Grass on Roof: Types, Examples, and Modern Applications

Grass on roof is a type of green roof that uses grasses and other plants to cover the roof of a building. This type of roof is perfect for areas with mild winters and warm summers.

There are several types of grasses that can be used on a roof, including buffalo grass, blue grama, and switchgrass. These grasses are all drought-tolerant and can thrive in a variety of conditions.

One example of a modern application of grass on roof is the green roof on the Chicago City Hall building. This roof is covered with a mix of grasses and sedges that require minimal maintenance.

Green roofs like the one on Chicago City Hall can help to reduce stormwater runoff and improve air quality in urban areas.

Explore further: Plant Grass

Having a grass roof on your house has numerous advantages that go beyond just the visual appeal. One of the major advantages of a grass roof is its positive impact on the environment, contributing to the reduction of urban heat island effect.

For your interest: Artificial Grass

Green roofs can reduce the amount of energy needed to regulate building temperatures, saving you an estimated $5,000 per year on heating and cooling your home.

A grass roof acts as a natural insulator, keeping your home warm in the winter and cool in the summer. This reduces the need for artificial heating and cooling systems.

Grass roofs have excellent soundproofing properties, absorbing sound waves and reducing noise levels inside the house. This can be particularly advantageous if you live in a noisy area or near a busy road.

Here are some of the key benefits of a grass roof:

By installing a grass roof, you can help lower the temperature of your house and the surrounding area, making it more comfortable and energy efficient. Buildings account for 38% of global energy-related CO2 emissions, but a green roof lowers a building's carbon footprint by absorbing carbon dioxide from the atmosphere.

Installing a green roof involves several steps, starting with a protective, multi-layered waterproof barrier between the soil and the roof decking. A monolithic type waterproof membrane, such as rubber or plastic, is installed on top of the roof decking.

To prevent roots from weakening or rotting the decking, a 6 millimeter sheet of plastic is placed on top of the waterproof membrane, serving as a root barrier. Thin sheets of three-quarter-inch foam insulation are then added on top, followed by a drainage mat with capillary spaces.

The sides of the roof are framed with mesh gutter guards, wood, or other edging that allows for drainage and holds the soil in place. Soil is added and distributed evenly throughout the garden space, and plants are set in place, with taller plants in back to allow sunlight to reach shorter ones in front.

To design and install a green roof, you'll need a few key things. A flat surface is a must, whether it's a single-or multi-family house, a commercial property, or even a parking garage. Professional structural analysis is also necessary to ensure the structure can support the weight of the green roof.

A waterproof membrane, typically made of rubber or plastic, should be installed on top of the roof decking. This will prevent water from seeping into the decking and causing damage. A 6 millimeter sheet of plastic should also be placed on top of the waterproof membrane to serve as a root barrier.

Drainage is crucial, as it can be the most common type of green roof "failure." To avoid this, you'll need to maintain your drains so the vegetation doesn't clog them out. You can also consider installing a drainage mat with capillary spaces on top of the insulation.

In terms of plants, perennial succulents like stonecrop and hens and chicks are great options for green roofs. These plants are low-maintenance and can thrive in a variety of conditions. You'll also need to consider the climate and sun exposure of your location to choose the right plants for your green roof.

Here are some key considerations to keep in mind when designing and installing a green roof:

By considering these factors, you can create a beautiful and sustainable green roof that provides numerous benefits for your home and the environment.

Modern roofs have come a long way from traditional turf roofs. In modern turf roof construction, bitumen roofing felt combined with dimpled plastic drainage membranes are usually used in place of birch bark.

A key advantage of modern turf roofs is their improved drainage system. This is achieved by laying a dimpled cavity drainage membrane over the top of the bitumen roofing felt, with the dimples facing down to form a drainage layer.

Drainage issues are a common problem with green roofs, but modern designs can mitigate this risk. To avoid drainage issues, it's essential to maintain your roof's drains regularly to prevent vegetation from choking them out.

For a successful green roof, the right plants are crucial. Common plants for green roofs include perennial succulents like stonecrop and hens and chicks or sedges and groundcovers.

The maintenance requirements for a green roof are relatively low, but regular upkeep is still necessary. Green roofs typically need to be weeded two or three times a year to avoid overgrown vegetation clogging up drains.

Here are some key considerations for green roof maintenance:

By following these guidelines, you can enjoy the benefits of a modern turf roof while minimizing the risks associated with green roofs.

There are several types of grass used for roofs, including Buffalo grass, Blue Grama grass, and Blue Grama grass's drought-tolerant cousin, Little Bluestem.

