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How to fix reinforcing steel

Updated: 23 October 2026

The bars are in the garage, the concrete is ordered, and the steel is still lying on the soil. That position has no cover. How to fix reinforcing steel, for a short straight pack, means chairs that hold a stated gap, ties that stop the cage walking, and a cut that does not cook the bar. The lap length comes from the drawing, not from a forum multiple of the diameter. The seven amazon.co.uk packs are on the [reinforcing steel comparison](/hub/diy-supplies/reinforcing-steel). This page does not rank them. Products Compared used the Concrete Society and LABC, and did not cast a test pour. A purchase through our links may earn a commission at no extra cost to you.

The bars are in the garage, the concrete is ordered, and the steel is still lying on the soil. That position has no cover.

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Just The Job Supplies Just The Job 8 mm bar, 10 × 1 m

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Just The Job Supplies Just The Job 8 mm bar, 10 × 1 m
9.2/10about £25.20
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Just The Job Supplies Just The Job 10 mm bar, 2 × 1 m

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Just The Job Supplies Just The Job 10 mm bar, 2 × 1 m
9.0/10about £12.26
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Just The Job Supplies Just The Job 12 mm bar, 5 × 450 mm

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Just The Job Supplies Just The Job 12 mm bar, 5 × 450 mm
9.0/10about £15.32
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On this page
  1. 1.Cover is a spacer, not a guess
  2. 2.Ties keep the bar where you put it
  3. 3.Cut and bend without damaging the bar
  4. 4.Where a short straight pack runs out

Cover is a spacer, not a guess

Cover is the concrete between the bar and the face that weather or soil will meet. The Concrete Society's figures are at least 40 mm on blinding and at least 75 mm cast against soil. LABC matches those two cases, and also prints 50 mm for external shuttered work and 25 mm internal. That table is not the enforcing body's decision. If the drawing names a different cover, the drawing wins. The trench bottom is not a chair. Plastic spacers suit a bar size and a cover. Steel chairs suit larger floors and may need a coating. Guidance points spacers to BS 7973. Put them in before the pour and keep people off the steel. Whether the footing should have bar at all is on reinforcing steel for foundations.

Ties keep the bar where you put it

Ties hold the pattern. They are not the strength of the pour. The Concrete Society describes 16 gauge annealed wire, or proprietary clips. Crop the tails so they do not steal cover. A loose cage will walk when the poker hits it. A lap passes force from one length to the next, and it comes from the design. About 35 times the diameter, or 40 times, is a forum figure, not the standard. This page does not print a lap in millimetres. If the drawing is silent, ask. Wire will not rescue oily, muddy, or flaking bar. Tight rust on self-colour steel can be acceptable in concrete. Flaky rust, oil, mud, and lost section are not.
Just The Job Supplies Just The Job 8 mm bar, 10 × 1 m

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Just The Job Supplies Just The Job 8 mm bar, 10 × 1 m
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Cut and bend without damaging the bar

The Concrete Society says bolt croppers can cut smaller bar up to about 12 mm, and that larger bar needs a shearing machine. About 12 mm is that source's limit, not a promise on a rusty end. Except for the smallest diameters, bending belongs on a machine, and small links need a BS 8666 former. Do not heat a bar to bend it. Prefer a rebar cutter. An HSENI comparison, reported through NISG, found a cutter lowest for noise, vibration, and dust, because it shears. A grinder needs a guard, two hands, and a clamped bar. Shared reviews report jagged or twisted ends. Do not drive a twisted end as if it were a pin.

Where a short straight pack runs out

Every pack here is straight 450 mm or 1 m bar. You can crop one shorter if the drawing is that simple. You cannot torch it into a link or a cage corner and still claim the grade. A scheduled shape should arrive cut and bent. Stop when the job is a lived-in foundation, a failed wall, B500C or stainless on the drawing, or any shape that needs a former. Stainless, where specified, is BS 6744. A 1 m pack avoids a long lift and still does not design the footing.

Common questions

Is 40 mm the cover against soil, or the cover on blinding?
Forty millimetres is the Concrete Society's minimum when concrete is cast on blinding, and it matches LABC's row for blinding or a membrane. Cast against soil, both sources publish at least 75 mm. LABC's 50 mm and 25 mm rows are for external shuttered work and internal work. The drawing, or the enforcing body, can ask for more. LABC says its table is not that decision.
Does tying wire add strength?
No. Sixteen-gauge annealed wire, or a proprietary clip, holds the bars where you placed them. The concrete and the bar do the structural work. A tie is not a lap. The lap length is a design length, and this page does not substitute a multiple of the diameter for that drawing.
Can you cut a 12 mm bar with bolt croppers, and what about a larger bar?
The Concrete Society says bolt croppers can cut smaller bar up to about 12 mm, and that larger bar needs a shearing machine. Treat about 12 mm as their limit, not as a guarantee on a damaged end. A rebar cutter that shears is the better first tool. A grinder needs a guard, two hands, and a clamped bar if you use one at all.
Can you heat the bar to bend it?
Do not. Site bending, except for the smallest diameters, belongs on a bending machine, and small links need a BS 8666 former. Heat is a way to damage the bar, not a way to make a hook. If the shape is on a schedule, order it cut and bent rather than altering straight 1 m stock.
At what point should a fixer stop and use a cut-and-bent schedule?
Stop when the shape is not a straight bar you can crop to length: links, hooks, and cage corners. Also stop for a lived-in foundation, a failed wall, or a drawing that specifies B500C or stainless. A short amazon.co.uk pack is straight bar. It does not become a schedule because you own croppers.

Related pages

Reinforcing steel buying guide

Reinforcing steel or mesh

Reinforcing steel

Best reinforcing steel bar for a short posted pack

Reinforcing steel for foundations and plain strips

Sources

Public UK sources and the amazon.co.uk listings compared on this page. Updated 23 October 2026.

  1. CARES specification guide (retrieved 23 October 2026)
  2. CARES bar mark (retrieved 23 October 2026)
  3. Concrete Centre: European standards for reinforcement (retrieved 23 October 2026)
  4. LABC: reinforcement in foundations (retrieved 23 October 2026)
  5. Concrete Society: cover to concrete cast against the ground (retrieved 23 October 2026)
  6. Concrete Society: reinforcement contamination and rust (retrieved 23 October 2026)
  7. Approved Document A (retrieved 23 October 2026)
  8. Next Day Steel: 10 mm rebar (retrieved 23 October 2026)
  9. The Metal Store: reinforcing bar (retrieved 23 October 2026)
  10. HSENI via NISG: alternatives to grinding (retrieved 23 October 2026)