Fixing and buying guide
S/K-90 1800MM KEYSTONE CAVITY WALL LINTEL
What this lintel is for
The S/K-90 is engineered for cavity wall applications where you need to bridge openings in external walls. The 1800mm length makes it suitable for larger window and door openings. It is designed to carry the weight of masonry and any loads above the opening, distributing them safely to the supporting walls on either side.
- Cavity wall construction with external and internal leaf masonry
- Window and door openings up to approximately 1800mm span
- New build and refurbishment projects
- Load-bearing applications in domestic and light commercial buildings
Sizing and compatibility
The 1800mm length is the critical dimension for this lintel. You must measure your opening width carefully and allow for proper bearing on each side—typically a minimum of 150mm bearing length on each supporting wall is required. The S/K-90 designation indicates the lintel profile and load capacity; confirm this matches your structural engineer's specification or building control requirements for your specific opening width and loading conditions.
- Measure opening width and add bearing lengths (minimum 150mm each side)
- Verify the S/K-90 profile is specified for your load case
- Check cavity width compatibility with your wall construction
- Confirm lintel depth suits your cavity and masonry leaf thickness
Installation and preparation
Before fixing, inspect the lintel for damage and ensure the bearing surfaces on both supporting walls are level, clean, and free from debris. The lintel must be bedded on mortar on both sides to distribute loads evenly. Position it centrally within the cavity or as specified in your design. Ensure temporary support is in place during installation until the masonry above has been built and cured.
- Check lintel for dents, corrosion, or damage before installation
- Prepare level, clean bearing surfaces on both supporting walls
- Bed lintel on fresh mortar—do not use dry bedding
- Use temporary props or acrow shores to support lintel during construction
- Allow mortar to cure before removing temporary support
Building control and specification
Always verify that this lintel meets your local building control requirements and matches your structural engineer's specification. The S/K-90 1800mm lintel must be certified and suitable for the specific loading and span conditions of your project. Keep documentation and certification on site for inspection.
- Confirm lintel specification with structural engineer or architect
- Check building control approval before installation
- Retain manufacturer's certification and test data
- Ensure lintel is CE marked or equivalent certification