Buffalo grass is a popular choice for its low water requirements and ability to thrive in poor soil conditions. It's also relatively low maintenance, requiring less mowing and fertilization than other types of grass.

Blue Grama grass, on the other hand, is known for its vibrant purple flowers and ability to add a pop of color to a roof garden. It's also relatively easy to establish and can tolerate a range of soil types.

Take a look at this: Pitched Roof Types

There are many different types of green roofs, and experts like landscape designers and architects determine which is most appropriate for a specific building.

Extensive green roofs are relatively simple and suitable for drought-tolerant plants that require little attention, making them easier to install and maintain.

These roofs are not designed for extensive use by humans, unlike a true roof garden.

Intensive green roofs, on the other hand, are accessible gardens that can accommodate plenty of soil and support heavier plants like perennial beds, grasses, shrubs, and even small trees.

This type of roof requires more maintenance and must be able to support the weight of the plants.

Let's take a look at some examples of types and how they play out in real life.

The concept of a "fixed mindset" was first introduced by Carol Dweck, a psychologist who studied how people's views on intelligence and ability can affect their behavior.

In a fixed mindset, individuals believe that their abilities are innate and unchangeable, leading them to avoid challenges and view failures as threats to their ego.

This fixed mindset can be seen in the story of a student who refuses to try a new subject in school because they're afraid of not being good at it.

On the other hand, a growth mindset is all about embracing challenges and viewing failures as opportunities for growth and learning.

For example, a musician who has been playing for years but still takes lessons to improve their skills is demonstrating a growth mindset.

The impact of having a growth mindset can be seen in the way it allows individuals to take on new challenges, persist in the face of obstacles, and develop a love for learning that lasts a lifetime.

In Scandinavia, people have been using natural materials to cover their roofs for thousands of years. Birch bark and sod were used since prehistory.

Roofs in Scandinavia were mostly covered with sod until the 18th century, when tile roofs became more common in rural areas. Tile roofs gradually replaced sod roofs in many areas.

The demand for mountain lodges and holiday homes in the 19th century helped revive the use of traditional materials like sod roofs. This revival was also driven by the preservation movement and the creation of open-air museums.

The traditional sod roof has been used for hundreds of years in Scandinavia, and its experience could benefit the development of modern green roofs.

Broaden your view: Unusual Roof Materials

To support the sod on your roof, you'll need some strong beams along the eaves. These logs or beams, known as turf logs, come in various shapes and sizes, depending on the building's quality and local tradition.

In Norway, the most common turf log is an undressed fir log 5 to 6 inches across. Squared timbers of similar size are also fairly common.

Turf logs were fastened to the roof boards and underlying rafters with wooden hooks, preferably from durable juniper. These hooks were fastened with wooden pegs and covered by additional sheets of birch bark.

A more refined fastening device was the kolv, an elaborately shaped stick of wood, around 60 cm long, pegged to the roof and extended through a hole in the turf log.

Here are some common types of turf logs:

Welham Studios is a great example of a grass green roof that resembles a wild flower hill meadow. The local grass species have colonised the roof, creating a natural and authentic look.

Mark Merer designed Welham Studios, which features a very angular form that contrasts beautifully with the grass roof. The result is a unique and visually striking building.

Curious to learn more? Check out: House with Grass Roof

Ecospace garden studios offer prefabricated buildings with a strong emphasis on sustainable materials and ultra-efficient specifications. They promote their green roofs as being environmental, low maintenance, and highly insulative.

One of the Ecospace options is a grass turf living roof, as seen in the example above. They also offer sedum plants as an alternative option for their green roofs.

The Kendram Turf Roof House, featured on Grand Designs, is an eco-home with a grass living roof that helps it blend into the surrounding landscape. The grass roof was formed from fresh rolled turf, but it's hoped that local grass species will naturally colonise the roof over time.

Before you start transforming your roof into a green sanctuary, it's essential to assess the structural stability of your roof. This will help you determine if any modifications or reinforcements are necessary to support the extra weight of the grass roof.

You'll want to choose the right type of vegetation for your green roof, and native plants are often a great choice as they are well-adapted to the local conditions and require less water and fertilizer.

A suitable growing medium is vital for the success of your green roof. Choose a lightweight, well-draining soil mix that provides the necessary nutrients for plant growth.

Regular maintenance is crucial to keep your green roof healthy and vibrant. This includes watering, fertilizing, pruning, and inspecting for any signs of pests or disease.

By following these simple steps, you can create a beautiful and sustainable green oasis on your roof that not only reduces the urban heat island effect but also improves air quality and adds an aesthetic appeal to your home.