How to make a pile foundation at home. DIY screw piles

We make piles ourselves

The foundation is the main part of any structure, so it is very important to choose the right type of foundation. On stable ground, any type of foundation can be built, and soils that are mobile and subject to seasonal heaving require a stronger foundation for the structure. The foundation on screw piles is an ideal solution for the construction of buildings on moving soils, in areas with a predominance of low air temperature, in places with a high level of groundwater.

Advantages of a pile foundation

The foundation on screw piles is very popular in individual construction due to the main advantages:

• Construction on any ground. Deep screwing of the pile into the ground allows the construction of structures on all types of soil, including wetlands where the construction of a foundation of another type is impossible. The only exceptions are rocky areas, where screwing piles is considered quite difficult.
• Minimum earthwork. For the arrangement of a pile-screw foundation, no excavation or trench is required. This allows you to save on the removal of excess soil from the construction site.
• The construction of the foundation at any time of the year. Minimal earthworks allow equipping regardless of the season.
• High bearing capacity. Piles are mounted below the level of soil freezing, which ensures the strength of the foundation in any conditions. Even with seasonal ground movement, the structure retains its integrity.
• Simple and fast installation. The installation of pile foundation elements can be performed by a person who does not have a building skill. At the same time, the foundation is being built as soon as possible, most often the whole process takes 2-3 days.

Independent production of screw piles

Having chosen the house as the base, it is necessary to determine which piles will be used. Factory-made items are different, but expensive. Self-made piles will require lower costs, but the quality guarantee in this case is reduced to a minimum.

Having opted for hand-made piles, it is important to carefully study the technology of its manufacture.

Pile construction

Piles of both factory and own production have the same structure:

• The main element of the screw pile is the shaft. It is a round pipe, the walls of which are at least 4 mm thick.
• Another important part is the cone-shaped tip located at the lower end of the pile.
• Equally important is the spiral blade welded to the conical tip.
• On the screw piles, which are supposed to be used as a base for wooden buildings, square plates with holes are additionally welded - heads.

Preparation for the manufacture of piles

Before you start making screw piles with your own hands, you need to make a drawing of the product. It indicates the main parameters of the pile:

• Barrel diameter.
• The height of the cone tip.
• The total length of the pile (shaft + tip).
• The distance between the lower edge of the blade and the top of the cone.

The drawing of the product will greatly facilitate its marking and assembly.

Making blades: step by step guide

1. To speed up the work process, it is recommended to make templates for future blades. To do this, cut out two circles of different diameters. The diameter of the large circle should be equal to the outer diameter of the blade. The diameter of the small circle should correspond to the diameter of the trunk.
2. The prepared templates are laid out on a strip of steel and circles are drawn: first - large, then - small.
3. You need to cut the blades in the following order: cut vertically to the inner circle, continue to cut along the inner mark, then cut the product along the contour from the outside. The result is a ring with a slot.
4. The product is clamped in a vice and the ends are bent in different directions along the cut. In this case, the distance between the ends should be no more than 15 cm.

Making a cone tip

1. As in the previous step, you first need to make a template. In this case, you need to cut a triangle. To determine the height of the template, you need to multiply the diameter of the pipe by two. To determine the size of the base of the triangle, the circumference of the pipe is divided into a certain number of sectors. Most often there are four of them.
2. The lower part of the pipe is marked into four sectors and cut out with a grinder.
3. The resulting triangles at the end of the pipe are knocked to the center until they are completely connected.
4. The seam lines are welded with a continuous seam. At the same time, it is important to monitor the quality of work.

Final assembly of piles

The assembly of a single element consists in welding a helical blade to the bottom edge of the pile. In this case, it is important to ensure that there is no gap between the main part of the pile and the screw element. If gaps are found between the surfaces of these elements, it is necessary to unbend the ends of the spiral more.

The bottom edge of the screw should be 5 cm from the top of the cone.

It is possible to weld elements only after the blade is completely adjacent to the surface of the cone. In this case, welding should be carried out with a continuous seam so that the screw does not come off during the pile twisting.

Calculation of the number of piles

Before you start making piles with your own hands, you need to determine the exact number of structural elements. When making a calculation, the following should be taken into account:

• Piles should be located at each corner of the building.
• It is necessary to install supports at the intersection of the load-bearing walls of the house.
• At least two piles must be installed at the location of the stove or fireplace.
• It is required to install piles under a future terrace or other extension.

This is how the number of main piles is calculated. For greater strength, additional supports must be installed. They are calculated according to the following principle:

• When erecting buildings from blocks or slabs, a distance of up to 2 meters must be maintained between additional supports.
• For frame structures from wood, it is enough to place piles at a distance of 2.5 meters.
• During the construction of timber or log houses, a gap of up to 3 meters can be made between the piles.

