Enhancing Your Property’s Aesthetic with M-Tray® Wildflower Roof Systems

Green roofs have gained traction in recent years as an eco-friendly alternative to traditional roofing materials, offering not only aesthetic appeal but also tangible environmental and financial benefits. They can help mitigate the urban heat island effect, improve air quality, and even extend the lifespan of the roof itself.

Types of Green Roofs

Green roofs can be broadly categorised into two main types: extensive and intensive. While they share the core goal of integrating vegetation into building design, they differ significantly in terms of depth, maintenance requirements, and purpose.

Extensive Green Roofs

Extensive green roofs are relatively shallow, typically ranging from 80 to 200 mm deep, and are designed for minimal maintenance. They feature hardy, drought-tolerant plants like sedums, requiring little irrigation or fertilisation. These roofs are lightweight, making them suitable for a wide range of structures, and are ideal for residential and many commercial projects.

Intensive Green Roofs

In contrast, intensive green roofs are much deeper, often exceeding 200 mm, and can accommodate a wider range of plant species, including shrubs and small trees. These roofs demand more intensive maintenance, such as regular watering and fertilisation, but offer greater aesthetic and recreational potential. Intensive green roofs magnify the environmental and aesthetic benefits of green roofs, offering greater biodiversity, improved thermal and sound insulation, and the potential to increase property value.

The M-Tray® Modular Green Roof System

The M-Tray® Modular Green Roof System represents a significant advancement in green roofing technology, meticulously designed by Wallbarn to address the challenges and limitations of traditional green roof installations. This innovative system comprises modular trays, pre-planted with a diverse selection of fully established flowering sedum or a mix of wildflowers and sedum upon request. These trays are engineered to seamlessly click together, creating a continuous, lush green surface.

Unique Design and Specifications

The M-Tray® is not just any modular tray; it is a specially designed and purpose-built solution for green roofing. Each module measures precisely 500 x 500 x 100mm, ensuring uniformity and ease in planning and installation. The design incorporates four gently ridged hand grips, making it easier for installers to carry and position each module. Furthermore, the trays are designed with carefully spaced drainage holes to optimise water retention, allowing plants to absorb more rainfall effectively. This not only enhances the growth and health of the vegetation but also contributes to the attenuation of stormwater, reducing runoff.

Seamless Integration and Instant Green Roof

One of the standout features of the M-Tray® is its ability to provide an instant green roof. The modules are grown and nurtured for at least nine months, including a full spring growing season, ensuring that the plants are strong, healthy, and well-integrated into the substrate. Unlike sedum blankets, which can suffer damage during transport and installation, the M-Tray® modules are designed to minimise shock to the plants, allowing them to continue maturing immediately upon installation.

The connecting brackets of the trays are engineered for a tight fit, with a minimal gap that quickly becomes invisible as the plants grow, ensuring a seamless verdant finish. This seamless integration contributes to the overall aesthetic appeal of the rooftop, creating a cohesive and visually pleasing green space.

Convenience and Accessibility

Wallbarn has gone to great lengths to ensure that the M-Tray® system is as convenient and accessible as possible. Each module is easily portable by one person, making it ideal for areas that are difficult to access, such as single-story extensions or domestic projects. This portability also means that the system can be installed much faster than traditional roll-out green roof systems, with a team of contractors being able to cover approximately 400 square meters in a single day.

Additionally, if access to the roof deck is needed for inspection or repairs, individual M-Tray® modules or sections can be lifted out without disrupting the entire roof, a significant advantage over traditional systems that would require extensive and costly removal and replacement of the green roof components.

Environmental and Economic Benefits

Beyond its aesthetic appeal, the M-Tray® system offers long-term environmental and economic advantages. The engineered substrate and plant selection are optimised for strong, healthy growth, contributing to biodiversity, air quality improvement, and mitigation against the urban heat island effect. The system’s design for water retention and attenuation further enhances its environmental performance.

