How to Make a Green Roof on a Shed

Green roofs – the perfect way to give your shed a makeover. Besides being very interesting and fun to look at, a green shed roof also comes with a list of benefits for Mother Nature.

But how does one make a green roof? As with most types of more “unconventional” garden projects, creating a green roof for your shed may sound a bit intimidating, but when in reality, it’s not. With that being said, in this article we are going to cover everything that you need to know about this type of garden project. So, if you someone that: 

• wants to know what are the benefits of green roofs;
• is interested in the different types of green roofs;
• wonders how to install their very own one.

We got you covered! 

What are green roofs and what are their benefits

As you can already guess by the name, green roofs are roofs that are partially or completely covered in vegetation. They can provide many benefits for your green space, including the following:

• You prolong the life of your shed;
• Green roofs attract wildlife, such as bees, butterflies, and birds; 
• They can improve the overall air quality;
• A green roof helps out the environment by reducing carbon dioxide emissions;
• They are just nice to look at.

Now that we’ve got the advantages of having a green roof covered, let’s talk about the different types, starting off with…

Extensive green roofs

These living roofs are most suitable for homeowners. They are lightweight, easy to maintain, and usually require little to no additional watering. Extensive green roofs can be built on top of existing or new roof decks. A charming low layer of vegetation is best for these types of roofs, because bigger plants are too heavy for the structure. You will  typically find sedum, grass, moss, or small flowers gracing an extensive green roof.

Intensive green roofs

Also called roof gardens, they are designed to support larger vegetation, such as small trees, bushes, and plants. Naturally, this requires irrigation options, as well as more structural stability to support the additional weight. You would normally find intensive green roofs on top of larger commercial buildings, where they are also used to provide green spaces for employees to use on their breaks.

Semi-extensive green roofs

A mix between the two types of green roofs mentioned above, semi-extensive living roofs are built similarly to extensive ones, but have a deeper growing substrate, meaning that they can support a variety of plants, but not bushes and trees.

How to plan your green shed roof

To get a great and functional green roof, you can’t just lay a carpet of sedums and expect them to just grow. There is a certain science to it. Fortunately, it’s not that difficult and almost anyone with a bit of gardening and handyman knowledge can create a good-looking, functional living roof.

Most green roofs include the following layers:

• Waterproof membrane
• Root barrier
• Drainage membrane
• Filter layer
• Growing medium/Substrate
• Vegetation

The waterproof and root barrier layers are laid in order to protect the roof from water damage and the roots of the plants. 

The drainage membrane serves to prevent structural damage, as well as saturation of the plants, since it ensures that the water drains away into the gutters and downpipes.

The filter layer prevents the substrate layer and debris from filling the drainage membrane cavities and stops the water outflow process.

The key to a successful green roof is to choose the best growing medium/vegetation combination. Many people think that they can only use soil as a substrate or that a sedum blanket doesn’t require one at all. Needless to say, that is not the case. While sedum roots are relatively shallow, a growing medium of at least 5cm is best. The perfect substrate is lightweight so as not to bear down on the shed itself, absorbent to support the plant growth needs, but also porous enough to assist with the drainage process. 

There are many commercially available growing mediums that are a blend of organic and non-organic materials, which create the perfect conditions for your plants. Some places even offer custom made substrates that can be tailored to your and your vegetation’s needs. It is a good idea to consult with a local supplier to find out what is best for your green roof shed.

It is vital to take note of how much the green roof weighs once the layers are substantially saturated. Reinforcing the shed or installing corner posts to bear the weight of the living roof may be needed. 

You can also install living roofs on sheds with a pitched roof up to 30 degrees. In that case, creating separate compartments is the best option in order to prevent the growing medium and vegetation from slipping down under its own weight. 

Step by step green shed roof installation process

Step 1

The first step is to measure and cut to size a piece of waterproof membrane, which you will need to attach to the sides of your shed roof.

Step 2

The next thing to do is to build the frame of the green shed roof. Cut 4 pieces of timber and screw them together to create a square or rectangle. Use decking screws to secure the frame onto the roof. Afterwards, drill drainage holes at the lower end. 

Step 3

For the third step, cut to size your plastic root barrier and overlap the waterproof membrane. This layer protects your shed from the roots of the vegetation. 

Step 4

Lay down a layer of gravel that is approximately 3 cm deep. What this does is that it improves the drainage of water and the aeration of the plants. Alternatively, you can use a drainage membrane, which is a porous material that helps rain water drain away, without causing structural damage or oversaturating the plant roots.

Step 5

Next comes the filter layer, which serves to protect the pores of the drainage membrane from getting clogged up with soil and other substrates. This layer is optional, if you have decided on gravel in the previous step.

Step 6

Depending on the vegetation that you have chosen and the structural characteristics of your shed, pour the substrate on top of all the other layers to the required depth. Spread the growing medium evenly.

Step 7

The final and probably most enjoyable step for all of you gardenheads out there is to plant your living roof seeds or the plants themselves. If you have chosen to use a sedum matt, unroll it over the growing medium.

What you can plant on your shed’s roof

Depending on your preferences, you can either use pre-vegetated blankets, plant cuttings, seeds, or already established plants.

The easiest option is to lay ready-to-roll sedum carpets on your green roof. You can also plant seeds or transplant vegetation directly into your growing medium. Sedums are alpine species, which don’t require a lot of maintenance and can withstand the harsher weather conditions.

It’s best to use a variety of species for your living roof, because not only will it look better and livelier this way, but will also make your small garden more resilient to pests. In fact, many suppliers and stores offer green roof seed mixes, especially chosen to ensure a self-maintaining, weather-resilient plant community. These collections usually include a variety of sedums and wild flowers. 

If you decide to select the species for your living roof yourself and you have a pitched roof, make sure to seed the drought-resistant plants near the top.

Another pro tip is to set up your garden in either spring or autumn. This way you will make the most of rainwater, without having to put extra time into maintenance.

Living shed roof maintenance 

Green shed roofs are known for providing a stylish yet effortless look to your garden. Maintenance requirements are low. However, there are a few things that you should check every now and again to ensure that your living roof is healthy.

First and foremost, make sure to water your plants during dry seasons, especially in the first year of planting. Afterwards, you need to water them only when there’s 6 or more weeks of drought. Bear in mind that excessive watering can damage or even kill your plants, so make sure not to overdo it.

Another important tip for maintaining your green roof is to check whether the drainage is working properly. Make sure that the outlets are clear from debris and vegetation.

If you see that parts of the roof have become bare, replant them with seeds, cuttings, or existing plants. Also, remove any weeds. This way your living roof will look nice and tidy.

Get Fantastic Services to help you out!

If you want to spruce up your green space by creating a green roof on your shed, but don’t have the time or the DIY skills, why not get help from Fantastic Services? We offer professional gardening services that can help you grow the perfect green roof! The specialists that we work with are highly experienced, work with industry-grade tools, products, and materials, so you can expect only the best service results. No matter if you need assistance with planning and designing your living roof or with supplying the materials and installation, Fantastic Services have got you covered!

We hope that you found our article on how to make a green roof on a shed helpful. Let us know what you would plant on your living roof in the comment section below!

Image source: Shutterstock /chorowitz