Houses made of timber / 04.08.2023

How to make a pile foundation. Do-it-yourself pile-strip foundation How to properly pour piles under a house

IC "Installation of Pile" is engaged in the construction of foundations on reinforced concrete piles. We are ready to equip a reliable turnkey foundation at the lowest cost in Moscow, completing all work in strict accordance with the requirements of SNiP in the shortest possible time. To cooperate with the company, fill out the “Leave a request” form located at the bottom of the site.

This article provides detailed instructions for manually installing a foundation from bored piles. We will consider all stages of creating a foundation - from its design and marking to pouring piles and tying them with a reinforced concrete grillage.

Independent foundation design

The first stage of arranging any pile foundation is its design, during which it is necessary to determine the load-bearing capacity of the reinforced concrete support and the total loads on the foundation, and based on them, calculate the required number of piles for building a house.

Important: the load-bearing properties of a pile are always determined “by the soil”, since the load-bearing characteristics of concrete as a material exceed those of the soil. For example, 1 sq. cm of M100 concrete can withstand a standard load of 100 kg/sq.cm, while 1 cm2 of clay soil, which is prevalent in the Moscow region, holds no more than 6 kg/cm2.

Fig 1.1

To find out the load-bearing properties of the soil, it is necessary to conduct geodetic surveys at the construction site. During their implementation, geodetic wells are drilled, from which soil samples are taken for laboratory analysis. The price of the service depends on the depth of soil development - from 2 to 3 thousand per 1 linear meter of well (the price includes the cost of laboratory work).

We offer you an average calculation of the load-bearing properties of piles based on clayey soil common in Moscow. The table shows the characteristics of piles with a diameter of 15-40 cm typical for individual construction.

Figure 1.2

To determine the number of piles in the foundation, you need to calculate the total mass of the building, which is done by multiplying the area of the structural elements of the building by the standard weight of building materials given in the following table:

Rice. 1.3

The following loads are added to the resulting mass of the building:

Useful operating load - 100 kg per sq.m. floors of the house (ground and interfloor);
Snow load on the roof (depending on the region of construction).

Rice. 1.4: Map of snow loads of the Russian Federation

The total sum of loads is multiplied by 1.2 (safety factor), after which the result is divided by the load-bearing capacity of one pile. This determines the required number of supports in the base.

The pile placement scheme is drawn up as follows:

The minimum distance between supports is 1 m, the maximum is 3 m;
It is mandatory to have piles at the junction points of the walls at the corners of the building and at the junction of internal and external walls;
The supports are deepened below the depth of soil freezing in a given region (to avoid negative loads from soil heaving).

Rice. 1.5: Map of soil freezing in Russian regions

Preparatory work

Before starting the installation of the foundation, it is necessary to purchase the required consumables - concrete, reinforcement and planed boards for installing the formwork under the grillage. The standard consumption of concrete and reinforcement for typical configurations of bored piles is shown in Figure 1.1

To build a bored foundation yourself, you will need the following tools and materials:

For marking - reinforcing bars, planed boards and bars, construction cord or twine, self-tapping screws, level, tape measure;
For the installation of reinforced concrete piles - a concrete mixer, shovels, a hand drill, buckets, rolled roofing felt, tape, a wheelbarrow for removing soil;
To create reinforced frames: welding machine, grinder, reinforcing bars (corrugated, 12-15 mm in diameter, and smooth, 8-12 mm in diameter);
For the grillage - ready-mixed concrete in the required quantity, boards for formwork, hacksaws, nails and screws, electric drill, wire, waterproofing material for the grillage to cover after pouring.

Important: Initially, it is necessary to prepare the construction site - remove surface vegetation, debris, stones and boulders that may interfere with the work. If there is a sloping terrain, the site is leveled to one level.

Do-it-yourself foundation marking

To mark the base, it is necessary to knock down stripping boards from planed boards and beams. The structure consists of two horizontal belts, the first of which is used to lay out the zero level of the piles (their height), the second - to break out the upper edge of the grillage.

Rice. 1.6

Initially, the base lines of the foundation (the contours of the walls of the building) are marked - the distance is counted from the landmark (fence or site boundary) and the cast-off of the first wall is installed, a string is pulled between the boards (the thread is fixed using a self-tapping screw screwed into the board).

An adjacent wall is marked perpendicular to the laid contour. The right angle is checked using the Egyptian triangle (a distance of 3 and 4 meters is given on intersecting laces, a mark is made with electrical tape and the length of the diagonal is measured - at the correct angle its length is 5 meters).

Rice. 1.7

Next, the two remaining walls are marked in the same way. At a distance of the thickness of the grillage, a second cord is installed on the cast-off, defining the internal contour of the walls. The positions of the piles are marked according to their design distance from each other - casting boards are installed and a plumb line is lowered from the intersection of the string, under which a reinforcing peg is driven in, which determines the installation location of the pile.

