Articles

Some industry related articles and information
 
Back to list
Rooflight Specification

Rooflight Specification

Nick Crooks, Customer Service Manager of Lumen Rooflight discusses the importance of specifying the right components for your rooflight

When specifying rooflights there are other aspects to consider beyond its shape, size, and the materials that it is made from.

If you are specifying a metal product then choosing the paint for your rooflight is more than just colour dependant and your specification will benefit from identifying the correct application for the location. The quality of the protective coating applied to a metal rooflight is directly linked to the lifespan of the product. Steel rooflights should receive zinc or iron phosphate coatings prior to painting as these help extend the corrosion protection and overall life of the rooflight.

Some products, such as the Cromadex Extra Life paint system, has been developed to protect against a wide range of environments, from the interiors of heated buildings to much more aggressive external situations, such as industrial or coastal areas. The system has six key environment classifications allowing customers to select the environment where their product will be used. Whenever in doubt it is always advisable to select the more aggressive environment.

Getting the paint durability wrong on your rooflight could be costly, as if the system doesn't last long enough, rectification could be expensive. However, with a more robust paint covering, you can be specific in terms of the robustness and investment required and durability ranges can be broken down into three-year intervals, enabling a more accurate coating specification.

For less aggressive or corrosive environments, rooflights will normally receive a primer undercoat and then a topcoat. In locations where more protection is required it is necessary to apply a third intermediate coating. As an example the Cromadex system offers the Interpon PZ790 application which is a powder coating primer containing zinc, which is designed to give enhanced corrosion protection of mild steel. Interpon PZ790 has been designed to be over-coated with powder topcoats and provides excellent protection against corrosion on the surface to which it is applied. A product such as Interpon PZ790 considerably limits the extent of spread of corrosion in the event of coating damage.

It is also worth remembering the industrial coatings used on rooflights are no different to the paint on your car - they need cleaning and maintaining. Accumulated dirt may affect the design life of the system, and any mechanical damage almost certainly will. Therefore regular inspections should take place and minor damage must be touched up. At the end of the design life, major maintenance must be carried out.

GLASS

Glazing can also be a tricky subject when specifying a rooflight, not least because there are so many different types of glass and glazing system available. Whatever your site considerations, be that for example, solar control, safety, fire protection, or sound control, there is a glazing system to match. Pilkington Glass provide a handy range of specification tools on their website http://www.pilkington.com/en-gb/uk/architects/tools which will help you better understand the types of product available.

Regardless of the type of glazing system you require, consideration must be given to thermal performance and improving carbon and energy reduction in buildings. Part L of the building regulations is one of the tools used by the government to achieve these objectives. These regulations are set to change in 2013, and again in 2016 and 2020. The 2013 changes are currently undergoing a consultation process and it is anticipated that the fine detail may change but the drive towards greater thermal efficiency is not negotiable.

Hand in hand with part L are the compliance tools such as SAP and SBEM. Although the tools contain default values for windows they do tend to be very conservative. It is advisable for all designers to use manufacturers values in these programs and real window sizes and orientations to realise the contribution that energy efficient windows can make.

Self-cleaning glass, a technological breakthrough first introduced to the UK in 2002 by Pilkington, is another option. Self-cleaning glass is effectively the same as conventional glass, but with a specially developed coating on the outside, that once exposed to daylight, reacts in two ways. Firstly, it breaks down any organic dirt deposits through a photocatalytic process, and secondly, when it rains, instead of forming droplets, the water spreads evenly over the surface and takes the dirt off with it. It is kinder to the environment than ordinary glass and it is the ideal choice for situations where cleaning will be costly or difficult.

Whatever your project, specifying the right components for your rooflight is just as important as the materials used.