Are you considering creating a green roof? There are many advantages to creating this type of roof, but it does require some careful planning and construction to make certain it really works for you.

Here’s all you need to know about planning and building your green roof.

What types of green roofs can you install?

There are three main types of green roofs to choose from depending on your budget and how much work you are willing to have done.

Extensive green roof

The first kind is an extensive green roof, which is the most popular. It requires virtually no maintenance and very little watering unless there is a drought. The extensive green roof uses grass and moss or sedum to cover the roof. None of these plants grows more than 10cm tall and creates a thick, low layer of greenery.

This type of roof does not require ongoing maintenance, though you can spray with water if there is a prolonged dry period. The extensive green roof is easy to build and can be on a slope, as the plants are low and will cling to the growth medium.

Intensive green roof

The second type of roof is the intensive green roof. These are meant to be garden rooftops in most cases and can handle larger and more care intensive plants, such as bushes, herbs and even small trees. You’ll need to include a layer of growth medium to ensure everything grows well. This type of roof usually requires you to get up on top of it and you’ll need to include irrigation. You’ll also need to perform more maintenance, as this is essentially a garden on a roof.

Semi extensive roof

Finally, you have the mixed roof, the semi-extensive roof. It uses lower growing plants (up to 20cm tall) so there are many different options, but it is not meant for trees and shrubs. You can plant grasses, flowers, or anything else you like. These types of roofs can be planted on sloping roofs, or on flat ones, depending on your preference. The end result will be a lovely space that helps protect your building and provides environmental benefits to those in the area.

Depending on how much work you want to put into your roof, you can determine which types of plants to include. Just remember that the roof must be able to support the extra weight with water, soil, and plants.

The Benefits of a Green Roof

Any amount of research will tell you that there are countless benefits to having a green roof. These include:

• Rainwater Buffer: The roof will use up much of the rain that falls on it. This helps prevent pooling on the ground and possible issues with water damage in your basement. It reduces the peak load on your drainage system, as well and lowers the chances of flooding. The rain is also cleaned as it goes through plants and soil, so purer water is released back to the earth.
• Cooler Air: Thanks to the fact that plants absorb and reflect sunlight, you’ll actually get a noticeably cooler ambiance around a green roof. In fact, green roofs and garden roofs have been shown to lower city temperatures by up to 3º. That’s an impressive drop and it can mean there is a major improvement in the summer if more people add green roofs.
• Purer Air: The plants help filter smog and pollution from the air and they also turn carbon dioxide into oxygen, giving your neighbourhood better, fresher air and more oxygen.
• Boost Biodiviersity: When you plant a green roof, it becomes a habitat for plenty of fauna in the area. Everything from birds and squirrels to butterflies and other insects will make their home there. This improves the biodiversity, particularly in areas where concrete has overtaken most of the greenery.
• Improve Solar Panel Efficiency: Did you know that cooler temperatures work better for solar panels? When you plant a green roof around your panels, they can work more efficiently and are better able to convert sunlight to energy.
• Lower Energy Usage: Flatter roofs tend to reduce energy bills, thanks to the minimal overhead space. Sloped roofs often trap warm air and that requires more energy to remove it.
• Reduced Construction Costs: Building a green roof is usually much cheaper than building a regular gabled or sloped roof. The more complex the angles, the more you end up paying. A flatter roof, which is usually what you’ll have for a green roof (though non-garden roofs may be planted on a sloped roof) is cheaper to build and this can reduce your overall costs.
• Lower Noise Pollution: The greenery on the roof not only insulates your home from outside noise, it also absorbs sound, creating a sound barrier that keeps your home or business quieter.
• Roof Protection: Your roof will last longer when you have a green roof. While it may seem like having plants on the roof is more likely to wear out the roof, the opposite is true. In fact, it can double or even triple the longevity of your roof, simply by adding plants. This is because it reduces the damage from rain, sun, and wind and maintains a fairly even temperature, all of which helps increase the lifespan of your roof.
• Boost Moods: Being surrounded by plants is good for your mental health, so load up your roof and take a stroll among the plants.
• Increase Building Value: A building with a green roof, thanks to the many benefits of having plants on your roof, is able to sell for a higher price. People are on the lookout for a building that has this many benefits.
• Fire Resistance: Your home will be more fire resistant with a layer of greenery atop the roof. The plants have a lot of moisture in them, and soil is not flammable, so you can actually help protect your building this way.

There are so many benefits to having a green roof that it would be ridiculous not to consider it for any flat or low sloping roof.

Who Can Build a Green Roof?

There are quite a few considerations when building a green roof and while it’s possible to do it yourself if you have the necessary skills and experience, it’s usually best to leave it to a professional roofing company, as they know what they’re doing and how to ensure the home is watertight.

The roof will need to be built carefully, with the proper barriers to prevent water and roots from wreaking havoc on the rooftop. This involves placing waterproofing layers, drainage membranes, and growth medium to ensure the entire roof works to support plants and still stay structurally sound.

It’s important to select a roofing company that understands the value of a green roof and has the necessary experience to create a watertight space for you to grow plants. Since many of these roofs are flat roofs, you have to ensure that they don’t have drainage issues, which can become a major problem. Standing water on a roof is never a good thing and that must be avoided from the start.

Look for a roofing company that can show you examples of their work. It’s even better if they have plenty of good reviews or if they are recommended by someone else you know and trust. A simple way to do this is to look for a green roof that you like in your area and then ask who handled the building. You can also look online to find a roofing company near you.

Should Your Green Roof Be a Garden Roof?

One option you have is to create a garden on the roof, rather than just having basic greens. This requires more planning, as it means you will be walking on the roof and not just planting there. However, you can turn it into a place where you grow fruit and vegetables, which can mean your home actually becomes a useful household garden where you can collect plants for food.

The selection of plants will determine if you are going to have a garden roof or not. Any taller plants will be more of a garden roof, but they also make the space even more useful. Whether you grow flowers and decorative plants or fruits and vegetables, the space is more useful because you can enjoy it. Add a bench and you can sit out in the garden and enjoy the beauty.

Are you ready to start planning your green roof? There are plenty of roofing companies out there, but if you want highly experienced roofers who know their way around a flat roof and a green roof, you want to talk to James Dunn Roofing. Contact us today to get a quote for your project.