DIY installation of bored piles

After marking the foundation, the stretched twine is dismantled and only the pegs are left in the places where the piles are arranged. The technology for creating supports is implemented in the following sequence:

Using a hand drill, wells for piles are developed. It makes sense to go through all the wells at once, so that in the future you can fill the supports with concrete in one go;
A cylinder equal to the diameter of the pile is formed from rolled roofing felt, which is fastened with tape. The cylinder in this case acts as the pile formwork, so its height should be equal to the full length of the reinforced concrete structure (if necessary, protrude from the well). Once created, the formwork is placed inside the cavity;

Rice. 1.8

Reinforcing bars in the amount of 4-8 pieces are inserted into the wells (depending on the diameter of the pile). The rods are immersed in the ground so that the soil securely fixes them. The length of the reinforcement should be 30-40 cm greater than the length of the pile, protrusions are necessary for joining with the reinforcement frame of the grillage;
A concrete mixture is poured into the prepared wells (concrete grades M200 or M300 are used). You can prepare the mixture yourself using a concrete mixer or order ready-mixed concrete in the required quantity;

Rice. 1.9

After pouring, the concrete is bayoneted with reinforcement, which is necessary to remove air cavities formed in it from the mixture.

Important: Having formed the concrete body of the piles, it is necessary to wait 20-30 days before subsequent work, during which the structures gain standard strength.

Self-installation of reinforced concrete piping

Before arranging the grillage, it is necessary to restore the base lines dismantled for installation of piles on the cast-off. In this case, the twine is stretched along the upper horizontal belt, which is responsible for the level of the grillage.

Wooden formwork is installed along the contours of the trim. Initially, you need to install U-shaped load-bearing elements made of timber between bored piles, after which the outer contour of the formwork is sheathed with boards knocked into a shield.

Rice. 2.1

After forming, the formwork walls are covered with waterproofing material and work begins on installing the reinforced frame. On the reinforcement protruding from the piles, horizontal rods are fixed, raised to a height of 5 centimeters, to which pre-prepared rectangular clamps are welded.

Rice. 2.2

The side contours of the clamps in this case perform the function of transverse reinforcement. The number of longitudinal belts is selected based on the width of the grillage; for tying a standard width of 40 cm, 4 belts are used.

Important: each side of the reinforcement cage should be placed at a distance of 5 cm from the walls of the formwork, since when the reinforcement leaves the concrete body, the frame will be subject to accelerated corrosion.

The upper contour of the longitudinal reinforcement is welded to the transverse clamps. Pay special attention to strengthening corner joints - cross-joining is not allowed here.

Problems with ensuring the stability of buildings on highly water-logged and mobile clay soils force developers to look for and use types of foundations that are more reliable and at the same time easier to manufacture. One of the options for solving the problem is the use of a pile-strip foundation, which combines in its design the features of two types of foundation systems - pile and strip.

What is a pile-strip foundation

A strip foundation on piles is a stable and durable structure that involves installing a strip on piles. The result is a monolith. This option is often chosen as the basis for low-rise massive houses.

A strip foundation on piles is obtained by connecting piles and a strip structure. This option is chosen when building houses in areas with problematic soils. Piles can have different lengths, shapes and diameters. The load from the building is distributed onto the belt, which avoids the destructive effects of moving soil. This system has a reinforced concrete element installed at different depths.

What does using a pile-strip foundation give?

From the name of the scheme, it becomes clear that one design combines two completely different systems - pile and classic strip, most often in the form of a simplified shallow concrete strip. The costs of constructing such systems are noticeably higher compared to strip or piles, but thanks to the design features of a pile-strip foundation, it is possible to achieve higher quality characteristics of the foundation of a future home:

The use of piles can significantly reduce the sensitivity of strip foundations to soil heaving. If the soil is excessively oversaturated with moisture, the pile-tape scheme will allow you to transfer most of the weight of the building box to more rigid layers of soil at a depth of 1.5-2 m;
A concrete strip grillage on a pile foundation increases the rigidity of the foundation several times, so on a pile-strip structure you can easily build houses from lightweight materials, for example, foam block, aerated concrete, wood concrete;
The presence of a “bridge” in a pile-strip system connecting individual piles does not mean that this option is suitable for buildings of any weight. Most often, the foundation is relatively cheap and rigid enough to support the weight of a frame or log building, no more than two floors high.

In some cases, for example, on quicksand, sandy and loamy soils with weak bearing capacity, and even with a slope and a high level of surface water, the construction of a pile-strip foundation is, in fact, the most optimal in terms of strength and cost of arranging a base for the building box .

For your information! You can, of course, drive reinforced concrete piles, but such a scheme will cost much more, and you will still need to assemble a frame from a steel channel or wooden beam for laying the walls.

In addition, for a foundation based on concrete piles, it will be necessary to make a fairly serious calculation and check the bearing capacity of the soil, and the driving of reinforced concrete supports, in contrast to the pile-and-belt version, is carried out with a diesel hammer. It is clear that it is almost impossible to do this part of the work with your own hands, especially since the rental of equipment and the piles themselves will cost half the cost of the entire pile-strip foundation.

Differences between the pile-strip foundation scheme

Like most modern foundation structures, a pile strip foundation has pros and cons, which it is better to learn about in advance and in detail before starting to make a pile strip foundation with your own hands.

