Have you ever heard of a living roof? I don’t mean a roof garden where plants grow in pots and planters, I am referring to a roof that you cover in soil and plants. The example in the image has grass growing on it, but alpine plants are ideally suited for that location too. It has excellent insulation properties that will help to keep the room below warm in the winter and cool in the summer, so you use less energy to maintain a comfortable temperature.
If you are building a flat roof extension on your home, you have the perfect opportunity to grow plants up there. Are you interested? Read on to discover how to go about it.
Your roof will need to carry more weight than an ordinary one. Explain your plans to Marcus Roofing, or any other contractor, and they will reinforce the roof to carry the extra weight. Of course, if you are putting a living roof on a shed you can add more timber supports yourself.
You must put down layers of material; each serves a purpose in the project. Here are my recommendations.
- A rubber roofing material will prevent any leaks. It is the best material for the job because it comes in one sheet and adheres to the roof surface. It is susceptible to damage, however, so be aware of it when you add other layers on top of it.
- Use large stones or boards around the edge of the roof to retain the garden. If you are using boards, drill holes in them to allow for drainage.
- Pond liner goes down next. It is one hundred percent leak proof as long as you don’t damage it.
- A layer of gravel will help with drainage. Make it at least 50mm thick; now you can see how the extra weight builds up.
- A layer of weed resistant membrane that you would usually use to suppress plant and weed growth goes down next. It is used to prevent plant roots finding their way into the gravel.
- Put down a moisture blanket that you can buy off a roll from your local garden centre, to hold on to valuable water, so that the soil will not dry out too quickly.
- A layer of potting compost comes next. Buy a high quality product because it is likely to be up there for a long time. Add a layer of at least fifteen centimeters, preferably more.
- Add a further fifteen centimeters of topsoil, and you are ready to introduce some plants.
You can plant anything you like up there. As mentioned earlier, alpine plants are resilient in dry conditions, so if you don’t want to water up there throughout the summer, they are a suitable choice. There is nothing to stop you growing food up there if you wish, as long as you don’t plant root vegetables that could damage the roof.
If you want a quirky feature that will get people talking, a living roof is for you. When you tell people about it, they will be astounded, and impressed. The wildlife will thank you for it too, so it has many advantages.