How To Make A Green Roof

How to make a green roof? – A green roof is a specific type of roof arrangement over a building that is either partially or fully covered with growing medium, as well as vegetation; it is planted over a specially designed water proofing membrane that ensures protection to the tradition roof of a building.

Green roofs are constructed by merging a number of layers over a normal roof in order to create a proper root barrier, an irrigation system, as well as drainage.

In some areas green roofs are installed just to create a specialized recreation place for local communities, it also contributes to the establishment of habitats for various insects, and bees, as well as birds, as they live a difficult life in urban areas.

Analysis says that green roofs are the perfect tool for controlling undesired climate changes in cities as well as towns.

These roofs can also contribute in the prevention of localized flooding because they work effectively to reduce the intensity or volume of water by absorbing some of it and directing the remaining part over the right path.

You will be happy to hear that green roofs provide a perfect control over the heating system of buildings, as in the winter season they add warmth to rooms, whereas in the summer season they contribute in the improvement of cooling for the buildings.

If you are searching for how to build a green roof, then the following information can be very useful for you; in order to install green roofs over traditional roofs we need to make some specific arrangements and the first step is to start proper planning for execution of this task.

Although this installation task must be executed by experts only,  many people prefer to follow DIY Green Roofing procedures.

For those people, here is a list of considerations that play an important role in green roofing installation:

  • Dimensions:

First of all, you have to make proper measurements for the overall dimensions of your roof so that you can estimate the required amount of wood for creation of the frame. Including this, you will need a specialized pond liner that helps to cover the complete roof surface as well as small overlaps.

  • Strengthening:

Note that the timber type frames, as well as growing medium contribute to some additional weight over a traditional roof; and this amount will further increase in rainy season when the green roof will absorb some quantity of water. So, in order to prevent cases of roof damage you have to make proper arrangements for strengthening of the original roof; by installing some type of support system to keep it strong under all conditions.

  • Materials:

Here is list of some basic materials that are required for green roof installation; these items must be collected by all those who are searching hard about how to make a green roof:

  • Tannalised pine wood material for a frame having the size 6 inches by 2 inches.
  • Tannalised pine wood is also required for construction of internal frames: size parameters are 4 inches by 2 inches.
  • You need some 5 inches’ as well as 2 inches’ screws.
  • 8 *90 degree type angle brackets.
  • Wood type end grain preserver.
  • Garden pond liner.
  • Graded soil.

Other than this, you will need some specific tools for green roof building such as a trowel for planting, buckets for lifting growing medium up to the roof, a spade for growing medium mixing, a staple gun and staples, a handheld type of electric powered drill, a paint brush, Stanley knife, a hand saw, pencil, measuring tape and ladders.


Before you start with green roof building; ensure that you have collected enough information about your roof design.

First of all, you must know about the angle of roof over which you want to construct your green roof. In case  this angle is more than 30 degrees, then green roofing is not preferred or you must get some advice from the experts.

Whereas for angles ranging below 2 degrees, as well as above 20 degrees, some specific design considerations are required.

One must also have a proper idea about the approximated weight of a green roof; generally, the simplest and lightest weighted green roof system will possess a total weight of about 150 Kg/m2.

Then, the next important part of green roof building is its design considerations; you have to design a strong, full frame that will surround the perimeter of the roof in order to hold all of the green roof materials.

In case the roof has an angle of more than 20 degrees, then you must ensure that it does not contribute to erosion, as well as that the plant layer will not face slipping or slumping with its weight.

All green roofs need an additional layer for waterproofing that is made up of bitumen felt or asphalt; one can make use of a heavy duty type of pond liner. Only one sheet is required so it can be fixed up with strong mastic sealant easily. A green roof generally possesses a total of five layers that include: waterproof membrane, drainage layer, filter layer, substrate as well as the planted portion.

The drainage layer is highly useful for those roofs in which the maximum angle is not more than 10 degrees. For roofs which have steeper angles, this layer is not required, as they provide natural drainage to water with an effective tilt.

This drainage layer can be constructed using some plastic material or can be designed using some course material such as expanded shade, pumice or gravel.

These layers are designed with perfect outlets so that water can find an easy path for draining.

Those who are thinking about how to build a green roof can go through the detailed information regarding the drainage process because it plays a very important role in green roofing.

After the drainage layer, we move ahead towards the installation of a Filter layer that provides effective separation between drainage, as well as the substrate layer.

The primary purpose of this layer is to provide strength to the soil by holding it tight so that soil clogging can be avoided.

In case the substrate layer is a very fine one, you must take more care towards installation of a filter layer so that it can improve the strength of your green roof.

Now the substrate depth is decided as per the type of vegetation you wish to plant over your green roof. This substrate depth is adjusted to between 20 to 100 mm in most of DIY green roof shed installation processes.

Note that soils become heavier during rainy season due to heavy water absorption; so your substrate layer must be designed with proper strength in order to avoid any damage.

Once you have installed all of these layers properly over your traditional roof, then the final task is to organize the  planting process.

You can apply any method of vegetation like blankets or pre-vegetated type mats, direct on site type of planting, seeding or plug plants, etc.

For each method there are some specific advantages, as well as disadvantages that must be taken under consideration depending upon the soil type and roof strength.

Once you have finished the installation process for green roofing, now it is time to pay attention towards its maintenance so that the plants can grow properly without any trouble.

More care is required during the first year of planting. You need to add a sufficient amount of water with proper timing and use well researched fertilizers in order to improve the efficiency of the soil.

Have regular visits to your green roof and pay major attention to the removal of weeds, as well as other unwanted plants.

Experts suggest that one should avoid the use of chemicals in green roofs in order to contribute to healthy environmental conditions.

DIY green roof systems must be implemented after proper search over the type of materials and plantings that are preferred in that particular area depending upon its weather conditions.

Here are some benefits of green roofs:

  1. Aesthetic:

We all know that flowers and plants provide a very beautiful appearance to areas and they attract many beautiful creatures  like humming birds and butterflies. Green roofs contribute towards a healthy environment and provide shelter to various creatures that live in nature. With green roofs our house presents most attractive structures with ultimate natural beauty.

  1. Environmental:

Green roofs act like home to various insects, small animals and birds; on the other hand, these indoor as well as outdoor plants help to cleanse air pollutants that are usually present in air due to heavy traffic on roads. Green roofs provide a major contribution towards a healthy environment.

  1. Economic:

You will be amazed to know that green roofs help to reduce the temperature of a roof by approximately 70 – 80 degrees F and that further contributes to more energy saving. These roofs provide natural warmth to a house during the winter season and keep it cool during the summer season.

If you are thinking about building a green roof on a shed, then this guide can be very helpful to you; designing a green roof over a shed will lead to a very attractive look for your house and it will contribute some positive effects to the environment.

Green roofs are the best options for urban area buildings because they provide enough energy saving ability and lead to attractive home construction.

Last update on 2023-07-04 / Affiliate links / Images from Amazon Product Advertising API

Founder & Editor

Hi, I’m Jim. I was a roofing constructor for 20 years, before deciding to start and gather the best content about roofing. I love woodworking and construction and it was only natural for me to start this passion project of mine. Thank you for visitng.