How To Create A Green Roof On Your Garden Shed
Developing additional green spaces is paramount to this planets’ well being.
Natural green areas are becoming more and more scarce, particularly in cities and towns, we can help the environment by using all the outdoor space we have to grow plants in.
So let’s take a look at how to create a green roof on your garden shed.
Benefits Of A Green Roof
There are many benefits that we can reap from a beautiful living roof.
- Living roofs attract pollinators and other wildlife by creating a natural habitat for all types of flora and fauna, insects, invertebrates, birds and small animals
- They provide habitat, shelter and food
- A green roof will increase the biodiversity in and around your garden
- A green roof aids in flood reduction by taking up water and reducing rainfall run off. Thereby reducing pollutants going into the ground
- Aids in improving air quality by reducing pollutants and harmful dust particles in the surrounding environment
- A living roof absorbs heat. In cities the temperature difference in comparison to a more rural area can be up to 5 degrees
- A green roof can help to lower the temperature by absorbing heat, natural evaporation of water from plants and growing medium helps to cool the air
- A green roof is more aesthetically pleasing to the eye, helping to blend a building into it’s natural surroundings
- It also helps to replace the growing area used up by the garden building in the first place
Other ways of increasing ecological diversity in your garden can be found in my article, how to make a rain garden.
Rain gardens go a long way to protecting our surroundings from flooding and pollution.
How Does A Green Roof Protect Your Building?
A green roof will help to increase the life expectancy of the building it is on.
Research shows that landscaping protects the waterproof membrane, in fact it can increase the design life of the shed roof by reducing UV and thermal damage.
Living roofs improve insulation and help with noise reduction.
Main Points To consider When Creating A Green Roof
There are a few things to consider before you begin creating a green roof.
The main points are:
The type of roof you wish to build a green roof onto
I am dealing with pent roof sheds but you can use the same method to build onto an apex shed or summerhouse. You could also create a green roof on refuse bin sheds, bike sheds, playhouses etc.
Main buildings will need more expert advice and possible planning consent.
The cost can be kept very low, and does depend on the size of the roof you’re planning. Plant mats are available and are priced per square meter. You can also grow plants from seed or propagate from existing plants to keep costs down.
A list is provided below
Which plants to use
This depends on the desired effect but generally sedums, Sempervivums or wildflower mixes are used
The ideal angle of the roof is between 1 and 5 degrees. If the roof is completely flat rain water cannot run off, leaving plants waterlogged. Too steep a pitch and the plants can become scorched and dehydrated.
With all garden design schemes, the rule “ right plant right place” applies. Green roofs are no exception, sedums, grasses and wildflowers need some sunshine…a roof in deep shade will not provide the best growing environment.
Some occasional maintenance of your green roof is required. Can you safely access the roof to maintain the roof and plants?
Is the building sufficiently strong enough to bear the weight of a green roof?
You would be advised to strengthen the roof prior to creating a green roof on it
How To Reinforce The Shed Roof
I recommend that you reinforce the shed roof before installing a living roof. You are about to add extra weight to the shed in terms of soil/growing medium, plant mats and a wooden frame so please do ensure that the roof is strong enough.
You can easily do this by adding additional support beams underneath the roof. By doing so you ensure a more even distribution of the extra weight.
What You Will Need For Your Green Roof
- Or pre planted Sedum/seed mats
- Growing medium
- Waterproof membrane
- Sedum Protective fleece
- Tantalised timber sufficient to build a frame with a 3cm lip on the existing roof
- Tools such as drill and drill bits, screw driver, scissors, galvanised screws, hammer/staple gun
- Protective equipment such as gloves and goggles
How To Create A Green Roof On Your Garden Shed
Your step-by-step guide:
It is not difficult to create your green roof. DIY enthusiasts from novice to experienced can soon build what is required. It is in fact, the perfect “Lockdown” garden project which will give you years of pleasure and knowledge that you have done something towards helping your surrounding environment.
- Build the wooden frame.
Carefully measure and cut the tanalised wood. Build your box frame to fit your existing shed roof. You need a 3cm lip around the roof felt. The waterproof membrane and fleece will be fitted into it and it will hold the growing medium and plants.
Do not attach the piece for the lower edge of the roof until after the waterproof membrane has been attached.
2. Use galvanised screws to secure the frame to the shed roof.
3. Measure and cut the waterproof membrane ( pond liner is ideal ) to fit inside the frame, and to come up the sides. This ensures that the shed roofing felt remains watertight and undamaged. Rainwater will drain off more effectively. Carefully secure it using a staple gun or hammer and tacks
4. Fit the final piece of the frame with the waterproof membrane overlapping the edge of the shed roof felt. Water will drain off from this edge.
5. Measure and cut to size the protective sedum fleece and fit it into the frame. This helps to protect your sedum plants and the roofs as it is impermeable.
6. Add a layer of growing medium, for sedums this should be a low nutrient mix of crushed stone, sand and grit with very little soil. 2cm depth is all you need. Use the rake to spread it evenly.
7. If using pre planted mats, cut them to size, water them, then fit them into the frame. Or plant your individual sedums or wildflower seedlings.
8. Water daily over the next few weeks or until plants are established.
9. Sit back with a well-earned cuppa and wait for your green roof to take on a life of its own.
Best Plants For Green Roofs
Green Roof Plant Mats are the most perfect way of getting a great mix of plants for your roof.
Or you can choose and plant your own selection. Sedum plants come in many lovely varieties. I have listed some possible contenders below.
- Sedum Hespanicum
- Sedum Reflexum
- Sedum Album coral carpet
- Album Athoum
- Album Mini
- Sedum Weihenstephaner Gold
- Sedum Acre Aureurm
- Sedum Summer Glory
Use a good mix of wildflowers for you green roof, to ensure you attract a wide diversity of wildlife. Bees and butterfly plants
- Herb Robert
- Rock Rose
- Wild Strawberry
- Birdsfoot Trefoil
- Wild Violets
- Sea Campion
Sempervivums (house leeks) are also ideal for green roof planting.
Where To Buy Plants For Green Roofs
I may earn commission when you shop through the links in this article.
You can help to improve air quality and reduce noise pollution in your garden and surrounding areas by planting a hedge, here’s how hedging works. Best Plants To Combat Pollution In Your Garden
I hope that this article has been helpful to you, encouraging you to create a green roof on your garden shed. Even small spaces can be filled with plants to provide more, much needed greenery. Help the environment and wildlife and build your living roof today.
Please share this article with friends and family and on social media, let’s grow green roofs everywhere.
If you have any questions about this or any other article then add them to the comments box below. I love to hear from you and I always reply as soon as possible.