UK Lintel Sizes — Steel & Concrete
Steel lintels, concrete lintels and timber lintels with span tables, bearing requirements and cavity widths for UK construction.
Standard Steel Lintel Lengths
Steel lintels are manufactured in standard lengths. The lintel length = opening width + (2 x bearing). Common Catnic/IG sizes:
| Lintel Length (mm) | Max Opening (mm) | Bearing Each End |
|---|---|---|
| 600 | 300 | 150 mm |
| 750 | 450 | 150 mm |
| 900 | 600 | 150 mm |
| 1200 | 900 | 150 mm |
| 1500 | 1200 | 150 mm |
| 1800 | 1500 | 150 mm |
| 2100 | 1800 | 150 mm |
| 2400 | 2100 | 150 mm |
| 2700 | 2400 | 150 mm |
| 3000 | 2700 | 150 mm |
| 4800 | 4500 | 150 mm |
Steel Lintel Types
| Type | Application | Cavity Widths | Typical Load |
|---|---|---|---|
| Standard cavity | Windows and doors, outer + inner leaf | 50–100 mm | Standard domestic |
| Heavy-duty cavity | Wide openings, heavy loads | 50–100 mm | Heavy or wide spans |
| Single leaf (angle) | Inner leaf only, internal walls | N/A | Inner leaf or partition |
| Box lintel | Wide openings, high loads | 50–100 mm | Patio doors, bi-folds |
Prestressed Concrete Lintels
| Section (mm) | Lengths (mm) | Typical Use | Approx. Weight (kg/m) |
|---|---|---|---|
| 65 x 100 | 600–1800 | Internal partitions, non-load-bearing | ~15 |
| 65 x 140 | 600–2400 | Inner leaf, light loads | ~21 |
| 100 x 140 | 600–3000 | Inner leaf, standard loads | ~33 |
| 100 x 215 | 600–3600 | Heavy loads, deep openings | ~50 |
Related Calculators
See the UK Brick Dimensions for coursing around lintels, or the UK Block Sizes for inner leaf dimensions.
How We Calculate This
Frequently Asked Questions
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Last updated: April 2026
All calculations are estimates. Verify with your supplier.