How to make a living roof. "Green" roofs: grass roofing technology

Today, the installation of green roofs in Europe is a modern trend in urban construction. This is even encouraged by the authorities.

In Russia, this invention of mankind appeared quite recently.

Such turf roofs are especially relevant in huge cities, where it is almost impossible to create a garden in the middle of the city, and the land there is “golden”.

Advantages

Green roofs not only delight the eyes of metropolitan residents, but also significantly cleanse the air of gases and impurities. Residents of the upper floors will also experience all the delights of such a wonder. After all, in summer the turf layer will not allow the roof to heat up, and in winter it will not allow it to freeze.

In the summer, in the sun, the roofs of skyscrapers simply melt, not only heating the air even more, but also evaporating harmful substances from their surface.

Such a roof will protect both the roof and the residents from this. And plants will enrich the air with oxygen, taking away carbon dioxide.

A green roof can regulate the flow of rain. It takes on all the water, restraining the flow rate. Passing through yourself storm water, cleanses them. Which improves the environmental situation. Having such a covering on the roof of their house, many residents can plant vegetable gardens there, thereby keeping themselves busy with useful work and providing their family with vegetables.

Also, roofs with green roofs are great places to create mini recreation areas where residents of the house can have a picnic and not waste time in traffic jams to go out of town.

3 types of green roof:

The main selection criterion for landscaping is slope. It should not be more than 40 degrees. The type of landscaping is also selected based on the degree of slope. And the shape of the slope can be any - single-slope, gable, or another shape.

And for a roof with a slope of less than 40 degrees, you can install special gratings and then the roof will not slide.

All green roofing is divided into 3 groups.

Each group differs from the other in the degree of load on the frame of the building where the roof will be installed; possible functions; installation technology. Thus, green roofing can be intensive, or intensively simple, or extensive.

• Intensive- makes it possible to create parks and gardens on your territory with the help of ornamental plants.

The created landscape can be made on several levels.

Of course, such a volume of everything has a very large weight, which creates a high load on the building frame. Also, such a roof surface will require careful maintenance. Even a special irrigation system is being created.

It is better to carry out installation where it has already been planned and included in the calculations of loads on the building still under construction.

Or you can lay out the roof of a building that has been in use for a long time, if when calculating the load it turns out that the roof will not cause harm to the building frame.

Roofing pie- in longitudinal section

• Extensive— the soil of such a roof is covered with grass, mosses, and unpretentious plants.

This is as close as possible to the conditions wildlife landscaping system.

Some plants can be used in roof design, but they are not planted in the soil, but in special containers with soil. These containers are placed throughout the coverage area according to the designer’s idea. This type puts minimal pressure on the building frame.

As has already been said, no maintenance is required, and therefore everything will take less cost, effort and finances.

• Intensive simple roof – this type has absorbed part of the functionality of the extensive type and part of the functionality of the intensive type.

The thickness and weight are much less than that of the extensive one, so trees and shrubs are also not provided for on it, but you can walk on the lawn calmly and relax, placing everything you need on the green cover.

Caring for such a cover is also minimal - water at the grass growth stage, clear weeds and periodically trim the lawn.

How to create a green roof with your own hands:

Before directly laying (a special inversion roof), it is necessary to carry out preparatory work on the roof of the house.

Installation of a parapet is required, the height of which must be at least 1-2 meters.

Installation of the roof itself occurs in the form of laying its layers:

1. The first layer is considered to be the surface of the roof itself - these are mainly reinforced concrete slabs.
2. There must be waterproofing. For this they use special materials in rolls to perform this function. Particular attention should be paid to areas adjacent to the wall, parapet, and water drains. If the slope is flat, then at this stage an artificial slope of 3-5% should be created.
3. The next layer is thermal insulation. Materials are used that do not rot and cannot be deformed over time. This can be basalt wool, foam glass, or extruded polystyrene foam.
4. Next, drainage is distributed over the surface of the insulation, which is covered with geotextile. Drainage removes excess water from plant roots, and geotextiles act as a filter for this water - preventing soil particles from leaving the top layer.
5. And the soil mixture is poured on top of this entire structure.

A green roof has its disadvantages:

• Fairly high cost;
• Complex and labor-intensive installation of the coating;
• This coating is not suitable for every roof, as it provides high pressure on the frame.

Should Special attention pay attention to the choice of waterproofing materials. They must be resistant to mechanical stress, since if trees grow on the roof, their roots can damage the fragile waterproofing.

Roofing should be laid only by specialists and only in compliance with all installation technology.

Since installing such a roof is expensive, the price of apartments in a building or an entire house also increases.

After all, they are not only aesthetically beautiful, but they also have a longer service life than ordinary ones.

Roofing with landscaping is the planting of plants, shrubs and trees instead of a traditional roof. Such roofs have been used for a long time, but modern engineering technologies have made it possible to bring the mechanism of their arrangement to almost perfection. A green roof provides effective heat conservation, protects the building from the effects of wind, precipitation and temperature fluctuations, serves as an additional source of oxygen and a place where you can have a good time.

