Zenon in-plane and barrel-vault GRP rooflights are built using different components dependent on the specification. There are two GRP rooflight sheet products available: Zenon Pro and Zenon Evolution. UKCA and CE marked in accordance with BS EN1013 and manufactured to match typical metal, aluminium and fibre cement profiles, Zenon rooflight sheets are ideal for industrial, commercial, or agricultural buildings.
Zenon Pro and Zenon Evolution carry a service life guarantee of 25 and 30 years depending on weight; service life is defined in BS 7543. These guarantees cover durability, serviceability, and structural integrity of the sheet material.
In Hambleside Danelaw’s journey to offer more sustainable options, the Zenon Insulator was developed. This insulation layer replaces the commonly used polycarbonate layer which sits between the liner and weather sheet. Compostable at the end of its service life, Insulator won the Queen’s Award for Innovation in 2006 and continues to be a sustainable and high performing component.
Traditional Methods of Rooflight Insulation
The most widely used method to insulate GRP rooflights is by using multiple layers of materials with high transparency. This approach is reasonably effective for uses where moderately improved U-values are required, and a common technique would be to use multi-wall or structured polycarbonate sheet.
Still air pockets are created, and conduction is minimised by using thin-walled sections to inter-connect the walls or layers within the polycarbonate; for each layer is added, there is a penalty in terms of light-transmission due to the cumulative effect of the reflectance of light at each layer. As the number of layers increase, so does the absorption into the increasing mass within the rooflight cavity and the greater the re-radiation of heat through the rooflight as a secondary component of solar gain.
Zenon Insulator
To overcome the problem of achieving a more environmentally conscious product, which still attains low U-value without significantly compromising the light transmission, Hambleside Danelaw developed the unique Zenon Insulator.
Made from cellulose acetate, a recycled wood pulp product, it provides much improved U-values without the penalties of creating multiple layers within the rooflight. It achieves this by trapping and containing the air in small pockets within the rooflight cavity thus significantly inhibiting the convection currents that carry the heat through the rooflight panels to the outside air.
The honeycomb Zenon Insulator core comprises a lightweight, transparent cell structure that is perpendicular to the plane of the rooflight. This requires only a single thin clear film layer to encapsulate the air pockets and has minimal interference with the light transmission. The light entering the cell structure is channelled directly, or by reflectance, into the building creating a better, wider spread of diffused light, irrespective of the angle of incidence of the light. Insulator also minimises the absorptance and re-radiation of the light energy as heat energy.
The standard thicknesses for insulation layers when using simple structured polycarbonate inserts for both site-assembled rooflight applications for built-up cladding systems, or composite panel rooflights for use with composite cladding systems, are 4mm twin-wall or 10mm four-wall panels.
Zenon Insulator is available for both site-assembled rooflights or composite panel rooflights. There are three standard thicknesses available, 20mm, 40mm and 80mm, depending upon thermal performance requirements. The thermal properties of any rooflight insulation layer should always be considered in conjunction with the U-value of the rooflight outer and liner sheets, and the type of assembly in which they are to be incorporated.
