When selecting rooflights for your home or building, it’s vital to understand the differences between framed and frameless systems. While frameless rooflights may offer a sleek, minimalist aesthetic, framed glass rooflights provide several key advantages, which is why we exclusively supply framed systems.
Weather Resistance
Frameless rooflights are typically installed using silicone seals, which are continuously exposed to the elements. Over time, rainwater and weathering can degrade these seals, significantly increasing the risk of leaks.
In contrast, framed rooflights incorporate a robust aluminium frame with features such as drip edges and integral water management systems. Even if the seal around the glass were to fail, the frame ensures that rainwater is directed safely onto the roof surface rather than into the building. This extra layer of protection ensures the durability and reliability of framed systems over time.
Thermal Performance
Thermal efficiency is a critical consideration, especially with energy conservation and compliance with building regulations in mind. Frameless rooflights are often advertised based only on the centre pane U-value of the glass. However, this measurement doesn’t account for the rooflight’s performance in a horizontal position, including the thermal impact of the glass edge seals and spacer bars.
Framed glass rooflights are designed with advanced thermal breaks within the frame, which improve insulation and reduce heat loss. Their overall U-values are calculated in the horizontal plane, ensuring compliance with UK building regulations in England, Scotland, and Wales, while contributing to reduced energy costs.
Security
Security is another important factor, particularly for rooflights installed on single-storey buildings or flat roofs. Frameless rooflights, which are bonded directly to an upstand, are generally less secure and may not meet the necessary security standards.
Framed glass rooflights, on the other hand, are mechanically fastened to the roof using security screws. These systems can be tested to meet strict security standards, such as PAS 24:2022, and are often accredited by initiatives like Secured by Design. This makes them a far safer choice for protecting your home or building.
Safety
The safety of rooflights cannot be understated. Reports have highlighted several risks associated with frameless rooflights, including:
- Rooflights being dislodged entirely by strong winds due to inadequate silicone seals.
- Inner glass panes falling into rooms below because they lack proper support or rely on failing seals.
- Breakage of inner panes caused by contact with sharp screw heads on the upstand, with toughened glass potentially shattering dangerously.
Framed rooflights address these issues with a laminated inner pane bonded to the aluminium frame using structural adhesive. This ensures the glass is securely held within the frame, even if broken. Additionally, many framed systems are classified as non-fragile under CWCT TN67 standards, providing safety for anyone accessing the roof.
Conclusion
While frameless rooflights may appeal aesthetically due to their minimal design, framed glass rooflights deliver significant advantages in terms of weather resistance, thermal performance, security, and safety. These benefits align with our commitment to offering products that prioritise durability, efficiency, and occupant safety. For these reasons, we choose to exclusively supply framed glass rooflights.