Create your own Living Roof

If you have a flat roofed shed or storage space in your outside space you have a wonderful opportunity to ‘green’ the space by adding a living roof on top of the roof. A living roof is a carpet of plants that you grow on the top of the roof to reclaim the space they take up and to improve the air quality of where you live. If you have low storage on your balcony you can make use of the space and create a green roof structure to grow plants and herbs for the kitchen.

Before you start to make your own living roof you need to assess the structure you are going to build it on. Is it solid enough to carry the weight of the frame, soil and plants? Is there somewhere for the water to drain? Have you got the right equipment to do it safely? Think about all these important issues and make sure you have solution for them before you start. If you are in any doubt, consult a professional and take advice. You do not want your structure to collapse after all the hard work!

This guide is for a flat roof, or a sloped roof in one direction. A living roof for an apex building is more skilled, so practise a little before you move onto anything more ambitious.

Sketch out you building and what it will look like. Look the depth of your finished roof, or how it will look with corner support s if you need to use them. Be sure it’s what you want before you go out and purchase anything.

You will need (2m x 1m (6ft 6 in x 3ft 3in) structure)

  • 3 x 2m (6ft 6in) lengths of 20 x 2.5cm (8 x 1″) timber
  • 2 x 1m (3ft 3in) lengths of 20 x 2.5cm (8 x 1″) timber
  • 4 x 50cm (1ft 6in) lengths of 20 x 2.5cm (8 x 1″) timber
  • 10 x L-brackets
  • Screws to attach the L-brackets
  • Butyl lining
  • 2m x 1m (6ft 6in x 3ft 3in) plywood board
  • Electric screwdriver
  • Tape measure

Build the frame

  • Build the outer frame by placing two of the long lengths of timber and two of the 3 ft 3in lengths in a rectangle on the floor. Then add a long length of timber as a central strut for strength.
  • Using the L-brackets, join together the outer sides of the green roof structure.
  • Measure carefully and use the L-brackets to attach a 2m (6ft 6in) length of wood as a central support through the middle of the framework.
  • Measure carefully again and use the L-brackets to attach the remaining lengths of wood widthways across the frame, creating a grid with six sections.
  • Line the roof of your shed with a piece of plywood wrapped in waterproof butyl lining. This will protect the roof of the shed from any potential water damage.
  • Lift the wooden frame into place.
  • If your shed has a sloping roof, nail the frame to two strong vertical posts which have been cemented into the ground on the lower side of the shed roof. Make sure it is secure, nailing it to the supports in the existing roof if necessary.
  • If you have enough butyl lining left, cut a square to snuggly fit each of the six section and overlap and secure so that no wood showing. This will protect the wood from water damage, and to stop the water from going through to the roof. Make drainage appropriate holes in each section. If you don’t have enough waterproof liner, this is optional.

Create Life

  • Fill the six sections you have created with potting compost mixed with a good amount of perlite. This will keep the weight down and provide good drainage.
  • Plant! Look for plants that are relatively low so that the wind does not carry them away in a storm or wind damage.

Great Plants for a Living Roof

The best plants for a living roof needs to be happy growing in a max depth of 10 cms of soil, likes to grow in full sun and is drought resistant. Succulents are a great choice for this.

  • Sedum matting is also a popular low-maintenance choice. A living carpet of sedum plants are grown on special matting which is simple to install. Remember to choose some evergreen species if you want year-round foliage on your roof.
  • Sedum spathulifolium ‘Cape Blanco’
  • Pulsatilla vulgaris, Pasque flower
  • Festuca glauca, Blue fescue
  • Saxifraga ‘Suendermannii’

 Be creative in the plants you choose but remember to pick those that are low maintenance as you won’t be able to get up there to tend to it. Keep a close eye on it as it establishes itself to make sure it is draining successfully and keeping healthy. It will attract a wide range of wildlife to your garden, so it’s good idea to encourage this with bird boxes or an insect hotel.

Living roofs are a great way to decrease the carbon footprint of your home, and to create a healthy atmosphere for you to relax in.

Like what we’re doing? Want to share your story or tell others? Do you have a green business in Calgary and want to get in front of a large local audience? Let’s build a green community together!