GREEN ROOFS AND ROOF GARDENS

The Urban Greening Company are green roof installers and green roof installation specialists. We have many years experience providing sustainable green roof solutions and systems from some of the worlds most respected suppliers; whether it’s an intensive or extensive green roof, a sedum or grass roof, we can plan and install a range of roof systems to suit your project.

Types of Green Roof

There are many types of green roofs and roof gardens (also called living roofs). These include intensive (roof gardens), and extensive (low maintenance green roofs) including Sedum roofs and bio-diverse and biosolar roofs.

Intensive Green Roofs

An intensive green roof is essentially a garden or park type area on a rooftop. These roofs have deeper soil layers and can support a wide variety of plants, including grass (as you would expect), shrubs, and even small trees. Key features of an intensive green roof include:

• Deep Soil Layers: This allows for a diverse range of plantings, from small plants and shrubs to large trees.
• High Maintenance: They require regular care, similar to ground-level gardens, including watering, fertilizing, and pruning.
• Structural Support: Due to the weight of the soil and plants, the building and roof must have strong structural support, also referred to as “load baring”.
• Big Eco Benefits: They provide excellent insulation, reduce stormwater runoff, and can enhance biodiversity and aesthetic appeal. (See below)

Extensive Green Roofs

An extensive green roof is a type of green roof designed to be lightweight and low-maintenance. These types of living roof are much more common and are comprised of primarily low-growing, drought tolerant plants such as sedum and hardy grasses or herbs. This is for a number of reasons including cost factors, lower maintenance needs and less structural demands.  So to summarise an extensive green roof:

• Shallow Soil Depth:  Typically ranging from 2 to 6 inches (5 to 15 cm).
• Plant Types: Primarily low-growing, drought-tolerant plants such as sedums, grasses, and herbs.
• Maintenance: Minimal, often requiring little irrigation and feeding.
• Weight: Lighter than intensive green roofs, making them suitable for buildings with less structural support.
• Cost: Generally less expensive to install and maintain compared to intensive green roofs.

We can advise of the most appropriate type of green roof for your building, whether it is a new build or retro-fit.  Our expert team make sure that every roof is designed to meet your functional and aesthetic requirements. This is achieved using the best quality materials and vegetation.

Benefits of Green Roofs

Among the many benefits of green living roofs, the most important ones are:

1. Stormwater Management: Green (and blue) roofs help absorb rainwater, reducing runoff and mitigating flooding.
2. Thermal Insulation: They provide good insulation, helping to reduce energy costs for heating and cooling.
3. Biodiversity: They can support a wide variety of plant species, contributing to urban biodiversity.
4. Air Quality: The plants can help filter pollutants from the air, particularly in urban environments.
5. Aesthetic Appeal: They can enhance the visual appeal of buildings and urban areas and also provide much needed green space in urban areas.

Installing Your Green Roof

In all cases we will inspect the proposed roof before installation. In particular we will assess the structural integrity of any exisiting or proposed roof to ensure it can support the weight of a green roof or living roof garden. It may also be necessary to consult a structural engineer. We will also look at access to the site and the type of roof or slope the roof has as this will affect the type of roof system we will propose.

Once we have discussed your ideas and seen the site the decision on what type of green roof is being installed (see top of page) will have been made. It is now time to prepare the roof. A green roof system is made up of several important parts, but the most important are the waterproof membrane, that protects the roof structure from the moisture in the green roof system above it, and the root barrier which stops the roots of the grass and plants from penetrating the roof as they grow and mature.

Next we will install a drainage layer to allow easy water flow from the roof and prevent excess waterlogging. This is then followed by the growing medium or soil layer. The depth of this will be dependant on the type of roof chosen – extensive or intensive.

Finally we will install pregrown vegetation mats or individual plants chosen for their hardiness and suitability to the local climate and area.   Sedums are a popular choice for extensive roofs in the UK due to their low maintenance needs.

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Raising Your Corporate Environmental Standards with a Green Roof System.

Green roofs are a recognised way to address corporate sustainability at the same time as raising environmental standards, saving money and even improving staff health.

Some of the ways a green roof achieves this are:

• Providing better thermal insulation.
• Acoustic insulation.
• Lower energy bills.
  
• Improving air quality.
• Alleviate storm water management problems.
  

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At TUGC we specify and use a number of different green roof systems to accommodate the simple fact that every green roof installation is different. We will make a decision based on the scope and requirements of the project and after discussion with the customer to ensure all needs are met. We use the highest quality Sedum grass and plants to ensure your green roof will thrive long after our work is finished and all our installations use industry recognised processes and materials.