Turnkey pile-screw foundation. Do-it-yourself screw foundation Making a pile screw foundation

Using a foundation on screw piles in the shortest possible time and at a minimum cost allows you to independently make the foundation for a bathhouse, private house or garage. Even a novice builder can handle installing piles in the form of steel screws. There are several types of such foundation supports with different load-bearing capacities; choosing them for a specific building and soil is not difficult.

What is a pile-screw foundation?

According to the structural design, a screw pile is an iron pipe that is hollow inside, at the lower cone-shaped end of which drill blades are welded for screwing it into the ground. After being immersed in the ground, these support pillars are connected by a grillage or the lower rows of the log house. As a result, each of the supports takes on part of the load from the building, distributing it across the entire pile field.

This is what the base looks like

The blade at the end of the tip from below, on one side, simplifies screwing the pipe into dense soil layers, and on the other, plays the role of a holding anchor. In some cases, if necessary, such a support is simply unscrewed from the ground and used in a new location for a new pile foundation. The main thing is that it does not rust by this time, being in the ground.

Types of screw foundation

According to the configuration and purpose of the blades there are:

Broad-bladed - a typical version with one blade in 1–1.5 strokes.

Multi-blade - with several blades.

Narrow bladed - with a tip in the form of a screw for 5–8 turns of the screw.

Various types depending on soil

The first option is intended for light buildings and stable soils. The second type of screw piles is used when it is necessary to improve the load-bearing capacity of a support with compensation for its vertical movements, as well as for tall and heavy cottages with a total weight of 2-3 floors.

The third type is for foundations on soils with an abundance of stones. For permafrost conditions, it is also recommended to take a narrow-bladed analogue, only it does not have a pointed end, but an open cut with teeth along the perimeter.

The pile tip can be cast (VSL) or welded (SWS). The first one costs more. However, it is more durable and able to withstand greater loads than its welded counterpart. If the soil at the construction site is dense or the foundation needs to be made for a large house, then it is better to spend money and get one with a cast tip.

Pros and cons of foundations on piles

Among the advantages of using such a base are:

Durability and high load-bearing capacity - such piles can withstand seasonal heaving without problems and last 50–80 years;

Cost-effective – costs 20–30% cheaper than other options;

Lack of construction waste and large volumes of earth excavation;

High speed of construction - two to three days will be enough for self-installation of a foundation from screw piles;

Possibility of creation on almost any type of soil;

Ease of implementation - it is much more difficult to make a slab or strip foundation with your own hands;

A large number of modifications of tips and heads;

Possibility of reuse;

There is no seasonality of work as such - screw supports can be screwed in even in winter, as long as the soil allows it.

There are also disadvantages to a screw foundation, but they are much fewer and are worth mentioning only:

Impossibility of arrangement below the floor of the basement or basement;

Additional costs for insulating the house from below.

Considering the pros and cons, it is clearly clear that the advantages greatly outweigh the disadvantages. However, there is one big “BUT”.

Electromechanical corrosion

The screw support must be manufactured in accordance with standards and from high-quality steel. And after that, it must also be checked by the Quality Control Department using ultrasound or X-ray. The main problems for developers who have opted for a pile-screw foundation usually arise precisely because of defective materials.

Installation of a pile-screw foundation

The technology for arranging a foundation with your own hands from screw piles is as follows:

A test screwing is carried out to determine the strength of the soil.

Calculations are carried out with the preparation of a support placement plan.

The site is marked.

The installation of support piles is carried out, followed by cutting them to the level.

Concrete is poured inside the support.

The created pile field is tied.

For each type and modification of a screw-shaped pile, its load-bearing capacity is indicated in the passport. Here, both the size and configuration of the blades, as well as the wall thickness and barrel length, play a role. Depending on the groundwater level, freezing depth and soil composition, the pile field placement plan is calculated in each case separately.

When designing, it is also necessary to take into account the mass of the entire future structure, under which the foundation is built on screw piles. Moreover, the calculation should include the weight of not only walls and ceilings, but also roofing and loads from snow and wind. After all, ondulin or membrane roofing obviously weighs less than slate or tiles. And all this must be foreseen in advance.

It is best to entrust the project preparation stage to a specialist. If you plan to make a screw foundation with your own hands, then calculations should be carried out on the basis of SP 24.13330. Or you will have to install more supports with a reserve, increasing the construction cost.

Step-by-step photo instructions

Marking the first foundation support according to site landmarks

There shouldn't be any difficulties with marking. You just need to mark the places for supports on the site in accordance with the project. The main thing during construction is the strict verticality of the pillars screwed into the ground.

We dig a “pit” 20-30 cm deep for the first support

Insert into the pit

Tighten using special levers (steel pipes)

To simplify the positioning of pile supports when they are immersed in the ground, you can use a drill or shovel to dig a small pit half a meter deep. Next, the supports are screwed into the soil using a crowbar, a powerful electric drill with a gearbox, or automotive special equipment that acts as a lever. This is done in increments of 1–3 meters.

When the pile stands strong enough, hang a magnetic level and adjust the last part of the screwing according to the level - level it with weight

The first one is screwed exactly to the level

We mark the second one - the corner one on the same side from the first one

We dig a pit, install a second support, level it and check the distance from the first

When installing and screwing them in, it is extremely important to ensure that the supports do not move to the side. This immediately reduces the ability of the pillar to withstand the design loads. It is better to unscrew such piles and do everything again. At the same time, placing them again in the same place is strictly prohibited. It will be necessary to move this “screw” a little to the side.

When the support is at the required distance, we tighten it in the same way as the first one.

Similarly, by tilting we adjust the distance between the pillars

After maintaining the distances, tighten the third

Similarly, mark and twist the fourth, observing the dimensions along the diagonal and side

We stretch the twine around the entire perimeter and mark the intermediate supports with a marker on the twine.

