Climate-proof buildings Introducing next-generation flat roof drainage systems

Due to the rising frequency of heavy rainfall and storms, efficient rainwater removal from flat rooftops has become more critical than ever to prevent structural damage, water accumulation and costly repairs. In response to these challenges, Pipelife has developed a state-of-the-art siphonic roof drainage system, offering superior performance, enhanced durability and seamless integration with modern construction requirements.

_{The role of roof drainage systems in preventing water damage}

In recent years, Europe has experienced a notable shift toward a warmer and wetter climate. Extreme weather events are now more frequent, with heavy downpours occurring even in regions where they were once rare. These evolving weather patterns have placed increasing pressure on property drainage infrastructure, most of which was not designed to handle the heightened demands of today's climate conditions. 

Modern roof drainage systems must be designed to manage higher rainfall intensities and flash floods while also withstanding stronger wind loads. Additionally, rising temperatures and increasingly frequent heat waves necessitate careful consideration of the UV and heat resistance of construction materials. Failure of a flat roof drainage system can lead to water accumulation, placing the building at risk of overflows, leaks and even structural failure.

_{High-performance drainage system for flat roofs: Test results} 

In response to evolving climate challenges, Pipelife has developed an industry-leading siphonic roof drainage solution that exceeds current safety and efficiency standards. 

An innovative outlet design is at the core of the new system. Pipelife's DN75 siphonic drainage outlets have been tested to perform at a flow rate of up to 20 l/s — surpassing standard siphonic drainage systems by 60%. The solution is designed for flat roofs of up to a 3% incline and a minimum area of 150 m2 and is fully compatible with cold, insulated, inverted and green roofs.

The service life of the system is at least 50 years, matching the expected lifetime of the building. Pipelife's air baffles are made from an automotive-grade ASA thermoplastic material, ensuring superior UV, abrasion and impact resistance. 

"The final product exceeds customer expectations for siphonic roof drainage systems, offering the highest flow rate on the market for a standard 75-mm outlet," states Ivan Milenovic, Business Development Manager at Pipelife.  

_{Making roof drainage hassle-free: Fast installation, effortless maintenance} 

Debris buildup is one of the most common causes of roof drainage system failures. Whether due to suboptimal design or insufficient maintenance, accumulated silt and blockages can lead to overflows and water damage. 

Pipelife's siphonic roof drainage systems are self-cleaning and require minimum maintenance. Due to the perfectly smooth inner pipe surface and the high water-discharge speed, debris that might have entered the system is naturally flushed away. If cleaning of the air baffles is needed, they can be quickly removed and reattached without tools, thanks to nut fasteners. 

The system is also designed for fast, efficient and error-free installation — crucial for the uncompromised performance of drainage solutions.  

Each roof outlet is preassembled at Pipelife's factory, welded to an adjoining 50-cm tailpipe and pre-connected to an insulation block and waterproof membrane — ensuring a quick and watertight connection. Pipelife's outlets can be prefabricated with various waterproofing layers, making them compatible with most roof sealing materials, including PVC-, bitumen-, FPO- and PVB-based systems. 

The air baffle itself can be installed and removed without tools, and a wide range of compatible HDPE pipe systems and fittings is available for both butt-welding and electro-fusion joint techniques.  

"Compared to standard, non-preassembled siphonic systems, we're seeing an installation speed increase of at least 15–20%," notes Milenovic. "Since all parts come from a single supplier, the system's overall reliability is exceptionally high, ensuring optimal performance and a long service life." 

_{Design service and BIM for flat roof drainage systems}  

For optimal performance, siphonic drainage solutions must be engineered with precise hydraulic calculations. To support this, Pipelife offers comprehensive dimensioning and design services alongside its roof drainage systems, ensuring that each project is equipped with the correct system parameters.  

Based on data from architects and building services engineers, Pipelife's designers create an isometric drawing alongside a complete list of required components, specifications and cost estimates. These designs account for both typical precipitation levels and forecast peak flows. A comprehensive BIM library of system assets is also available for customers who prefer to develop their own designs. 

Given that modifications and deviations from the original construction plan are common, Pipelife provides continuous design support to its customers throughout the entire project lifecycle.  

"Our experts stay in close contact with customers not only during the design and delivery phases but also throughout installation," emphasizes Milenovic. "Unexpected changes can arise during construction. When they do, we help our customers find the best solution."