Green roofs: waterproofing products contribute to sustainability

Green roofs bring numerous benefits, yet their design and installation demand strict waterproofing measures to ensure their longevity. Proper waterproofing not only extends the life of the roof but also enhances home protection through thermal insulation, soundproofing, and preventing infiltration caused by plant growth or natural precipitation.

The benefits of green roofs

The popularity of green roofs is rising due to their multifaceted advantages, enhancing both residential living and environmental health. They offer:

1. Rainwater retention to mitigate run-off and flooding.
2. Thermal insulation, keeping homes cooler in summer and warmer in winter.
3. Sound insulation, reducing external noise and the sound of precipitation like rain or hail.
4. Enhanced roof longevity, safeguarded against UV rays and temperature extremes.
5. A haven for biodiversity, including birds and pollinating insects.
6. Reduction of urban heat.
7. Potential for agricultural use, like vegetable gardens and beehives.
8. CO2 absorption and filtration of fine particles and pollutants.

Waterproofing a green roof

For a green roof to be effective, it must be watertight and durable. The waterproof bitumen roofing is layered with:

– A mechanical protection layer to prevent root contact with the bitumen.

– A drainage layer, consisting of materials like coconut fiber mats, composite mats, clay granulate, or grooved polystyrene panels, to remove excess rainwater.

– A filter layer made from a geotextile membrane, preventing substrate blockage in the drainage layer.

– A substrate layer that supports plants and retains essential water, air, and nutrients.

Choosing bitumen for a perfectly watertight green roof

Bitumen is a prime choice for waterproofing green roofs due to its impermeability, flexibility, and adaptability to temperature changes. Increasingly eco-friendly, it’s recyclable and offers long-lasting protection against leaks and water damage. Its ease of installation and repair, coupled with low cost, make bitumen an attractive waterproofing solution.

How to lay a layer of bitumen to support your green roof

The application of the bitumen layer requires a clean, dry, and debris-free roof surface. A bituminous primer is applied first to enhance the adhesion between the bitumen and the substrate. Bitumen rolls are then laid side by side, heated with a blowtorch, and welded together, ensuring a watertight seal at the joints.