We install each support in the pits according to the marks and level and compact it with earth

After twisting all the pillars, we mark the same marks with a hydraulic level

Using a grinder we cut all the supports to the level

Fill the pile with cement-sand mortar to a level of 10 cm to the end

The remaining part is filled with ready-made dry cement-sand mixture.

After the piles are installed in place, they are cut at the desired level from the ground. Then it is recommended to fill these supports, which make up the considered version of the foundation, with concrete from the inside. This helps protect the metal from corrosion and further strengthens the entire pile screw field.

A head in the form of a square steel plate measuring about 25 x 25 cm is welded on top of each installed post. And finally, all welds are treated with protective compounds. Then on this pile foundation you can lay a grillage or immediately the crowns of the log house.

To prevent the wind from blowing under the house and cooling it down, the pillars must be covered with external cladding along the entire perimeter of the building. Corrugated sheeting or sheet metal is perfect for this. But you can also use facing bricks. Everything is at the choice of the cottage owner.

Application of foundations on screw piles

To build a screw foundation made of iron piles, a team of 5–7 people often needs one day. In this case, there is no need to wait for the concrete to settle or set. Such a foundation is completely ready for further construction of the building. This strip or monolithic slab foundation must be maintained for at least 20–30 days. With screw supports, the stage of installing supports for the house takes much less time.

House made of SIP panels

If the site has weak soil (swampy, watery sands, peat bogs), and the load on the foundation is expected to be high, the most reliable foundation for a house is a pile foundation.

In addition to reliability, a pile foundation has another important advantage: undemanding to the terrain. There is no need for careful leveling of the construction site. This greatly simplifies the process of installing a pile foundation with your own hands and reduces environmental damage to the surrounding landscape.

What types of foundations are there on piles?

Based on the nature of their interaction with the ground, a distinction is made between hanging piles and rack piles. The former rest on the ground with their side surface and withstand the load due to friction; the latter are installed with support on hard rocks underlying looser layers.

a) pile rack, b) hanging pile. 1 - pile, 2 - weak soil, 3 - strong soil.

According to the method of immersion, piles are:

• driven - reinforced concrete, steel or wood, driven by impact directly into the ground or into leader holes;

• reinforced concrete shell piles. They are immersed using the vibration method, followed by excavation of soil from the cavities or without excavation, with or without filling with concrete;

• for the foundation. Wells are drilled in the ground, reinforcement is placed in them and concrete is poured;

1 - immersion of the casing string into the ground. 2 - Extracting soil from the casing. 3 - Immersion of the reinforced frame into the well. 4 - Filling the well with concrete. 5 - Removing casing pipes.

• screw pile foundation.

Features of foundations on screw piles

A screw pile is a hollow steel rod with a sharp tip and spiral blades. The diameter of the rod is 10-30 centimeters, the length is from a quarter of a meter to 2.5 meters.

If more is required, the pile is increased. The upper end of the pipe (heel) can be rectangular, round, or U-shaped. The pile is screwed into the ground like a screw, hence the name.

During manufacturing, the surface of the rod is coated with special anti-corrosion compounds.

The service life of a pile-screw foundation is over half a century (50 years - manufacturer's warranty).

Pros and cons of a pile-screw foundation

The main advantage of a screw foundation is the ability to do without excavation work and pouring concrete. This dramatically reduces work time and energy consumption:

• no need for a concrete mixer or a large amount of material - concrete itself, reinforcement, ;
• no need to wait for the foundation to gain strength;
• no heavy equipment required. For small structures, the piles can be screwed in manually.

The exception is combined pile-strip foundations. When constructing them, you cannot do without concrete (sometimes brick is used instead, but this increases the energy intensity of the work).

Under a heavy brick house you will need a concrete strip or reinforced concrete belt.

In other cases, the piping of a pile-screw foundation is made of metal beams, for light houses -.

A) The foundation option is suitable for the construction of a frame, wooden block and brick house. B) The foundation option is suitable for the construction of a frame, wooden, block and brick house. C) The foundation option is suitable for the construction of a wooden house. D) The foundation option is suitable for the construction of a frame, wooden, block and brick house.

If the grillage is metal, the only way to connect the foundation parts is welding. With the appropriate equipment and skills, this greatly simplifies the process of building a foundation for a house.

Concrete is also needed when constructing a screw foundation: it fills the hollow cores of the piles themselves. But the amount of material and scope of work are not comparable to the construction of reinforced concrete structures.

Pay attention!

The construction of a pile foundation of this type is possible on all soils except rocky ones, incl. on flooded soils.

The length of the rod can be chosen so that the pile passes through the unreliable soil and is secured in a stable layer.

• screw piles are used for private development and for small-sized structures. High-rise buildings with a large mass are not built on them;
• When screwing a pile, it is impossible to control its passage through the soil. Solid inclusions contained in the ground can damage the anti-corrosion coating;
• in the absence of a reinforced concrete base, arrangement of the basement floor is problematic;
• settlement of piles is uneven, highly dependent on soil characteristics within one area;
• despite the lack of excavation and concreting, the prices for a pile-screw foundation are significant due to the cost of the piles themselves.

Calculation of foundations on screw piles

To determine the required number of piles, you need to divide the total pressure on the ground by the load-bearing capacity of the pile.

The calculation of a pile foundation is carried out in three stages:

1. The total load is determined - the total weight of the structure, including floors, internal walls, furniture, roof, people and all the contents of the house. According to SNiP 2.01.07-85 for private houses, the payload is 150 kilograms per square. The snow load should also be added here. It depends on the region (for example, in the north of the Moscow region - 240 kilograms per square). The total value is multiplied by a factor of 1.2.
2. Additional loads are taken into account - wind force, etc. Typically, the safety margin is 30% of the design figure.
3. The bearing capacity of the soil is determined either based on the results of geological research (2.02.03-85 SNiP) or according to existing tables.

