Balustrade installation in a warm roof scenario
colin • September 18, 2025
Installing a balustrade on a warm roof presents a significant challenge: preserving the integrity of the waterproof membrane. A warm roof system has its insulation above the structural deck and below the membrane, meaning any penetration for a balustrade post could create a leak path.
Solutions for Installation
To avoid puncturing the membrane, specialised methods are used, which generally fall into three categories:
- Non-Penetrative Systems: This is the most popular solution. These systems use a
freestanding or "floating" frame that rests on top of the waterproof membrane. The weight of the system, sometimes coupled with a decking or paving subframe, provides the stability required to meet building codes without any bolts or fixings going through the roof. This method is ideal for retrofitting and preserves the roof's warranty.
- Vertical Wall Fix: Also known as a side-fix, this method involves bolting the balustrade directly to a supporting vertical wall or a parapet wall on the roof's edge. Since the fixings are on the side, they bypass the horizontal roof surface entirely, thus not compromising the membrane. This is a secure and reliable option when a suitable wall is available.
- Integrated/Pre-planned Systems: For new builds, the best approach is to plan the balustrade installation before the roof is constructed. This allows for the use of specialized fixing points, such as a Balustrade Fixing Point (BFP), that are installed directly to the structural deck beneath the insulation and membrane. The membrane is then sealed around a pre-installed upstand, creating a watertight connection for the balustrade post above. This method ensures a strong, structural connection while maintaining the roof's waterproof seal from the outset.
Duplex 2205 is a high-performance stainless steel alloy widely used for glass spigots, offering significant advantages over traditional grades like 304 and 316. Its superior properties are a result of a unique dual-phase microstructure, consisting of a mix of austenitic and ferritic stainless steel. Unmatched Corrosion Resistance The primary advantage of Duplex 2205 is its exceptional corrosion resistance . It has a high content of chromium, molybdenum, and nitrogen, which makes it far more resistant to localised corrosion, such as pitting and crevice corrosion , especially in environments with high chloride content. This makes it an ideal "marine-grade" material, perfect for applications near saltwater pools, coastal areas, or anywhere exposed to harsh, wet conditions. While 316 stainless steel is often called marine-grade, Duplex 2205 provides a much higher level of protection, ensuring the spigots will not rust or discolour over time. Superior Strength and Durability Duplex 2205 is not only corrosion-resistant but also incredibly strong. It has a yield strength that is roughly double that of 316 stainless steel . This enhanced strength allows spigots to securely hold heavy glass panels with a smaller footprint, maintaining the sleek, frameless aesthetic of a glass balustrade without compromising safety. The higher strength also means the spigots are more resistant to damage from impacts and can better withstand extreme weather conditions, such as high winds. This combination of strength and durability provides a more robust and longer-lasting solution, reducing the need for maintenance and replacement. Long-Term Value Although the initial cost of Duplex 2205 can be higher than other grades, it offers excellent long-term value . Its resistance to corrosion and high strength mean it maintains its integrity and appearance for much longer, minimising maintenance and eliminating the costly need for premature replacement. This makes it a smart investment for residential and commercial projects where safety, durability, and a pristine aesthetic are top priorities.
Choosing between powder-coated aluminium and painted mild steel is a critical decision in construction and manufacturing, with each material offering distinct advantages. Ultimately, powder-coated aluminum is a superior option for applications where longevity, corrosion resistance, and a low-maintenance, aesthetically pleasing finish are paramount. Corrosion Resistance & Durability Mild steel is highly susceptible to rust and corrosion, especially when exposed to moisture and oxygen. To prevent this, it must be coated, but even a high-quality paint finish can be prone to chipping, scratching, and peeling over time. Once the paint's barrier is compromised, moisture can reach the steel, initiating the rusting process and leading to premature failure. In contrast, powder-coated aluminium provides a robust, two-tiered defence against corrosion. First, aluminium naturally forms a protective oxide layer that shields it from rust. Second, the powder coating itself is a thick, durable polymer finish that is significantly more resistant to impacts, scratches, and UV degradation than conventional paint. The electrostatic application and heat-curing process create a tough, uniform layer that bonds to the aluminium, ensuring a long-lasting, impermeable barrier that does not chip or flake. Weight and Maintenance Another major advantage of aluminium is its lightweight nature. It is approximately one-third the weight of steel, which makes powder-coated aluminium components easier to transport, handle, and install. This can lead to reduced labour costs and more efficient project timelines, particularly for large or complex installations like façade panels or balustrades. Furthermore, the superior durability of powder-coated aluminium translates directly into minimal maintenance . Unlike painted mild steel, which may require frequent touch-ups and repainting to prevent rust, a powder-coated aluminium finish can last for decades with little more than occasional cleaning. This long-term durability and resistance to fading ensure the product maintains its aesthetic quality and structural integrity without ongoing intervention, providing significant cost savings over the product's lifespan.
