Drainage is used to drain soils on summer cottages and construction sites. And many people are concerned about the question of what crushed stone is used for drainage. After all, the right choice of material will allow you to make a high-quality and efficient structure!
What functions does crushed stone perform in the drainage system?
While planning suburban area, it is advisable to think through a plan in advance drainage system. The durability and practicality of the buildings you will build depends on its functioning. The main task of such a system is to drain liquid from buildings and protect materials from dampness. The pipes used in the drainage structure have small holes through which water enters. This is greatly helped by the difference in pressure both inside and outside the pipes.
For such a system to function efficiently, there should be no impurities or dirt in the water. And therefore, before laying pipes at the bottom of the dug hole, you need to put sand and crushed stone there– they will serve as filters that retain fine dirt and other particles. As you can see, a lot depends on what kind of crushed stone is used, on its properties and qualities. But if you carefully read our articles and study video tutorials, you will not have any special problems with choosing materials.
Gravel and crushed stone for drainage: the main differences in the material
Many people believe that gravel and crushed stone are no different, because at first glance there is no fundamental difference between them. But if you look at the materials in detail, you can notice the difference! Let's start by learning the definitions of what gravel is and what crushed stone is.
- Crushed stone is a material that is formed by crushing rock. Crushed stone for drainage, the fraction of which can have different sizes and shapes, is used in a variety of fields, including the production of concrete mixtures.
- Gravel is obtained from the natural destruction of rock. This material is characterized by the presence of various impurities and a smooth surface, which significantly impairs its adhesion quality to the concrete mixture.
Main differences:
- Appearance of the stone. Gravel has a fairly smooth surface, but crushed stone has sharp corners and roughness. If we talk about size and color, then crushed stone is larger than gravel and has a uniform shade.
- Usage. Gravel due to its appearance It is more often used for decorative purposes, but crushed stone, due to its properties, is used in the construction of drainage and when pouring foundations.
What crushed stone is used for drainage: varieties
To choose the right one, you need to know what types exist, what characteristics they have, what their advantages and disadvantages are. This will allow you to make high-quality and practical drainage in your summer cottage.
Types of crushed stone:
- Gravel, different low level radioactive background. This material is quite cheap, but not as durable as other types of crushed stone. There are several varieties of it: crushed, which is mined mechanically(rock is crushed) and natural (pebbles or gravel). Despite the fact that the price of each type is almost the same, it is advisable to choose crushed gravel for drainage systems. And all due to the fact that the surface of this material has sharp edges - they hold dirt much better. When choosing this type when installing drainage, pay attention Special attention its tight laying.
- The granite type is best suited for drainage due to its hardness, strength, frost resistance and durability - its service life is about 40 years. However, this type of material is also the most expensive. Many people are afraid that this stone has a radioactive background, but there is no need to be afraid. But to protect yourself, check in advance with suppliers for quality certificates and other documents confirming that the material corresponds to the first class (less than 370 Bq/kg) of radioactivity. If your financial capabilities allow, be sure to purchase this type of material.
- Dolomite crushed stone extracted from sedimentary rocks. Compared to other types of crushed stone, it is considered the cheapest. At the same time, it has a number of advantages - zero level of radioactivity, environmental friendliness, complete harmlessness to health, absence harmful additives and impurities. But also, when compared with crushed granite and gravel, it is worth noting that it is not so durable and reliable - its service life on average is about 15 years. That is why it is better to use it in a dry area; the soil should have a low acidity level.
Advice: to avoid making mistakes when choosing the required materials, study samples in advance - before you decide to deliver a batch of material to your site. It is also important to remember that you need to thoroughly rinse the crushed stone, as this will significantly reduce siltation of the entire drainage system.
A lot depends on the fraction of the material, which you also need to know about in order to make drainage high-quality and practical, because this affects the entire system. Unfortunately, few people pay attention to this factor, missing it, which ultimately often leads to problems. Crushed stone can be divided into the following fractions, which depend on the size of the “grain”:
- Small crushed stone – up to 2 cm.
- Medium – up to 4 cm.
- Large – up to 7 cm
- Material non-standard shape– up to 12 cm.
- Screening is the residual material of crushing, in which the material reaches only 5 mm.
