Do Green Roofs Need Drainage?

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If you’re considering putting a green roof on your home or office building, you’ll likely have a lot of questions that you need answered first.

Green roofs are great for the environment and are also aesthetically pleasing to everyone in the general vicinity, not just the people who live or work there.

While green roofs are not that complex, they should still be designed and installed by a professional so they can turn out just right.

And if you’re curious about green roofs’ drainage rules, just know that they do indeed need some type of drainage system in order to work properly.

In fact, the drainage system in a green roof is one of its most important aspects, which means that this type of roof can’t be installed without knowing ahead of time exactly what type of drainage system will go in it. Green roofs are also called living roofs and serve many purposes, but the main one seems to be a commitment to the environment and simply a greener way of building a roof on either a house or an office building.

Regardless of its size or exact design, a green roof does indeed need a high-quality and efficient drainage system.

How Is a Green Roof Designed?

Green roof design
Design your own green roof

When a green roof is designed, you won’t just plant things up on the roof and let it be.

A green roof is installed in layers, and each of these layers has a specific purpose.

Some of those layers allow for proper drainage so that the plants can receive the right amount of water from the rain without being over-saturated.

There also must be a system that allows for excess water to drain off of the roof while leaving enough water to keep all of the plants healthy and growing.

In other words, it’s a fine balance, but fortunately, there are companies that specialize in drainage systems made just for green roofs.

What Are the Layers Needed to Make Sure Your Green Roof Is a Success?

They can vary slightly from one company to the next, but for the most part, these are the layers installed:

  • Layer 1: a waterproofing membrane. The first layer is a very important layer because it protects the roof from the effects of rainwater. It also must be checked for anything that might cause it to leak at some point, which would be disastrous.
  • Layer 2: the root barrier. This prevents your roots from puncturing the waterproofing membrane and causing structural damage. It is there to protect both the roof and the roots themselves so that the waterproofing membrane doesn’t get punctured and start to leak.
  • Layer 3: the drainage layer. This is the layer that steers the water towards some type of drainage device so that the greenery doesn’t get too much water. You can also install an optional water retention layer at this point, which helps the drainage to be more effective.
  • Layer 4: the filter fabric. This fabric filters out silts and other particles and allows only the clean water to run through the system, making for healthier plants.
  • Layer 5: the growing medium. This is where you’ll put your soil in so that you can plant the greenery next. You have various choices when it comes to the medium you use, so you should do some research to decide on the best medium for your needs.
  • Layer 6: the plants. Finally, the sixth layer will be the greenery you plant so that the roof looks amazing afterwards.

Not only do green roofs need a good drainage system, but each layer of the system has to be designed specifically for a green or living roof.

In other words, you may not be able to use the same type of soil or the same plants as you would if you were growing them outside in your garden.

The good news is that you won’t be designing your green roof on your own.


Decision To Make: There are experts available who can guide you every step of the way so that each decision is made together with a professional and the final product is designed and installed properly in the end.


How to Get Started?

Start building green roof
Green roof system

If a green roof is something you’re interested in, just keep in mind that it does need to drain so that the plants stay healthy and the roof isn’t ruined.

When you consult with a company that specializes in green roofs, they’ll be able to answer all of your questions and help you decide which type of roof is best for you.

Installing a green roof is a big decision, but it doesn’t have to be a complicated one.

You won’t have to do the job all by yourself because there are always experts to help you every step of the way.

Final Thoughts

Green roofs are not only attractive but they are also great for the environment.

They can even be used in conjunction with solar panels if you like.

It’s good to know that these types of roofs exist and that they can be easy to install once you know how to get started.

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