Pondering over installing a green roof? Experts share their essential advice for beginners, encompassing installation procedures, costs, maintenance, and suitable plant choices.
A green roof, also known as a living or sedum roof, is a unique and environmentally friendly alternative to traditional roofing. These roofs are partially or completely covered with plants, offering a host of benefits and contributing to a greener urban landscape.
But before embarking on this eco-friendly journey, it's essential to consider several key factors to ensure a successful and safe installation.
Structural Capacity
Green roofs add significant weight due to layers such as waterproofing, root barrier, drainage, filter fabric, growing medium, and plants. A professional structural engineer should evaluate whether your existing roof can bear this load safely.
Type of Green Roof
There are three main types of green roofs: extensive, semi-extensive, intensive, and brown roof. Extensive green roofs are lighter, with shallow soil and low-maintenance plants, suitable for lighter roofs. Intensive green roofs require deeper soil and support a wider variety of plants but are heavier.
Roof Slope
Green roofs work best with a slope under 20%. Steeper roofs may require additional structural support and erosion control measures.
Waterproofing and Drainage
Proper waterproof membranes and root barriers are essential to prevent leaks and root damage. Drainage layers and filter fabrics help manage water and maintain plant health.
Fire Safety
Updated fire safety guidance requires compliance with regulations on fire breaks and materials used in green roofs to reduce risk. Best practice guidance is available and should be followed to ensure safety.
Building Regulations and Permissions
Rules vary by location; some green roofs may require planning permission or adherence to building codes concerning load-bearing capacity and safety.
Maintenance Requirements
Different plant selections and roof systems have varied maintenance needs, which should align with your availability to care for the roof. Regular visual inspections can help identify potential issues.
Cost
Installation is more expensive than traditional roofs, partly due to structural reinforcements needed to support the additional load. The cost of a green roof installation can vary significantly based on the type, size, and construction method, with an approximate guide of £600 - £1400 for a 20m2 extensive wildflower green roof.
Advantages of a Green Roof
Green roofs offer numerous advantages, including increased biodiversity, additional insulation, improved lifespan of the roof, minimal maintenance, absorption of CO2 and heat, aesthetic benefits, and the ability to be installed on various structures.
Choosing the Right Plants
Grasses, mosses, sedum, and certain types of wildflowers are common plants for green roofs. Choosing plants native to the local area is a sound choice for green roofs. The Royal Horticultural Society provides detailed information on suitable plants for green roofs.
DIY or Professional Installation
While it is possible to install a green roof yourself, it's advisable to work with a professional to ensure it is done correctly. Pre-grown sedum mats are available for easy installation.
In summary, the safest and most effective way to proceed is to consult with roofing specialists and structural engineers, review local building codes, and plan your green roof system according to your roof's characteristics and your maintenance capacity. If installed correctly and properly maintained, a green roof can last between 40 and 50 years, providing a beautiful, eco-friendly, and sustainable solution for your home or business.
- For a successful and safe installation of a green roof, one should consult with roofing specialists and structural engineers to ensure the existing roof can bear the additional weight.
- The type of green roof chosen, such as extensive, semi-extensive, intensive, and brown roof, will depend on the structural capacity of the roof and maintenance requirements.
- Proper waterproof membranes, root barriers, drainage layers, and filter fabrics are crucial for preventing leaks and maintaining plant health.
- Incorporating native plants, such as grasses, mosses, sedum, and wildflowers, can support local biodiversity and reduce maintenance needs.
- The initial installation cost is higher than traditional roofs, but this investment can yield benefits like increased insulation, CO2 absorption, and aesthetic appeal.
- One can choose between DIY installation or professional installation for a green roof, with pre-grown sedum mats available for easier setups. For a long-lasting green roof (between 40 to 50 years), proper planning, professional guidance, and regular maintenance are key.