You can also use well-washed screenings instead of expanded clay or fine sand when laying the bottom layer of drainage. Small crushed stone is the most expensive type, however, despite this, it is in great demand. However, it is not very suitable for creating drainage due to its small size and poor filtration capabilities.
For practical arrangement of the system, medium-sized crushed stone (up to 4 cm) is most often used. This option can be called the most optimal, since such material provides high-quality filtration, eliminating contaminants and stopping siltation. Large fractions are characterized by the passage of dirt and small debris, which threatens pipe breakdowns.
Do-it-yourself drainage - quickly and cheaply
After reading our instructions for creating drainage, you will understand that you no longer need to spend money using the services of expensive specialists. There will not be any particular difficulties in this work; the main thing, as you understand, is to choose high-quality crushed stone. The installation of this system begins with digging a trench - dig it around the house, which will protect the structure from flooding. The distance between buildings and the trench should be about a meter.
After the trench is ready, we fill its bottom with a layer (5-7 cm) of fine sand, then lay a similar layer of medium-fraction crushed stone. This “cushion” will become the main one for laying pipes, on top of which we will refill smaller crushed stone. The final stage is leveling the trench using the top layer of soil that we removed when digging the ditch. The experience of many summer residents shows that this drainage system is the best, working flawlessly. As you can see, it is not difficult, and this work does not take much time.
During the construction of buildings and structures, a drainage system is used to drain groundwater. These can be channels, wells or pipes. Lack of drainage can allow water to seep into your home, thereby reducing its strength. In the process of creating a protective system, crushed stone is used for drainage. But to use it competently, you need to know which material is best suited for this work, and what fraction of gravel is necessary for laying a reliable drainage system.
Crushed stone accompanies the construction of houses and landscaping everywhere Source sslandscapesupply.com
What you need to know about crushed stone
This is a natural free-flowing granular product obtained during the processing of rocks. The production of gravel consists of dividing large rock fragments using special crushing machines. This makes it possible to produce crushed stone different varieties, of a certain caliber. One of the advantages of crushed stone is the rough fracture line, which has a positive effect on filtration in general.
About the characteristics of crushed stone
The main characteristics of the product include the following concepts:
flakiness;
frost resistance;
strength;
radioactivity.
Now about the characteristics of each direction separately.
Flakiness
This parameter determines the number of grains of needle-shaped and lamellar shapes. According to the level of flakiness, crushed stone is divided into 3 groups:
Cuboid no more than 10%.
An improved option with rates of 10-15%.
Standard (regular) from 15 to 25%.
If you choose which crushed stone to use for drainage according to this classification, experts recommend a product with high flakiness, since in this case for the manufacture concrete mixtures less binding component will be needed.
Individual stones in a pile of rubble may vary, but the best option is a mixture with a large portion of flaky Source homerenovates.com
Frost resistance
Assess this indicator of resistance to negative temperatures possible through cycles of thawing and freezing. If resistance is low, then this is no more than 15 cycles. A brand of material with high performance can go through up to 400 cycles. Experts suggest using material that can last 300 or more cycles.
Strength
The overall strength of the material is determined by the ability of the grain to collapse in a water-saturated state. In this case, the pressure on the grains of weak rocks should correspond to 200 atm. The indicator in question is:
High strength – up to 5%.
Durable: 5-10%.
Average 10 to 15%.
Weak strength: 15% or more.
Radioactivity
Those who decide to engage in individual construction are interested in the issue of radioactivity of the drainage material. Crushed stone is divided into three classes of radioactivity:
No more than 370 Bq per kilogram.
From 370 to 740 Bq/kg.
More than 740 Bq/kg.
When choosing which class of crushed stone is needed for drainage, you can safely use the first two. By the way, the third class is also allowed for construction, but is recommended for work on non-residential buildings outside the city limits.
Regardless of the fraction of crushed stone, the level of its radioactivity is also important, the lower the better Source tiu.ru
On our website you can find contacts construction companies that offer sewerage and water supply services. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.
Types of crushed stone
According to the type of rock that is suitable for the production of crushed stone, the product is divided into three types:
Granite
This is the most durable and frost-resistant natural material. Operational life is within 50 years. It is important that granite does not crack due to temperature changes.
This is interesting! A centimeter bedding can withstand up to 100 tons of rated load.
