Thermal breaks are a critical part of external wall systems and play a pivotal role in meeting the revised Building Safety Act 2022.
Following the Grenfell tragedy and the subsequent Hackett Review, The Building (Amendment) Regulations were introduced in December 2018 and set out restrictions on the combustibility criteria of materials which form part of the external wall. This includes ‘specified attachments’ (for example: balconies, solar panels or solar shading) attached to the external wall of a ‘relevant building’ in England (that is over 18m above ground level, or seven storeys).
The combustibility criteria in such cases will need to be European Classification A2-s1, d0 or Class A1, classified in accordance with BS EN 13501-1:2007+A1:2009. The Building Safety Act 2022 now significantly reforms building safety regulation and has introduced a Building Safety Regulator, whose primary goal is to improve the design, construction and management of higher-risk ‘relevant’ buildings.
The Schöck Isokorb complies with the Amended Regulations
In part 7(3) of Approved Document B in the Amended Regulations there is a list of materials exempt from the restrictions, which includes thermal breaks. Schöck Isokorb thermal breaks form part of the external wall, so it is critical that they comply with the Amended Regulations.
The Isokorb uses thermal insulation material to improve thermal performance (verified to meet the requirement of Part L by independent thermal testing from Oxford Brooks university) and they are exempt according to the amended regulations.
The Schöck Isokorb range is the most comprehensive in Europe and offers load-bearing thermal insulation solutions for a variety of connectivity applications such as balconies, canopies and solar shading. Connections can be made between concrete-to-concrete, steel-to-concrete and steel-to-steel
What makes Schöck thermal breaks so effective in meeting Part L
The quality of the components used in the construction of the Isokorb are the reason for its superior thermal performance. Stainless steel (in the thermal zone) is used for its greatly reduced thermal conductivity when compared with carbon steel. The HTE (High-performance Thermal Element) module used in the Isokorb system, is a concrete thrust bearing designed to transmit compressive forces and also optimise thermal conductivity. When Neopor®, an expanded polystyrene (EPS) insulation known for its superior thermal performance, is used together with the HTE module, thermal bridging is almost entirely eradicated.
Design of the Isokorb range addresses key safety requirements
The Building Safety Act emphasises the importance of using tested and certified components in safety-critical systems. Substituting specified products, such as thermal breaks, without ensuring compliance and suitability, could breach the Act’s regulations, leading to significant liability risks. Using certified solutions like the Schöck Isokorb ensures that safety and compliance are not compromised.
The design of the Isokorb range meets the demands of the Building Safety Act by addressing key safety key issues such as: BBA Agrément Certified to exceed fire resistance standards (REI120); helps mitigate fire spread risk as required by the Act for use in high-risk residential buildings – and provides critical documentation (including design calculations) to support the ‘golden thread’ of safety information.
As thermal breaks are classified as safety-critical components and are normally designed by structural engineers as continuous supported systems imparting UDL forces to the internal slab edge, by using the ‘golden thread’ information, the best practice Gateway Approval Process for thermal breaks is recommended as:
- Scenario:
Early-stage design consultation for Gateway 1 approval
- Problem:
Developer needs assurance that the thermal break solution will meet both thermal and structural regulations
- Solution:
Collaboration between structural engineer and Schöck to design a linear thermal break system
- Outcome:
Gateway 1 approval obtained with no additional redesign costs
at Gateway 2.
Contact Schöck for full details of the Isokorb range of solutions by using the details below.