You can make a screw pile yourself, you just need to stock up on suitable materials and follow the manufacturing technology. However, do-it-yourself piles are safer to use as a base for light buildings or protective structures.

In fact, not a single building is complete without creating a foundation for it, that is, a foundation. As you know, in the construction industry there is a wide variety of their types. This article will focus on the features of the device pile foundation. Consider the main stages of work on installing this type of foundation with your own hands, we will study its design.

What is a pile foundation, design features

The pile foundation is a foundation of rigid piles immersed in the ground, which are placed along the perimeter of the structure of the future building. These same piles are various kinds, they are classified according to a variety of criteria:

• according to the method of deepening the support;
• according to the method of impact on the soil;
• by material;
• by section type, etc.

It is worth clarifying that this type of foundation is most often used when building in difficult areas dominated by heaving soil. The pile itself is a rod, the upper part of which is called the head, and the lower sole. The sole itself can be expanded or pointed, it is also purchased either in finished form, or made independently at the workplace. The table shows the main types of piles, according to the method of deepening the support.

Regarding the method of impact on the ground, hanging - and pile-racks are distinguished. The first type implies the distribution of loads that appear as a result of friction of the earth against the sides of the support. The second transfers the load to a solid layer of the earth, it is not characterized by sediment.

As for the division of piles into types relative to the material, here they distinguish:

• reinforced concrete;
• wooden;
• steel piles.

Reinforced concrete supports are distinguished by durability, steel supports are high financial costs, and wooden ones are cheap.

Pile-type foundations are of the following types: field, tape, single and cluster. The simplicity of the installation process is distinguished by single piles, they are used as supports in the construction of a porch, etc. For the construction of frame structures, a tape type is used; it is economical and reliable. Cluster piles are used on large, overall construction sites, with an increased load on the land area. Field piles are usually placed at regular intervals. They build multi-storey buildings. The choice of one or another type depends on the climatic features of the territory, relief land plot, specifications planned building.

A number of advantages of using a pile foundation with a grillage include:

• minimization of financial costs for construction;
• reduced terms for the construction of the foundation for the building;
• make it possible to do without wet work, when installing stuffed and screw piles;
• the ability to carry out construction work at any time of the year;
• minimal harm to the environment;
• installation work on the grillage does not harm the nearest buildings;
• on properly selected soil, the service life of such a foundation is more than 100 years;
• pile foundation structures are famous for their reliability and durability.

When and why choose a pile foundation

Usually pile foundation choose in the construction of low-rise, civil, industrial, small-sized houses. This type of foundation is considered an excellent option when creating country cottages, summer cottages. The pile foundation is implemented on such types of soil as:

• vegetable soils;
• quicksand;
• loess-like;
• clay soils, etc.

In areas with high density soil, the choice of a pile foundation can significantly reduce labor-intensive excavation. This type foundation does not require heavy digging of the pit.

Another excuse for using a pile foundation is high level groundwater deposits. It is suitable for soil that is prone to deep freezing in winter, but the pile foundation is not able to conquer the rocks.

Stages for installing a pile foundation

The creation of a pile foundation can be described based on several stages and it is worth noting that it does not require lengthy preparation before starting work. So,

Stage 1. Digging holes for piles. It is customary to place them around the entire perimeter of the construction site, while the diameter of the excavated pits depends on the future dimensions of the structure.

Stage 2. Installation of roofing pipes. At this point, it is worth considering that the length of this type of pipe should be 3 meters the length of the very depth of the pit, since the formwork of the building structure is created on the basis of the upper parts of the piles. Installations without the use of a ruberoid pipe have a lot of problems and inaccuracies, they are prone to rapid destruction.

Stage 3. Concreting and reinforcing piles. First, the reinforcement process takes place, which consists in the use of reinforcing bars to connect the supports to the grillage. After that, concreting can begin, which, by the way, also depends on the use of roofing materials, since their absence leads to the diffusion of cement laitance. The process of concreting piles involves pouring the mortar in portions so that the concrete layer does not exceed 5 meters.

The most common foundation options for the construction of small country, private houses are the foundation on screw and self-leveling piles.

The creation of the first option requires the presence of such tools as a welding machine, a building (water) level, a tape measure, etc. The whole process of installing the foundation on screw piles can be displayed in a step-by-step manner.

1. Marking the site. For this reason, it is better to use a hole breakdown of the territory; the use of peg and cord in this case is not a rational option. It should be borne in mind that these holes should not be deep, otherwise it will disrupt the entire technological process.

