How and where to use guide
S/K-90 1200MM KEYSTONE CAVITY WALL LINTEL
Typical applications
This 1200mm lintel is commonly used to span window and door openings in cavity wall construction up to 1200mm wide. It is suitable for domestic and light commercial buildings where standard cavity wall construction is employed. The lintel bridges the gap created by the opening whilst the cavity wall continues above it, maintaining thermal and moisture separation between inner and outer leaves.
- Window openings in cavity walls up to 1200mm span
- Door openings in cavity walls up to 1200mm span
- New build and renovation projects with cavity wall specification
- Domestic and light commercial applications
Installation and support
The lintel must be installed level and bedded firmly on both sides of the opening on suitable bearing surfaces. Adequate bearing length is essential for structural integrity; typically a minimum of 150mm bearing is required on each side of the opening, though this should be confirmed with structural specifications for your project. The lintel should be positioned to maintain the cavity width and allow for proper cavity tray installation beneath it.
- Install level with adequate bearing on both sides
- Ensure minimum bearing length as per structural design
- Position to maintain cavity width continuity
- Bed firmly in mortar on supporting masonry
- Install cavity tray beneath lintel to manage moisture
On-site handling and limitations
Handle the lintel carefully to avoid damage during transport and installation. The 1200mm length is the maximum span for this product; openings wider than 1200mm require a longer lintel or alternative structural solution. Do not use this lintel in situations where the opening exceeds the lintel length, as this will result in inadequate bearing and structural failure. Ensure the supporting masonry is sound and capable of carrying the imposed loads.
- Maximum span 1200mm; do not use for wider openings
- Inspect for damage before installation
- Ensure supporting walls are structurally sound
- Do not modify or cut the lintel on site
- Confirm load-bearing capacity with structural engineer for heavy loads
Maintenance and durability
Once installed and properly bedded, the lintel requires minimal maintenance. Ensure that any cavity trays and damp-proof courses are correctly installed and maintained to prevent moisture ingress. Periodically inspect the mortar bed around the lintel, particularly after settlement or movement, to ensure it remains sound. The lintel should be protected from water penetration through proper detailing of the cavity tray system.
- Maintain cavity tray system to prevent moisture ingress
- Inspect mortar bed for cracks or voids
- Ensure proper flashing and damp-proof course details
- Check for signs of movement or settlement