Sustainable building envelopes include roof constructions that are designed to reduce heat loss and promote energy efficiency within new and existing buildings The fully patented E-clip by Kalzip is designed to provide minimal thermal bridging through the Kalzip system and contributes to a highly effective thermal insulation layer and simultaneously provides excellent load-bearing capacity.
In response to the increased requirements of the previously introduced statutory guidance document: Conservation of Fuel and Power : Approved Document L
Kalzip introduced its patented E-Clip 20 years ago. Previously only available as a full-metal version, the updated version now offers a range of advantages due to its construction. The steel insert ensures excellent load-bearing capacity and stability of the clip. The steel insert is injection moulded with a glass fibre-reinforced, UV-resistant polyamide that is made from 100 percent recycled material and ensures that the E-Clip has significantly lower thermal conductivity than its predecessor.
Proven Improvement in U-Value
In order to comply with the U-values prescribed in the Approved Document L and to comply with future changes with legislation on our journey to tackle energy efficiency and greenhouse gas emissions, a sustainable and flexible thermally efficient roof construction is needed – without neglecting the design aspects of the architecture. With the enhanced and officially approved Kalzip E-Clip, various roof geometries can be realised that easily comply with the required statutory guidance Depending on the roof structure, the height of the E-Clips, and the thermal conductivity of the insulation, corresponding U values are achieved. For instance, the E-Clip achieves a U-value of less than 0.16 W/(m2K) in a standard insulated Kalzip roof construction. With our additional roof systems Duo Plus E and Duo E, the values can be improved: installed on a walkable insulation, the thermal performance of the roof structure with E-Clip can be improved to achieve U Values less than 0.13 W/(m2K). Compared to the thermal bridging effect of the metal clip, the heat loss is approximately 30 percent lower for almost all constructions utilising Kalzip E clips.
Secure and Easy Installation
For the development of the E-Clip, the aspect of ease of installation was also considered in addition to improving U-value performance The steel insert not only ensures a stable clip and excellent load-bearing capacity for the roof construction, but also offers safety during installation: the torque-oriented SDK screws facilitate an easy and secure installation of the E-Clips to various substrates. Thanks to the symmetrical clip head, the Kalzip profile sheet can easily and quickly installed. The polyamide coating of the clips allows the Kalzip sheets to expand and contract unrestricted making the installation of long Kalzip sheets easier. In terms of fire performance, the Kalzip system achieves a classification of B[Roof]T4 when tested to EN13501-5
With the E-clip, various roof geometries can be realized without disregarding the legal requirements of the GEG.
(Photos: Kalzip GmbH)