If you have limited garden space or you want a greener surrounding for wildlife in your urban paradise, then installing a green roof is a great idea.
What are green roofs?
Also known as living roofs, green roofs are a fantastic sustainable feature. They can range from roof gardens with raised beds and green carpets, to roofs with planting cells covered in grasses, shrubs, and low growing perennials.
You can add a green roof to your existing garden shed. Or, if you are feeling adventurous, use can cover your main house roof with one.
Green roofs can vary depending on the manufacturer, but the three basic types are:
The intensive green roof
This is a thick layer of soil in which a large variety of flowers, grasses, herbs, and shrubs can grow. Depending on the size, intensive green roofs can even make lovely recreation spaces.
The extensive green roof
An extensive green roof is a shallower layer of soil in which low-growing grasses, moss and sedum can grow. They require much less maintenance than intensive roofs.
The semi-extensive green roof
A semi-extensive green roof is lightly deeper than extensive roofs. But it’s still low-maintenance.
Benefits of green roofs
Having a green roof as a number of positive side-effects which may not be the main motivation for building one but certainly supports your case for taking on the project.
🌱 Improved drainage
The vegetation on a green roof absorbs rainwater which is then released back into the environment naturally through evaporation. And this drainage layer delays the discharge of rainwater into sewage, which stabilises groundwater level and minimises flooding risk.
🌱 Purer, more breathable air
Plants convert carbon dioxide into oxygen, which removes toxins from the air. That means a green roof can help to purify the air around your home and garden. Air pollution is a silent but big killer in the UK, with an estimated 28,000 – 36,000 deaths a year due to long term exposure to the pollution. So green roofs are a small step in the right direction, especially in urban areas.
🌱 Better thermal insulation
One of the biggest advantages of a green roof is its insulating properties. Many British homes lack proper insulation, leading to heat loss in winter and overheating in the summer months. This also makes your energy bills much higher than they should be. Green roofs are a great insulator, as the plants absorb sunlight and reduce the temperature of the house in the summer, and trap heat in the winter.
🌱 Reduces noise inside your house
As well as insulating heat, green roofs also insulate noise. Plants and vegetation are a great sound barrier and can make a much quieter environment within your home.
🌱 Increase biodiversity in your garden
Green roofs support diverse wildlife attracting birds and insects depending on the type of vegetation that’s planted. Bees and butterflies will love your new rooftop wildflower mini-meadow.
🌱 Extends life span of roof
Roofs go through a lot of battering each year – wind, snow, rain, UV light and fluctuating temperatures. Green roofs can double the life expectancy of your roof by providing a barrier of greenery protecting the slate or felt underneath.
Downsides
As long as the green roof is assembled by a reputable carpenter or roofer with the correct waterproofing barrier in place, there really aren’t many downsides. Costs of materials are relatively cheap depending on the size of your chosen roof garden and shrubs can be planted over time. Or fill it with soil and let nature take its course.
Always consider the weight of your roof garden. When soaked through with rainwater it will weigh a substantial amount. Assume a rectangular green roof 2m x 2m x 0.15m will weigh at least 50kg – 100kg depending on the materials used and will weigh more when wet.
Cost
The cost of green roofs can vary depending on the material, size and type of roofing, but indicative costs are between £60m² and £140m².
OPOH recommends
Eco Green Roofs are one of the market leaders in the UK for eco-friendly roofing. They supply green roofs, blue roofs, and solar panel roofing. The company offers handy extras as well, such as expert advice, installation, and maintenance. They also offer insurance cover for all their roofs so you can have full peace of mind.
And if you want to try a green roof, the garden shed roof is a great starting place for a cheaper build cost and low risk entry into the world of roof-top meadows.