3. When all the supports are installed, they are concreted and the grillage is mounted.

As for the foundation on self-leveling piles, the process of its installation is considered more costly, financially and materially, as well as complex. But be that as it may, practice shows that it is quite realistic to build it. For this:

• with the help of a cord and a peg mark the construction area;
• hand drill, in the indicated places, foundation pits are created for piles. Their depth should be at least 1.5 meters.
• piles are treated with waterproofing material (roofing material), it is better to do this in two layers, for reliability. The roofing material protects concrete supports from moisture provided by nearby groundwater.
• all piles are connected by a reinforcing cage.
• after reinforcement, the pits with piles are poured with concrete. At this stage, you will need a special vibrating technique that allows you to compact the solution.
• it is possible to deal with the foundation grillage only after the concrete layer has completely dried.

Well drilling, concreting and reinforcement. grillage device

After marking the area allotted for the construction of the foundation, you can start drilling pits for piles, the number of which depends on the estimated weight of the future building. The diameter of a hand drill for this purpose is no more than 30 cm, and they can be purchased at almost any industrial store. Such designs allow you to make a pit up to 5 meters deep. In cases where it is planned to create a multi-dimensional building and the installation of significant supports is required, then motorized and electric drills are used, the diameter of which is 50-60 cm. In difficult areas, drilling machines are used.

In construction, the grillage is divided into two varieties: prefabricated, represents the construction of iron sticks, and monolithic. For both, there are weighty rules that should not be ignored:

1. The height of the grillage must be more than 3 meters.

2. The width must be less than 4 meters.

For prefabricated devices, fastening on the head of the supports is typical; for this, at the stage of concreting, the piles are supplemented with T - shaped rods. A reinforced rod is additionally fixed in a horizontal position on the pile head.

The formation of a monolithic grillage takes place in several steps.

1. Installation work on the creation of formwork.

2. Reinforcing piles.

3. Filling the grillage tape.

It is worth pointing out that the main task of the grillage is to evenly distribute the loads on the foundation. No less significant is the classification of the grillage with respect to the level of penetration into the soil. Allocate high, advanced and in-depth levels. The first is located above the ground, the second is installed at ground level, and the third is completely in the soil.

Basic location and materials of piles

Most often in construction there are metal and reinforced concrete piles. In the production of the first type, metal beams of various diameters are used, which depends on the dimensions of the foundation. In addition to beams, steel profiles and pipes are used. Metal structures have one of the main advantages - durability. Before sinking into the ground, this type of pile is carefully treated with anti-corrosion solutions. Piles from are widely used for:

• construction of various fences, fences;
• arrangement of non-permanent foundations of non-stationary structures such as, for example, shopping pavilions.
• construction of the foundation of small-sized, lightweight structures made of foam concrete, panel panels, etc.

Reinforced concrete piles are resistant to any type of soil. The structures are suitable for the construction of houses with more than 5 floors, as they are considered sufficiently resistant to heavy weight and loads. This group of piles is actively used for:

• creating a foundation for hydraulic structures;
• laying the foundation of auto- and - railway bridges.
• when constructing engineering structures such as power lines.
• arrangement of hangars, etc.

Restrictions on the use of pile foundation

Along with a wide range of applications, due to its price and advantages, the pile foundation also has limitations in use. This type of base is not suitable for:

• A horizontally moving type of soil that is not resistant to overturning. Therefore, at each construction site, before starting work, it is recommended, without fail, to send the soil to the laboratory for geological examination.
• The pile foundation has difficulties with the construction of the base, in which cracks form between the piles, in order to neutralize them (create a pick-up), large financial investments will be required.

Necessary materials and tools for installing a pile foundation

In the process of installing a pile foundation, you will need the following tools:

• shovel;
• metal rods;
• roulette;
• building level;
• welding machine;
• cord etc.

In a row necessary materials include crushed stone, mortar cement, sand, etc.

The most important tool in the production of a pile foundation, of course, is a drill, with the help of which the number of wells for piles necessary for the construction site is prepared. Drills are different in design and type, but most often, a hand drill is used to create such a base. Such a tool does not require special skills and technologies of use and has an affordable market price. Some amateur craftsmen are engaged in assembling the drill at home. The right toolkit will allow, without unnecessary physical costs, to make the required depth of the pit, while maintaining its qualities of strength and heat resistance.

For more information on the topic, watch the video:

Pile foundation - a foundation consisting of elements vertically installed in the ground, interconnected, which perceive the total weight of the structure and all existing loads. Pile foundations in Russia in the field of private housing construction began to be widely used for 15-20 years with the advent of frame construction and light piece building materials. Today at middle lane In our country, every tenth cottage is built on a pile foundation, and in the northern and southern regions of such buildings, about 50%.

Scope of pile foundations

The choice in favor of a pile foundation is appropriate in the following cases:

1. The characteristics of the soil on the site do not allow the use of shallow and ground-type foundations. Such soils include: peat bogs, swampy soils, unstable loams, heaving, loess-like and swelling soils, quicksand, etc.
2. The high level of groundwater in the area, as well as the existing threat of flooding during seasonal floods.
3. Construction is carried out in a seismically unfavorable region.
4. In areas of permafrost or when soils freeze more than 2 meters.
5. The presence of elevation differences on the site, the construction of a house on a slope.

