HDPE geomembrane used for roof root separation layer processing - used for roof root separation layerseepage control effect of root separation double

With the deepening of reform and opening up and the extent of the city continues to expand, the survival of the people of the city space is becoming smaller and smaller. In order to improve the city 's green coverage rate,improve zoology environment, beautify the city landscape, the implementation of the green roof is the mosteffective way to.

One, development of planted roof

Be imperative in the modern society with the rapid development of today, China's large and medium-sized cityland resource is the " gold ", can be used for green land area is less and less. However, hundreds of millions of roofing is bare, and make full use of this has yet to be green " open space " development of planting roof, be imperative.

1, the development of planting roof, slowed the city's " heat island effect "

Building surface temperature with time

Due to the various types of building roof, wall and road are the good performance of the " large accumulator ",their daytime absorption of solar radiation energy, night heat, resulting in urban night high temperature,leading to the urban temperature than suburban temperature 2～ 3 ℃. Because the temperature rise is partlyIsland, it called for " heat island effect ". If the roof built in planting roof, roof planting flowers, grass, trees, wide,through the roof greening, realize the " ping changed green ", not only can greatly improve the city 's green coverage rate, but also can effectively ease the city's " heat island effect ". According to the report, every hectare green day to absorb heat from the environment, equivalent to the 1890 power of 1000 Watts air conditioning effect.

2, the implementation of roof greening

Have the added benefit of city atmospheric oxygen content roof greening by plant photosynthesis, absorb carbon dioxide in the atmosphere, release oxygen, easy to maintain the carbon dioxide in air and oxygen balance, improve air quality, according to the determination, 24 square meters of bluegrass Ping, a day canmake oxygen 1380 grams, enough to supply an adult normal the 1 day of life need of oxygen; a beech daycan absorb carbon dioxide and produce oxygen 2352 grams, 1712 grams, played the role of air purification.

3, roof planting plants

Can absorb harmful substances, reduce atmospheric pollution roof plants with adsorption, fixed dust, heavy metal elements and atmospheric absorption of NH3, SO2, NO2, HF and CL2 and other harmful substances,and can reduce city noise function. According to the determination of the thickness of 120mm, plant insulation layer up to 40 dB, which can obviously reduce air and noise pollution.

4, regulation of ecological environment

Beautify the city landscape implementation of planting roof, helps regulate the city climate environment,reduce stormwater drain, suppression of heavy rain, sandstorm weather, improvement of city landscape, for the development of residential ecological environment, realize the harmony between man and nature, to create a " garden city " and the benefit of the people.

Two, planted roof drainage system design and construction of planted roof structure more, technical demand is high, relates to the construction, forestry and gardening and other professional disciplines, it is project of a system, must from design, material selection, construction and management of maintenance and other aspects of the comprehensive research and treatment.

In order to ensure the planting roof plants can not only foster growth, and waterproof and drain the water, dono leakage, in order to meet the housing architectural use function. Therefore, its structure more complexstructural hierarchy, each has its own function and role, once the leakage, the entire roof must rework redo, not only large quantities, costs are more expensive. Therefore, in the design, according to the roofing waterproofing rank for grade one and grade two for multi-channel waterproofing, and good drainage structuresystem. The planting of roof the structural hierarchy of composition, function, material selection and construction key points are described as follows:

1, the growing medium cultivation medium is roof plants grown in soil layer. Requirements of selected plantingmedium should have light weight, does not harden, water and fertilizer retention, suitable for plant cultivationgrowth, simple construction and economic and environmental performance. The general choice of planting soil, peat, vermiculite, perlite, fine sand and treated through fermentation of animal manure and other materials, according to a certain proportion of mixed and compounded. The peat and fermented animal fecesfor plant growth, and the effect of humic acid organic fertilizer; expanded vermiculite and perlite can not only reduce the growing medium bulk density, and is conducive to preserving water, ventilation, prevention of plantroot, is a plant growth promoting material, can replenish needed by the growth of plants iron, magnesium,potassium and other elements, but also the growing medium in the pH value of buffer and regulator.