There are few disadvantages, but they are all quite significant:

The construction of a pile-strip foundation requires a large amount of manual labor, since the traditional use of excavators for digging trenches is often impossible due to the holes drilled for the piles;
When tying piles to a concrete-reinforcement grillage of a pile-strip foundation, confident skills in working with tying reinforcement, setting the height of the supports' heads and accurately laying out the horizontal reinforcement frame are required. It depends on this whether the individual elements of the pile-strip foundation can work as one;
Before making a pile strip foundation, it is necessary to obtain complete information about the degree of heaving of the soil and its bearing capacity. Based on the data obtained, the load on the supporting strip surface of the foundation system is calculated.

The most common pile-tape scheme involves deepening the horizontal strip base 35-42 cm below the zero mark. In fact, when preparing a pit, the fertile layer is simply removed to the load-bearing level, deepened by the amount of a backfill of sand and gravel, and a belt perimeter at least 20 cm high above the ground level is poured.

The total height of the concrete strip of a pile-strip foundation is calculated from the load conditions from the weight of the building according to the bearing capacity of the soil. Thanks to the use of piles, not even a shallowly buried, but a partially buried strip foundation is obtained. In essence, the pile-tape scheme is a full-fledged concrete grillage tied to the ground.

For highly heaving soils, there is a danger of the strip base being squeezed out by the top layer of soil. In the most unfavorable conditions, the soil pressure on the strip is so great that the concrete supports on which the pile-strip foundation stands are pulled out of the wells during heaving or break off at the ends if the joining of the pile to the strip foundation is carried out in violation of the technology. To prevent such problems, concrete must be equipped with a “warm” blind area, use more durable Tise supports, or convert the pile strip foundation to a pile-grillage version. But this is more an exception to the rule than the rule itself.

Types of piles

Such a foundation is built on screw and bored type piles. The first group includes products made from metal pipes. At the end of the piles there are blades designed for screwing into the ground. Based on the principle of operation, these elements can be compared to screws. The blades give rigidity to the screw pile. They sink into a hard layer of soil.

Piles are made in different diameters - from 57 to 133 mm. For low-rise buildings, pipes with a length of 165 to 350 cm are chosen. Such piles are screwed into the ground using special equipment. Hand-held devices can be used. To extend the life of the piles, they are coated with a primer and a layer of paint.

Bored piles are made by hand. First, a well is drilled until it is immersed 60 cm into a solid layer of soil. The bottom should be covered with sand to a depth of 30 cm. Then the cushion is thoroughly compacted. The well is reinforced with steel rods. Then it is filled with concrete. For pile formwork, pipes made of asbestos cement, cardboard or plastic are chosen. The work does not require special skills or knowledge.

A pile-screw foundation, unlike a pile foundation, has a reinforced concrete grillage. Tape bases are made recessed, shallowly recessed or not recessed. In some cases, concrete grillages are created that are above the zero mark.

When erected independently, a strip foundation with piles is usually made shallow. A monolithic reinforced concrete strip is buried 20-40 cm into the ground. It is placed on a bed of gravel and sand 30 cm deep and piles. These foundations are poured on slightly heaving and non-heaving soil. If the soil is heaving, make a hanging type tape.

Any construction on your own requires a thoughtful approach, so the best assistant would be a step-by-step manual made with your own hands for working with a pile-strip foundation. Pre-thought-out steps will help you avoid serious mistakes. For example, before planning a building with a strip pile foundation with your own hands, as in the video, you must first perform drainage on the site. Otherwise, rain and surface waters will negate all efforts to make wells and cast a pile-strip foundation:

DIY pile-strip foundation: step-by-step instructions

Today construction work is quite expensive. Therefore, many owners of suburban areas decide to build a strip foundation on piles themselves, using improvised means. This type of work has some peculiarities.

Cleaning up the area

Preparing the site for installing a pile-strip foundation begins with cleaning the area. This may take several days. Before the construction of a strip foundation on piles, garbage is removed from the territory, trees and bushes are removed. At this stage, some difficulties may arise.

It is important to determine a place for the fire in which unnecessary garbage will be burned. It should not be stored on site. The fireplace is dug up a little. This is necessary to comply with fire safety requirements. Stumps are removed with roots.

When clearing the area for a strip foundation on piles, it is important to remove weeds. The better this work is done, the fewer problems will arise in the future with landscape design. In areas where there will be beds and a lawn, remove the soil layer to a depth of 4-5 cm.

Axle breakdown

First, the site where the strip foundation on piles will be erected is leveled. Then they make a breakdown. This process involves transferring the plan from paper to the construction site. Using cords and cast-offs, mark the position of the foundation axes, the width of the tape and the points where the piles will be installed. All this data is determined based on preliminary calculations.

Before choosing materials and starting construction work, determine the type of structure and think through an action plan. It includes a detailed layout of the house on the territory, features of the foundation on stilts.

Then the breakdown begins. This type of work has several specific features, so it is better to contact surveyors. This is due to elevation changes on the site. If they are not taken into account, in the future there will be problems associated with shrinkage of the house and deformation of the foundation. The cost of axle alignment is affected by the volume of work.

Layout consists of transferring the dimensions of the building axes to the site and creating markings. Afterwards, trenches are dug on the piles for the foundation. The dimensional axis is a conditional guide indicating the center or boundaries of the location of floors and formwork. The guides correspond to the dimensions of each supporting structure and the foundation as a whole.

