Retention roof (Blue roof)
A green roof with additional water storage capacity, ideal for urban areas to reduce flooding and sewer loading. The system captures rainwater and discharges it in a controlled manner, contributing to sustainable water management.
Requesting a quoteWhy choose Retention Roofing
Maximum water buffering, cooling and future-proof water drainage in one smart roof solution.
Water buffering and reduced flooding
A retention roof captures large amounts of rainwater and releases it delayed, reducing peak loads on the sewer system and preventing flooding.
Cooling and better indoor climate
The stored water and vegetation provide natural cooling, reducing heat stress and contributing to a more stable and comfortable indoor climate.
Sustainable and future-proof
Retention roofs respond to more stringent climate requirements and can contribute to subsidies, water management and longer roof life.
The retention roof from Green Roof Specialist
This package has an extra-thick drainage layer that can capture and retain large amounts of rainwater, combined with a smart water management system that provides controlled drainage of excess water. This prevents flooding and allows the roof to effectively contribute to improved water management even during heavy rainfall.
Technical data
Water buffering: 75-100 L/m²
Weight saturated: 120-200 kg/m²
Must be placed on a 0 to 2% slope
Construction Retention Roof
A properly constructed retention roof will last for years and requires little maintenance. The combination of water-buffering and draining layers temporarily stores and disposes of rainwater in a controlled manner, reducing sewer load and providing a sustainably functioning roof.
1
Vegetation layer (sedum or herbs)
2
Substrate layer (growth layer)
3
Drainage mat + filter fleece (20 mm) Root resistant
4
Drainage and retention layer (water buffering)
5
Roof garden substrate extensive (50 mm substrate, bagged)
More about the retention roof
A smart solution for stormwater management
The Retention Roof, also known as a blue roof, offers an innovative approach to rainwater harvesting and management. With a water buffering capacity of 75 to 100 liters per square meter, this green roof significantly reduces the load on the sewer system during heavy rainfall events. The roof temporarily retains water and discharges it slowly, effectively preventing flooding in urban areas.
Durable and multifunctional
In addition to collecting rainwater, the Retention Roof contributes to a better microclimate and helps cool buildings in the summer. The water management system is fully integrated into the structure of the roof, making it not only functional but also contributing to a greener and more livable environment. This makes the Retention Roof an excellent choice for projects that value sustainability and climate adaptation.
Suitable for flat roofs
The Retention Roof is specifically designed for roofs with a minimum slope of 0 to 2%. This makes it ideal for flat roofs of residential, office and commercial properties. With its robust design and durable materials, the system can withstand large amounts of water and long-term loads, making it long-lasting and reliable.
Frequently asked questions about Retentia roof (blue roof)
A Retentia Roof, also known as a Blue Roof, is a green roof specifically designed to collect and dispose of rainwater in a controlled manner. It combines a vegetation layer with an extra-thick drainage layer and a smart water management system to prevent flooding in urban areas.
A Retention Roof is designed for flat roofs with a slope of 0 to 2%. The system is not suitable for pitched roofs because of the specific requirements for water storage and stability.
The Retention Roof requires minimal maintenance. Annual maintenance includes checking drainage, removing weeds and inspecting the vegetation layer. This ensures that the system continues to function optimally.
The Retention Roof has a water buffering capacity of 75 to 100 liters per square meter. This makes it an excellent solution for stormwater management in areas where flooding is a problem.
Although it is technically possible to install a Retentia roof yourself, it is recommended to leave it to professionals. Installation requires specific knowledge of water management systems and stabilization techniques.
With proper maintenance, a Retentia roof can have a lifespan of 20 to 50 years. The use of high-quality materials and robust design contributes to the system’s durability.
The cost of a Retentia roof depends on the size of the roof, the materials used and the installation. You can calculate a price indication on Groendakspecialist.nl and request a no-obligation quote.
Groendakpecialist.co.uk offers a total service for Retention Roofs, including advice, design, delivery, professional installation and maintenance. They guide you through every step of the process.
Yes, Retention Roofs are often eligible for grants because of their contribution to stormwater management and sustainability. Greenroofspecialist.com can help you apply for available subsidies.
Yes, Groendakpecialist.co.uk offers maintenance contracts and one-time maintenance services to ensure that your Retentia roof continues to function optimally and remain in good condition.
Turnaround time depends on the size and complexity of the project. After agreeing to the quote, installation is usually scheduled and performed within a few weeks.
Contact Groendakspecialist.nl via the website or by phone at 070 – 20 42 092. You’ll receive free advice, a no-obligation quote and can schedule a roof inspection to discuss your options.
