2 minute read
Don’t Compromise on Rooflight Safety or Service Life
By Hambleside Danelaw
Rooflights are an integral part of a metal roofing system in modern industrial buildings, bringing natural daylight into the building and thus reducing the dependence on artificial lighting.
At the same time, they have to deliver structural integrity, contribute to the non-fragility classification of the overall roof and satisfy the HSE requirements for roof safety. Most reputable rooflight manufacturers can now satisfy the HSE’s preferred option of products delivering long term non-fragile performance.
However, regardless of their stated non-fragility classification, industrial rooflights should never be walked on. They perform all of the functions listed above, but are not designed for foot traffic. Walking on rooflights may damage the performance, structural integrity and also risk the safety of those on the roof. The safety performance of a given rooflight must be tested as part of the whole roof assembly including all components needed to install it and the roofing system it is installed in. Successful rigorous testing in accordance with the recommendations from the Advisory Committee for Roofsafety (ACR) has seen the development of GRP rooflights which incorporate a woven continuous glass filament reinforcement mat resulting in Class B non-fragility classification for 30 years.
Hambleside Danelaw Zenon rooflight installed in a distribution centre
The service life of a rooflight is dependent on several factors, most importantly the rooflight assembly or configuration. Technological developments have led to the introduction of stronger thinner and lighter products, which when used in the correct assembly can give an expected service life well in excess of 30 years. It is generally accepted that the current market expectation for service life is a minimum 25 years. Despite this there are systems on the market that fall below this requirement as they are either using long-outdated configurations or materials that aren’t as durable as GRP.
And yet this remains a critical consideration to get right.
The combination of a long service life and long period of non-fragility offers real benefits to building owners and those accessing the roof, enhancing safety and reducing lifetime costs. In addition, further benefits can be obtained with the use of thinner, lighter and lower embodied carbon alternative materials. Examples of advancements in these areas include sheets reinforced with the woven continuous filament glass mat, and a cellulose acetate insulation system that increases the level of light transmission and that is compostable at end of life.
Like many elements of the roof assembly, properly specified rooflights can deliver a package of benefits that all help to enhance the overall performance and value of the building.
This isn’t something that should be decided at the last minute. Speak to your rooflight manufacturer early in the process. Get a clear statement on the key performance criteria of non-fragility classification and service life expectancy. You may be surprised at what else you can deliver to your client.