Pay attention!

Usually, under a small private house, piles are installed with a design step of 2-3 meters.

How to make a pile foundation with your own hands?

Installation of a pile-screw foundation begins with markings. The corners of the structure are marked, and a marking cord is pulled between them. The immersion points of the piles are marked with pegs in accordance with the calculated step.

The piles are immersed at the marked points. At a immersion depth of up to one and a half meters (freezing level in the middle zone), this can be done manually.

If the depth is greater or the soil in the area is very dense, special equipment is used for screwing.

• align the piles in height (tighten some, cut others);
• fill the cavities with concrete mortar;
• install grillage.

Price of foundation on screw piles

The price of a screw foundation depends on the length of the piles, cross-section, and wall thickness. The cost of a screw pile for a foundation is influenced by its design features: reinforced tip, reinforced blade.

Approximate prices:

• pile 5.7 cm (for gazebos and other lightweight structures), steel thickness 3.5 mm, length 1.5 meters - from 800 rubles, immersion - from 1.2 thousand rubles;
• pile 8.9 cm (and), thickness 3.5 mm, length 2 meters - 1.1 thousand rubles, immersion - 1.4 thousand rubles;
• pile 13.3 cm (for a private cottage), thickness 4 mm, length 3 meters - from 2 thousand rubles, immersion - from 1.8 thousand rubles.

The cost of a pile-screw foundation also includes the price of grillage materials and its installation.

Until recently, pile foundations were almost never used in individual construction, with the exception of regions with difficult climates and soils. The pile foundation for a house gained its popularity simultaneously with frame construction technology. It was the companies that produce light-weight houses suitable for year-round living that first began to use them quite widely.

Example of a finished pile foundation

They were looking for a way to reduce construction costs without sacrificing quality, and the solution turned out to be replacing the traditional strip foundation with a pile foundation.

It is not always possible to directly support building foundation structures on the underlying soil layer. Depending on the conditions, the soil may be unsuitable for this, having low or insufficient bearing capacity, unstable nature of its occurrence, being located in the permafrost zone, etc.

In such cases, pile foundations are designed and installed, which makes it possible to transfer the load from the building to the underlying, stronger and denser layers of soil with predictable characteristics.

Pile foundations are widely used in construction, so a huge number of options have been developed that take into account almost any construction conditions and offer a variety of solutions, both taking into account technological capabilities and economic aspects.

Today, foundations on piles are one of the most popular in the private and commercial construction market. Since in terms of its price indicators it turns out to be much more profitable than classical solutions, and in terms of its technical characteristics and service life it even surpasses traditional foundations.

In most Russian regions, pile foundations are used for building houses on soft soils. These will be peat bogs and marshy soils. By the way, it will also be where the groundwater level is quite high.

A slab or shallow strip foundation will be ineffective on such land, since the top layer of soil simply cannot withstand the heavy load.

The design and construction of pile foundations is regulated not only by Building Codes and Rules, in particular SNiP 2.02.03-85, but also by other regulatory documents, which include, for example "Guide to the design of pile foundations". It sets out all the recommended solutions used for the construction of this type of foundation, defines the parameters of the necessary survey work, methods for performing design and types of calculation and design work carried out.

The issues of calculating piles based on bearing capacity, calculating pile foundations and foundations based on deformations, and general issues of designing pile foundations are considered.

The features of design in specific conditions, such as subsidence soils, swelling soils, undermined areas or seismic areas, are separately highlighted.

A pile foundation is a more complex system than just a set of piles, therefore, for qualified calculations of other elements, other materials recommended for use are also used, for example, “Manual for the design of reinforced concrete grillages for pile foundations.”

The use of normative literature allows us to ensure high quality of design work and informed adoption of economic decisions without compromising the safety and durability of buildings and structures.

This is what piles are used for. Vertical structures are lowered to a sufficient depth into the ground and transfer the load to denser layers of soil that are located below. The price of such a foundation is lower than that of classic types of foundations with excavation.

Also, installing a pile foundation will be the optimal solution in permafrost areas and where there are mobile soils.


It is also better to place a holiday house on the bank of a river or near a reservoir on a pile foundation. When using high-quality waterproofing, the structure will last much longer than other types of foundations.

Types of piles used

Pile foundations differ in several ways. A certain type is suitable for use in specific conditions. The cost of arranging the foundation, which includes the required building materials and the work of specialized equipment, also depends on this.

By materials used

Piles can be made from various materials. For foundations for various buildings and structures, piles made of wood, metal, concrete and reinforced concrete, as well as combined types of piles, are used.

The latter type is considered one of the most reliable, since different materials are subject to corrosion in different ways, and as a result, they retain their original appearance longer and perform basic functions.

By immersion method

The first and main difference between piles is the use of completely finished units that are lowered into the ground and piles that require fabrication on site.
The first type includes driven, drilled and screw piles. To the second -

bored and combined.

Driven and drilled piles are more often used in the construction of foundations in multi-story construction. They are very voluminous concrete or reinforced concrete beams. The price of the structures themselves is quite high, and their installation requires large construction equipment.

Renting special vehicles for individual construction will cost a pretty penny.

All piles are divided into two main types:

1. Post piles that penetrate soft and unstable layers of soil and ultimately rest on solid rock.
2. Piles that remain “hanging” in the ground. Such piles are used when hard rock is at an unattainable depth or simply does not exist, for example, in permafrost conditions, or in swamps and peat bogs.

In the first case, the entire load-bearing load transferred from the building to the foundation is transferred to the solid layers of rock, and the building, it turns out, has reliable support underneath it.