On soils with medium characteristics, where a ground foundation is possible, the choice in favor of piles can significantly reduce the amount of earthwork and concrete work, which leads to a reduction in construction costs. The foundation on piles is great for wooden, timber and frame houses, as well as buildings made of light piece materials: gas and foam blocks, silicate brick, expanded clay and slag concrete. For cottages made of reinforced concrete slabs and ceramic bricks, it is also possible to use a pile foundation, but at the same time, the load, as a rule, is taken not by individual supports, but by pile bushes, the calculation of which should only be done by a professional.

Pile foundation: pros and cons

Advantages of pile supports used as a foundation:

• versatility, can be used for a wide range of soils;
• the ability to save on earthwork and concrete work;
• the possibility of application in areas with difficult terrain;
• the minimum level of mechanization, you can do it yourself;
• high reliability and bearing capacity;
• operational construction at any time of the year;
• the ability to preserve the existing landscaping on the site;
• low cost in comparison with the slab-monolithic base.

Flaws:

• the need for calculations;
• if the calculation is incorrect, shrinkage and deformation of the base are possible;
• lack of a basement;
• the impossibility of the device on rocky and dense soils;
• necessarily insulation and high-quality waterproofing of the ground part;
• difficulties with strapping - connecting piles into a single structure.

Almost all the disadvantages of a pile foundation are completely eliminated if you approach the design, calculations and construction responsibly. The current regulatory documents, which are recommended to be studied before starting work, will help to do this.

Expert opinion

Sergei Fedorov

Regulatory documents for the construction of pile-type foundations:

SP 24.13330.2011 or SNiP 2.02.03-85.
SP 50-101-2004 Design and arrangement of bases and foundations for buildings and structures.
SP 50-102-2003 Design and installation of pile foundations.

SNiP 2.02.04-88 Bases and foundations on permafrost soils.
SNiP 2.02.05-87 Foundations of machines with dynamic loads.
SNiP 3.02.01-87 Earthworks, bases and foundations.

Types of pile foundations

Currently, the construction industry uses more than 30 types of pile foundations. Almost all of them belong to the bases of the combined type, which consist not only of the underground part - piles, but also of the ground. The ground part performs two main functions: 1) connects the pile supports into a single structure; 2) takes on up to 50% of the load from the weight of the structure.

In private construction, the following types of foundations are most in demand:

• Pile-slab combined foundation. The ground part is a monolithic concrete slab, inside of which there is a reinforcing frame.

Application: for houses made of heavy materials. It is built only on dense soils!

Expert opinion

Sergei Fedorov

Professional builder. Experience 18 years

Advantages: the highest bearing capacity.

Flaws:

• complexity of calculations;
• a large amount of concrete work;
• the complexity of the implementation;
• high price.

The foundation of a pile-slab type for a house is used quite rarely. A monolithic slab has a huge weight, so the piles must be of large diameter. Such piles cannot be installed manually, therefore, it is necessary to use specialized equipment, which significantly increases the cost of construction.

Pile-grillage foundation. For its device, both bored and screw piles are used, the ground parts of which are interconnected by a grillage. The grillage material can also be different: wood, metal, monolithic reinforced concrete or prefabricated.

Application: light structures ( country houses, gazebos, outbuildings, baths).

Advantages:

• ease of installation;
• minimum settlements;
• low cost.

Expert opinion

Sergei Fedorov

Professional builder. Experience 18 years

Disadvantages: small bearing capacity.

The cost and technology of performing work on the installation of a pile-grillage foundation depend on the type of piles and the material of the grillage. In many cases, the grillage is not only a binding for the pile part, but also perceives the load from the structure.

• Pile-strip foundation. The ground part of such a base is a monolithic or prefabricated reinforced concrete tape installed around the perimeter and bearing walls future home. In terms of bearing capacity, cost and labor intensity, a pile-strip foundation is the best option for a cottage made of light building materials.

Application: for houses made of light materials, frame structures.

Advantages:

• simple and fast installation;
• the minimum volume of concrete and earthworks;
• wide scope of application;
• low cost.

Expert opinion

Sergei Fedorov

Professional builder. Experience 18 years

Disadvantages: not suitable for massive buildings

Design and calculation of pile foundations

Calculations and design for pile foundations are carried out on the basis of hydrogeological survey data, the purpose of which is to determine the type and characteristics of soils on the site. When conducting surveys, the most important parameter is determined - the depth of the piles, which depends on the depth of the bearing soils and freezing.