Green roof technology

The basis of creating a green roof that can last long years, lies the design and installation of a multi-layer roofing pie. Each of its layers performs its own function:

1. Thermal insulation. To create this layer, foam glass, extruded polystyrene foam, and basalt wool can be used. The main thing is that the material ensures heat retention, is non-hygroscopic, and also withstands the pressure of plant roots.
2. Waterproofing. This layer is laid using a special waterproofing membrane, which can be made on a bitumen or synthetic base. It is necessary both to protect building structures from moisture and to provide a comfortable microclimate for plant life. Together with the waterproofing membrane, an anti-root film can be used, which enhances protection from the mechanical impact of plant roots, as well as aluminum or copper foil, which provides additional protection for load-bearing structures from dampness.
3. Drainage. A drainage system is necessary when installing a green roof in order to provide plants with the maximum comfortable conditions for growth. It is created on the basis of durable roll materials, which are made from perforated polyethylene or high-pressure polystyrene. Drainage system maintains the level of humidity that plants need and removes excess liquid.
4. Filtration. To create this layer, geotextiles or special thermally riveted material can be used. Its main task is to prevent the drainage system from becoming clogged with pieces of soil, and also to prevent the leaching of nutrients that vegetation needs for healthy growth and development.
5. Soil substrate. It may have different ingredients in its composition, but it has one task: to serve as the basis for the vital activity of the plant layer. Modern technologies allow you to create substrates rich in nutrients and capable of maintaining the functioning of a green roof for many years.
6. Vegetation layer. The last layer of any roof of this type is the plants themselves, flowers, shrubs and even trees. It can be used to plant almost any type of crop that can easily withstand exposure large quantity sunlight. IN Lately Even real vegetable gardens placed on roofs are becoming popular.

In order for the design of a green roof to delight the residents of the house with its beauty and practicality for many years, the presence of all these six layers is necessary, although their composition and features may vary depending on the project.

Extensive roof greening

All options for creating a green roof can be divided into two large groups, the first of which is extensive landscaping. It involves creating a beautiful grass cover that will be evenly distributed over the entire surface of the roof or part of it, and, accordingly, using a fairly thin layer of soil substrate.
Extensive landscaping, in the vast majority of cases, is classified as non-exploitable. This means that it does not imply the presence of people - it will be possible to go out onto such a roof only occasionally, and then to ensure care for it. The latter will be very simple and rare. For an extensive green roof, plants (for example, sedum) and lawn grasses are used that are resistant to temperature changes and lack of moisture.

Intensive roof greening

Intensive installation of a green roof is the creation of a full-fledged garden, vegetable garden, flower beds and similar objects on the roof surface. This is a more complex system, but it leaves the possibility of exploitation, that is, people going to the surface for recreation and entertainment. Such a green roof requires not only more complex and painstaking development of the project, but also more complex and frequent maintenance.


Landscape designers are often involved in creating an intensive green roof, who help organize a real work of plant art on the roof surface. Another one distinctive feature Such a roof lies in the fact that sometimes the heat and waterproofing layers are swapped for it, that is, the waterproofing is placed under the thermal insulation. Thanks to this, the waterproofing layer performs its functions in warm temperature conditions and is less subject to mechanical stress.

Main types of green roofs

The design of a green roof depends not only on the type of landscaping chosen, but also on what type the roof itself is. So, we can distinguish the following main varieties:

• Green roof on a slope.

The main problem when greening a roof with a large slope is the possibility of soil sliding under the influence of gravity. Therefore, when arranging it, transverse supports or a special geogrid with small elements are used, inside of which the soil substrate is placed. Another nuance of green roofs with a slope is that they are usually exposed to prolonged and severe exposure solar radiation. Therefore, lawn grasses, sedum, and unpretentious wildflowers are used for them. Most often, such roofs are planted with extensive greenery.

• Green pitched roof.

A pitched roof also implies the presence of a slope, but it can be relatively small, which makes it possible for use (that is, people walking on it). To prevent the soil layer from sliding and the formation of “bald spots” that contribute to rapid erosion, for pitched roofs a geogrid with small cells is also used. Additionally, an irrigation system can be thought out, since precipitation flows from such a roof quite quickly.

• Green roof "pie".

A classic six-layer “pie” can be laid on a flat roof according to the scheme described above. The installation of a green “pie” roof gives great scope for imagination and allows you to use not only the simplest herbs and flowers, but also plants that are more demanding to care for, as well as shrubs and trees. If desired, on the surface of a flat roof you can create a full-fledged relaxation and entertainment area, as well as a vegetable garden, garden or even a greenhouse.
In regions with long and cold winter To install a green roof, you can create greenhouses or glazed rooms on the roof surface. Another option is to plant lawn and field herbs, and place more whimsical plants in pots that can be removed inside the house during the cold season. At the same time, the remaining vegetation cover in winter will help conserve heat throughout the building.