You can lay out a strip foundation with bored piles using the following tools:

red paint;
hammer;
red rags;
nails;
pegs;
construction tape;
boards;
wire or twine.

The casting angles must be created ideal. This will allow you to properly lay out the foundation. Otherwise, the walls will be at an angle to each other, which will reduce the strength of the entire structure. When creating floors from standard materials, the dimensions of the axes should be exactly transferred to the area for the strip foundation on piles. It is important to constantly take measurements and triple check each result obtained.

Dimensional axes are lines that show on the site the dimensions of the foundation of the house and its shape. Finding the overall axles is quite simple:

Two points are placed on the site, distant from each other at the distance of the longest axis, located horizontally.
Indicate on the diagram of a strip foundation on piles the distances between the guides and the connection of the base to them.

The procedure for laying out a strip foundation on piles is as follows:

identify the main axes;
apply them to the site;
carry out stripping (attach house markings to the ground).

It is quite difficult to determine the main axes, so it is better to invite surveyors for such work. The main axes are called perpendicularly located lines starting from the supporting structure to the central points. Where they intersect, there should be an intersection of diagonals built from the corners of the house.

Then, using the available data, you can find out the location of other points. The place where the main axes intersect is marked with pegs. When building a small house with a simple shape, it is not necessary to break it down. You can immediately find the overall axes. They are fixed with wooden stakes and reinforcement so that they do not become loose.

Professional builders adhere to two mandatory rules that help when marking the foundation:

If the building is rectangular or square, you should carefully ensure that each corner is right.
If the floors are made of concrete panels with large voids, you should ensure that the dimensions of the strip foundation correspond to them.

After the breakdown, you will need to dig trenches whose width corresponds to the width of the tape and formwork walls. The depth is selected based on the depth of the foundation strip. It should be below zero, taking into account the gravel-sand cushion. The average is half a meter.

When installing a pile foundation on soft soils, settlement may occur. To prevent this from happening, it is worth performing a series of calculations that will help determine the limiting states of soils. When calculating the settlement of a pile-strip foundation, the main value is the total settlement indicator S, which should not be greater than the maximum permissible deformation Su.

Excavation

If there is stable soil on the site, the width of the trench is chosen equal to the width of the foundation strip on piles. In such cases, formwork is not required. Its role will be played by the walls of the trench. If the soil is unstable, the width of the trench increases - with the expectation of installing formwork for the foundation on both sides.

After calculating the pile-strip foundation, wells are drilled along the axis of the trench to a depth exceeding the soil freezing level by half a meter. The sand cushion occupies 30 cm. Wells are drilled with a hand or garden drill. The distance between them is no more than two meters. The diameter of the wells should be greater than 1/3 of the width of the strip base.

After all the holes are made, sand 10-20 cm high is poured into the bottom of each well. The pillow is compacted. It is capable of well protecting the foundation strip on piles from water. Then piles are installed in the holes. The walls of the wells are covered with roofing felt.

You can reduce the cost of constructing a pile-screw foundation by doing the construction work yourself. The concrete is mixed on site. Usually the power of concrete mixers is not enough to pour everything at once. Therefore, first a pile field is created, and only after that the strip base is concreted. A foundation made of tape on piles can be made monolithic if you order mixers. In this case, concrete is poured directly into the piles and MZLF formwork.

Pile field

A pile field is a platform for a strip foundation on which piles are installed according to a pre-created pattern. Usually this is a continuous field prepared for the construction of a house. Pile fields consist of two or more rows of supports. In fields with a small area, it is permissible to place piles in a row. Typically, this option is applicable when constructing foundations for various fences.

A continuous field is an area prepared for the construction of a monolithic foundation or a prefabricated foundation. Often piles are installed in a staggered pattern.

When designing a pile field for a strip foundation, the following parameters are taken into account:

Selecting the type of piles taking into account the characteristics of the soil on the site.
High groundwater level.
Determination of pile sizes taking into account the type of grillage and the expected load on the base.
An indicator of the bearing capacity of a pile. It is calculated based on the data on the ultimate soil resistance, length and cross-section of the pile.
Number of piles and their placement scheme.

When constructing a pile field, it is important to keep excavation work to a minimum.

Installation of foundation piles

When installing a pile-strip foundation with your own hands, first formwork is made under the supports, then reinforced and filled with concrete. If the foundation is installed on screw piles, small holes - 10-15 cm - are dug in the places where they are installed.

When purchasing ready-made concrete piles, the cost of building a foundation increases significantly. They are driven into the ground using special equipment. It is important to create a footing for each pile. Concrete should be poured into the pipe by 40 cm, and then the pipe should be raised by 30 cm. From below, the concrete begins to spread and forms a heel - an extension on which each support of the pile-strip foundation is fixed.

Metal piles with blades are twisted manually or using special equipment. In the first case, it is necessary to monitor their vertical position. A crowbar is inserted into the technological holes on top of the pipe, and hollow pipes are put on its ends. They serve as levers with which it is easy to screw the piles into the ground.

