Fixing and buying guide
S/K-90 2100MM KEYSTONE CAVITY WALL LINTEL
What this lintel is for
This lintel is suitable for cavity wall construction where you need to bridge an opening up to 2100mm wide. It is commonly used above window and door openings in masonry cavity walls, providing load-bearing support to the masonry above whilst the cavity width designation ensures proper thermal performance and weather protection. The Keystone range is engineered for standard UK cavity wall applications in domestic and light commercial buildings.
- Load-bearing support for cavity wall openings
- Suitable for window and door installations
- Designed for standard cavity wall construction
- 2100mm span capacity
Sizing and compatibility
The 2100mm dimension refers to the effective span of the lintel across the opening. Before ordering, measure the clear opening width and confirm it does not exceed 2100mm. The S/K-90 designation indicates this is a Keystone lintel with a 90mm cavity width specification, which is standard for modern UK cavity wall construction. Ensure your cavity width matches this specification and that your masonry and supporting walls are compatible with steel lintel installation.
- Measure your clear opening width — must not exceed 2100mm
- Confirm your cavity wall width is 90mm
- Check that supporting walls can carry the load
- Verify opening is square and level before installation
Pre-installation checks
Before fixing, inspect the lintel for any damage or corrosion. Ensure the bearing surfaces on both sides of the opening are clean, level, and capable of supporting the lintel weight plus the masonry load above. The opening must be properly squared and the cavity must be clear of debris, mortar droppings, and obstructions. Plan your installation sequence so the lintel is installed before the opening is closed off, and allow adequate bearing length on each side as per building regulations.
- Inspect lintel for damage or corrosion
- Clean bearing surfaces of dirt, dust, and loose mortar
- Ensure opening is square and level
- Clear cavity of debris and mortar droppings
- Confirm adequate bearing length on both sides of opening
Installation and support
The lintel must be bedded on a full mortar bed on both the inner and outer leaves of the cavity wall. Ensure the lintel is level and properly supported across its full length. Once positioned, build up the masonry above according to your building design, maintaining proper cavity width and cavity tray installation where required. Do not remove temporary support props until the mortar has fully cured and the masonry above has gained sufficient strength.
- Bed lintel on full mortar bed on both leaves
- Check level in both directions
- Maintain cavity width and install cavity tray as required
- Keep temporary support in place until mortar cures
- Allow adequate curing time before loading