Green roof design and installation

The installation of a green roof at any facility is necessarily preceded by the careful development of a plan in accordance with which its installation will be carried out. This plan must include:

• List and sequence of arrangement of layers of vegetable roofing.
• Information about the materials that will be used to create each layer.
• An exact layout of all components of the green roof structure, including geogrids for pitched roofs and irrigation systems for steep roofs, as well as additional systems for the care of intensively greened roofs.
• Information on methods of fastening all parts of each system and the materials that must be used for this.
• Data on plant varieties and places of planting.
• Layout of decorative elements.

Professional installation of a green roof is carried out in full accordance with project documentation, since even the slightest violation of technology can significantly reduce its quality and viability.

The calculations take into account, among other things, the load that such a roof exerts on bearing structures building. The minimum load is created by extensive landscaping with simple lawn grasses or sedum, the maximum by intensive landscaping with complex landscape structures, shrubs and trees. For regions with severe winters, all snow during the cold season is additionally taken into account.

Benefits of a green roof

Green roof - device technology grass roof– has many advantages, the main ones of which include the following:

• Passive heat saving. In houses with such a roof, you can get by with a less powerful heating system.
• Protecting the building from precipitation and wind, as well as improving sound insulation.
• Increasing the fire safety of buildings. When a fire occurs, it will spread on a green roof more slowly than on a conventional one.
• Creating an additional source of oxygen - green roofing as a type of ecological construction allows you to create a green area without spending a new plot of land.
• Creating a place for pleasant relaxation and entertainment.
• Reduced dust and harmful substances in the air.

Green roofing on small houses

The installation of a green roof can be performed not only on large city buildings, but also on low-rise construction sites.

In a country house

Depending on the size of such a house, both intensive and extensive landscaping can be done on its roof. In any case, it will contribute to hydro- and thermal insulation, and
It will also serve to increase the area of ​​green zone, for which many people move outside the city.

In a wooden house

A green roof can even be created on a roof wooden building– you just need to take care of the strength of its lower layers, which protect the roof from moisture and mechanical damage. In the context of wooden buildings, a particularly important advantage of a green roof is its ability to slow down the spread of fire in the event of a fire.

On the farm

On a farm, a green roof can become not only an additional source of oxygen, a means of insulating a building and purifying the air, but also even a site for planting various crops. Plants that need a lot of sunlight will do well on the surface of a building.
Thus, a green roof is modern system, created using sophisticated technology and giving residents of any home many advantages. This is also effective remedy protection environment, purifying the air and producing oxygen so necessary for our lives.

Recently, the technology of arranging vegetable roofs has become very popular. A green roof is a multi-level roofing “pie” on which you can grow unpretentious beautiful lawns or even plant a real garden. Today, green roofs are installed with your own hands not only on the roof of a private house in rural areas, but also on urban high-rise buildings.

Features of a green roof

Trees and grass growing on the roof are by no means a tribute to modern fashion. Suffice it to recall the Gardens of Babylon, which glorified ancient Babylon. In the 18th century, Icelanders lived in turf houses that they carved out of the hills. At the same time, it was discovered that the vegetation living on the roof can protect against cold and wind in bad weather.

Green roofs are a national tradition in Norway that has existed for several centuries. They are covered with birch bark, peat and overgrown with grass and moss. Green roofs have firmly established themselves on the roofs of Toronto, Zurich, San Francisco, London, and Madrid.

Plant eco-roofs are very popular, and there are several good reasons for this. Let's find out what's the matter:

• Durability. Green vegetative roof with gas will last longer regular roof. After all, soil and plants best protect it from negative factors. external environment, as well as from weather conditions. If you properly care for such a roof, the service life of the roof will exceed 20 years.
• Rainwater retention. This is especially true when there are heavy rainfalls, because the drainage system often cannot cope with large amounts of water. Lawns and other vegetation located on the roof are able to absorb part of the precipitation - about 27%. This is in an effective way designed to help prevent flooding. In addition, pollution of nearby rivers and reservoirs is reduced.
• High levels of sound insulation. By setting up a roof garden, you will notice that the background noise in the living area has been significantly reduced. And this is especially important for residents whose houses are located in areas where it is very noisy.
• Great thermal insulation. The house under a plant roof is warm in the winter, and cool in the summer heat. Therefore, heating and air conditioning costs are reduced.
• Extra space. The area of ​​the exploited green roof provides additional usable space for landscape design. Here you can sow a lawn, lay out a garden, and arrange a swimming pool. This will give you a great place to relax.
• Improving the situation from an environmental perspective. This is especially true for large cities. After all, sometimes it’s difficult to find a place for a park among concrete and asphalt. Plants located on the roof can clean the air efficiently. They retain more than 25% of dust, harmful impurities and substances contained in the atmosphere. They also reduce Greenhouse effect and I could. For example, in Chicago in 2001, a lot of green roofs were built - about 1000 square meters. m.
• Aesthetics. A house under a green roof looks unusual and original. And I can’t tell you how much attention it attracts to itself! In America there is even a special corporation for green roofs. She is studying free installation eco-roofs for any home. In Russia, such trends are not yet common.

