Safer, more efficient external cladding

A common approach to thermally insulate buildings is to apply a ventilated rainscreen cladding system at the building exterior. Individual rainscreen panels tend to be supported on a framework system formed from brackets, boards and rails to create an air-space between the external cladding layer and inner leaf components (such as plaster boards).

Case Study

Case Type

Patent application


Identifying patentable features


Successful patent registration


The cavity between the external cladding and the inner leaf components is ventilated to the outside air to prevent entrapment of water, avoiding humidity and condensation problems. Where it’s required to thermally insulate the building, it would include one or more layers of insulation material behind the cladding panels. Accordingly, the external surface structure of the building is concealed from the sun, wind and rain to provide thermal efficiency management of the building interior.

SIG plc identified the need for improvements in existing rainscreen systems, firstly with regard to improving thermal insulation and secondly (and potentially more significantly), to provide a system adapted to withstand significant sheer and loading forces (due to environmental factors such as wind and rain). This is in addition to offering improved structural integrity in the event of fire or other structural damage to the building.

SIG developed a novel rainscreen support system that includes specifically designed bracketry to reduce thermal bridging between the external panels and the building interior and to prevent the transferring of heat energy out of the building.

The new ‘Chi-Gasket’ component and systems are based around a high-temperature insulation pad infill that is supported by a specifically designed cage. The new Chi-Gasket includes a non-combustible insulation material, resulting in a new system that meets technical standards with regard to thermal insulation and fire performance of building facades.


As might be expected, the existing patent landscape included many different configurations of rainscreen cladding systems. We worked with SIG to identify the aspects of its design that solve specific problems and provide significant improvements over earlier forms, in order to secure the maximum possible patent protection.


By protecting the new cladding system, we’ve provided SIG with a sound commercial position to maximise its business opportunities with existing and new customers. SIG comments that its Chi-Gasket system now provides businesses with a number of advantages, including:

  • a reduction in materials and cost savings
  • SAP and SBEM improvements
  • an improved BREEAM rating
  • ‘thinner’ build-up, increased footprint and leasable space
  • a direct route to satisfy BCA Technical Guidance Note 18, BRE135 and CWCT TN98

Further information about the SIG Chi-Gasket can be found here.

Need help with a patent application?

For more information please contact Martin Neilson

0113 245 2388

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