What is a lintel?
A lintel is a horizontal beam above an opening in a wall (such as a door or window) that supports the weight of the masonry above and transfers it to the sides. Without a lintel, the masonry above the opening would collapse. Every door and window opening in a load-bearing wall requires a lintel.
How does a lintel work?
A wall is strong under compression, but an opening interrupts the load path. The lintel forms a bridge over the opening:
- The weight of the masonry above the opening presses on the lintel
- The lintel transfers this load to the wall sections on either side of the opening (the reveals)
- The bearing length on each side must be at least 10 cm — more for heavier loads
Types of lintels
Concrete lintel (precast)
The most commonly used lintel in new construction. A prefabricated reinforced concrete beam. Available in standard sizes and easy to install.
Steel lintel
For large openings or heavy loads, a steel profile (U- or I-section) is used. Steel lintels are slimmer than concrete lintels at the same load-bearing capacity.
Brick lintel (soldier course)
An arch or straight row of bricks laid on edge above the opening. A traditional method, nowadays mainly decorative.
Timber lintel
In timber frame construction or lighter structures, a timber beam is used as a lintel. Suitable for non-load-bearing walls or lighter constructions.
Lintel for a garage or renovation
When building a garage, the lintel is crucial:
- Garage door opening — A wide opening (often 2.4 to 3 metres) with a lot of masonry above. A strong lintel is necessary here, often steel.
- Windows and personnel door — Smaller openings where a standard concrete lintel suffices.
When renovating and breaking through a wall or enlarging an opening:
- First place temporary supports (props)
- Build in the new lintel with sufficient bearing length
- Only then remove the masonry below the lintel
- Remove the props only after the mortar has cured
> Note: For load-bearing walls, a structural engineer must calculate the lintel. A lintel that is too light can cause cracks in the wall or worse.
Choosing dimensions
The required size depends on:
- Width of the opening — The wider, the stronger the lintel must be
- Load above — How much masonry or floor sits above the opening
- Type of wall — Cavity wall, half-brick, or full-brick
Rule of thumb for a concrete lintel in a half-brick wall:
| Opening | Lintel size (indication) |
|---|---|
| Up to 1.0 m | 100 x 65 mm |
| 1.0 – 1.5 m | 100 x 100 mm |
| 1.5 – 2.0 m | 100 x 135 mm |
| Over 2.0 m | Steel or structural engineer calculation |
Common mistakes
- Too little bearing — The lintel must rest at least 10 cm on the wall on each side
- No lintel in internal wall — Internal walls can also be load-bearing. Always check.
- Lintel placed upside down — Some concrete lintels have a top and bottom. Check the markings.
Related terms
- Window frame
- Reveal size
- Soldier course
- Cavity wall
- Half-brick wall