Types of green roofs

There are several types of vegetable roofs, depending on the technology of their arrangement. Let's look at them in more detail.

Extensive green roofs

Such roof gardening involves using light soil (the layer should be 5-15 cm thick) and unpretentious plants that do not require constant watering. As a rule, evergreen and hardy species are chosen for planting, which form a continuous carpet on the roof, for example, sedums and other succulent specimens. The weight of the soil layer, as well as planted plants, per 1 sq. m. averages 20 kg. Therefore, there is no need to further strengthen the base.

This is enough simple technique protecting the roof and creating an autonomous ecosystem. It is usually used to install a green roof on country gazebos, outbuildings, garages and private houses. The creation of recreation areas is not expected. Therefore, such a solution can hardly be called a full-fledged garden.

Intensive green roofs

This option involves laying out a full-fledged garden on the roof and creating paths. It is possible to design an area where household members will have a picnic and install gazebos. Often, swimming pools and other bodies of water are located on such roofs. Most often they are formed on multi-storey buildings, shopping and entertainment centers. Green roofs have long been not uncommon for expensive hotels.

To plant trees and shrubs, a reliable foundation is built and a layer of soil is poured, which is up to 1.5 meters thick. The load of the entire system with soil and plants, which is on one square meter, in this case it reaches 700 kg. Intensive systems require regular watering. Other care is also needed - mowing and fertilizing.

Flat and pitched eco-roofs

Roofs with a lawn or garden are divided into flat and pitched. For many centuries, vegetable roofs were installed exclusively on flat surfaces. For example, this is what tarred roofs in the city look like today. However, you can also create a green cover on the sloping roof of a private house located in a village. For this purpose, special screens are used. They are intended for plants on the roof. Thus, both landscaping techniques are used on flat roofs. On a pitched roof, it will be possible to arrange a lawn only using extensive green roof technology.

Green vegetative roof design

Any green roof is a so-called “layer cake”. It consists of several mandatory layers. Let's take a closer look at them.

1. Base

The first layer of vegetable roofing is the supporting structures of the roof itself. For a flat roof this is concrete plates floors, for pitched floors - continuous sheathing. If available roof covering, for example, tiles, they are first removed. In case of flat plate It is recommended to create a slight roof slope. It should be directed towards the drain and be about 1.5-5 degrees. For this, a cement-sand screed is used.

2. Waterproofing layer

Before you make a green roof, worry about waterproofing. Without exception, all plants need moisture and regular watering. But such exposure is extremely harmful to the materials from which the roof is made. Therefore, waterproofing is used, which fences off the soil on which the plants grow from the roof itself.

Make sure that the waterproofing layer is as reliable as possible. Otherwise, if there is a leak, you will have a hard time getting it repaired. After all, removing all the layers located on top of the waterproofing is very expensive and time-consuming.

For this purpose they use plastic film or polymer membranes. Also great for this liquid rubber. Waterproofing can be placed directly on the roofing. Or they can pre-create a coating from marine plywood. If you use boards, there should be no gaps between them. Usually 2 layers of waterproofing are done. The lower one is mechanically attached to the base. The top one needs to be fused. The seams are securely soldered.

3. Thermal insulation

The thermal insulation layer is usually created from slabs made of cork. Polyurethane foam or extruded polystyrene foam are also successfully used. The slabs are stacked closer together. If the top layers do not create enough pressure, connect them using special glue.

There is no need to attach the slabs to the base. On pitched roof additional insulation is not required, since this layer is already laid on the attic side between the rafters. If you decide to build a roof made of green moss, it will be useful to know that this plant has been used since ancient times to insulate the roofs of houses.

4. Root barrier

A root protection layer is necessary to prevent damage that can be caused by roots growing deep into the roof. The barrier for roots is usually ordinary polymer film or foil. A film that has a metal coating is ideal. It is laid on a layer of waterproofing.

Many manufacturers produce waterproofing materials that contain anti-root additives. If you want to plant ground cover species on the roof, then you don’t have to lay such a covering. This also applies to the procedure for creating a lawn; do ordinary waterproofing, that will be enough.

5. Drainage layer

Drainage material is capable of retaining a certain amount of water, which is necessary for the life of plants. In this case, water should move freely along the roof towards the drain. In the case of a sloping roof, the water drains off on its own if you provide special holes for this in its corners.

On a flat roof, care must be taken to ensure that water does not stagnate. To create bottom drainage, it is recommended to lay expanded clay, which has a large or medium fraction. Good results are demonstrated by crushed pumice, perlite coconut or polyamide.

You can buy special artificial mats. These include “geomat” made of plastic, which are mesh grids of great flexibility, similar to rough washcloths. In extreme cases, loosened clay and ordinary gravel are suitable. When arranging the drainage layer, take care to install perforated pipes to improve water flow.