In the second case, a different principle applies. The load is distributed evenly across all piles, and the piles are held in the ground due to the frictional force between the surfaces of the pile and the ground. Both have proven themselves well and are used in construction on equal terms.

Read also

Construction and installation of slab foundations

Types of pile foundations

A pile foundation is a field of individual piles. Their number, the distance between the piles, the method of distribution and tying are calculated individually for each house project. On top, each pile may have a small platform or exposed reinforcement. This is necessary for subsequent installation of the harness.

Foundation on screw piles

Screw piles are the undisputed leader in the field of private construction. Most frame projects are based on a foundation on screw piles. The pile is a metal pipe, pointed at the bottom and with a welded helical blade.

In fact, this is nothing more than a large self-tapping screw, only without a head. Such a pile is simply screwed into the ground. For this, construction equipment can be used, or it is possible to equip a pile foundation with your own hands. One of the most budget and labor-intensive technologies.

Screw piles can be combined. If the classic screw pile is a hollow metal pipe, then the combined one involves filling the void with concrete or reinforced concrete mortar.
The advantages of a foundation on screw piles include its low cost, the possibility of installation without the use of heavy equipment, and use in permafrost conditions and on marshy soils.

The disadvantages of such a foundation are its fragility; according to reviews, it can last about 70 years. Another drawback is that a foundation on screw piles without a grillage can only support lightweight structures, such as wooden or frame houses. For stone, brick or block buildings, it is better to use other, more durable foundations.

Foundation on bored piles

Bored piles are a type of piles that are manufactured on site using concrete or reinforced concrete mortar and reinforcement. To begin with, wells are drilled on the construction field, marked according to the drawing. Vertical shafts are reinforced with reinforcement and then filled with mortar.

Depending on the type of soil on which the foundation is installed on bored piles, various casing materials can be used.

For example, in the case of loose and sandy soils, a special hollow pipe can be lowered into the shaft. The technology allows the wall to be insulated with roofing felt, roofing felt, or polyethylene film. Depending on the material used, after pouring the casing can be removed, or it can be left in the shaft, performing the function of waterproofing.

Piles made according to the latest scheme, using casing and insulating materials, last longer than simple bored piles.

The advantages of such a foundation are ease of installation. One of the types of bored foundation is columnar. Such a foundation can be built without the use of special equipment. Dig or drill holes for the piles by hand, make your own mortar and fill the base.

Another advantage is the ability to place the house even in a place difficult to reach for equipment, almost right next to other buildings.

However, such a foundation will be short-lived and less strong. Without special waterproofing, cast-in-place piles are destroyed quite quickly. The disadvantages include the impossibility of their operation in regions where horizontal ground movements are observed.

Types of harness used

The piles themselves are simply pillars or posts. In order for them to turn into a full-fledged foundation, it is necessary to tie the pile foundation. The pile-grillage foundation is superior in its characteristics to strip and monolithic slab foundations. It is considered more resistant to any soil movements. Depending on the weight of the structure, various solutions are used.

Piles-columns

The simplest type of pile is a column pile, which is used as a foundation for a fence or a light summer house. It will also be a continuation and basis of the structure, which will be mounted around the pile. In this case, no strapping is required.

Timber strapping

Most often used when arranging a pile-screw foundation for the construction of a light frame or log house.


In this case, the function of the grillage is performed by the 200th larch beam. If you are making a pile foundation with your own hands, then the timber should be laid on special platforms with which each pile is equipped, and securely fastened with bolts and ties. The junction points of two strapping elements are formed with a groove.

Metal harness

A grillage on a pile-screw foundation can be made of a profile, channel or corner. In this case, installation occurs using welding.

Fastening with bolts is also possible if the pile-grillage foundation initially provides for such a design. To do this, each pile must be equipped with a small platform with holes for two or four bolts, as well as the strapping included in the kit.

In this case, the pile field must be installed with the minimum permissible error, otherwise the arrangement of the grillage will become impossible.

Monolithic grillage

A pile-grillage foundation is a hybrid of a pile foundation and a classic strip or slab foundation. In cases where special structural rigidity is required, the following scheme is used: formwork is assembled on top of the piles and a monolithic grillage is made in the form of a slab or strip.

This design is best combined with bored piles. In this case, the reinforcing elements of each pile are brought up and become the basis of the grillage. In this case, additional reinforcement of the grillage is also necessary.

Stages of work when constructing pile foundations

Entrust it to specialists or build a pile foundation yourself - both options are possible. The work can be carried out either using construction equipment, or using an electric or manual hole drill, or even digging the shafts manually.

Land survey

The construction of pile foundations occurs on fairly complex soils. To avoid design errors and calculate the settlement of a pile foundation, it is advisable to order land surveys. Several drilled information shafts and a detailed analysis by a specialist, which will be presented in the form of official documents - soil maps, will allow you to make an accurate calculation and determine the optimal depth of the shafts for the piles.

If you order a pile foundation without geological exploration, there is a risk of making piles of insufficient length.

The second problem that you may encounter is running into rock in one of the sections of the pile field, which will not allow you to screw in the piles to the required depth.

Design

The construction of pile foundations involves not only the process of physical work, but also includes a mandatory paperwork period. During the design of pile foundations, calculations are made that allow us to determine the size of the pile field, the depth of the shafts and their number, and the distance between the piles.

Lighter structures allow the piles to be placed in the foundation at a distance of 2.5 meters from each other. Calculation of the foundation for heavy structures and on difficult soil requires an increase in frequency - the distance can be reduced to 1 meter. Also, piles can be lowered into the ground not vertically, but at a certain angle, which strengthens the structure.

This technology is used to speed up the construction of not too heavy buildings and other architectural structures. It is suitable for constructing reliable foundations even on soft soils. Its use helps prudent owners. Within the framework of this guide, we will tell you what it is like to build it on screw piles, with your own hands or with the help of specialists, what pros and cons you should pay attention to, as well as how to repair and finish piled structures.