During the calculation of a pile foundation of any type, the following data are established:

1. Pile field parameters. The distance between the piles, the diameter of the supports, their number are calculated. For a screw foundation, the standard size of metal piles, the number and location of the blades are determined. For a bored foundation, reinforcement is additionally calculated.
2. The depth of the ground part. Distinguish between shallow and deep-buried species monolithic slab and ribbons. There are also options with an elevated and hanging base. Each type of penetration uses its own calculation method. In most cases, private construction uses shallow foundations or elevated foundations for wooden house.
3. Foundation dimensions. The width and height of the reinforced concrete tape or grillage is determined based on the total loads that will act on the base. The calculation takes into account permanent and temporary loads, soil properties, etc.
4. Calculation of the final draft. This calculation is complex, it is impossible to make it yourself. When piles are supported on dense soils with normal physical and mechanical characteristics, shrinkage for 2-3 storey building will be no more than 1.5%, so this calculation can be neglected in order not to pay designers for it. However, if the cottage is being built in difficult hydrogeological conditions, on swampy soil or in a seismic zone, then the settlement calculation is required.

The result of the development of the foundation project on piles, which you carried out on your own, should be a drawing or diagram, which indicates the location of the pile supports, taking into account the selected step, the parameters of the piles and the ground part: slabs, tapes or grillages.

Pile foundation technology

The technology for arranging the foundation on piles for all types of foundation is the same:

1. Installation of pile supports.
2. Binding of pile heads and arrangement of the ground part.
3. Warming and waterproofing.
4. Finishing the basement, arranging the blind area and drainage.

Regardless of the chosen type of pile-combined foundation, work on its installation always begins with clearing the territory and planning. If necessary, a foundation pit or a trench is dug under a shallow base, and the "cushion" is backfilled.

Installation of a pile foundation: installation of supports

Step-by-step installation instructions will be different for each type of pile. Most often, the following types of piles are used for a private house, barn or bath:

1. Screw piles. Products are produced by the manufacturer, have their own sizes and varieties. For the production of screw supports, metal alloys with different characteristics are used. The most durable and expensive are galvanized products. The supports are very easy to install. They are screwed into the ground, without pre-drilling a well, and heads are welded to them from above.
2. Bored piles. Supports are arranged directly on the construction site in pre-prepared wells. Bored piles are durable, low cost and excellent bearing capacity. The base of the bored type can be made independently without buying supports. How to make piles for the foundation with your own hands is described in detail in SNiP 2.02.03-85.

After the installation of the supports, the heads are aligned in height and interconnected into a single structure by strapping.

Pile foundation tying

Timber, metal products can be used to tie a pile foundation, and if we are talking about a massive structure, then reinforced concrete or metal grillage is used as a tie. The choice of the type and material of the strapping depends on the mass of the house and the material from which it will be built, pile supports, and the type of ground part.

1. Strapping with timber is used for wooden and frame houses. To connect the piles with the strapping beam, it is necessary that the heads are metal, therefore this connection is used mainly for screw supports.
2. Channel strapping is used for buildings made of piece materials. The channel is welded to the heads of screw piles or special metal heads-platforms of bored supports, creating a rigid structure that has increased strength and stability.
3. strapping profile pipe possible only for light houses and outbuildings. The strapping technology in this case repeats the design with a channel, but instead of a rolled metal product, a thick-walled hollow pipe is used.

Separately, it is worth mentioning the strapping, which is used to connect bored piles and a monolithic ground part. In this case, the two parts of the foundation are connected with reinforcement, forming a reinforcement assembly. The rods are connected to each other by wire and welding in accordance with the previously selected scheme.

Pouring the ground part of the pile foundation

The ground part of the pile foundation is a slab, tape or grillage. All elements according to the variation of execution can be both prefabricated and monolithic. Prefabricated structures are used infrequently due to their high cost, the need for transportation and use for installation lifting mechanisms. Monolithic structures can be easily made independently, while step-by-step instruction in terms of pouring the ground part of the pile foundation, it will not differ much for the slab, tape and grillage.

The issue of strengthening the pile foundation should be addressed at the design stage. It must be remembered that the reinforcement will put an additional load on the supports.

Waterproofing and insulation of the pile foundation

Waterproofing is essential for any pile foundation. The choice and application of waterproofing depends on the design of the base, for example, for a pile-grillage foundation using metal products or timber, the best option would be coating waterproofing, which is applied to the pile heads and piping elements. Roll waterproofing suitable for reinforced concrete slab, tape and grillage: the material is placed at the junction of the supports and the ground part, as well as on top.

When pouring reinforced concrete foundation regardless of its position relative to the zero level, the structure will draw heat from the future home and be blown by the wind. That is why pile foundations need high-quality thermal insulation, while only the ground part is subjected to insulation. There are many options and ways to insulate pile foundations. The simplest and cheapest is thermal insulation using foam boards. Many manufacturers produce product lines marked "Foundation". Insulation plates are attached inside, outside and on the sides of the monolithic tape.

