Lead Sizing Comparison: A Simple Guide
Lead colour codes are the correct BSEN 12588:2006 references. The over-specification saving shows how much heavier the old numeric lead code is versus the minimum usable thickness in that range.
| Colour | Colour code | Old numeric | Thickness (mm) | Typical use | Overspec saving |
|---|---|---|---|---|---|
| Code Green | Code 3 | 1.25 to 1.32 | Soakers |
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| Code Yellow New | No equivalent | 1.50 to 1.59 | Flashings |
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| Code Blue | Code 4 | 1.75 to 1.80 | Flashings & sheet |
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| Code Red | Code 5 | 2.00 to 2.24 | Sheet |
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| Code Black | Code 6 | 2.50 to 2.65 | Sheet |
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| Code White | Code 7 | 3.00 to 3.15 | Sheet |
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| Code Orange | Code 8 | 3.50 to 3.55 | Sheet |
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| No colour code | No equivalent | 4.00 / 5.00 / 6.00 | Specified by thickness |
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Saving calculated as (max thickness − min thickness) / max thickness. Standard: BSEN 12588:2006. Code Yellow lead has no imperial equivalent but can be used to replace blue 'code 4' lead in certain circumstances. Thicknesses above 3.55mm are specified by thickness only.