How and where to use guide
S/K1503000 KEYSTONE S/K-150 X 3000mm Standard Cavity Wall Lintel
Typical applications
This standard cavity wall lintel is commonly used to support masonry above window and door openings in residential properties and light commercial buildings. The 3000mm length accommodates larger openings or allows for cutting to suit specific opening widths. It is designed for use in cavity wall construction where the cavity is maintained between inner and outer leaves of masonry.
- Window and door openings in cavity walls
- Domestic and light commercial masonry construction
- Openings up to approximately 3000mm in length
- Standard load-bearing applications in residential properties
Installation and bedding
The lintel must be installed level across the opening with adequate bearing length on both supporting walls. Minimum bearing of 150mm on each side is standard practice, though always verify specific structural requirements for your project. Bed the lintel firmly in a full bed of mortar to ensure even load distribution and prevent point loading. The lintel should be positioned at the correct height to support the masonry course above the opening. Ensure the cavity is maintained across the lintel opening to prevent moisture bridging.
- Install level with minimum 150mm bearing on each supporting wall
- Bed firmly in full mortar bed for even load distribution
- Maintain cavity width across the opening
- Check that lintel is properly supported before laying masonry above
- Allow mortar to cure fully before applying significant loads
Limitations and site considerations
This is a standard cavity wall lintel and is not suitable for applications requiring special fire ratings, enhanced thermal performance, or non-standard load conditions. Do not use in solid wall construction or where cavity maintenance is not possible. The lintel length of 3000mm may require cutting on site to suit smaller openings; ensure cuts are made cleanly and any cut edges are protected from corrosion. Always check structural drawings and building control requirements for your specific project, as load capacity and bearing lengths may vary depending on the loads above the opening.
- Verify load requirements and bearing lengths with structural engineer if loads are heavy
- Not suitable for solid wall construction
- Protect any cut edges from corrosion
- Confirm compliance with local building regulations before installation
- Do not use where cavity cannot be maintained
Maintenance and durability
Steel lintels require protection from corrosion. Ensure the lintel is fully bedded in mortar and that the cavity is kept clear of debris and mortar droppings that could trap moisture against the steel. The lintel should not be exposed to the weather during storage or before installation. Once installed and properly bedded, the lintel will provide long-term structural support with minimal maintenance. Periodically check that mortar joints around the lintel remain intact and repoint if necessary to prevent water ingress.
- Keep lintel dry during storage and before installation
- Ensure full mortar bedding to protect steel from moisture
- Keep cavity clear of mortar droppings and debris
- Inspect mortar joints periodically and repoint if damaged
- Avoid exposure to harsh weather conditions before installation