Expert opinion

Sergei Fedorov

Professional builder. Experience 18 years

When choosing a heater for the foundation of a wooden house, it is necessary to give preference to materials with a low flammability class (NG marking) to ensure the fire safety of the building.

Another solution for creating reliable thermal insulation of the foundation is sprayed polyurethane foam (PPU). This is a relatively new method of insulation, which has many advantages: the absence of seams and joints, moisture resistance, durability. The only disadvantage of PPU is the high cost. To insulate the pile foundation in accordance with all the rules, it is necessary to be guided by SNiP 3.01.01-85 and SNiP III-4-80.

Finishing the basement and blind area for a pile foundation

One of the disadvantages of the pile foundation is the lack of a full-fledged basement. For elevated and hanging bases, the role of the base is played by a false base, and for recessed bases, the ground part of the base. The most popular way to close the space between the base of the house and the ground of an elevated pile foundation is brickwork. This option is suitable for houses made of piece materials, timber. For masonry, it is recommended to use ceramic bricks, which have excellent moisture resistance and strength. You can immediately use decorative bricks or apply plaster or other finishes on top. Today, building materials markets offer a huge selection of basement finishes for any budget: artificial and a natural stone, tiles, facade panels, etc.

The false base needs insulation, therefore, for its arrangement, choose materials that can withstand the load of thermal insulation and decorative finishes.

For a private house, the blind area is very important, which should have a slight slope. It is necessary to build a blind area for the following reasons:

• preventing the penetration of precipitation under the foundation;
• prevention of soil erosion around piles;
• reduction of the destructive effect of heaving soils.

In addition, the blind area gives the structure a finished aesthetic appearance. The width depends on the size of the house: the larger the building, the wider the blind area should be. Minimum Width- 0.2 m. The blind area must be insulated with high-density insulation boards. The material of the blind area can be different: concrete, tile, cobblestone, granite. The most commonly used traditional option is cladding. paving slabs. If the blind area will play the role of a path, then it should be reinforced with a layer of concrete.

How much does a pile foundation cost?

A pile-combined foundation that you can do yourself is one of the cheapest types of foundation for a cottage. The cost of construction depends on the type of piles and the ground part. An economical option is a pile-strip foundation on bored supports. The foundation device on screw piles will cost more due to the purchase of ready-made metal supports.

You can calculate the approximate cost by adding up all the materials that will be used to build the structure. The easiest way to do this is using the special "Foundation Calculator". When choosing the type of foundation for a house, remember that the cost of its construction (labor + materials) should not exceed 30% of the estimated cost of the entire construction.

Making screw piles is a fairly simple process. The main thing is the presence of a small arsenal of cutting tools and a welding machine. The quality of the piles depends on the selected post material, shape, blade size and tip.

Long service life, high reliability, ease of installation, the ability to use on most types of soil determined the high prevalence of screw piles in private housing construction. Every zealous owner can make screw piles with his own hands.

The choice of rolled metal

Many factors influence the quality and durability of the operation of piles. The main one is the quality of rolled metal of all pile components. In Russia, there are no clear rules, including the state standard, that would regulate all the characteristics of screw piles. For the manufacture of piles, steels with a low carbon content - up to 0.25% are excellent. When buying rolled metal, ask the seller for a quality certificate and documents on passing technical control.

In the manufacture of piles, they mainly use a pipe of the following diameters: 57, 76, 89, 108, 133 mm.

The design of the screw pile consists of three parts:

• trunk;
• tip with a screw blade;
• cap.

The design of the piles provides for two options for the execution of the tip:

• welded - a part of the pile shaft is used, which is narrowed into a cone;
• cast with a blade - welded onto the pile shaft.

A steel pipe is used as the pile shaft. It can be seamless pipes or with a welded seam. Very often, used pipe from the oil industry is used for homemade piles.

The bearing capacity of the pile is provided by a helical blade. The blade can be attached both to the tip itself and to the pile shaft. This is of no fundamental importance. At home, it is very problematic to ensure accurate calculation and a snug fit of the blade to the tip, therefore, basically, the blade is mounted on the pile shaft.

To reduce labor costs, you can use ready-made cast tips with helical blades, to which the pile shaft is welded. The use of a cast tip will ensure the correct entry of the screw turn, as well as the absence of the danger of breaking the blade, guaranteeing high reliability of the product. In turn, the use of a finished tip increases the cost of a screw pile. For example, a cast tip for a 108th pipe from different manufacturers costs from 750 rubles apiece.

Calculation of pile parameters

The bearing capacity of the support is calculated from several factors:

• blade diameter;
• depth of penetration of the blade;
• type of soil;
• soil resistance.

The number of piles for a building depends on:

• the weight of the building, including partitions and roofing;
• operating load (weight of furniture and equipment);
• snow load in winter.

The number of piles must be calculated individually, based on the relief of the site, structural and operational features of the structure.

