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During the arrangement of drainage, a special filter material is used - geotextile. Strong and environmentally friendly fabric belongs to the group of geosynthetics. The main purpose of the material is to separate soil layers of different composition and purpose. The fabric prevents them from mixing, but at the same time allows water to pass through. Several types of such material are produced. What geotextile is needed for drainage, we will now figure it out.
Application of geotextiles
Geotextiles can be called a filter. Passing moisture through itself, but preventing the passage of solid particles, the fabric does not allow mixing of dissimilar layers of soil. Due to these properties, the canvas is widely used in the arrangement of drainage systems. They help drain rainwater as well as melt water from buildings, sidewalks and other structures.
In addition to filtering function, geotextiles prevent germination weeds... If the canvas is placed under the decorative layer of a loose garden path, then water will never accumulate on it and weeds will never grow. It should be taken into account that there are drainage systems of different types, therefore, the choice of the type of geotextile takes place on an individual basis.
Variety of canvas
The appearance of the geotextile resembles a fabric. But her properties are completely different. The canvas is distinguished by its strength, high resistance to stress and mechanical stress.
There are two main types of geotextiles:
- The woven fabric is called geotextile. The material is made from natural or synthetic raw materials by weaving fibers. The main purpose of geotextile is soil reinforcement. The cloth is closed on large slopes to prevent landslides, and is used in the manufacture of geocontainers and other similar structures.
- Nonwoven material is called geotextile. It is completely made from synthetic raw materials by combining polymer fibers. Geotextile is used in the construction of drainage systems.
Today we are considering what kind of geotextile is needed for drainage, so we will dwell on the geotextile in detail. There are three ways to produce filter media:
- with the thermal method of production, the polypropylene filaments are soldered.
- the chemical method is based on gluing synthetic fibers.
- the mechanical or needle-punching method is based on the weaving of synthetic threads or fibers.
Geopolitics made only by one of the considered methods rarely go on sale. Typically, this type of geotextile is produced using several polymers. In this case, a combination of, for example, a chemical and a mechanical method is used.
Which geotextiles can and cannot be used for drainage
First, let's figure out what material cannot be used for drainage:
- Such material for drainage as geotextile produced by a thermal method is not suitable. The adhesion of the threads is so strong that the material practically does not allow water to pass through. The material is very dense, but it cannot be used as a substitute for waterproofing.
- It is impossible to choose geotextiles for drainage, which contain natural fibers, for example, cotton or wool. Such a canvas will rot in dampness.
- The material is made of polyester threads, it is highly durable and resistant to decay. However, such a geotextile perfectly absorbs water, but does not give it away, but keeps it in itself. Such a canvas will not work for drainage.
A geotextile made of polypropylene threads is ideal for drainage. The fabric is characterized by increased strength, excellent moisture permeability, resistance to decay and chemicals.
What are the parameters for choosing a canvas for drainage
Considering how to choose a material for arranging drainage, you must first pay attention to its thickness. A thin web will break during the movement of the soil, and a thick fabric will quickly silt up, which will stop the filtration process. It is optimal when the geotextile used for drainage is of medium thickness.
Now let's look at the main parameters for which the selected material is suitable for drainage:
- To begin with, for drainage, the density of the geotextile must be selected, guided by the depth to which it will be buried. It is also important to consider the type of soil. For example, when arranging shallow drainage, it is enough to use a canvas with a density of 150 g / m3... On inactive soils, when laying drainage pipes, a material with a density of 200 g / m is used3... Where there is seasonal movement of the ground, a canvas with a density of at least 300 g / m2 is suitable.3.
- For drainage, it is only necessary to lay geotextiles with high moisture permeability. This type of material includes a geotextile made of polypropylene filaments.
- There is such an indicator as the filtration coefficient. It indicates the amount of moisture that the geotextile can filter out per day. For the drainage system, a minimum value of 300 m is allowed3/day.
- In order for the laid geotextile to serve for a long time, it is necessary to optimally select the material for its mechanical strength. For drainage, a sheet with a transverse tensile load of 1.5–2.4 kN / m is used, and a longitudinal one - from 1.9 to 3 kN / m.
Often geotextiles for drainage systems are simply identified by their white color.
Rules for the use of geotextile when arranging drainage
Laying the geotextile is very simple, since the canvas is easily cut with a knife, rolls up, taking the desired shape. To get effective drainage, you need to follow simple rules:
- Being in the heat under the sun for a long time, the geotextile can deteriorate the filtering qualities. It is optimal to unpack the material immediately before its use and immediately cover it with earth.
- To prevent the canvas from tearing, it must be laid in the trench after leveling the bottom and side walls. The fabric should not be too tight or wrinkled. If a hole has formed on the geotextile, this piece must be cut off and then replaced with a new one.
- The width of the canvas is selected so that it can overlap the pipe with drainage filling. Here you need to make calculations before installing the drainage system. The section of the pipe, as well as the thickness of the backfill, are taken into account. Ideally, drainage is obtained if it is enough to roll out a whole piece of geotextile along the trench.
- To have a better idea of laying geotextile, let's take a closer look at the drainage arrangement. So, a canvas is spread at the bottom of the trench. Its edges should go beyond the pit, where they are temporarily pressed by the load. On top of the geotextile, rubble is poured with a thickness of about 300 mm. Next, the pipe is laid and backfilled on top with a similar layer of rubble. After that, the entire filtering system is wrapped with the free edges of the geotextile. At the end, the trench is backfilled with soil.
If the laying of geotextile crushed stone and pipes was done correctly, the drainage system will function properly for many years.
The video tells about geotextile:
It is not difficult to choose the right geotextile for arranging drainage. As a last resort, you can use the recommendations of the sellers. The main thing is to strictly observe the technology of laying the material.