Economically, the ease and speed of installation, combined with the durability and low maintenance requirements of the system, make it an overall cost-effective solution for both commercial and domestic projects. The initial investment in the M-Tray® system can yield long-term savings through reduced energy costs and extended roof lifespan, making it an attractive choice for property owners and developers alike.

Benefits of the M-Tray® Modular Green Roof System

Immediate Green Coverage

One of the most significant advantages of the M-Tray® Modular Green Roof System is its ability to provide immediate green coverage upon installation. The pre-grown modules arrive with a minimum of 90% vegetative cover, ensuring that as soon as the modules click together, a lush, verdant surface is created. This instant aesthetic appeal is a stark contrast to traditional green roof systems, which may take months or even years to establish a fully covered and visually appealing green space.

Water Retention and Drainage

The M-Tray® system has been meticulously engineered to enhance water retention and effective drainage. Each module features carefully spaced drainage holes that retain water for longer periods, allowing plants to absorb more rainfall. This not only supports plant health but also increases attenuation and delays discharge into drainage systems, which is crucial in managing stormwater in urban settings.

Additionally, the design ensures greater water retention at the edges of the module, preventing the sedum from drying out and promoting stronger plant growth at the edges for a more uniform and seamless vegetation layer. This attention to detail contributes to the overall aesthetic appeal of the green roof, creating a cohesive and visually pleasing appearance.

Biodiversity Enhancement

Wallbarn’s M-Tray® supports a significant enhancement in biodiversity, particularly in urban environments. By offering a mix of flowering sedum and wildflowers, the trays provide a habitat that attracts and supports various wildlife, including bees, butterflies, and birds. This mix is specifically chosen to replicate native species, which are optimal for promoting local fauna.

The biodiversity benefits are crucial for urban greening schemes, helping to replace lost habitats and improve the environmental quality of urban areas. The selection of plants in the M-Tray® not only adds to the aesthetic value throughout the year but also plays a pivotal role in ecological conservation efforts, creating a visually appealing and environmentally conscious rooftop space.

Components and Specifications

Tray Dimensions and Weight

The M-Tray® Modular Green Roof System is meticulously engineered to facilitate easy handling and precise installation. Each tray measures 500mm x 500mm x 100mm, strategically designed to fit exactly four units per square meter. This uniformity simplifies the estimation and planning process for installation projects.

Regarding weight, the empty trays weigh approximately 1.1kg, while the filled and fully saturated trays can reach up to 100kg/m². It is advisable to consult with an engineering professional to ensure that the roof structure can support this weight, taking into account factors such as wind uplift and snow loads, which may require considering a weight of up to 120 kg/m².

Substrate Composition

The substrate used in the M-Tray® is a critical component, contributing significantly to the system’s efficiency and environmental benefits. This specially developed and constructed substrate is 100mm thick and is specially formulated to support extensive green roof plants while adhering to construction and environmental standards. It contains less than 50% organic content and is fully compliant with BS 8616:2019 and the GRO code, which dictate the requirements for green roof substrates.

Crucially, every element of the M-Tray® and its substrate is made up of recycled sources. The composition includes coir (a waste product from the coconut industry), green compost from local sources, and recycled lightweight aggregate. This mix not only provides essential nutrients and aeration but also ensures optimal water retention and drainage. The substrate’s design avoids the use of peat, which can shrink over time, making it an environmentally responsible choice.

The substrate has been independently tested and certified to comply with all relevant building regulations and to promote long-term growth and health of the plants. These components and specifications showcase the extensive development and thoughtfulness put into the M-Tray® system, emphasising its benefits not only in terms of installation and maintenance but also environmental sustainability.

Installation Process

Preparation of the Roof

Before commencing the installation of the M-Tray® Modular Green Roof System, it is crucial to ensure that the roof membrane is properly protected and free from dirt and debris. If necessary, a root barrier should be installed. This initial step is vital as it safeguards the underlying structure from potential damage during the installation process and ensures the longevity of the green roof.