As mentioned above, almost all types of pipes can be used as a barrel. The main parameter will be the wall thickness of the pipe. For all piles, the wall thickness of the shaft should be at least 3.5-4 mm; with a smaller metal thickness, the pile can simply break. And the greater the wall thickness, the longer the life of the pile. Increased wall thickness has a large margin of safety. It also reduces the effect of corrosion on the bearing capacity of the column.

Barrel manufacturing

From one end of the pipe you need to make a crown. Crown length 200-250 mm. It is necessary to cut 4-6 teeth, depending on the diameter of the pipe. The teeth are bent towards the center, getting a cone. The resulting cone must be thoroughly boiled along all cuts.

On the reverse side of the pipe at a distance of 70-100 mm from the edge, two holes must be made. They serve to attach the mounting device when screwing the pile. The diameter of the holes depends on the diameter of the pipe. For pipes of small diameters, holes are not drilled, but small lugs are welded into which levers are inserted when the pile is screwed in.

If, when making a pile with your own hands, you use a cast tip with a blade, you just need to put it on a pipe of the appropriate diameter and weld it around the entire circumference, getting a finished end.

headroom

For the manufacture of the pile head, a plate in the form of a square 250x250 mm is required. The thickness of the metal is 5-7 mm, if you use a thinner plate, there is a possibility of its deformation. It is necessary to provide technological holes for fastenings of the upper trim in the plate.

On one side of the plate, it is necessary to weld a small piece of pipe 100-200 mm long, the inner diameter of which is 1-2 mm larger than the outer diameter of the pile. Additionally, the plate is welded with small jibs to the pipe segment. The head is mounted already on the screwed pile after cutting or building up to the required level of the pile shaft.

If the piles are tied with a profiled pipe or an I-beam, then the head can be omitted.

Helical blade geometry

When making piles with your own hands, the main problem that you will encounter will be the geometry of the blade. Sharp bends, uneven helix lift, unsuccessful turn of the blade and an incorrectly chosen turn pitch can “bury” your pile on initial stage screwing.

The width of the pile blade depends on the diameter of the shaft. The barrel with a diameter of 56 mm has a blade diameter of 86 mm, for the 108th pipe - 300 mm. The thickness of the metal sheet for the manufacture of the blade is 5-7 mm. It is better to cut the inner diameter of the blade with a plasma cutter, this will provide a smooth cut edge.

After receiving the circle of the blade, it must be stretched into a screw. The blade pitch is 40-70 mm. The larger the step, the more difficult the pile enters the ground.

One of the most simple ways stretch the blade - tighten one end of the blade into a vise and hammer on the other end to give necessary form. It should be remembered that with this method there is a strong vibration of the material.

We suggest that you familiarize yourself with the video, which clearly shows the method of making a screw pile with your own hands.

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 yourself, for this you need to immerse the piles to a layer with a bearing capacity. Technology does not depend on the weather, cottage or garden house is guaranteed to be built in the same season, since there is no need to wait for the strength of the concrete elements of the base.

Compared to all known technologies, the 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, the presence of trees on the site, the passage of third-party communications;
• minimum budget - almost complete absence of concrete, earthworks, formwork, waiting for curing concrete structures, rental of special equipment;
• variability of construction technologies - a screw foundation is suitable for log cabins, brick, panel buildings, panel, half-timbered frame buildings, house ground loops, fences, MAF;
• maximum number of storeys - three-story buildings with an attic allowed 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 the connection of the ground wire to the body of the foundation pile field. Piles for the ground loop should not have non-conductive protective coatings.

The only disadvantage of SHS is that it is unsuitable for basement/basement projects. Manual installation of screw piles is not only acceptable, but also recommended by experts. When these structures are immersed 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

Due to a fairly simple design, with the necessary tools and equipment (welding machine, gas cutter), screw foundations can be made at home. Installation is carried out according to the technology:

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

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

Calculation of the pile-screw foundation

The technology has been sufficiently developed in all regions of the Russian Federation, for calculating the SVF, you can use the joint venture of 2011, number 24. 13330 for pile foundations. The main calculations are:

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

In order not to order expensive geological surveys of the site, in 75% of cases test screwing is used, which allows calculating the data necessary for the project:

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

The main characteristics of the piles are indicated by the 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;
• base reinforcement - 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, 40 - 80 cm blades;
• 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 bearing capacity of the pile to calculate required amount SHS.