Making formwork for the foundation

A sand cushion is poured into the bottom of the trench for a pile-strip foundation. It is made at least 15 cm. The pillow should be laid in an even layer along the entire perimeter of the foundation. As for piles, sand is filled with water and then compacted. To give the structure additional strength, you can fill in a layer of crushed stone.

Then they begin to manufacture the formwork for the strip foundation on piles. It is usually made from chipboard, boards, and special panels. If it is necessary to use the formwork material in the future, it is worth covering the walls with plastic film.

The finished shields are nailed to stakes driven into the ground every meter. Supports for the formwork walls are located on the outside. Additional strips are nailed along the bottom and top of the formwork to hold the walls.

When completing the installation of the formwork, you should make sure that it is located above the concrete pouring mark. Then bricks can be laid on the bottom and reinforcement can begin. For reliability, it is worth strengthening the foundation walls with ties and struts.

Reinforcement of piles and grillage

Steel rods are placed inside the formwork. They should be laid in three directions, forming a three-dimensional grid. At the points where the rods intersect, they are tied with knitting wire. Be sure to tie the reinforcement of the strip foundation and piles together. This connection ensures the strength of the base.

There should be 3 rods for each pile. They are mounted in the form of a triangle. The ends of the rods should protrude 20 cm above the top of each pile. To enhance the reinforcement, it is possible to create a solid frame from rods.

All that remains is to mix the solution and begin pouring the pile-strip foundation. It is worth remembering the method of creating the base when concreting piles. During pouring, the solution is compacted by bayonet.

Features of pouring a pile-screw foundation

Portland cement grades M200-M500 are chosen as the binding element of the concrete mixture. Subtleties of preparing and pouring a pile-strip foundation:

The solution is made of medium density; it should not be liquid.
The pouring of strip foundations on piles is carried out simultaneously over a short period of time. First, all piles are concreted. However, this should be done only after connecting all the reinforcement bars - both pile and strip.
First, it is recommended to fill the load-bearing structures (piles). Then they are left for a couple of days to allow the concrete to gain strength. It is better not to fill the tape immediately after the piles. This is explained by the fact that it is quite difficult to achieve a tight seal on a pipe on a sand bed. Some of the concrete will still leave the bottom of the pipe.
When the concrete gains strength, the strip foundation is poured simultaneously at several points. To do this, it is better to use several concrete mixers. The process must be automated.
After filling the tape part of the base, it is left for a week. During this time, the concrete will gain half its strength.

After shaking the foundation, check the horizontality of the grillage. If necessary, level the surface.

Important! The foundation should not be poured in wet weather. If this condition is not met, the strength coefficient of concrete will decrease significantly.

Waterproofing and ventilation

When constructing a pile-screw foundation, it is important to protect it from moisture. It is also necessary to ensure proper ventilation of the structure. Asbestos-cement and metal pipes do not require waterproofing. If ready-made pipes were not used for the piles, they are covered with the same waterproofing as the concrete strip.

Features of creating reliable waterproofing of a pile-strip foundation:

Sheets of roofing felt are rolled into a tube and placed in the pile hole. In the trench, all the walls are lined with this material and covered on top.
Surfaces covered with roofing felt can be additionally treated with hot resin.
A modern mixture added to concrete creates reliable waterproofing not only from above, but also protects the structure from the inside.

When choosing any material, waterproofing is done for the sole purpose of preserving the concrete strip foundation from the destructive effects of moisture and protecting it from mold. Afterwards they do ventilation.

Parts of an asbestos-cement pipe are laid horizontally along the perimeter of the strip base and then covered with sand. This is necessary so that concrete does not get into them. After the solution has hardened, the pipes are removed. The result is ventilation holes.

Pouring the foundation with concrete

One of the final stages of constructing a pile-strip foundation is pouring concrete. It's better to do this kind of work in one go. This will require several people and more than one concrete mixer. In this case, the tape will be monolithic, which will give it strength. During the pouring process, the solution is compacted using a submersible vibrator.

When pouring piles, it is important to control the density of the solution. This will help eliminate voids inside the piles. Otherwise, the supports will collapse. To connect concrete piles to a strip foundation, you should not wait until the concrete in them has completely hardened. It is necessary to start pouring the tape two days after concreting the piles.

When making concrete yourself, it is important to maintain the optimal proportions of sand and cement. It is better to choose a high quality binder (not lower than M200). This will prevent cracking of the monolithic tape. If the weather is hot after pouring, the foundation should be watered. At high humidity it is covered with film.

To reduce time, you can buy ready-made concrete, which is supplied in a special mixer. To save money, prepare the solution yourself. In this case, you will need to prepare sand, gravel and cement. It is important to observe the following ratio of components of the solution for the strip base on piles:

one part binder;
three parts sand;
four to five parts crushed stone or gravel.

The volume of water used is monitored visually. The solution for a pile-strip foundation should have a consistency that is not too liquid and not too thick. The quality can be improved by adding various modifiers and plasticizers. It is not recommended to violate the proportions, as this will significantly reduce the quality of the concrete.