Placing the Geotextile Layer

The installation begins by rolling out the supplied geotextile fabric across the roof. Wallbarn typically provides a recycled fleece, which acts as a separation and filtration layer. This fabric not only protects the waterproofing but also prevents abrasive damage. Make sure to overlap each strip of fabric by about 20cm to ensure complete coverage. This layer serves as a critical filter for drainage, enhancing the overall effectiveness of the green roof system.

Clicking the Trays Together

Once the geotextile layer is in place, the next step is to start laying the M-Tray® modules. Begin from the middle of the roof and work outwards towards the edges. This method helps in maintaining an even distribution of the trays and facilitates easier alignment. Each tray is designed with two connection points on two sides, allowing them to click into place securely. It is important to ensure that each module is laid in the same direction so that the clips can all fit around the grooves on their neighbors and be connected tightly on all four sides. This not only secures the trays but also maintains the aesthetic continuity of the green coverage.

Continue this process across the entire roof, taking care to ensure that the rows of M-Tray® are properly aligned and the clips are connected over the recess points. Remember to always install suitable fire breaks and perimeter sections using rounded washed pebbles according to relevant building regulations and guidance. For any exposed edges or areas near drainage outlets, an aluminum edge trim can be added to maintain cleanliness and safety. The modular design also allows for easy integration of hard landscaping elements like paving or decking, which can be mounted on Wallbarn pedestals to ensure uninterrupted drainage.

By following these steps, a successful installation of the M-Tray® Modular Green Roof System can be achieved, providing immediate ecological and aesthetic benefits while ensuring the system’s longevity and performance.

Maintenance and Care

Maintaining the health and sustainability of a green roof, especially when utilising the innovative M-Tray® system developed by Wallbarn, involves a comprehensive approach that encompasses both seasonal maintenance and specific fertilisation and irrigation needs. Our focus here is to provide you with a detailed guide to ensure your green roof thrives throughout the year, leveraging the benefits offered by the M-Tray® system.

Seasonal Maintenance Tips

Spring (March to May)

Inspect and Repair: Begin with a thorough inspection to identify any potential damage from winter. Ensure that the waterproof membrane is intact, and all drainage paths are clear.

Weeding and Cleaning: Remove any weeds, debris, and dead vegetation to prevent blockages and infestation by invasive species.

Fertilisation: Apply Wallbarn’s slow-release granular fertiliser at a rate of 50 grams per square meter to encourage robust growth.

Planting and Replanting: Spring is an ideal time to introduce new plants or replace those that did not survive the winter. Either insert plug plants into gaps or use cuttings from the sedum itself to fill in any bare patches. For M-Tray® systems, consider adding or replacing modules as necessary.

Summer (June to August)

Irrigation: Adjust your watering schedule based on weather conditions. The M-Tray® system’s design helps in retaining moisture, but remember that the substrate is specifically designed to give free drainage off the roof, so additional watering may be required during dry spells.

Weed Control: Continue to monitor and remove weeds regularly to prevent them from competing with your green roof plants.

Pest and Disease Monitoring: Keep an eye out for any signs of pests or diseases and treat them promptly to prevent spread.

Autumn (September to November)

Clearance: Remove autumn leaves, dead stalks, and other debris to keep drainage channels clear and prevent waterlogging.

Seeding: When removing dead stalks and flowered sections of plants, vigorously shake the seed heads over the surface of the green roof to encourage as many seeds as possible to resow into it, helping to self-seed the green roof, promoting true sustainability.

Last Fertilisation: Apply a final round of fertiliser to support plant health through the colder months.

Inspection: Check the integrity of the M-Tray® modules, insulation, and waterproof layers for any signs of wear or damage. Check drainage outlets are not blocked.

Winter (December to February)

Snow and Ice Management: Avoid using salt to melt snow or ice. Instead, gently remove snow to prevent excessive loading on your green roof.

