Recently, the construction of small buildings and structures is considered popular. Increasingly, for their construction, the installation of a pile-screw foundation is used. Thanks to the achievements of scientific and technological progress, literally anyone who is more or less familiar with the fundamentals of construction will be able to build their own pile-screw foundation. This technology is not new and has long been used as a low-cost type of construction of the foundation of the future building. In the article, we will consider in more detail the pros and cons of the pile-screw foundation, as well as the step-by-step technology for installing pipes.
What is a pile-screw base
The device of the pile-screw foundation is a certain number of screw piles that are screwed into the ground manually or using special equipment. On top of the piles, a so-called grillage is formed, which is the connecting frame of all freestanding screw piles. The grillage, as a rule, can be made of wood or metal.
What does one pile look like
Examining one individual pile, you can notice that it is made in the form of a thickened metal pipe, the wall thickness of which is 0.4-1.2 cm. A blade in the form of a large thread is located at one end of the pipe. Due to this structure, piles are easily screwed into the ground. The tip in the form of a blade at the same time will be the support of the entire structure. For the convenience of installing a pile-screw foundation, most often on sale you can find piles 0.25-2.5 m long.
Design advantages
The use of screw piles allows you to create a strong, high-quality and durable foundation for a cottage, cottage, country house, bathhouse, gazebo or other structure in the shortest possible time and at the best price.
Advantages of installing a pile-screw foundation:
- Profitability: the cost of such a design is significantly lower than the cost of constructing a strip foundation or foundation slab. Significant savings are achieved through the use of a fundamentally different technology, the use of cheaper materials, and most importantly - simpler and faster installation methods.
- Quick installation and readiness for use: most often, building a reliable foundation takes half a day, and the foundation can be operated immediately after installation.
- High environmental friendliness: the installation of a pile-screw foundation is completely harmless to the landscape - there are no mountains of construction debris, dust, traces of overall construction equipment.
- Year-round: the fastening of piles is carried out both in the warm and in the cold season, and without increasing the cost of work.
- Universality: this type of foundation is excellent for building low-rise buildings of any type on different soils (except rocky and rocky), as well as building houses on a site with a vertical drop.
- Lack of dampness and low heat loss: during the operation of screw piles under the building, an air cushion is formed, which prevents the occurrence of dampness and retains heat.
Disadvantages of pile-screw foundation
Today, screw piles are made from various metals and their alloys, mainly from steel or stainless steel. Such products are subject to corrosion. The design collapses over time under the influence of alkaline soil compounds. The durability of literally the entire structure directly depends on the quality of the anti-corrosion treatment of piles. Corrosion-resistant coating is applied after sandblasting. This process is carried out only in industrial production. It is not possible to self-coat against corrosion. The costs of anti-corrosion treatment significantly increase the cost of building a house.
The maximum service life of screw piles today is up to 85-90 years. It is important to buy piles made of high-quality metal, which will guarantee a long service life of the entire structure.
Mounting options
Turnkey pile-screw foundation installation can be carried out by two main methods:
- Manual method involves screwing metal piles into the soil manually. To do this, use the well-known scrap or ordinary steel bar, which are inserted into a special hole in the upper part of the pile. To build a pile-screw foundation with your own hands, you need only two specialists who screw up to 15 piles in one shift. Base construction should be carried out only in the warm season.
- The mechanical method of building a turnkey pile-screw foundation is to hammer in metal pipes using special hydraulic equipment. The application of this method allows building in the winter, as well as building houses near the water. Thanks to the automation of almost the entire process per shift, a team of three people screw up to 30 piles.
Basic installation steps
In order to correctly install the pile-screw foundation, it will be necessary to observe the installation technology, which includes several stages:
- Calculation and markup. The first step is to determine the type of soil and the amount of work involved in driving piles. Experts also calculate the structure of soil strata and the level of their freezing in winter. Based on the calculations, the installation locations of metal piles and their required number are noted.
- Pipes are installed vertically at previously marked places.
- Since construction is most often carried out in a non-standard landscape, pipe trimming is almost always carried out at the same level. This procedure is important to create a solid foundation.
- In addition, reinforcing the pile-screw foundation and protecting the structure from internal corrosion and external negative factors will allow concreting. Pouring concrete pipes is carried out at the last stage of the foundation.
How to deeply lay a pile-screw foundation
The depth at which it is necessary to screw in screw piles is determined before their purchase and installation, because their overall characteristics directly depend on this.
The basic rule in determining the installation depth of a pile-screw foundation is that it must be below the level of freezing of the soil. This will avoid the heaving of the soil in winter and pushing piles to the soil surface. If this type of soil is observed on the site, then the piles are screwed in not just below the freezing depth, but to the so-called good soil.
It is recommended to focus not only on the level of freezing of land in a particular area. This applies to soils of marshy, sandy, peat types, where more or less solid ground is located at great depths.
It is important to recall: it happens that dense layers of soil lie at a depth greater than the length of the pile being bought. In this case, experts recommend building up metal pipes. Sometimes a pile-screw foundation has to be installed to a depth of more than 5 meters.
Soil preparation
First of all, before screwing the screw piles, the top layer with the vegetation located on it is removed to facilitate construction work at the pipe installation sites. This is done with a drill of a smaller diameter than the diameter of the pile blade, or they clean the soil with a conventional bayonet shovel. It is advisable to do these works in the process of laying piles.
How to choose piles
When choosing supplies, you must pay attention to the following:
- Before you screw the screw piles, you need to conduct a detailed analysis of soil indicators on the land. In this situation, the type of soil, the depth of the groundwater, the period and level of soil freezing are determined.
- Before buying the material, the mass and design of the future structure, as well as the subsequent load of the snow cover, must be taken into account. It is important to remember that the larger the diameter of the piles, the stronger the whole structure will be. Today, the recognized optimal option for the construction of a suburban low-rise building is the diameter of metal piles 108-120 mm.
- The wall thickness of the pipes must be at least 4 mm.
- Piles for the foundation should be selected only from new steel. Mandatory is the use of sandblasting and anti-corrosion treatment of pipes.
- It is recommended to select piles without welds with the correct and geometrically verified blade without defects in the form of dents.
Screw pile prices
The cost of screw piles can be different, depending on the material from which the pipes are made, and the dimensional characteristics. Please note that piles may vary in length, diameter and wall thickness. Also, the cost of screw piles may vary. The reason for this is the use of materials of increased strength, the price of which is much higher.
Before building a pile-screw foundation, the pros and cons should be evaluated not only by the owner of the future building, but also by specialists. With a competent approach, it is possible to build a durable and durable building. It’s quite possible to create a pile-screw foundation with your own hands, the main thing is to adhere to the technology and the sequence of work.