What is a green roof?

A green roof is a layer of growing media and plants that sits on top of a standard roof.  Not only does it look amazing, a green roof brings with it a whole host of benefits.

How do I make a green roof?

Creating a green roof is easy but it requires forethought and planning.  Throwing some mud and seeds on top of a building 
and hoping for the best is simply not going to work.

There are many different ways to make a green roof, all of them have pros and cons.  Your job is to decide which method best suits your building and your lifestyle.

What is involved in green roof design?

When designing a green roof, it’s important to remember that conditions on top of a building are quite different to 
conditions on the ground.

man with a heavy load

1. Weights and loadings

For a start, a building can only support a finite amount of weight.  That means there are limits to how much growing medium you can put up there.  If you make the substrate layer too deep, you may compromise the structure of the building.

2. Plant choices

Any plants on your green roof will be growing in a limited depth of growing medium. Any gardener will tell you that it’s no 
good putting deep rooting plants into shallow soil and expecting them to survive.

It’s also going to be quite dry up there, unless you have an irrigation system in place.

In summer, the roof is the hottest place on the whole building.  In winter it’s the coldest.  

A green roof will insulate the inside of the structure against heat and cold but the plants are on the outside.  They need to be able to withstand 
temperature extremes.

3. Safe access

Don’t forget too, that the plants will need a little bit of TLC during the year.  Choose your plants wisely and the 
maintenance will be minimal.  Nevertheless, you will need to access the roof at least twice a year.  When working at 
heights, Health and Safety is more important than ever.   Make sure that access is good and that you have safety measures 
in place.

Where can I learn more about green roof design?

All of the above factors and more are crucial to the success of a green roof. If you want to avoid disappointment, they all need careful consideration BEFORE you start building.

Enviromat’s “Designing for Maintenance” green roof guide will help you to make the right choices for your project.
Download it for free or contact Q Lawns’ sales office to have a copy posted to you.