Thermal insulation

Typically, the design of a pile-strip foundation provides only external insulation and moisture protection. The side walls form a base, which should be insulated. For this work use:

Bitumen. This material covers the side surfaces of the grillage. This waterproofing protects the base well from moisture.
Polystyrene foam or polystyrene foam. These materials are polymer thermal insulation. It is glued to bitumen or to a leveled grillage.
Then each seam is sealed with polyurethane foam to prevent the formation of cold bridges. However, when choosing penoplex, you should not install it in several layers. Sheets of this material have special projections and depressions for reliable connection with each other.
Reinforcing mesh is used as additional thermal insulation. It is used to protect insulation material from rodents, and also as a base for plaster applied to the base.
When the adhesive composition dries completely, a mesh is tightened under the slabs. The top of the structure is plastered.

The work of insulating pile-strip foundations differs little from the thermal insulation of standard strip grillages. Along the perimeter of the building a base is created from ready-made blocks or bricks. From the inside, the foundation space is filled with expanded clay. This type of work is complex and time-consuming.

Features of insulation of a pile-strip foundation:

First, waterproofing of all areas of the base is done and drainage is provided under the blind area. All open elements of the grillage are covered with roofing material or bitumen. It is possible to use a liquid waterproofing agent. Its only drawback is the high price.
Then the vertical surfaces of the strip foundation on piles are waterproofed - both inside and outside. The waterproofing technology is quite simple - it is similar to the method of insulating a grillage from the outside. The upper part is covered with roofing felt. The well itself is made with a larger diameter than the size of the pile.
After installing the piles, a bulk cushion is created. It is performed between the zero mark and the lower level of the strip foundation on piles. The pillow is made from a mixture of expanded clay and sand.

Despite the variety of modern insulation materials, people often prefer to use traditional insulation methods. The reasons for this behavior lie in the durability of the methods used. When insulating with traditional materials, it’s easy to do all the work yourself. A properly executed blind area, which has an optimal slope and waterproofing of the junction of the plinth with the concrete platform, can provide good protection from rain. Inexpensive and lightweight foam is excellent for insulation.

However, polystyrene foam is suitable for soils with high humidity. It is better to use waterproof thermal insulation materials, since only they can withstand the prolonged action of groundwater.

Any technology used to insulate a pile-grillage foundation has its pros and cons. It is important to take into account the cost of materials and work performed, the features of the strip foundation and its shape. Therefore, it is important to independently determine how to insulate a structure on stilts and how to save on construction work.

Conclusion

There are quite a large number of fables and notions about the effectiveness of pile-strip foundations, most of them have no basis in reality. A properly assembled foundation on piles can easily overwinter without load, but with mandatory insulation of the blind area. The strength and rigidity of the structure is sufficient for most variants of dachas, one and two-story houses.

The final cost of construction of a strip foundation on piles depends on several factors. The most important are:

cost of drilling wells for piles;
costs of construction and consumables;
time spent on the construction of a pile-strip foundation.

The assessment can be carried out by an employee of the construction company. These calculations will help when creating a pile-and-tape structure for the house. In addition, it is important to determine the settlement of strip-pile foundations.

If you follow the rules for installing piles and pouring the grillage, the base will be strong and durable. When installing the foundation yourself, it is worth enlisting the help of several people.

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 stretched. 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 built, 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 designed 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 fence. 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 framing of the “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 - beams, 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, for 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 plinth 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.

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Since ancient times, in areas that are often subject to flooding, people have built houses on stilts driven into the ground. The piles were made of logs and driven into the soil by hand - although the process took a lot of time and effort, it nevertheless made it possible to raise the house by one or two meters and save property from water. Pile foundations are still often used in cases where a house has to be built on weak, highly compressible or low-strength soil, that is, on soil that is not suitable for a conventional shallow foundation.

Driven pile foundation design

A pile foundation (photos of which you will find in the tab) has many advantages and is considered one of the most reliable among builders. If we compare columnar and pile foundations, the technology of the latter is much simpler, since there is no need to dig holes, make formwork, or fill in sinuses. When constructing a pile foundation, you can do without excavation work at all - driven piles are driven into the ground using special equipment, and for bored piles, wells can be drilled with a hand-held construction drill.

When constructing a pile foundation, you can do without excavation work at all.

On any type of soil, except those containing impenetrable inclusions, it is possible to use driven piles. Driven piles are made from wood (mainly coniferous species: cedar, pine, larch, oak), steel or reinforced concrete. The end of the wooden pile that is intended for driving into the ground is sharpened and protected by a steel tip from possible damage when immersed in the ground. A steel ring is put on the upper end to prevent the pile from splitting due to hammer blows. For reinforced concrete piles, the lower end is also sharpened.

Video about pile foundation

It is quite possible to build a pile foundation with your own hands, since it does not require removing the soil: the piles are driven into the ground using special hammers, pressing devices and vibratory hammers. The installed driven piles are cut at the same level and connected from above with a grillage, which ensures uniform distribution of the load on all piles.

A pile foundation can also be made of metal tubular piles that are hollow inside. Their main advantage is that they are much lighter than other types of driven piles. In addition, they can be driven very deep, filled with concrete for stability. This also includes screw piles with a welded screw strip, used for...

How are bored pile foundations made?