6. Filtration layer

This layer is necessary to retain unnecessary precipitation. After all, they are capable of clogging drainage, coming from the soil with water. Geotextiles, which have a high density, are a good filter. In addition, the geotextile helps to avoid mixing the drainage layer with the soil, which occurs over time. It is laid with an overlap.

7. Lathing

If you are planning to green a low-slope roof, you should use a geogrid. After all, if the slopes are inclined more than 25 degrees, the soil will slide without fixation. The geogrid has the form of plastic cells. It's quite light.

When installing a green roof with your own hands on a roof that has a slight slope, it is enough to make special partitions from wood. They will not allow the soil to slide. To create aesthetic effect, lay out a beautiful geometric pattern with latticework. Don’t forget to make borders around the perimeter to hold the “layer cake” together.

8. Fertile soil

At this stage, a layer of soil is created. This is where you will plant your plants. When choosing a soil mixture, the requirements of the plants being planted are taken into account. For ground cover species and grass, a layer 5-10 cm thick is required to create a lawn. The height of the soil for planting shrubs and trees should be up to 1 m. Soils for use on the roof should be light in weight, warm, moisture-absorbing and porous. It's good if they are resistant to compaction. The usual mixture from the garden is not suitable for this task.

You are recommended to use a light soil mixture, which consists of neutral peat with special components, such as fine expanded clay and perlite. Also add sand, clay and shale. If desired, crushed bark and wood chips. Don't forget about fertilizers. The top layer can be mixed with grass seeds, which is intended for growing lawns.

9. Plants on the roof

After laying all the layers for the green roof wooden house you can start planting plants.

• When choosing representatives of the flora, keep in mind that conditions will be created here that are close to desert ones. This is the sun and the wind. Therefore, choose the most unpretentious species.
• Among the trees, give preference dwarf species. They must have a small root system.
• A roof planted with frost-resistant grass looks advantageous, as well as ground cover plants using extensive gardening technology - sedum, sedum, young, creeping phlox.
• Choose moss, various meadow flowers, some bulbous flowers, and bells for planting on the roof. Also consider cloves, oregano and lavender.

Thus, roof greening is fashion trend, which allows you to radically change the appearance of buildings and add usable space to your garden. In addition, if you follow the technology correctly, you can protect your home from bad weather and excessive noise.

The primary task of the roof structure is protection from cold air, snow, rain or other atmospheric phenomena. However, the lack of space for construction, poor ecology in cities, and the low quality of crop products make it necessary to rely on roofing additional functions, introducing innovative architectural solutions. One of the most current trends in ecological housing construction is considered to be a plant roof, on which you can create not only a lawn, but also a real vegetable garden where you can grow healthy and safe fruits or vegetables. In this article we will discuss whether a green roof can be installed with your own hands.

Roofs on which grass or other plants grow are not a new invention. Although even more ancient examples of this architectural tradition are known, the most significant example of the use of vegetable roofs is the turf dwellings of the Icelanders, which date back to the 18th century. Moss-covered houses characteristic peoples living in the territory of modern Norway, Canada, Great Britain, Switzerland.

Residents of the country, which is characterized by a harsh, cold, windy climate, immediately noticed that a roof covered with vegetation better protects against low temperatures, retains heat inside the house, creating a pleasant microclimate for living inside the home. IN modern conditions eco-roofs used for planting a lawn or setting up a mini-garden - more likely fashion trend, which allows you to take care of nature, your own health and rationally organize your living space.

It is interesting that in modern megacities, where the level of air pollution and stress exceeds all reasonable limits, it is necessary to organize green recreational areas for people. Even in the projects of Soviet modernist architects, eco-roofs appeared, designed for walking, relaxing, or placing greenhouses that could provide residents with fresh greenery all year round.

Advantages

Pervasive landscaping – necessary condition comfortable life in modern cities built of glass and concrete. However, often in cities covered with asphalt there is simply not enough space to accommodate green areas. The way out of this situation is a green roof, which allows not only to use living space more efficiently, but also to significantly improve the environmental situation. The advantages of this technology include:

1. Durability. A plant layer that tightly covers the roof surface protects roofing material from mechanical damage, temperature changes, moisture, so it will last more than 20 years.
2. Rationalization of the use of rainwater. Green spaces located on the roof slopes retain more than 25% of precipitation, preventing spontaneous water runoff and flooding. Instead of aimlessly merging into storm sewer, the water is used for irrigation and feeds the crops.
3. High insulating properties. The layer of soil and turf of an eco-roof serves as an excellent insulating material that helps preserve the interior of the home. comfortable temperature and protects from external noise.
4. Organization of additional living space. A green roof can become a place for relaxation, sports, fresh air, placement of swimming pools and even cafes.

But the most important thing is that the technology of arranging eco-roofs makes it possible to improve the environmental situation in completely polluted megacities, preserve and increase the health of modern people.