Read in the article

Foundation on screw piles

When preparing to build a house, you need to correctly answer various practical questions:

• It should be determined whether a pile-screw foundation is really suitable for a building of a certain size made of.
• Information on how to select basic materials and components to implement a project at a reasonable cost will be useful.
• You definitely need to learn how to make the calculation correctly so that the created structure remains stable over a long service life.
• It is necessary to clarify how to properly mount the base, so as not to complicate subsequent construction operations, whether it is necessary.
• After determining whether piping is needed, you will have to decide what to cover the base with in order to get a good appearance and improve consumer performance.

The answers to these questions are given in this article. When studying it, one must not forget about the individual characteristics of the use of the building. For example, the load will increase significantly if the house is often used to receive a large number of guests.

For your information! We must remember that sewerage and other utility networks are installed in a residential building.

Pile foundation with monolithic grillage

This design is installed according to the following scheme:

• Calculate the loads that will be created during operation.
• Depending on it and taking into account the characteristics of the soil, products that are suitable in terms of technical parameters are selected.

• Products are screwed in manually or with the help of power units, to the level of dense layers.
• The levels of the pillars are cut horizontally.
• Support plates are attached to them and installed.
• If necessary, make cladding.

This part of the structure prevents water from accumulating near the building. With an efficiently operating storm drainage system, liquid will be discharged in a timely manner. It will not provoke corrosive processes that can destroy metal immersed in the ground.

Taking into account the expected loads, not only the parameters are selected, but also the grillage material. Below we will discuss various areas of application of this type of piles using specific examples.

For such a project, pipes with a diameter of 55 to 80 mm and a wall thickness of 3 to 4 mm are suitable. If you purchase products of sufficient length, the upper part can be used as a power frame.

In this combined version, piles from 75 mm in diameter are used. A shallow concrete grillage is mounted on them. During pouring, protruding mortgages are installed in it. A support structure with transverse stiffeners is welded on top.

Such structures are subject to strong dynamic mechanical loads, so the requirements for reliability increase.

If massive equipment is installed, then this is where additional reinforcing elements must be installed.

A wooden grillage is suitable for this type of construction. When the load increases, a metal channel is used. If the dimensions of the building exceed 10x10 meters, the walls are made of foam blocks and large piles are used. Choose a diameter of 108 mm or more with walls made of 9 mm steel.

Important! After completion of installation, the supporting screw part should be at a level below the maximum freezing of the soil in a certain region. The required values ​​can be found on the Internet, or by contacting the municipal architectural bureau.

This figure shows how standard components are modified to solve individual engineering problems:

• Different loads are distributed on piles with a diameter of 108 mm (1) and 76 mm (2).
• To strengthen the central part, steel channels (3) were added. The side parts rest on corner supports (4).
• To prevent the metal heads (5) from contacting the wood, a layer is installed on top.
• (8) with floor covering (10) rest on a wooden grillage. The log wall is mounted on strong pillars.
• To prevent deformation for a wooden house (1-2 floors), a distance between piles of 200-270 cm is recommended.

For your information! Even for a gazebo or other light structure, it is necessary to make an accurate calculation. The data provided in this section is approximate. They are adjusted taking into account the building materials, soil characteristics and other important factors.

Related article:

How to do it (detailed step-by-step instructions with photos) and how difficult such work is - these are the issues we will look into in our review. We’ll also get acquainted with useful tips and recommendations from experts.

Disadvantages of a pile-screw foundation

When studying the question of what to choose to create a support for a building structure, the negative nuances and advantages are studied together. During the comparison, they check the complexity of technological operations, durability, which is cheaper from the presented options. For domestic climatic conditions, it matters whether installation can be carried out in winter.

If the soil is classified as heaving, or frequent flooding of the area occurs, enlarged blades are used. To penetrate the frozen layer in winter, they use not a sharp tip, but a drill (the serrated edge of a pipe).

Piles are suitable for working in areas with difficult terrain. They can be used to install not only the house itself, but also a pier. They will provide a solid service life when placing the object near an open body of water. They can be installed in frosty weather, so you can eliminate the corresponding restrictions when working with pouring concrete products.

An experienced team, even without the use of power drives, is capable of driving more than 20 piles in a day.

For your information! The figure shows that for high-quality reproduction of the technique, at least four people are required. Two create the necessary forces using levers. One – supports the pillar during rotation. The manager controls the verticality of the installation and coordinates the actions of workers.

In this embodiment, a gearbox with a large gear ratio is used. A powerful drill is suitable for the drive. If there is no 220 V network on the site yet, a mobile electric generator is used.

Such equipment will allow you to quickly create a large support field. When comparing different options, all real costs must be taken into account together. Sometimes ordering specialists with equipment is cheaper than independent experiments. It should be remembered that manual technology will require assistants.

Will a typical concrete foundation be reliable without preliminary calculations? Will the base settle over time or not if it is not installed on the site? The answers to these questions are given above. But the following nuances also deserve attention:

• Piles of this type do not draw moisture from the soil, so the structure is not subject to corresponding negative influences.
• In a building raised on supports it is necessary. It is much simpler and more effective compared to a standard concrete foundation.
• The use of this technique is not accompanied by large earthworks. Eliminating the need for level ground reduces overall costs. Compared to a typical strip foundation for a similar load, they will be 25-45% less.

For a full analysis, it is necessary to find out which is better, TISE or screw supports.

These products are created as follows:

• Using a drill, a hole is formed in the ground.
• A special lower nozzle allows you to form a dome-shaped extension in the lower part.
• A tube made of roofing felt and construction pins are installed in the well channel.
• Next, concrete is poured.