Drainage Checks: Regularly inspect drainage points to ensure they are not blocked by ice or debris.

Structural Assessment: Periodically check the roof’s structure for signs of stress due to weather extremes.

Fertilisation and Irrigation Needs

The M-Tray® system is designed to simplify the maintenance of your green roof, but understanding the specific fertilisation and irrigation needs of your plants is essential for their health and longevity.

Fertilisation: Use Wallbarn’s slow-release granular fertiliser in spring and autumn to provide sustained nutrients.

• For specific plant needs, such as sedum or wildflowers, adjust the type and amount of fertiliser accordingly. Sedum requires less frequent fertilisation, while wildflowers may benefit from a more nutrient-rich mix.

Irrigation: The amount of watering required for your M-Tray® green roof largely depends on the type of plants used and the prevailing weather conditions.

• Sedum roofs are particularly drought-resistant and may require minimal additional watering. However, during prolonged dry periods, even sedum may need supplemental watering. If the sedum turns red, it is time to water.
• Wildflowers and intensive green roofs with larger plants may need more frequent watering, especially during hot, dry weather. Utilise the M-Tray® system’s efficient drainage design to prevent overwatering and ensure optimal soil moisture levels.
• Implement a watering schedule after one week without rain, increasing the frequency if dry conditions persist for two weeks or more. Always water in the evening to reduce evaporation and stress on the plants.

By adhering to these maintenance and care guidelines and leveraging the benefits of the M-Tray® system, you can ensure that your green roof remains a vibrant, healthy, and sustainable addition to your building. Wallbarn’s commitment to innovation and environmental sustainability is evident in the design of the M-Tray®, making green roof maintenance both effective and straightforward.

Comparisons with Traditional Green Roof Systems

Rollout Systems vs. Modular Systems

Traditional green roof systems, often referred to as rollout systems, involve layers that must be built directly on the roof. This method, akin to laying sod on a new lawn, requires the installation of multiple layers, including a waterproof membrane, root barrier, drainage layer, growing medium, and then the vegetation itself, typically in the form of a pre-grown blanket Seed, plugs, or cuttings. With the other methods of planting, the initial vegetation coverage is usually between 5-15%, and it can take anywhere from one to three years for the plants to fully mature and establish.

In contrast, Wallbarn’s M-Tray® modular system offers a significant advancement with its pre-vegetated trays. These trays come with mature plants and 90+% vegetation coverage right from the point of delivery, allowing for instant green coverage upon installation. The trays, designed to interlock, provide immediate structural stability and are especially effective in hard-to-reach areas. This modular approach not only simplifies the installation process but also reduces the time required for plants to establish.

Cost and Labor Differences

The financial and labour implications of choosing between traditional rollout systems and modular systems like the M-Tray® are considerable. Traditional green roofs can initially be less costly than modular tray systems, but they are more complicated to install and often require a professional installer. However, the long-term benefits and reduced maintenance of modular systems will offset the initial higher costs.

The ease of installation of the M-Tray® significantly reduces labour costs, and its design minimises future maintenance expenses. Modules can be individually removed and replaced if access to the roof is needed or if any module requires attention, unlike traditional systems where such interventions can be disruptive and costly. For example, if a rollout green roof system needs to be lifted to investigate a leak, the green roof is most often so badly disrupted that it will need to be disposed of and replaced entirely.

Furthermore, the M-Tray® system’s ability to be quickly installed over a few days supports immediate operational and ecological functionality, which is a significant advantage over traditional systems that require gradual vegetation growth and establishment. This feature not only saves time but also reduces labour costs associated with long-term care and maintenance.

Common Applications and Use Cases

Residential Applications

The M-Tray® Modular Green Roof System is ideally suited for residential settings, particularly in urban environments where green space is limited. Our system transforms roofs into lush gardens that not only enhance the aesthetic appeal of the home but also contribute to environmental sustainability. The ease of installation makes M-Tray® particularly valuable for single-story extensions or homes with limited access, where traditional roll-out green roof systems would be challenging to install. The modules can be hand-carried to the roof and clicked together, providing immediate green coverage and ecological benefits.

