate flow around bars and bond develops — typically ≥ bar diameter or aggregate size + a margin) and maximums (to control crack width and distribute reinforcement). Congested joints may need bundled bars or a coupler instead of laps to keep spacing workable.
Getting it built right
Detailing is only as good as the fixing: specify spacer type and frequency, chair heights for top mats, and tie every intersection needed for stability. We supply the full accessory range — spacers, chairs, tie wire and couplers — so the design cover and spacing survive the pour.
FAQ
What is concrete cover to rebar?
The distance from the bar surface to the concrete face — the primary durability control, set by exposure class.
What is minimum rebar spacing?
Enough for concrete/aggregate to flow and bond to develop — commonly at least the bar diameter (or aggregate size + margin), per code.
How is cover guaranteed on site?
With correctly sized spacers and chairs holding the bars at the specified distance from the formwork.
Need spacers & accessories at export prices?
Send sizes, tonnage and destination — written wholesale quote against today’s mill schedule within 24 hours. See Spacers & Accessories, all products and export & delivery.
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