The main advantage of TISE piles is the absence of corrosion processes. But they cannot be used immediately. You need to wait until the mortar hardens, which under normal temperature conditions ranges from 7 to 10 days. On the other hand, it should be noted that reinforced concrete structures have a relatively greater load-bearing capacity.

Do-it-yourself pile foundation: step-by-step instructions, video

The video below shows the corresponding technology. But simply copying it is not acceptable. A project should be prepared. Let it not be made according to the canons of engineering standards. But even a basic support arrangement scheme is better than the complete absence of working documentation.

You need to find out for yourself what new products manufacturers offer. Some new types of piles are inexpensive, but have excellent consumer characteristics.

Laying out a site for a foundation in this case is simpler than carefully leveling a part of the land for a monolithic slab. However, we must not forget about the possibility of using high plinths to solve economic issues. You should remember the need for laying, networks and communications.

Important! Below are detailed step-by-step instructions. She will help you build a reliable foundation with your own hands without mistakes. But we must add to this description corrections that are determined by the parameters of a particular structure and its application.

Screw piles for foundation

Above were only some types of metal products in this category.

Increasing the number of blades simplifies screwing, provides greater support strength and increases load capacity. To simplify the connection of levers and other devices, holes are cut out. To simplify the connection of grillages, flat or “U”-shaped platforms are welded. A second screw is added to make it easier to maintain the vertical position.

To strengthen the structure of the head, stiffening ribs (2) are added to it. The surface is protected from corrosion by multi-layer paint coatings (3).

Such products are made from cast iron. Casting helps eliminate the disadvantages of welded joints. These tips, even without special treatment, are highly resistant to corrosion. They are not damaged when passing through dense rocks and retain excellent functional condition after decades of use.

Responsible manufacturers use GOST standards to prevent destructive oxidation processes. Cold technology is cheaper than hot galvanizing. But the second version of the protective coating is held more firmly on the surface of the base metal. Powder coating ensures a high quality layer. But if there are stray currents in the soil, it can be damaged in 30-40 years.

To extend service life, experts recommend paying special attention to the ground-to-air transition area. In some cases, it is suggested to wrap the corresponding area with a polymer film. Regular inspections with updating the paint layer are also used.

To eliminate unnecessary hassle, you can make additional investments.

The calculated value of the bearing capacity is determined by multiplying the area of ​​the screw (projection on the horizontal plane) by the soil resistance to loads. The second parameter is taken from a specialized table. It is given in kilograms per cm2. taking into account the level. For soft loams, for example, use the value: 3.5 units.

The correction factor is more difficult to determine:

• From 1.1 to 1.2 are used if the composition of the soil is determined using a comprehensive geological survey of the site. The corresponding task is entrusted to a specialized organization. Its specialists take samples at several points down to the depth of hard rock, which are tested in laboratory conditions. You will have to spend some money and time, but you will get the most accurate result.
• The second method is simpler and cheaper. A drill is used to measure dynamometer characteristics as it is immersed in the soil. If such a technique is chosen, the correction factor is set at 1.2-1.25.
• In the next option, you should increase it to 1.35-1.4. Here you will need to dig holes yourself. The soil at the final installation depth of the screw part is checked independently. For example, you can measure sand fractions and then select the appropriate soil resistance from the table.

With a limited construction budget, a pile-screw foundation (SVF) is a rational choice for a prudent owner. If you have time and energy, you can make a screw foundation with your own hands; to do this, you need to immerse the piles to a layer with bearing capacity. The technology does not depend on the weather; a cottage or garden house is guaranteed to be built in the same season, since there is no need to wait for the concrete elements of the base to gain strength.

In comparison with all known technologies, a do-it-yourself screw foundation is the most economical foundation for any above-ground structures. The advantages of SVF are:

• construction in difficult conditions - hilly, swampy terrain, coastal zone, dense buildings, presence of trees on the site, passage of third-party communications;
• minimum budget - almost complete absence of concrete, earthworks, formwork, waiting for concrete structures to gain strength, rental of special equipment;
• variability of construction technologies - a screw foundation is suitable for log houses, brick, panel buildings, panel buildings, half-timbered frame buildings, house grounding loops, fences, MAF;
• maximum number of storeys - three-story buildings with an attic permitted in individual construction are allowed;
• high resource - with normal anti-corrosion treatment, the service life of screw piles is 75 - 100 years.

Please note that grounding is a separate structure, and not connecting the grounding wire to the body of the foundation pile field. Piles for the grounding loop should not have protective coatings that do not conduct current.

The only drawback of SHS is its unsuitability for projects with a basement/basement floor. Manual installation of screw piles is not only acceptable, but also recommended by experts. When immersing these structures with special equipment, it is more difficult to control the tightening force when reaching the bearing layers.

Step-by-step foundation technology on screw piles

Thanks to a fairly simple design, if you have the necessary tools and equipment (welding machine, gas cutter), screw foundations can be made at home. Installation is carried out using the following technology:

• control screwing;
• design;
• marking;
• production of guide wells;
• SHS dive;
• trimming the level of pipes rising above the ground;
• pouring concrete;
• installation of heads;
• tying the pile field with a grillage;
• input of communications.

To plan the work time, it is enough to measure the pitch of the propeller blades. With each rotation, the pile will sink to this depth, allowing the time of each cycle to be calculated. For example, with a step of 5 cm, 40 circles will be required to screw in the SWS to a depth of 2 m. A professional team installs 15 - 25 SWS per shift, creating a field for a cottage with an area of ​​100 m².

Calculation of a pile-screw foundation

The technology has been sufficiently developed in all regions of the Russian Federation; to calculate the SVF, you can use the SP from 2011, number 24. 13330 for pile foundations. The main calculations are:

• the bearing capacity of the formation at the immersion depth of the pile blade; the bearing capacity of one pile is calculated from this parameter;
• quantity - SHS pitch on straight sections, positioning at the junction of walls, laying piles under individual structures (boiler/furnace, porch/internal staircase, emergency generator/pumping equipment.

