Why are steel lintels preferred for a masonry cavity wall?
Masonry cavity wall construction is the most common construction method in the UK, especially for residential developments. An inner and outer leaf of masonry is separated by an air cavity, which is either fully or partially filled with thermal insulation.
Openings in a cavity wall require structural support for each masonry leaf. A separate lintel used to be the common solution, with two different lintels specified (one for each leaf).
Now, a one-piece steel lintel is preferred. The main body of the lintel sits within the cavity, and a toe projects from the front and back of the lintel to support the outer and inner leaf. The lintels are designed to contribute thermal performance and moisture resistance at the door or window head detail, as well as the necessary structural stability.
The one-piece lintel also closes the cavity, avoiding the need to specify a cavity closer separately
What type of lintels are available for cavity walls?
Cavity lintel specification is determined by the build-up of the cavity wall, the size of the opening the lintel has to span, and the load imposed by the structure above. Catnic offers a complete range of one-piece steel lintels to suit standard or heavy duty applications.
All cavity lintels come with integral insulation to help reduce the thermal bridging impact of the steel. Where the thermal performance of the lintel detail is particularly critical, the Thermally Broken Lintel (TBL) range guarantees psi values of 0.05 W/mK or lower.
Extreme load cavity lintels are also available. These resemble a conventional steel beam, being an I-profile in shape and not featuring integral insulation. A separate DPC is required with the extreme load lintels in all cases, because of the difference in shape compared to the standard and heavy duty lintels.
The Catnic lintel product selector allows users to narrow the range of available cavity lintel solutions, based on masonry and cavity thicknesses, as well as loading conditions. An appropriate lintel can then be specified for the clear span of the opening and the safe working load required.
Catnic’s lintel product selector tool can also be used to specify lintels for other applications. Alternatively, Catnic has a dedicated technical support team available to assist with any questions or non-standard requirements. Contact us to discuss the details of your project.