To ensure the integrity of the foundation on heaving soils, it is better to use bored piles. Although this method is more labor-intensive compared to the one described above, you do not have to spend money on renting expensive pile-driving equipment: the foundation on bored piles is made by concreting pre-drilled wells.

A pile foundation can also be made of metal tubular piles, hollow inside

Drilling piles under the foundation can be carried out with a hand drill with a maximum diameter of up to 30 cm and a rod length of over 5 m. Thanks to the special arrangement of the cutting blades, drilling requires little effort. The required depth and diameter of the well are calculated based on the characteristics of the soil (most often, a depth of about 10 m and a diameter of about 20 cm are sufficient).

Further construction of pile foundations made of bored piles looks like this:

along the entire length of the wells, a cover made of several layers of roofing material, PVC film or galvanized steel is provided to prevent the piles from being pushed out under the influence of swelling of the soil during frosts (nothing will harm the foundation if the soil slides over the protective cover);
a reinforcing cage is installed in the wells in the form of connected reinforcement rods, 3 pieces each, with the rods extending above the poured piles to the height of the future grillage - the reinforcement will subsequently serve as a connecting link between the cast-in-place pile and the grillage, and will also prevent possible rupture of the foundation as a result of soil heaving;
The pile foundation is poured with “heavy” concrete (with quartz sand or crushed rock), filling occurs continuously in each well in layers, the concrete is compacted by bayonet.

The poured foundation on piles can only be loaded after a month, when the concrete has finally set.

The poured foundation on piles can only be loaded after a month, when the concrete has finally set

Grillage design for a pile foundation

A pile foundation with a grillage makes the structure more reliable and durable, giving it rigidity. You can make a grillage from prefabricated reinforced concrete elements, or pour a monolithic foundation. A pile foundation with a monolithic grillage is preferable for independent construction, since it is much more convenient to pour concrete than to place heavy reinforced concrete blocks on the piles.

There must be a gap between the soil and the lower part of the grillage so that when the soil swells, it does not lift the grillage itself; therefore, in no case should the grillage be placed directly on the ground.

A pile foundation with a grillage makes the structure more reliable and durable, gives it rigidity

The pile-grillage foundation is performed as follows:

formwork is installed on the piles;
inside the formwork, the reinforcement cage is firmly fixed, placing small bars under the lower bars so that the reinforcement is completely immersed in concrete;
the rods protruding from the bored piles are connected to the reinforcement frame of the grillage for greater reliability of the foundation;
The grillage is filled with concrete (the same as in).

Pile foundation: reviews, advantages and disadvantages

Of course, the pile-grillage foundation has many advantages: it allows you to reduce the heat costs of the house, since the grillage does not touch the frozen ground; reduces the level of vibrations, which is especially important in areas located near a highway or railway; eliminates the need for excavation work; requires less cost than a strip foundation.

Video about pile foundations. Pros, cons and recommendations

However, a pile foundation also has disadvantages - just read the varied reviews of those who chose this type of foundation for their home. For example, the disadvantages include the fact that installing a basement in a house will cause certain difficulties due to the grillage raised above the ground: the space between the piles will have to be filled with something. In addition, the pile foundation is not stable enough on subsiding and swelling soils.

When choosing a foundation for your home, think carefully about all the possible pros and cons to make the right decision. A pile foundation can be either an ideal option in one case or a big mistake in another.

With high groundwater levels and unstable soil, the foundation for a private house often has to be made of piles. It turns out to be too irrational to use other options in such a situation. They will either be too expensive or short-lived due to high soil moisture. Reinforced concrete pile foundation of bored type is cheaper and easier to implement. You can do it yourself without any problems.

What is a pile foundation?

Pile foundations are vertical reinforced concrete supports immersed in the ground. They are usually connected on top with a grillage or a monolithic slab, which serves as the base for the walls of the house. Depending on the type of piles, they are driven into the soil, twisted, or simply immersed in pre-drilled holes in the ground.

Scheme of one of the types with an underground grillage

The reinforced concrete grillage option in appearance and general design is a direct analogue of a strip foundation. Only the “tape” here is smaller in size and lies not in the ground, but on piles. This perfectly protects the grillage from moisture and heaving. Moreover, all the energy of seasonal expansion/contraction of soil layers passes by the pile supports. They initially sink below ground freezing levels, standing on a dense, stationary base.

Types of foundation on piles

Depending on the technology of immersion of supports, pile foundations are:

On hanging stilts;

On retaining piles.

In the first case, the pillars seem to hang in the ground without support from the supporting layer due to banal friction forces. In the second, on the contrary, they rest on solid layers of soil. A suspended foundation requires a large number of piles and more thorough calculations based on serious geodetic studies of the site. This technology is not used for the construction of private cottages with two or three floors.

In low-rise housing construction, the retaining option is more in demand. The piles here are not driven into a continuous field; much less of them are required. For an ordinary house outside the city, four supports in the corners and several under the load-bearing walls are enough. It is much easier to do such a pile foundation with your own hands.

Piles for constructing such a foundation can be taken:

Screw-in (screw-in) steel.

Driven reinforced concrete.

Bored from asbestos-cement pipe and reinforced concrete inside.