In order not to order expensive geological surveys of the site, in 75% of cases a trial screw-in is used, which allows one to calculate the data necessary for the project:

• depth of the bearing layer (necessarily below the freezing level of the region);
• soil composition (presence of large stones, gravel, limestone in different layers);
• GWL level (very conditional).

The main characteristics of piles are indicated by manufacturers. For example, the dimensions of the SHS are selected based on the type of structure for which a foundation is needed:

• berth/pier – pipe 89 – 108 mm, wall 3 – 4 mm, screw 20 – 25 cm;
• reinforcement of bases – pipe 89 – 108 mm, wall 3 – 4 mm, blade 20 – 25 cm;
• retaining wall – 54 – 89 pipe (2 – 3 mm wall), screw 15 – 20 cm;
• MAF, gazebos, fences - 54 - 76 mm pipe with a wall of 2 - 3 mm, propeller blade 15 - 20 cm;
• combination with tape MZLF – pipe 108 – 168 mm, wall 4 – 8 mm, blade 25 – 40 cm;
• block, brick cottage - wall 6 - 10 mm, body diameter 168 - 270 mm, blades 40 - 80 cm;
• panel, half-timbered, panel, frame, log house - 89 - 114 mm pipe with 3 - 5 mm wall, 20 - 30 cm blade.

Thus, after calculating the prefabricated loads (operational + wind + structural + snow), the figure is divided by the load-bearing capacity of the pile to calculate the required number of SHS.

Preparation and marking of the site

Due to the lack of planning and excavation work, marking the construction site is simplified as much as possible. It is enough to bring the axes of walls, partitions and additional heavy equipment (boiler, ladder, pump, etc.) to the area. To do this, pegs are installed slightly further from the corners of the house along which the cords are pulled. Instead, you can use a more complex design of two stakes with a horizontal jumper, which allows you to install two cords along the outer dimensions of the pile.

Driving piles

Step-by-step instructions for screwing in SHS, regardless of the type of blades, tip, groundwater level, and other factors, are as follows:

• production of pits - guide holes are created to a depth of 0.5 - 0.7 m using a manual or motorized drill, they allow precise positioning of piles, facilitate the entry of the blade into the ground, the diameter of the leader hole should be slightly less than the size of the SHS blade;
• immersion of the pile - a crowbar is inserted into the holes inside the pipe body, tubular levers are put on it, two workers move them in a circle, creating a torque, the third controls the vertical of the shaft with a bubble level, with a sharp increase in tightening force (necessarily below the freezing mark) the work stops;

There is a technology for mechanical immersion of SHS without the use of special equipment, which slightly increases the construction budget:

• a torque amplification device (reducer) is put on the upper end of the SHS;
• an electric drill is installed on it (power from 1.5 kW);
• the structure is installed in a vertical position above the guide well;
• the drill is connected to the electrical network.

The torque amplifier device is a gearbox with a gear ratio of 1/60. Instead of levers, an electric tool drive is used; the operation can be performed by two workers.

Alignment of SHS in the horizontal plane

The pile field must be tied with a grillage in the form of concrete, metal or wooden beams located on the heads. To do this, the pipes protruding from the ground must be brought back to normal. The leveling technology looks like:

• single level mark - use a level, theodolite or laser plane builder, level;
• trimming - the body of the pipe is cut with an angle grinder according to the markings.

At this point, the construction of the pile field is considered complete when using a monolithic or metal grillage. If a frame, log, panel or panel house is being erected, it is necessary to mount heads on which timber or calibrated logs can rest. The head has several modifications:

• square – 10 x 10 – 30 x 30 cm plate welded to the pile;
• reinforced - the size is similar to the previous case, the plate is welded to a pipe, the internal size of which is equal to the outer diameter of the pile, there are 4 stiffeners (kerchiefs);
• U-shaped - the internal dimension between the shelves is 17 cm for laying timber 15 x 15 cm.

This element is put on the SHS body and attached to it by welding (less often with bolts). The holes in the plate allow you to fix the wooden beams of the grillage to obtain a single spatial structure.

Pouring concrete

The pile, even with a hermetically welded head, is covered with moisture from the inside. To prevent this phenomenon, special protection is used - filling the pile body with concrete after immersion to the design depth. Several technologies are usually used:

• dry mix - packaged sand concrete M 300, which, upon contact with condensate, is independently cemented inside the product;
• ready-mixed concrete - classic pouring through a funnel, the technology has a significant drawback - the presence of voids and cavities inside the mixture;
• sand concrete – grades M 300 – M 400, due to the absence of coarse filler, there are practically no voids in the concrete;

In addition, concrete injections make it possible to increase the spatial rigidity of the structure, which is important for thin-walled piles.

Tying piles with a grillage

On straight sections, the recommended height of the grillage base from the ground is 0.5 - 0.7 m. This is the optimal size for placing ventilation ducts in the grillage. Without it, the floors of the lower floor will be a source of heat loss; in the absence of natural ventilation, the power frame will quickly become unusable. For each type of grillage there are installation features.

Monolithic grillage

The technology is the most complex and is more expensive than other options, but it is the only one possible for brick cottages on difficult terrain, in the coastal strip and in swamps. Installation of a monolithic grillage using technology:

• formwork assembly - the bottom panels are put on the pipes, supported by jumpers attached to two pegs, the side panels are attached to the bottom, connected to each other by spacers and ties;
• reinforcement - two belts of periodic cross-section rods (12 - 16 mm corrugated) are connected to horizontal and vertical 6 mm jumpers or clamps;
• connection with piles - holes are burned or drilled in the pipes into which additional reinforcement is inserted, connected with tying wire to the reinforced belts of the structure;
• pouring - the formwork is filled with concrete mixture to the design level, compacted with reinforcement bars or deep-seated vibrators.