Flaws

Despite obvious advantages, the technology for installing green eco-roofs has not yet become widespread. This is primarily due to the high complexity of installation and the large number of costs for installation and maintenance of the structure. The disadvantages of plant roofs are considered to be:

• Heavy weight. A layer of drainage, soil and plants adds up to 50 kg/m2 of area, so the green structure significantly increases the load on the floors and foundation of the structure.
• High price. To install an eco-roof, it is necessary to use only environmentally friendly materials, so its installation is much more expensive than a conventional pitched or flat roof.
• Difficult to install. Due to the heavy load on the foundation and floors, installation of a plant roof requires a project based on accurate calculations. Therefore, it is quite difficult to do this work with your own hands; most often you have to resort to the services of contractors.

Note! Most experienced roofing craftsmen and architects believe that it is dangerous to convert an old roof into a plant roof, since the floors and foundation may simply not withstand the additional load and cause irreversible deformations.

Kinds

Depending on the height and purpose of the building, the types of plants used and the landscaping goals pursued, an eco-roof can change its appearance. It can be successfully installed on both sloped and flat surfaces. roofing structures. Depending on the nature of use, the following types of vegetable roofs are distinguished:

Important! So that the green roof pleases with its aesthetic appearance for a long time, it is necessary to carefully select plants that tolerate climatic conditions in the region where construction is taking place and are not demanding in care. In addition, it is worth considering that the thickness of the soil layer is limited, so you should choose plants whose roots are located not vertically, but horizontally.

Structure

Eco-roofs, just like conventional roofs, resemble a layer cake in their structure, however, their components are slightly different due to the characteristics of their operation. They must ensure structural reliability in the following areas: foundation strength, protection against water penetration, and prevention of heat loss. The roofing pie of vegetable roofs has the following structure:

• Base. The base of the roof can be wood or concrete, the main thing is that it has a sufficient margin of strength to withstand the weight of the soil and plants.
• Waterproofing. To protect against moisture penetration, several overlapping layers are laid on the base. waterproofing material. Moreover, it must have increased strength.
• Barrier. A root barrier is placed on top of the waterproofing, which should prevent plants from growing below this level. Without this layer, roots will grow into the waterproofing material, damaging it.
• Drainage. A drainage layer is necessary to rationally distribute moisture entering the soil. It retains some of the water, preventing plants from drying out during dry periods, and directs the excess into the drain.
• Filter. A filtration layer or geotextile is spread over the drainage to limit the penetration of small particles that can clog it.
• Geogrid. The geogrid prevents the soil from sliding down and scattering when exposed to wind. It is most often used if the slope is more than 25 degrees.
• Substrate. The fertile substrate is poured in a uniform layer 5-20 cm thick onto the geogrid. To grow a lawn, a soil layer of 5 cm is enough, but to grow fresh cucumbers on the roof you will need a depth of 20-25 cm.

Please note that the soil for an eco-roof should be quite light, but retain moisture well. Landscape designers It is recommended to use fine expanded clay, peat and sand for lightening. In addition, it is worth taking care of soil fertility by adding organic and mineral fertilizers.

Selection of plants

To prevent the plant roof from withering away in the first dry summer or from freezing in the cold winter, it is necessary to select unpretentious and winter-hardy plants, which can exist well in a closed ecosystem. Landscape designers and plant growers recommend adhering to next rules when selecting flora:

1. Small and horizontally located root system. Mosses and grasses best meet this criterion.
2. Frost resistance. Plants should tolerate well negative temperatures, characteristic of the winter period.
3. Drought resistance. It is necessary to choose plants so that they only need natural watering during rain.

remember, that exotic plants, not typical for our climate zone requires more careful care, so you can plant them only if you are ready to spend a lot of time and money to provide them with appropriate living conditions.

Video instruction

In the modern world, the urbanization of society is growing every day, the number of cars and tall buildings is increasing, the “green” world and environmental pollution are being displaced.

For more comfortable living in houses and cities, back in the past millennia, people built houses with a green roof, in the form of grass and low-growing trees, which made it possible to maintain a microclimate not only in the house, but also on the streets of the city. Gardens and small lawn areas for recreation were built in Assyria and Babylon more than 2,500 years ago. The most striking example is the Hanging Gardens of Babylon, which we know from school textbooks, photo 1.

Photo 1. Hanging Gardens of Babylon

Gradually, hanging gardens or green roofs began to spread not only in Asia, but also in Europe. In Scandinavian countries, particularly in Norway, the use of turf for roofing has been practiced for several centuries. A striking example in Europe, the construction of a roof garden in its modern form was arranged by the Austrian architect Friedensreich Hundertwasser , back in the middle of the 20th century.

What is a green roof? Varieties, layers

Nowadays, the technology of installing a lawn, various vegetation, low-growing bushes and trees on flat and sloping roofs is called “ green roof".

Green roof – installation of a roof using soil and vegetation as the main element. This is the roof of a building, which is partially or completely covered with soil and vegetation and the system of its life activity of this micro ecosystem.

