Green Roofs

What Are Green Roofs?

A green roof is a vegetation layer and waterproofing system installed on a slightly sloped or flat surface. They are also known as vegetative, eco, or garden roofs. Typically a green roof falls into three core categories:

• Intensive
• Extensive
• Semi-intensive

Hence, the more components that are added to the vegetation, the more this definition changes. This involves adding waterproofing, drainage system, filter cloth, root repellent system, or other components to the green roof. Additionally, they could either be part of the same ecosystem or be built in a way where each element is installed separately. As a result, garden roofs provide a diverse range of private and public benefits and are used globally. 

Advantages Of A Green Roof

Green roof systems have multiple benefits at ecological, societal, and economic levels. Here are the most important ones:

Covers From Rainwater

A nature roof or green roof absorbs rainwater by creating a layer of plants, drainage, and substrate. This keeps any excess seepage from entering the house. Moreover, groundwater stabilizes due to this process, the sewage system’s peak load is reduced, and flood risk is minimized. 

Purifies Air

Plants in nature roof filter particles from the air and convert carbon dioxide to oxygen. Having a green roof contributes to air purification. 

Reduces Temperature

Plants are excellent absorbers of sunlight; they absorb 50% and reflect the 30%. This helps in creating a more pleasant and cooler atmosphere. 

Serves As A Sound Barrier

Grass roofs act as a sound barrier to the building. They absorb sound and provide a quieter environment, both outside and inside the building. 

Increases Roof’s Life Span

A garden roof can also be used with TPO membranes, protecting the roof from external factors like rain, sun, wind, and temperature fluctuation. This increases the life span of the roof by a lot.  

Green Roof Application

Green roofs offer a lot of variety in how they are applied because they can be used on industrial, commercial, and residential structures.

Furthermore, they can be installed into a newly constructed building or added to existing buildings during roofing or renovation. 

Ideally, green roofs are laid on a low angle or flat rooftops; however, some have been installed on pitched slopes with specific features to ensure plant survival. 

Layering

As green roofs are made on top of a refined surface, their layers must follow a pattern to ensure adhesion:

• First layer: Structural support – the asphalt/cemented ground
• Second layer: Roofing membrane – the roof sealant
• Third layer: Protection – a barrier the keeps the roots from penetrating
• Fourth layer: Insulation – another layer of insulation
• Fifth layer: Water storage – moisture supply for the vegetation
• Sixth layer: Growth supplement/Fertilizer – fuel for the plants
• Seventh layer: Vegetation – The plants

As a result of this meticulous layering, green roofs are impeccable at protecting roof foundations, such as mastic asphalt. 

Various Types Of Green Roofs

There are three different types of green roofs, and they are categorized based on how thorough their application is:

Extensive Green Roofs

These types of green roofs are designed for their environmental efficiency. Some of the features of extensive living roof systems are:

• Require 3 to 6 inches of lightweight growing medium
• Are perfect for apartments and flat-roof buildings
• Do not require watering after one year of being installed
• Are the ideal solution for retrofits and low-sloped residential roofs
• Carry low maintenance ground-cover plants
• Only require maintenance annually during spring, mainly to weed out weeds and tree seedlings brought in by wind and birds

Intensive Green Roofs

Intensive green roofs are the standard rooftop gardens. However, they differ from the extensive ones in how they are fully landscaped. Some of their prevalent features are:

• Need 8 to 12 inches or more of growing medium
• Maintenance is extensive, and they need regular maintenance just like an at-grade garden
• Can have railings, walkways, and lighting
• As they are fully landscaped, they can hold a diverse mix of trees and plants; however, it is better to avoid plants with invasive root systems

Semi-Intensive Green Roofs

As the name suggests, they contain both elements of intensive and extensive systems. They are usually set up as a reasonable solution to green roofing. As a result, homeowners get a diverse vegetation plantation on a manageable maintenance budget. 

Green Roof Installation

A green roof can be installed in five simple steps. However, the following steps are for an extensive green roof. Intensive green roof construction is similar, but it differs according to the owner’s preference. 

First Step – Primary Waterproofing

The roof deck, whether it is screed or concrete, needs to be waterproofed. Some roofs already have a waterproof layer, but butyl rubber membranes are a perfect choice if they do not. However, EPDM membranes are widely used in low slope roofing.

Second Step – Root Barrier Installation

Membrane roofing is essential to create an airtight covering protecting the interior of the building and creating a root barrier. 

Third Step – Drainage Membrane

After placing the root barrier, the green roof drainage membrane can be rolled across the length of the roof. 

Fourth Step – Growing Substrate

Now comes the part of adding substrate, which is common in organic material and aggregate combination. Spread it evenly across the roof as per required depth. 

Fifth Step – Vegetation Layer

Plant the green roof seed or plants.

Conclusion

Nature roofs are perfect for enhancing the look of an urban neighborhood home or one out in the suburbs. With excellent benefits, green roofs provide a cost-effective and more natural aura. 

ArchiPro provides thorough green roof systems and waterproof membranes such as torch-on membranes; visit today and look through comprehensive garden roof layering solutions.