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green roof past and present

In many countries for hundreds (if not thousands) of years « green roofs » It was the standard design, mainly due to the excellent insulating qualities and fertile layer of turf. In cold climates of Iceland and the Scandinavian sod roofs helped to retain heat in houses and in tropical countries such as Tanzania, kept cool in the buildings. The Canadian provinces of Newfoundland and Nova Scotia is still possible to meet early copies of « green roofs », imported by the Vikings and later — French colonists.

Up until the mid XX century. « green roof » We considered only as a local construction practices. However, in the 1960s. concern over the deteriorating environmental situation and the rapid decline in the area of ​​landscaping in the large cities have revived interest in the « green roof », primarily in Northern Europe. It was carried out a wide range of new technology research, including protivokornevyh study components, membranes, drainage systems, light fertile layers, as well as research on the acceptability of the plant.

A key motivation for this support became public benefits associated with a reduction in the volume of stormwater, as well as improving water and air quality. As a result, the whole sector has been created and the construction industry « green roof » have become an integral part of the modern urban landscape.

According to some sources, the United States and Canada lag behind Europe, at least ten years in terms of investment in infrastructure « green roofs », as the ways to resolve many of the problems of quality of life experienced by the modern metropolis. At the beginning of the 1990s. several major European « green » Roofing companies have begun to penetrate the North American market. However, planting of roofs it was difficult to advance without active learning, without a local research technical characteristics of these systems, no illustrative examples.

In modern « green roof », as generally operated by a roof, taking the first cautious steps in the first place in Moscow and other large cities. Most often it is the site of the underground parking lots and shopping malls. EXAMPLE — shopping mall « Okhotny Ryad » on Manezh Square in Moscow, with flower beds and fountains, as well as several underground car parks in the elite residential complexes. Inhibiting factors are the lack of technical expertise in this field, tradition and support of municipal authorities, and the lack of good examples that could overcome the inertia of the consumer. However, today the situation is beginning to change.

The device is a green roof

« green roof » — this green space created by the addition of over traditional roofing system of additional layers of fertile soil and plants. Not to be confused « green roof » with a traditional roof garden when the plants are placed in separate containers (tubs) operated on the roof terrace or the parking lot.

Modern « green » roofing system must contain the following layers (from top to bottom):

plants, often specially selected for specific applications; engineered plant medium (substrate) generally may not include a ground; landscaping or filter fabric, which comprises the plant roots or vegetation, at the same time water permeable; Special drainage layer, sometimes with integrated reservoir for water; rigid insulation XPS; Traditional roofing construction with roofing/waterproofing membrane with included protivokornevymi supplements.

There are two main types of green roof systems: extensive and intensive. They differ mainly value vegetative medium thickness and used for this plant.

Extensive « green roof » (often unexploited) characterized by: low weight, low capital investment, low diversity of plants used and the minimum requirements to maintain. Plant substrates are generally produced from a mixture of sand, gravel, broken bricks, expanded clay, peat, organic matter and a quantity of soil. The thickness of the substrate ranges from 5 to 15 cm and its weight in moisture saturated condition — from 70 to 170 kg/m2.

Because of the small depth of the substrate and extreme climate on the roof, which resembles the desert plants for green roofs should be low and hardy. This is usually alpine or native plants or plants from arid regions.

These plants were watered and fertilized only as long as they do not accept, i.e. for one year. After this period, measures to support the « green roof » includes only two visits per year: for weeding and checking the roof membrane.

Intensive « green roof » are more often exploited. They are characterized by a greater thickness of the substrate, greater weight, higher capital costs, a wide variety of plants, high maintenance requirements. Substrate intensive roofs organized on the basis of soil at 20 – 60 cm, with a weight in a saturated state from 250 to 950 kg/m2. Due to the greater thickness of the substrate list of plants is more diverse and may include shrubs and trees, with which you can organize a more complex ecosystem. However, the maintenance requirements of intensive roofs, especially for their irrigation, higher: it is necessary to provide special systems for irrigation. We recommend professional counseling designers and landscape designers, and requires an experienced roofer to mount the system.

It should be noted that, depending on such characteristics of the roof as its location, bearing capacity building, budget, customer needs, availability of materials and plants, each « green roof » It will be different from the rest. Most likely, it will be some combination of intensive and extensive systems.

Valuation « green roof » during its life cycle it shows that it does not exceed the cost of a conventional roof. « Green roofs » are a type of investment that brings a range of social, economic and environmental benefits, public and private in nature. These benefits include increased energy savings of the building (due to cooling in the hot season, and additional insulation in the winter), extending the life of roofing membranes, additional sound insulation and more comfortable space available to tenants.

« Green roofs » Thaya is filtered of solid particles from the air, delay and cleaning out rain water and provide new possibilities for biodiversity conservation and the creation of new habitat. They provide aesthetic benefits Mogae and reduce the effect of urban « heat island » — Cities overheating in the summer, which contributes to air pollution and increased energy consumption tion.

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