Against the backdrop of global climate change in the world, developed countries, in particular North America and Europe include green roofs in their environmental programs, especially in megacities, photo 2. For example, green roofs are actively developing in cities such as Copenhagen, Paris, London, Berlin, Frankfurt am Main, New York, etc.

Photo 2. Examples of green roofing in different cities

Let's look at the basic design and types of green roofing.

Basically, a green roof consists of 6 layers:

1. plant layer;
2. soil substrate;
3. filter layer;
4. drainage system;
5. waterproofing layer;
6. layer of thermal insulation.

In some cases, the structure or material of the green roof layers may differ, so photo3 given different kinds green roof structures.

Photo 3. Green roof compositions

There are two types of green roofing:

• extensive;
• intense (inversion).

Extensive green roof (photo 4) is intended for temporary use and is not actually intended for walking on it. You can only walk on such a roof in certain places. The thickness of the soil layer is no more than 0.07...0.15 m, which only allows planting small plants. Lawn plants and mosses are usually planted on such a roof in special containers or trays. Plants must have a horizontal root system (fibrous or bulbous). average cost extensive green roof is approximately 29...35 €/m 2.

Photo 4. Extensive green roof

The load from an extensive green roof in a water-saturated state is 80...100 kg/m2.

Intensive green roof (inversion) - this is a type of roof, the design of which allows you to arrange not only a lawn on the roof, but also an entire garden with trees, bushes and even a pool and a fountain, photo 5. An intensive green roof must have a parapet height of at least 1.2 m, and a soil layer of 0.2...0.6 m.

Typically, an intensive green roof is installed on public buildings, where a business center, hotel, restaurant, sanatoriums, hospitals, etc. are located. The significant thickness of the soil and other elements of an intensive green roof (swimming pools, fountains, benches, trees, etc.) significantly increases the load on load-bearing elements building coverings. Therefore, the design of an intensive green roof is provided for at the design stage. Otherwise, you should carefully calculate permissible load from a green roof that can be supported by the supporting structures of the building.

Photo 5. Intensive green roof

The average cost of an intensive green roof is approximately 52 €/m2.

What does a green roof consist of?

Let's take a closer look at the structure (construction) of a green roof, what layers it consists of:

1. selected individually depending on the climate, roof location, soil thickness and the wishes of the owner, photo 6. Mosses, lawn grass, wildflowers and mountain vegetation are often chosen for green roof vegetation, since such vegetation is not picky about specific climatic conditions. In regions with harsh and cold winters, frost-resistant plants should be chosen.

Photo 6. Vegetation layer

1. , photo 7. The soil used is a substrate that is much lighter than ordinary soil, which can significantly reduce the load on the roof base. Lightening the structure of a green roof is especially important for roofs of an intensive type. The substrate can be purchased in specialized stores or you can prepare it yourself.

The optimal composition of the substrate is a mixture of:

• perlite (preferably large particle size);
• expanded clay or vermiculite;
• brick chips (60...70%, medium-sized particles);
• compost (high quality).

The second option for the optimal composition of the substrate is a mixture (by weight):

• expanded clay (10%);
• large tree bark mixed with leaves (15%);
• perlite, preferably with large size particles (15%);
• fine tree bark (30%);
• compost (10%);
• coconut fiber (20%).

The third simplified version of the substrate is a mixture (by weight):

• compost (33%);
• perlite (34%);
• expanded clay (33%).

Photo 7. Soil substrate

1. Filter layer (usually consists of geotextile and root protection film). Geotextiles are used as a filter layer to prevent clogging of drainage with soil particles, photo 8.

Geotextiles are produced in three types:

• needle-punched;
• thermally bonded;
• combined (needle-punched + heat-bonded).

Photo 8. Geotextiles

For a green roof, you should choose thermally bonded geotextiles; its design is made in such a way that it practically does not silt and has maximum durability under these operating conditions.

After the geotextile, a root protection film is laid ( photo 9), preferably from non-woven polypropylene. It is not recommended to use a concrete or asphalt concrete layer as a root protection layer.

Photo 9. Root protection film installed on the roof

1. Drainage system performed in several options:

• Perforated drainage layer with drainage pipes.
• Perforated polystyrene plates.
• Gravel or expanded clay.
• Geomats are rectangular gratings, photo 10.

Drainage pipes should be used from high-strength perforated polystyrene or high-pressure polyethylene. These pipes have spike-shaped convexities. Asbestos pipes can also be used, but before installation it is necessary to make holes (perforations) in them. You can also arrange drainage from expanded clay (cheap option).