Can also be directly used for planting roofing, specialized production, composition and particle size of reasonable configuration, water and fertilizer, can promote plant root development and growth, and bulk density of only 450Kg / m3 around the artificial synthesis of inorganic materials for plant cultivation medium.

Cultivation of dielectric layer thickness should be based on the medium and plant type, general lawn is 150 ～ 250mm; small shrubs from 300 to 400mm; large shrub to 500 ～ 600mm; arbor is more than 800mm.

2, filtration layer in a growing medium layer and drainage layer between, should use the weight of not less than 250G / m2 polyester fiber earthwork cloth as a filtration layer, in order to water retention and drainageeffect. It is intended to be a growing medium layer due to rain or watering after excess water through the filter layer in time out, in order to prevent root rot of the plant, at the same time can be a growing medium preserved,to prevent erosion.

In 3, a drainage layer filtration layer is arranged at the lower part of the drainage layer, a drainage layer may be used, leaving enough space and have a certain bearing capacity of plastic drainage plate, rubber drainage board or particle size of 20 ～40mm, thickness of 80mm over the pebbles. Its role is to be passed through the filtering layer water, rapidly from the drainage layer in the gap together to the drain hole out.

In 4, root of puncture of the waterproof layer as everyone knows, all kinds of plant root system has strongpuncture ability, many of the traditional waterproof material is easy to plant root penetration, which led to theroofing leakage. Therefore, in planting roof, must in general flexible waterproof layer, empty shop or paste aroot system with sufficient puncture functional materials, such as high density HDPE geomembrane, low density polyethylene ( LDPE ) geomembrane, polyvinyl chloride ( PVC ) membrane, polyolefin (TPO )membrane and lead alloy ( PSS ) membrane for root system puncture proof layer.

To ensure that the plant roots not only cannot penetrate the material body, also do not penetrate the materialof joint, thus requiring root system puncture waterproof layer shall be used for welding seam construction method, and shall make the seam welding firm, tight seal. The thermoplastic material, using a single seam welding, lap width is 60mm; the effective width of the weld shall be not less than 25mm; double seam welding,lap width is 80mm, its effective weld width of 10mm× 2 + cavity width, lead alloy sheet joint, used to be the toolelectrode and welding.

5, material or coating waterproof layer in planting roof construction, except the root of puncture of thewaterproof layer outside, still should be in its lower part 1～ 2 props are laying waterproof, corrosion resistance, mildew and primary expansion or cracking deformation adaptability of material (such as polyestermodified asphalt waterproof coiled material, synthetic high polymer waterproof coiled material etc) or coating (such as a two-component or single component polyurethane waterproofing coating etc. ) for flexible waterproof layer. When using the web as a waterproof layer, according to the national standard of " technical code for roof engineering " and " code for acceptance of construction quality of roof " provisions, should give priority to the empty shop law, point sticking method and adhesive construction method, but the coil joints andthe surrounding membrane waterproof layer should be full bonding.

Planted roof masonry retaining wall around should be lower, retaining wall should be indwelling drain,drainage hole position should be accurate, and should be communicated with water, no clogging, so as toeliminate the water planting roof.

In 6, a leveling layer to facilitate the laying of flexible waterproof layer, the sloping layer should do on cement mortar screed-coat. The leveling layer should be compacted to smooth, leveling layer water, should be two times the screeding press polishing and sufficient maintenance, there shall be no loose, sand, bark andhollowing phenomenon.

In 7, the sloping layer to facilitate rapid elimination of planting roof seeper, ensure the normal growth of plants,should adopt the structure for slope roof. When not used for slope structure and must use the material to find the slope, choose a certain strength of lightweight material ( such as ceramic, aerated concrete, foamed glass) do the sloping layer, the slope should be 1%～ 3%.

In 8, the roof structure layer of roofing structure layer should be according to the planting roof types and loaddesign and construction, should in general be using cast-in-place reinforced concrete roof structure layer.When the assembled reinforced concrete slab, application of strength grade of not less than C20 of fine stone concrete will be filled in dense seam; seam width greater than 40mm or narrow width, should be in the gapplaced reinforcement strengthening, plate end seams should also be filled sealing material sealing is tight.