Private developers usually choose screw or injection (bored) technology for the construction of pile reinforced concrete foundations. At the same time, steel “screws” have a serious limitation - the depth of installation during self-assembly. If the dense layers are shallow (up to 2 meters), you can still screw them into the ground yourself, but for longer supports you will need specialized equipment.

With drilled analogues the situation is fundamentally different. They are made from pipes, to immerse them in the ground it is necessary to dig a hole of the appropriate size. Even if it is needed a couple of meters deep, it will not be difficult to dig such a pit with your own hands for the future foundation in dense, non-crumbling soil.

Pros and cons of a pile foundation

Each foundation has pros and cons. This is far from a universal option for any soil. It is not suitable for every site. But such a foundation for a private house is not as expensive as a slab foundation or a reinforced concrete strip analog buried below the freezing point. In the screw version, the support on piles will cost 30–40%, and in the bored version – 20–25% cheaper.

Among the advantages of the option under consideration are:

Possibility of installation where classical options cannot be made due to high groundwater level, heaving soil or large freezing depth;

High speed and extreme simplicity of work when doing it yourself;

Cost-effectiveness - by choosing a foundation on piles, in many cases you can save up to a third of the funds allocated for arranging a support for a house;

Minimum excavation work - for a strip or slab-monolithic analogue, you will have to dig many times more land.

The disadvantages of a pile foundation are as follows:

Difficulty in carrying out calculations during design;

Can only be used for light buildings;

The need for floor insulation and the impossibility of constructing a basement.

In order for such a foundation to last for a long time, it is better to entrust the preparation of its project to professionals. Careful soil research and competent calculations are very important here. It is necessary to foresee in advance how each pile will behave under load in the future. The slightest mistake - the grillage and the walls on it will immediately collapse. As a result, even the corrugated sheeting on the roof will be damaged, not to mention cracked partitions inside the building.

Example on driven piles

The second important point is the weight restrictions of the structure. It’s definitely not worth using heavy ceramic bricks or concrete for a cottage on a pile foundation. Frame or foam concrete technologies are more acceptable here. They allow you to build lightweight walls that will stand on screw or bored supports for a long time and without problems.

And in general, before choosing the type of foundation for your home, you should carefully study what SIP panels, brick, timber, logs, gas and foam blocks are with all their characteristics and pros and cons. The weight of the building materials of the walls greatly influences the choice of the type of foundation.

DIY bored pile foundation

The step-by-step instructions presented below provide for the independent construction of a bored pile foundation with a grillage on top. This is the most popular option among private owners, as it is easy to implement. For the work you only need asbestos cement pipes, concrete mortar and steel or fiberglass reinforcement.

The device is completed in five stages:

Excavation.

Installation of asbestos-cement pipes and laying fittings in them.

Pouring concrete.

Grillage arrangement.

Closing the base.

For the manufacture of bored piles, asbestos-cement pipes with a diameter of 300–400 mm are required. They will serve as a guarantee that the foundation will have good load-bearing capacity both vertically and horizontally. And unlike the steel version, asbestos cement will not rust in the ground.

The easiest way to make holes for supports is to use a hand drill with a gasoline or electric motor. The depth of these holes should ultimately be 30–40 cm below the freezing point of the soil.

Pile pillars are located around the perimeter of the building and under the load-bearing walls inside in increments of up to two meters. After drilling the wells, a sand cushion 10–15 cm thick is poured at their bottom. Then, another 25–30 cm of concrete is poured on top as a support for the piles. And asbestos-cement pipes are installed into this uncured solution. At the same time, they must protrude at least 30 cm above the ground.

To ensure that the pipes remain strictly in an upright position, they are sprinkled with sand, which is compacted during this process. Next, the support pillars are reinforced. For this, 3-4 rods made of steel or fiberglass with a cross-section of 10–12 mm are used.

Reinforcing rods must be placed in the center of the pipe at an equal distance from each other. To simplify installation, they can be tied together on the ground with wire crossbars. In height, these vertical rods should be higher than the upper edge of the pipe, protruding from the latter by 15–20 cm. After reinforcement, all that remains is to fill this permanent formwork with concrete, making sure that no voids form inside the solution.

After just 3-4 days, a grillage made of reinforced concrete (with laying of formwork, reinforcement and pouring of concrete mixture), steel channel or timber can be mounted on the resulting supports. As a result, there should be a gap of 25–30 cm between it and the ground. It is impossible to lay the grillage directly on the ground; when it heaves, it can simply be squeezed up and demolished along with the building.

At the end of the arrangement, it is best to cover the sides with sheathing after the walls have been erected. Corrugated sheeting for the roof or facade or decorative bricks are perfect here. Just first you need to lay out all communications. Fortunately, water supply and sewerage in a house on stilts are carried out between the supports without additional tricks or drilling of concrete.

The use of foundations on piles in construction

The foundation on reinforced concrete piles is perfect for many types of private low-rise buildings. Making it yourself, guided by the step-by-step instructions presented above, should not be difficult. But it’s better to order calculations from specialists. For a garage or bathhouse, a similar basis can be calculated independently. And for a cottage, the foundation design should only be completed by a professional.