Photo 10. Geomats (drainage layer)

1. Waterproofing layer – performs a protective function – preventing water and moisture from entering through the structure into the building or onto external walls. Green roof waterproofing can be done in various options, For example:

• polymer waterproofing membranes on a bitumen (EPDM) basis with root protection ( environmentally friendly material), photo 11;

Photo 11. Polymer waterproofing membrane on a bitumen (EPDM) basis

• polymer waterproofing membranes on a synthetic (PVC membrane) basis with root protection (service life up to 60 years), photo 12;

Photo 12. Installation of a polymer waterproofing membrane on a synthetic (PVC) basis

• additional copper or aluminum foil layer to the above membranes;
• liquid rubber;
• polyethylene film (has low efficiency).

If the roof is flat, then waterproofing is arranged with a slope of 3...5%.

1. A layer of thermal insulation. It is recommended that the thermal insulation layer be made of foam glass or perlite sand. Foam glass does not allow moisture to pass through and is not toxic to plants and soil microflora. Also used as insulation are extruded polystyrene foam boards and mineral wool.

Often, to simplify work and on-line maintenance, soil is poured into small plastic boxes (for example, 0.5 × 0.5 m), which are installed on pallets, photo 13.

The design of an intensive green roof differs from an extensive one in the thickness of the soil layer and the location of the insulation - it is located not below, but on top of the waterproofing, which protects it from mechanical damage.

Photo 14 shows a graph from which you can determine the load on the roof depending on the thickness of the soil.

Photo 13. Plastic boxes for soil; installing boxes on pallets

Photo 14. Determination of the load depending on the thickness of the soil layer and the variety of plants for a green roof

In table 1. The advantages of two types of green roofing are presented.

Table 1

Advantages of two types of green roofing

Extensive landscaping	Intensive landscaping
Does not require permanent presence of people on the roof	Allows you to create a full-fledged garden on the roof with areas accessible to pedestrians and vehicles
Small variety of plants	Unlimited variety of plants and trees
Does not require special care and requires virtually no watering	Requires care like a full-fledged garden
Does not require frequent maintenance	Requires a high level of maintenance
Allows you to create green roofs with different angles of inclination	Allows you to place flower beds, shrubs, recreation areas, gazebos, and ponds on the roof
Light weight	Medium and heavy weight
Acceptable solution for already erected buildings	Developed at the building design stage
Low cost. Economical option	High cost option

Thus, we highlight the main advantages of extensive roofing compared to intensive roofing:

• relatively low price;
• simple maintenance and care.

Sloping green roofs

Sloping green roofs are mainly installed on private residential low-rise buildings, photo 15. Let's look at the features of a sloping green roof.

Photo 15. Pitched green roofs

It is believed that the ideal roof slope angle for installing a green roof is an angle of 5...8° (in some sources - up to 12°). With this slope, the possibility of the entire layer of soil and turf sliding under its own weight is eliminated and there are no problems with any type of plant. Specific gravity turf (soil + vegetation) is 100...300 kg/m 2.

When the roof slope increases by more than 12°, it is necessary to install transverse supports ( wooden boards, geogrids or cassettes) that will hold back the soil, photo 16. Using devices that prevent soil sliding, it is possible to install vegetable gardening on roofs with an angle of up to 45°. True, the cost is sloping roof will be higher.

Photo 16. Transverse clamps that prevent soil and vegetation from sliding when installing a green roof

The design of a green roof on inclined surfaces is practically no different from flat ones, with the exception of the design of restraining devices, photo 17.

Advantages of a green roof

1. Green roof plants reduce the level of harmful substances in the air by absorbing carbon dioxide CO 2 and releasing oxygen. It is calculated that a lawn of 150 m2 in size releases in a year an amount of oxygen equivalent to the amount that 100 people inhale in a year. Green roof vegetation neutralizes a significant amount of dust and harmful gases. In 1 year, 1000 m 2 of extensive green roof absorbs 8 kg of dust and the air on the green roof is much cleaner and contains 37% less SO 2 (sulfur dioxide) and 21% less CO (less carbon monoxide).
2. Reduces noise level (up to 8...10 dB). The soil can absorb low frequencies, and vegetation can absorb high frequencies.
3. A green roof additionally humidifies the air. Roof vegetation can retain and partially absorb up to 50...90% of rainwater.
4. Increases the durability of the roof structure several times (3…4 times), since the green roof performs a protective function against the effects of UV rays and overheating (a dark roof can heat up to 80°C from the sun’s rays). The durability of a traditional flat roof with a green layer increases by 60%. It is estimated that the use of a green roof can save up to 60% on operating costs (approximately 40 €/m2).
5. The earth cover layer is fireproof, and in the event of a fire it will prevent its spread.
6. A green roof functions as a natural heat insulator, and thus reduces energy costs for heating and cooling premises.
7. The green roof can be used (additional recreation area).
8. Additional area for many plant distributions and habitats for insects and birds.
9. Such roofs have a beautiful aesthetic appearance.
10. A green roof improves the microclimate in the building.

Disadvantages of a green roof

1. High cost of roofing.
2. Complex roof structure.
3. Poor installation of a green roof can lead to leaks and extensive destruction of the building.
4. Green roof plants require care.

Publication prepared by an expert

Konev Alexander Anatolievich