Commercial and Urban Installations

In commercial settings, the M-Tray® system offers a practical solution for creating green roofs on office buildings, hotels, and other business premises. Companies, including large corporations like Google and Facebook, have adopted green roofing to enhance their buildings’ sustainability and provide a natural setting for employees and visitors. The M-Tray® system’s modular nature allows for discreet installation with minimal disruption, which is crucial in busy commercial environments. Additionally, if maintenance or roof inspections are needed, individual trays can be easily removed and replaced, significantly reducing the potential costs and disruptions associated with traditional green roof systems.

In urban areas, the M-Tray® facilitates the development of green spaces on rooftops, which can help mitigate the urban heat island effect, improve local air quality, and promote biodiversity. The system is designed to support a variety of plant species, from hardy sedums to lush wildflowers, catering to different aesthetic and ecological goals. This adaptability makes M-Tray® an excellent choice for city planners and developers looking to integrate green spaces into new or existing buildings to meet environmental targets and enhance the quality of urban life.

Environmental and Economic Impact

Energy Efficiency and Insulation Benefits

Green roof systems, such as the M-Tray® Modular Green Roof System developed by Wallbarn, significantly enhance the energy performance of buildings. This improvement is primarily due to the insulating properties of the green roof, which reduce the amount of heating required in winter and, particularly, cooling in summer. The substrate and vegetation layers act as natural insulators, reducing heat flow into and out of the building. This thermal regulation contributes to a decrease in energy consumption, leading to lower utility costs and a reduction in carbon emissions.

Moreover, the evaporative cooling effect of the vegetation reverses the heat absorption typical of urban building materials like concrete, which absorb heat during the day and radiate it back into the environment. Instead of the sun’s energy being absorbed and radiated out by the building, it is turned into plant growth. This natural cooling process not only lowers the ambient air temperature but also reduces the building’s reliance on air conditioning, further decreasing its carbon footprint.

Contribution to Urban Greening

The M-Tray® system plays a crucial role in urban greening, transforming barren rooftops into vibrant green spaces. By incorporating pre-grown sedum and wildflower mixes, these modular green roofs provide immediate ecological and aesthetic benefits. They enhance biodiversity by creating habitats for a variety of urban wildlife, including pollinators like bees, which are essential for the health of the ecosystem.

The green roofs contribute to the creation of ‘green bridges’ or ‘bee corridors,’ facilitating the movement and interaction of flora and fauna across urban areas. This not only beautifies the cityscape but also plays a vital role in reducing air pollution and managing stormwater runoff, which are critical issues in urban settings.

Conclusion

Reflecting on the comprehensive analysis of Wallbarn’s innovative M-Tray® Modular Green Roof System, it becomes evident how vital such advancements are to the broader objectives of sustainable urban development and construction. The detailed exploration of the system sheds light on its remarkable design, highlighting the ease of installation, maintenance, and various ecological benefits, affirming its superiority and versatility in comparison to traditional green roof systems. By encapsulating these insights, the article reinforces the pivotal role that the M-Tray® system plays in enhancing urban environments, supporting biodiversity, and promoting environmental stewardship.

The significance of Wallbarn’s M-Tray® extends beyond its architectural appeal, embedding itself into the fabric of sustainable urban planning. It offers a practical and cost-effective solution for integrating green spaces within dense urban settings, addressing critical environmental challenges such as the urban heat island effect, stormwater management, and air quality improvement. As cities continue to grow, the adoption of modular green roof systems like the M-Tray® becomes not just beneficial but imperative for creating resilient, sustainable, and livable urban habitats. Encouraging further research and innovation in this field could drive widespread acceptance and utilisation, paving the way for greener, healthier cities around the world.