Green roof: advantages and types

The green roof is an innovative technology that allows you to transform even the most gray building, increasing the efficiency of engineering solutions. It is noteworthy that such structures were in demand in the Stone Age in the construction of yurts, dugouts and huts. Today, such a roof is a complex system, which should be built according to a certain technology, taking into account the structural features of the building itself.

What does it consist of?

The green roof is a whole system consisting of several components:

• Anti-root layer, which is laid on the waterproofing layer. Its task is to protect the roof from root germination;
• Protective moisture accumulation layer: it is needed to protect waterproofing from mechanical damage and accumulation of additional moisture;
• Drainage-accumulative layer: its purpose is to accumulate an optimum amount of moisture, which is sufficient to maintain the life of the planted plants and regulate the outflow of excess water;
• Filtering layer: it filters water, during which the fine particles of the substrate do not enter the drainage-storage element and protect the entire system from siltation;
• Layer of soil-substrate, where planting occurs;
• A vegetative layer, that is directly planted plants - sedums, a lawn, perennials, trees or small bushes.

As we see, the device of the green roof is not easy, and therefore you need to take into account every detail when it is erected.

"For" from the point of view of ecology

Greening the roof is now used in many countries, and in Russia as well. The popularity of such systems is explained by their universality: they can be built in any climate where there is a vegetative soil cover. In addition, such a decision plays an important role from an environmental point of view:

• The climate improves. Due to the greened roof, the air is humidified, thus ensuring a natural coolness. Especially noticeable is the positive impact of the green roof in the office premises.
• The air is cleaned, and dust and harmful substances are absorbed: the green roof in use most often has a large area of gardening, and vegetation on the roof absorbs about 20% of dust from the air, delaying and assimilating nitrates and other toxins.
• Sound insulation increases: a vegetative coating on the roof contributes to the improvement of sound insulation, which is especially important if a building with a roof in use is erected near airports and other structures with a high noise level.
• The part of green plantings is compensated: as a rule, at building of buildings the site is cleared of trees, bushes, and a green roof - an opportunity to compensate even a part of landings.
• When creating the system, recycled materials are used: the drainage system is created from rubber, polyethylene, expanded polystyrene, which guarantees the ecological safety of the structure.

And what does the financial aspect say?

The green roof, of course, is one of the expensive systems, but experts say that it is still profitable to build it. Why? Let's try to understand:

1. The cost of reconstruction of the roofing system is lower. The vegetative layer allows to provide protection of a roof against ultra-violet beams, difference of temperatures. Accordingly, landscaping significantly increases the service life of the roof waterproofing up to 40 years.

2. Heat insulation becomes better. Due to gardening, good heat-shielding properties are provided throughout the whole year of operation of the roofing system, which makes it possible to reduce waste for heating the room.

3 . Well retained moisture. The effect of moisture retention is manifested in the fact that the green roof can hold up to 90% of the moisture, which is formed due to precipitation. Some part of the moisture evaporates, some - absorbed by the plants, and some goes into the drains. This design reduces the cost of installing pipelines and drainage systems.

Features of design and construction

Green exploited roofs can be erected in any climatic zone. This is possible due to the fact that plants are resistant to moisture, temperature changes in a particular region. The gardening system can be installed on any flat roof at any stage of the construction process. Green roof - the technology of erecting a roof using bitumen or polymer waterproofing against the roots. According to the technology, the load-carrying roof structure should be resistant to additional load. The very installation of the gardening system is very simple and fast, and the main requirement is the maximum angle of its tilt of 25 ^° C.

Extensive roofing

Today it is possible to make an exploited roof of two types - extensive and intensive. First, let's look at the features of an extensive system. It involves the use of only the grass cover, evenly distributed on a thin layer of soil. The remaining plants are simply planted in separate containers with a mixture of soil. The roof of green color is obtained from lawn grass and drought-resistant plants, and it should be watered only during the growth of plantations. Care for such systems involves periodic cleaning of weeds and grass cutting. Soil mixture is a mixture of gravel, expanded clay, sand and organic substances, which are collected in a certain ratio.

Variants of extensive systems

Extensive landscaping roofing is ideal for standard roof structures. Make the roof of the building beautiful can be due to different versions of the system:

1. Low vegetation cover with a substrate height of 60 mm. This is the easiest and inexpensive option to operate. To increase the flowering time, about 7 species of plants can be planted.
2. To give the roof a personality, you can plant it with drought-resistant perennials, which will please your beauty until late autumn.
3. No less beautiful looks pitched green roof. The photo shows that such gardening is very original. But there are nuances, from the structural point of view: for any deviation, you need to think about reducing the load on the supports, parapets and overhangs of the roof, and the substrate - to protect against erosion. In accordance with the slope of the roof should be selected and plants.

Intense landscaping

An intensive green roof is a cover in which low plants combine with bushes and trees. And the height of planting can reach 4 m with a fertile layer of more than 1 m and a layer of drainage more than 20 cm. In addition to the original appearance, this design serves to retain heat and prevent overheating of the internal space. The ground layer on the roof is able to smooth the temperature fluctuations, protect it from the sun's rays. Similar systems are being built by many companies in Moscow, for example, LLC "Green Roof", which deals with complex roofing works of any complexity.

Features of an intensive system

In the most standard version, the key component of the intensive roof is a special drainage membrane that removes moisture along the roof slope and some part of it keeps. The task of this membrane is not to let the roots of plants grow into the roof. A pitched green roof of this type can not be filled with garden soil, as it will be poorly drained, too heavy for the roof and has no nutritional value.

Pitched green inversion roof can not be filled with ordinary garden land. The usual land on the inverse green roof is poorly drained, quite heavy for the roof and not nutritious for plant growth. The optimal substratum for green roofing is a mixture of 60-70% of a brick of medium size, perlite, vermiculite or expanded clay and 40-30% of good compost.

How to choose a substrate?

In addition to the company "Green roof" (Moscow), a lot of companies offer services for the greening of flat and pitched roofs . And it is very important that the formulation of the substrate is properly selected. It is based on compost, old leaves, wood fodder in small and large pieces, perlite, expanded clay, coconut fiber. The thickness of the substrate should be 40 mm, not less, and if the roof is inversion, then the thickness should be not less than 80 mm.

The vegetation cover of the green roof is built on the basis of alpine alpine plants of sedums, mosses, wildflowers and lawn grass (or rolled lawns). And on the roof surface you can create whole plant compositions.