Site preparation and marking

Due to the lack of planning and excavation, the marking of the building spot is simplified as much as possible. It is enough to bring the axes of walls, partitions and additional heavy equipment (boiler, ladder, pump, etc.) onto the terrain. To do this, a little farther than the corners of the house, pegs are installed 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 on the outer dimensions of the pile.

pile driving

A step-by-step instruction for screwing in the SHS, regardless of the type of blades, tip, groundwater level, and other factors, is as follows:

• production of pits - pilot holes are created to a depth of 0.5 - 0.7 m with a manual or motor drill, they allow you to accurately position the piles, facilitate the entry of the blade into the ground, the diameter of the leader hole should be slightly smaller than the size of the SHS blade;
• pile immersion - scrap 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 one controls the vertical of the trunk with a bubble level, with sharp increase tightening forces (mandatory below the freezing mark) work stops;

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

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

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

Alignment of the 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, pipes protruding from the ground must be brought back to normal. The alignment technology looks like this:

• mark of a single level - a level, theodolite or laser plane builder, level is used;
• trimming - the body of the pipe is cut off by the angle grinder according to the marking.

On this, the pile field device is considered complete when using a monolithic or metal grillage. If a frame, log house, panel or panel house is being built, it is necessary to mount the heads on which the beam, calibrated log can rest. The header 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 inner size of which is equal to the outer diameter of the pile, there are 4 stiffeners (kerchiefs);
• U-shaped - internal dimension between shelves 17 cm for laying timber 15 x 15 cm.

This element is put on the SHS body and attached to it by welding (rarely by bolts). 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. Usually several technologies are 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, cavities inside the mixture;
• sand concrete - grades M 300 - M 400, due to the absence of large fillers, there are practically no voids in 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 grillage

On straight sections, the recommended height of the grillage sole from the ground is 0.5 - 0.7 m. This optimal size for the location of ventilation products in the intake. 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, 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. The device of a monolithic grillage according to technology:

• formwork assembly - the lower shields are put on the pipes, supported by jumpers fixed on two pegs, the side shields are attached to the bottom, interconnected by spacers and ties;
• reinforcement - two belts of bars of a periodic section (12 - 16 mm corrugated) are connected with horizontal and vertical 6 mm jumpers or clamps;
• a bunch with piles - holes are burned or drilled in the pipes, into which additional reinforcement is launched, joined with knitting wire to the armored belts of the structure;
• pouring - the formwork is filled concrete mix to the design level, compacted with reinforcement bars or internal vibrators.

On a monolithic grillage, all types of masonry for walls are allowed brick house and any other construction technologies.

Wooden grillage

Construction technology wooden houses facilitates the task of the developer, who needs to tie the pile field with long elements to ensure the spatial rigidity of the house. The lower rims of the log house (calibrated log), the framing of the “framework” are a finished grillage.

Manufacturing technology looks like:

• installation of flat heads - necessary to increase the area of ​​\u200b\u200bthe supporting surface;
• laying beams - a beam, a log is 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 not suitable for brickwork, high-rise projects. The height of the building cannot exceed one floor with an attic.

metal grillage

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

• laying pieces of the channel with shelves down, wall up on SHS pipes or an I-beam on the bottom shelf in exactly the same way;
• docking of grillage elements, tacking in several places;
• scalding with a double seam of each joint.

A metal grillage is suitable for one-story brick buildings only when the pile field pitch 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.

Entering engineering systems into the building on screw piles

Most often, SHS pipes protrude slightly above the ground. This makes it difficult to lay communications underground 0.5 - 1 m in height. Therefore, it is more reasonable to implement the introduction of life support systems at the foundation stage. Later, for this, it will be necessary to open the subfloor, to carry out earthworks in a confined space. For the normal operation of the building, it is necessary to bring:

• water supply - in the 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 - drains enter the external sewer circuit warm, therefore it is enough to wind the air pipes with one layer of basalt wool, underground pipelines with polystyrene foam shells to a depth of 1–1.5 m;
• grounding of the house - SHS of a minimum diameter can be used in the form of a triangular contour immersed at a mark of 2 m, tied with thick wire or tires from a metal strip, while the piles should not have a protective coating that does not transmit current;
• power cable - sometimes an underground input is used, always in a protective casing.

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

Pickup on screw piles

There is no full-fledged basement in pile foundations; a pick-up is made to protect against blowing, penetration into the underground of precipitation. For the construction of a false basement, several technologies can be used:

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

The pick-up is supplemented by a blind area for the removal of storm and flood drains. Facing materials these structures must be waterproofed. For this you need:

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

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

Screw pile resource

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

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

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

Even when buying SHS with a factory anti-corrosion layer, it is necessary to cover the piles with the indicated compositions for reliability.

Appointment 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 pile modifications are used for:

• building a house in a swamp, slope, in dense buildings, forest zone, on soils with high groundwater level, low bearing capacity;
• budgetary construction of fences, IAF, gazebos, outbuildings;
• reinforcement of tape, slab bases;
• manufacturing engineering systems, such as grounding a house, a water intake well.

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

This instruction is suitable for installation of screw piles under a building erected using any technology from different wall materials. Recommendations will help to avoid mistakes, increase the operational life of the home.