All types of masonry for the walls of a brick house and any other construction technologies are allowed on a monolithic grillage.

Wooden grillage

The technology for constructing wooden houses facilitates the task of the developer, who needs to connect the pile field with long elements to ensure the spatial rigidity of the house. The lower crowns of the log house (calibrated logs) and the frame frame are a ready-made grillage.

The manufacturing technology looks like:

• installation of flat heads - necessary to increase the area of ​​the supporting surface;
• laying beams - timber, logs are joined into half a tree, attached to the heads with self-tapping screws, bolts or nails.

This is the fastest grillage device, however, the technology is unsuitable for brickwork and high-rise projects. The height of the building cannot exceed one floor with an attic.

Metal grillage

If the height of the log house or “frame” exceeds the standard floor, the wooden grillage may not withstand prefabricated loads. It is not economically profitable to pour monolithic beams for wooden buildings; you can use a grillage made of rolled metal. The technology looks like:

• laying pieces of channel with shelves down, wall up on SHS pipes or I-beams on the bottom shelf in exactly the same way;
• joining grillage elements, tack welding in several places;
• double welding of each joint.

A metal grillage is suitable for one-story brick buildings only if the pitch of the pile field is reduced to 1 - 1.5 m. This is due to the large structural mass of the material - for example, the channel begins to bend under its own weight already in 3 m spans.

Insertion of engineering systems into a building on screw piles

Most often, SHS pipes protrude slightly above the ground surface. This makes it difficult to lay out communications in an underground 0.5 - 1 m high. Therefore, it makes more sense to introduce life support systems at the foundation stage. Later, to do this, you will have to open up the subfloor and carry out excavation work in a confined space. For normal operation of the building it is necessary to provide:

• plumbing - in a frozen underground, pipes must be insulated, both in the ground to the freezing mark and above its surface with polystyrene shells or mineral wool (2 - 3 layers) and a heating cable, respectively;
• sewerage - wastewater enters the external sewer circuit warm, so it is enough to wrap air pipes with one layer of basalt wool, underground pipelines with polystyrene foam shell to a depth of 1–1.5 m;
• grounding of the house - SHS of minimum diameter can be used in the form of a triangular circuit immersed at the 2 m mark, tied with thick wire or tires made of a metal strip, while the piles should not have a protective coating that does not allow current to pass through;
• power supply cable - sometimes an underground input is used, always in a protective casing.

After wiring the engineering systems, you can install a fence. If the project includes brick walls, a false base is made at the façade finishing stage. Because in this case there is a high probability of damage to the facing materials by random stone or mortar.

Climbing on screw piles

There is no full-fledged base in the pile foundations; a fence is made to protect against blowing and penetration of precipitation into the underground. Several technologies can be used to build a false plinth:

• frame system - a beam or galvanized profile is attached to the piles, the lattice is sheathed with basement siding, corrugated sheets, panels;
• masonry - ceramic, clay brick, rubble stone.

The intake is complemented by a blind area for drainage of storm and flood runoff. The facing materials of these structures must be waterproofed. To do this you need:

• install frame sheathing;
• fix the roofing material vertically on it;
• run it under a horizontal blind area;
• install siding and paving slabs.

Natural ventilation of the underground is carried out due to the vents left in the false base, the total area of ​​which should be equal to 1/400 of the surface of the intake. There is no need to insulate the structure, since there is no heating inside the underground.

Resource of screw piles

To increase the service life of SHS, anti-corrosion treatment of each product is necessary in accordance with GOST R 9.905, 9.908, 5272. Manufacturers use the following anti-corrosion technologies:

• cold galvanizing - peels off almost completely even when the pile is immersed due to abrasives contained in the ground;
• hot galvanized – lasts a little longer, does not provide the declared 75-year service life;
• powder coating – lasts 30 – 50 years after installation, is destroyed by walking currents in the ground;
• painting with bituminous compounds – protects against groundwater, regardless of the height of the groundwater level, ensures a 50-70 year service life

• primer VL 05 + cold galvanizing (enamel IR 02) + fiberglass – service life 300 – 400 years in extreme conditions, no electrochemical corrosion;
• IR02 or Zinga Metall enamel + polyurethane or epoxy two-component enamel - created to protect oil pipelines (overhead, underground), have a 50-100 year lifespan;
• primer VL 05 + polyurethane enamel Hempel, Masco - standard level of protection for the bottoms of icebreakers, submarines, fuel tanks, 30 - 70 year life.

Even when purchasing SHS with a factory-made anti-corrosion layer, it is necessary to coat the piles with the specified compounds for reliability.

Purpose of screw piles

The first pile structures with screw tips in the Russian Federation began to be used exclusively for the needs of the army in the middle of the 19th century. They could be used for temporary structures or in difficult operating conditions. The declared resource was 100 - 180 years, which modern manufacturers cannot boast of. Currently, SHS and other modifications of piles are used for:

• building a house in a swamp, slope, in dense buildings, forest zones, on soils with high groundwater level, low bearing capacity;
• budget construction of fences, MAF, gazebos, outbuildings;
• strengthening strip and slab foundations;
• production of engineering systems, for example, grounding of a house, water intake wells.

The height of the SHS is practically unlimited - when the lower element with the auger blades is immersed to ground level, the next piece or several can be welded to the pipe to ensure that layers with load-bearing properties are achieved. For installation, three people or one specialist with a powerful electric drive with a gearbox are enough.

This step-by-step instruction is suitable for installing screw piles under a building constructed using any technology from different wall materials. Recommendations will help you avoid mistakes and increase the service life of your home.