Hi-therm Advances to Meet Market Demands


The award winning Hi-therm lintel has just been updated in response to requests from house builders to further its application. The Keystone Group’s National Technical & Specification Manager Richard Kinloch explains how this new version secures all the benefits of the original and adds new features, which widen its appeal.

Hi-therm has made a significant impact on the energy efficiency of new homes. It remains the only BBA approved thermally efficient lintel on the market and has won multiple awards for innovation. Now, its design has been upgraded to offer even greater practicality to builders and to make its benefits open to even more projects.

Richard explains:
“Originally our design was based on the most common wall construction types and the typical opening sizes found in most developers’ homes. Now, four years on, we are starting to get more demands and this has required us to re-engineer the design. For a start, Hi-therm+ will now be available to suit both wide outer leaf and cant brick applications rather than just standard leaf. In addition, longer lintel lengths are now available to accommodate larger openings.”

The same but different!

Hi-therm is a patented innovation based around introducing a polymer element into a steel lintel. This creates a powerful thermal break which dramatically reduces thermal bridging through the junction with beneficial cost and performance outcomes. Previously the design utilised a polymer outer leaf as the thermal break. This new Hi-therm+ lintel features a structural polymer thermal break in the cavity linking an outer and inner steel leaf. The resulting improvement in Psi value is considerable with figures of between 0.03 – 0.06 W/m.k to be expected depending on the specific wall make up.

Richard explains the benefits of the new design.

“Buildability lies at the heart of Hi-therm’s success because what the builder wants is a high performance lintel that can be handled and built on site in exactly the same way as standard lintels. Split lintels and other non-structural thermal breaks are not comparable in terms of buildablity and do not offer the simplicity of the Hi-therm lintel.
Hi-therm+ takes practicality to a higher level again, so it will be even easier to handle on site than before. This is an increasingly important benefit and addresses the challenge of maintaining good detailing when skill levels are under pressure and introducing specialist techniques can be problematic.”

Expert support

SAP is a complex subject and even the most experienced technical managers are likely to rely on a trained energy assessor, either from within the team or from an external consultant. It’s therefore reassuring to know that IG & Keystone’s own expert support is available. Online tools such as the Hi-therm Psi value calculator, which issues certified performance for any given wall type, will assist energy assessors.

This, coupled with the fact that Hi-therm+ is a highly tested and certified product, will give reassurance that IG is the ideal partner to provide the optimum lintel solution going forward.

Real cost savings

As more plots fall under Part L 2013, the need to reduce thermal bridging increases. It is here that Hi-therm+ makes a significant impact as its cost benefit relationship is so effective, offering significant cost savings compared to many of the popular alternatives, which builders might be considering as a solution to improved SAP performance.

For example, in a comparative case study for a house type, using Hi-therm+ would incur less than 20% of the cost of increasing the cavity width by 50mm for the same saving in CO2. These CO2 savings are important within SAP because they give flexibility for compliance in situations where other built details are not meeting the standards in Appendix R of Part L 2013.

Please visit our Hi-therm+ Lintels page for more information.