Unfortunately, granite has a number of significant disadvantages, which include: natural background radiation and high cost.
Granite crushed stone is the strongest, but also the most expensive Source avtogeko.ru
Gravel
The strength is lower than granite, but the background radiation is lower. The cost is slightly less compared to the material described above. There are two types of crushed gravel: crushed, which is obtained by crushing rock. And a natural product, which includes river and sea pebbles.
Gravel is more accessible and safer in terms of radioactivity Source grand-oxota.msk.ru
Lime crushed stone
The product has another name - dolomite. The material is cheaper than granite and does not emit radiation. And absolutely inert, which is important from an environmental point of view. Unfortunately, the service life is limited to 15 years. In this regard, it is not used as a material for the drainage system.
On our website you can find contacts of construction companies that offer landscaping services, which include installation of drainage systems. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.
About fraction sizes
One of the important factors that you should pay attention to when arranging drainage is the fraction of the material and its size. The gradation is as follows:
Screening is the smallest fraction. The particle size of the residual product during granite mining does not exceed 5 mm.
The size of the fine fraction is within 5-20 millimeters.
The middle fraction is considered to be a product with particle sizes from 20 to 40 mm.
The large fraction includes the fraction from 40 to 70 mm.
A non-standard option is fractions from 70 to 120 millimeters.
On a note! To arrange a drainage system, it is better to take crushed stone with a medium fraction.
Video description
What to look for when choosing the characteristics of crushed stone, watch the video,
About the construction of a drainage system without the use of gravel
It is known that in drainage, natural material reinforces the soil and acts as a filter for runoff. The use of natural material and the installation of a water drainage system make it heavier construction estimate. The cost of the system is affected by the crushed stone fraction.
Scheme of a drainage system without the use of crushed stone Source flowercenter.spb.ru
But today you can refuse to use crushed stone. Eg, trademark Softrock offers drainage systems that replace crushed stone with foam or polystyrene foam.
Video description
How crushed stone is used in a drainage device can be seen in the video:
Dolomite crushed stone has the shortest service life, which is not very good for the drainage system Source vse-o-kanalizacii.ru
Conclusion
Which crushed stone will be better for drainage primarily depends on the size of the fractions, their “purity” and the cost of the crushed stone itself. With an eye to the last point, you can pay attention to the use of modern crushed stone-free systems - but for this you need to calculate the cost of drainage specifically for your home and determine what financially more profitable.
What to do if groundwater comes close to the surface in the area? Constant soaking in moisture harms the soil itself, the roots of most plantings, and buildings. There is only one way out: to build a drainage system.
Draining an area on clay soils with crushed stone is the most suitable method for constructing deep trenches. A properly designed system can last for decades. One of the most important factors is the correct choice of crushed stone.
Advantages of crushed stone over gravel
These two types of materials are often confused. The concept of crushed gravel especially contributes to this. Sometimes misconceptions about the identity of these materials are helped by unscrupulous sellers.
What is the difference between crushed stone and gravel, and why is it better not to use the latter in drainage?
Gravel is a natural material. It is formed during the natural destruction of rock, when water freezes in the cracks of the stone and splits the massifs, during earthquakes. Then such fragments are polished (also naturally) and smoothed.
Crushed stone is obtained by forced crushing. It has a rough surface and angular shapes of the elements. The differences between materials form the pros and cons of their use in water drainage systems.
If smooth gravel is poured into a drainage ditch, it quickly cakes, the voids between the particles are reduced, and this reduces the quality and volume of drainage. Another disadvantage: gravel is rarely found without impurities. Their presence will further reduce the conductive qualities of the trench.
If drainage is performed using perforated drainage pipes, then gravel impurities can clog them quite quickly.
Crushed stone for drainage does not have any of the disadvantages of gravel: the angular structure prevents caking and provides excellent conductivity. Because crushed stone is manufactured rather than quarried, impurities are also minimal.
What kind of crushed stone is there?
On what basis do you choose crushed stone for drainage? Some have a limited budget, while for others, long service life of the drainage system is paramount.
Among existing species There are several main types of crushed stone.
Which crushed stone is best for drainage is up to you to decide. The parameters of the site, the drainage system itself and your financial capabilities are important here.
Choosing a faction
After choosing the drainage material, the next stage begins. You will need to determine what size crushed stone for drainage will be optimal for your drainage system.
