Case Study

Keystone Lintels

Keystone Lintels is the UK and Ireland’s largest Steel Lintel manufacturer. With a strong focus on innovation, the company works closely with its customers to develop structural solutions for a range of challenges, establishing a reputation for supplying high-quality specialist products to the industry.

Aware of the challenge to builders to help achieve ever more stringent Part L building regulations in a cost-effective way Keystone was first to market with Hi-therm lintels, a low-cost solution to reducing carbon emissions.  The innovative design of Hi-therm utilises a rigid polymer thermal isolator making it up to five times more thermally efficient than a standard steel lintel.  Hi-therm is a one-piece design that creates stability during the building process as it is easier to install than a two-part lintel solution which requires extra labour to install insulation under the DPC membrane; a process that can be cumbersome and result in quality control issues.

Keystone’s original Hi-therm lintel had the added advantage of being the only BBA Certified one-piece lintel solution on the market which achieved the appendix R-value for steel lintels in Part L 2013. When Keystone upgraded the design of Hi-therm to make it even easier to install Hi-therm+ Lintel was born. While still utilising a rigid polymer thermal isolator as an effective thermal break, Hi-therm+ incorporates a steel inner and external leaf. The product is as thermally efficient as the original but is now similar to a standard steel lintel for simplified installation.

As a manufacturer who supplies critical structural components Keystone has testing and quality at the top of their agenda.

The challenge

For that reason, Keystone invested in BBA testing for the new Hi-therm+ design.  The BBA undertook laboratory tests, on-site evaluations, quality management checks and inspections of production to make sure Keystone’s Hi-therm+ product satisfied the latest Building Regulations.

David Grace, Sales Director at Keystone’s Lintels commented that the BBA’s assistance in this project was ‘phenomenal’. The expertise and support provided right from the start ensured Keystone achieved an excellent product that they could comfortably take to market. From the beginning, they were well informed as to what was required as they were already familiar with the product.

The tests

To ensure that the new Hi-therm+ product met the new standards and continued to be compliant with quality management audit requirements, it was duly tested to establish the flexural and shear strength of the lintel in accordance with BS EN 846-9: 2016. The resistance to load under fire conditions was also tested to BS EN 1363-1: 2012.

Data was examined relating to thermal performance, minimum temperature factors and practicability of installation and durability.

Finally, the BBA carried out a number of laboratory tests and evaluations of on-site processes, plus a series of quality management checks and inspections of production. These were necessary to establish that  Keystone’s previously awarded Agrément Certificate continued to be valid.

The result

After completing the testing and inspection processes and subsequent in-depth analysis of the results, the BBA was pleased to conclude that a detailed update of Keystone’s existing certificate was sufficient to meet the new industry requirements.

With the updated certification in place, Keystone has enjoyed many successes with Hi-therm+ Lintel and their product is now sought after on a regular basis in the market place.

Mr Grace added: “The experience and expertise the BBA have to offer is unrivalled. Products that receive Agrément Certificates are recognised by building control, government departments, architects, specifiers and industry insurers. It’s a mark of quality, safety and reliability that provides reassurance of the product’s fitness-for-purpose. We are delighted to work the leading technical assessment and certification body in the UK”.