Properties of Glazing Materials

The main glazing materials used in the UK are glass and polycarbonate - the only rooflight glazing materials used in Xtralite products. Whilst their primary function is to let in daylight, all materials must be durable and meet the regulatory standards for thermal, fire and safety performance.

GLASS GLAZING

Safety glass is a very common material in the commercial and retail environment. It is also used in traditional pitched roofs. The optical performance of all other glazing solution are benchmarked against glass glazing.

  • Excellent fire retardant properties.
  • Good impact performance.
  • Unrivalled light transmission.
  • Long service life with zero UV discolouration.
  • Can be supplied with laminates, surface treatments and interlayers to provide coloured and textured surfaces, for obscure and diffused finishes, solar control and total UV protection.

POLYCARBONATE GLAZING

Polycarbonate is a clear thermoplastic formed under heat and fixed in shape by cooling. Polycarbonate glazing can be recycled and reused by re-heating into a plastic state.

  • Exceptional impact resistance.
  • High level of light transmission.
  • High levels of UV resistance.
  • Good fire resistance properties.
  • Wide range of clear, tinted, patterned and opaque finishes.
  • Co-extruded UV protection eliminates up to 95% of UV radiation from inside the building.
  • Polycarbon can be moulded into various shapes, including domes and pyramids.

PVC, ACRYLIC AND PET IN ROOFLIGHT GLAZING

PVC is seldom used in industrial, domestic, commercial or retail environments because of its poor impact resistance, limited UV resistance and susceptibility to degradation, discolouration and demoulding.

Acrylic does not meet the UK standards for fire resistance.
PET is a high impact thermoplastic with good clarity but it has a low temperature distortion value, which makes it unsuitable for rooflights.

LUMIRA SHEET TECHNOLOGY - EFFECTIVE LIGHTING, THERMALLY EFFICIENT, LIGHTWEIGHT, ACOUSTICALLY INSULATED

Xtralite have introduced our own innovative Lumira technology, combining impressive thermal efficiency, light diffusion and acoustic insulation into one product. Lumira consists of translucent aerogel granules - used to fill clear polycarbonate glazing panel constructions - that allow light to pass through whilst serving as a highly effective thermal insulation. The extremely small pore size means that air molecules collide with the silica lattice, rather than each other, transferring energy to it, substantially limiting heat conduction - vastly improving the insulation performance, with Ud values for a triple-walled rooflight reduced from 2.4 W/m²K without Nanogel to just 1.3 W/m²K. Lumira also offers excellent light diffusion with diffusion giving a ‘shadow-less’ light quality, as well as a 25% reduction in sound transmittance (at 1,000Hz frequency).