Fractions, that is, the size of stone grains, are quite conventionally divided into five groups: especially large, simply large, medium, small, screening. Corresponding particle size (in millimeters):
- 70 – 120;
- 40 – 70;
- 20 – 40;
- 5 – 20;
- less than five.
The crushed stone fraction for drainage should be average, that is, from twenty to forty millimeters. Screenings (along with sand) are useful for constructing the lower underlying layer of a drainage trench.
Should a faction really be kept within such strict limits? If you take small crushed stone, this can slow down filtration. After all, the voids between the particles will turn out to be relatively small, so that water will literally ooze between them.
Significant voids can form between large “grains”. Water will pass through them at high speed, but it can simultaneously erode the soil, which will quickly penetrate into the drainage layer. As a result, the entire system will silt and stop working.
Now you know what crushed stone is needed for drainage. There are a few nuances left to consider.
When deviations from general rules are possible
Here are some subtleties of the water drainage system that may be useful to you:
- If your drainage system is laid at a depth of more than 0.8 meters, the use of coarse crushed stone is allowed, that is, 40 - 70 mm.
- For some reason it is impossible to lead drainage channels to the place of low ground? Then you can install a drainage sewer well. It must be covered with large crushed stone, covered with geotextile, and on top it can be disguised with a flower bed.
Geotextiles significantly slow down the clogging of drainage systems and are strongly recommended for use in drainage trenches.
Only correctly selected crushed stone for drainage will ensure full, high-quality and long-term operation of the entire drainage system.
A properly designed drainage pipe system will prevent moisture from penetrating into the building, erosion and pressure on the load-bearing foundation and the entire structure as a whole. The principle of operation of underground collection and drainage of water is based on its entry into receiving pipes (drains) through joints, holes or cracks in the walls.
This supply occurs due to the difference in water pressure provided by the depth of installation of system elements below the water level. The calculation of such depth, quantity and types of materials for the entire structure is based on the indicators of the “wettest” periods of the year - autumn and spring.
Most often used horizontal system with a regular arrangement of tubular cavity drains with aggregates (crushed stone or gravel for drainage). In it for reception groundwater holes are made in the walls of the pipes where water flows due to the already mentioned pressure drop.
Crushed stone and gravel for drainage - the main differences
What is filler used for in tubular elements? Its purpose is to prevent them from silting, in which case it performs a filtration function. According to the rules, drains are laid in trenches prepared in advance according to the design, at the bottom of which there is a sand cushion no thinner than fifteen centimeters, and on top of it is the same layer of crushed stone or gravel.
All components are installed on top: geotextiles (if used), pipes, couplings and corners (other styles), wells (drainage and manifold with a check valve), after which they should be backfilled with crushed stone and earth. For the proper functioning of the entire complex for removing excess moisture, it matters what kind of crushed stone is used for drainage.
As is known, gravel consists of rounded fragments of rock or minerals different sizes. It is generally accepted that gravel fragments can reach twenty millimeters. In this case, small (up to three millimeters), medium (up to ten) and large fractions of the material are distinguished.
Unlike gravel crushed stone has the appearance of acute-angled fragments of the same rocks or minerals. Its elements, which can reach one hundred millimeters, are obtained by crushing natural or artificial stone and other materials.
For the purpose of removing moisture using a drain system, it is best to use fractional material (gravel or crushed stone) with a fraction size of twenty to forty millimeters.
Crushed stone for drainage - conditions of use
It must be taken into account that only well-washed material can be used. The same applies to coarse sand for base cushioning in trenches. Flushing is mandatory to reduce siltation of the entire system. After laying and installing pipes with filler, backfilling with a layer of crushed stone or gravel of the required fraction, the drainage is covered with fabric geotextiles, over which the previously excavated soil is filled.
In this case, it is important to ensure the installation slope for natural moisture drainage towards the system wells. The layer of crushed stone top filling also depends on the characteristics of the soil in which moisture removal is arranged. And the denser the soil, the thicker the backfill will be required.
The entire designed system must collect water in a special well located at the lowest point of the relief plan. Its design provides the ability to receive the maximum amount of moisture determined during the above-mentioned “wet” periods of the year. If necessary, several wells can be made. By the way, experts advise using water from such wells for irrigation.