1000/32 Box Profile
Polycarbonate Rooflights
View of Clearlight in the Manchester United Stadium

Prolight® Box profile Polycarbonate sheet (MarlonCS Longlife) is a high performance rooflight sheet, which admits natural light into domestic, commercial, industrial and other buildings.

Prolight® can be used to form complete roof coverings or can be incorporated into profiled metal roofing and cladding systems, ranging from single skin to advanced composite panels.

Stock sheets
1000/32 Box profiled sheet in 1.3mm thick is available from stock to match our steel 1000/32 steel box profiled range of sheeting (Proclad®, Procolor® and Profarm®). Other profiles and thicknesses are also available on order, please contact our sales Department.

UV resistance
A protective co-extruded layer on the outer surface of the sheet forms a barrier which is resistant to the detrimental effects of UV light, minimising long term yellowing and maintaining mechanical properties.
The protected surface is always clearly identified. The sheet must always be fitted with the UV protected side out, otherwise it will deteriorate, as will be shown by yellowing and decline of physical properties, eg. the sheet will become brittle and lose impact resistance.

Impact resistance
Prolight® is a very durable material, many times tougher than glass, with excellent light transmission, fire performance and stability in extreme temperatures. Of all glazing materials polycarbonate exhibits greatest resistance to impact over a temperature range of -40 to +130˚C. It is approximately 200 times more resistant to impact than glass; PVC has limited impact resistance at low temperatures; GRP sheet is resistant to impact but will show impact abrasions much more easily than Polycarbonate. High impact resistance means that Prolight® is suitable for use in areas where hail storms would cause excessive damage to other glazing materials.

View of Clearlight in the Manchester United Stadium



Accelerated weathering tests in a weatherometer produce little change in light transmission or yellowness index. Significantly, accelerated and natural weathering have negligible influence on the physical properties of Prolight®, eg. tensile strength, impact resistance. During the life of the sheet natural weathering will leave its thermal or mechanical properties essentially unaltered.

Fire Performance
Prolight® exhibits excellent fire performance and in the event of a fire it will soften and open, allowing smoke, heat and gases produced by the fire to escape. This 'venting' property means that damage within buildings can be limited. For details of fire ratings please contact our technical department.

Chemical Resistance
Prolight® has in general excellent resistance to most chemicals; resistance to specific compounds depends on concentration and temperature, duration of exposure and stress within the sheet. Contact with plastic coated metal sheets, wet wood preservatives, solvents and alkali cleaners should be avoided.

Condensation will form on the underside of a roof made from any thin sheeting material. To minimise condensation within an enclosed structure, sources of moisture should be minimised and good ventilation should be provided.


Prolight®, is manufactured under Quality Management Systems registered to BS EN ISO 9001:2000 by Brett Martin as MarlonCS Longlife. The sheet carries a 10 year Guarantee in respect of light transmission and a 3 year Guarantee in respect of weather breakage.

View of Prolight in the building Duggan Steel in Kilkenny, Callan Road

Isolation from plastisol coating

Plastisol coating on roofing sheets is aggressive to polycarbonate. It is essential that the lapped area of metal sheet at either side of and at the lower end of the polycarbonate rooflight has an aluminium foil adhesive tape applied to completely isolate the polycarbonate from the plastisol-coated metal.
Profile Prolight