The foundation of the house is a monolithic reinforced concrete grillage on piles. Pile foundation with a monolithic grillage: features and application. Foundation on bored piles

The design of a pile foundation can be selected depending on the mass of the entire building and the materials used in construction and types of piles. It can be wooden, metal or concrete. Concrete can be monolithic or consist of concrete beams or panels. The connection between the strip part and the pile head has many design options. Depending on the needs and financial capabilities, a wide variety of pile foundation designs are used. But there are types of soil, for example swampy, on which it is possible to use only piles.

Most often, a foundation with bored supports and a monolithic concrete grillage is used. Other options for pile foundations cause various complications in operation. Wooden beams are relatively short-lived and their load-bearing capacity is significantly limited. Wood is susceptible to fungi and rot. Metal structures are subject to corrosion, and their installation requires the use of lifting equipment. Concrete foundation of blocks requires a lifting crane during installation. With a monolith of a bored pile foundation, the immobility of the connection between the grillage and the pile heads is ensured, which ensures high structural rigidity and the required stability of the entire pile foundation. When erecting a monolithic structure, you can do without lifting mechanisms.

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Design features of a monolithic grillage

Installation of a grillage in a monolithic foundation.

To ensure high strength, the structure of a bored foundation does not allow communication channels to be laid in its body. Reinforcement is performed in at least two tiers. Each tier must contain at least two rods. The grillage experiences a load from above from the weight of the entire building, and on heaving soils In winter, loads from soil movement from below are added. For longitudinal bars of a pile foundation, reinforcement with a variable cross-section with a diameter of up to 12 mm is used. Transverse rods do not carry loads and serve only for the construction of the reinforcement frame. Their diameter can be half that size. The reinforcement frame must be recessed into concrete to prevent contact with the environment and to protect the rods from corrosion.

The technology for constructing bored foundations with a grillage requires attention Special attention connecting the pile reinforcement with long rods in the tape frame. When preparing the head, the pile rods should protrude from the top. To create a good connection, these rods are bent and tied with tying wire to the grillage rods. To fill the monolithic reinforced concrete grillage of the pile foundation, wooden formwork is installed.

Depending on how the foundation body is located relative to the soil level, there are different design features. On swampy and other heaving soils, the body of the foundation is raised above the soil surface to a level of up to 150 mm. Such a high grillage is made in order to prevent the influence of forces from the ground when the soil swells in winter. As a result of soil swelling, the grillage may be torn off from the pile heads or pulled out of the soil. But this arrangement of the grillage has a major drawback. After construction is completed, a void remains between the floor of the house and the ground, which requires additional insulation of the floor below. The design of such a house does not have a basement.

A design in which the lower part of the tape is at the level of the ground surface or buried below this level avoids voids under the floor. But this option requires providing an air gap directly under the grillage. The recess is made to the same 150 mm.

To prevent the resulting space from being filled with collapsing soil, barrier plates made of slate or sheet metal are installed.

A fence is used to cover the space under the foundation. When installing a pick-up, the recess is filled with a material that is not subject to swelling and has looseness. Both recessing and additional fencing require additional costs, so a raised foundation has clear advantages in this regard.

Pile foundations with a monolithic grillage have a fairly large number of positive qualities, unlike other types of foundation. This type of support can provide high quality and the reliability of the support, despite the fact that the costs of its construction will be much less than the costs of other types of foundation. In addition, the peculiarity of the manufacturing technology of pile foundations with a monolithic grillage is that such supports can be used in almost any area, not only on flat surfaces, but also on weak, unreliable soils consisting of sand or water-saturated soil.

When viewed in plane, a pile foundation looks like individual installed piles; it does not look like a solid surface or a concrete strip. It is this technology for constructing a support that allows you to install a foundation anywhere. They are driven into the soil to any depth and additionally secured with a special strapping, which serves as a fixation for the supports. Pile foundations can be presented in various varieties, including those with a monolithic grillage. A similar design is used when the supports are arranged in a row.

Advantages of a pile foundation

Pile foundation with a monolithic slab is often used in construction, as it has a number of advantages:

Ease of arrangement. Compared to other varieties, a pile foundation is less labor-intensive.
Speed of construction. The time required for the construction of pile supports is significantly less than the time required for the construction of the strip base of the building.
The consumption of concrete solution is less than with other types of structural support.
The need for transport work is significantly reduced, by approximately 70-80%.
The risk of structure shrinkage is reduced by approximately half.
A pile grillage foundation can be constructed even in winter period subject to technology.
The cost of foundation construction work is significantly reduced. The final price will be 15% less than the cost of installing another type of support.

Thus, the use of pile foundations today is becoming increasingly popular and in demand. This technology is used both for construction apartment buildings and large structures, as well as for the construction of private houses.

Types of pile supports

The construction of a pile foundation with monolithic inclusions can be carried out in various options:

A base with a hanging grillage, the design of which includes a small hole between the grillage and the soil, up to one hundred millimeters, so that externally the base of the house seems to hang over the soil. This technology is used to protect the monolithic surface from the bad effects of the soil. This type of foundation is used by specialists for the construction of structures from various materials.
With the deepening of the foundation piles into a special monolithic foundation grillage. With this technology, there is no distance between the base and the soil, but there is a base, which is ensured precisely by the grillage. When using conventional pile supports, it will not be possible to build a base. The grillage can be made from a variety of options, including concrete, reinforced concrete, wood and steel. Reinforced concrete is considered the most suitable, durable, reliable and safe option (according to experts).

In order to equip a pile-grillage foundation using a monolithic slab, it is necessary to first perform a number of preparatory works:

Select the piles of the required size, and also cut down the heads of the supports to the required size.
The upper part of the supports is cleaned, rinsed well, and then air dried.
Formwork construction is in progress.
To install removable formwork, it is protected from the mortar, usually using polyethylene.
The monolithic grillage is being poured. Concrete is poured in successive layers over the surface.

Before starting work, you must carefully study all the drawings. Work on arranging the foundation of a house is a rather labor-intensive and costly step in terms of financial resources, so all plans and drawings must be drawn up in advance, taking into account the terrain and soil quality.

How to arrange a pile foundation for a house?

A monolithic pile foundation differs from other types of foundation in the relative simplicity of its construction. To build such a foundation, you need to perform a certain sequence of actions:

The first step is to study the soil in the selected area. This is necessary in order to determine the bearing capacity of the soil, its ability to withstand the weight of the proposed structure. In addition, the nature of the soil also determines the length of the piles, as well as the degree of their penetration into the soil.
Next, after engineering research, basic drawings of the future foundation are drawn up, on which the locations of the supports, their length, driving depth and other parameters are precisely determined. The drawing is a complete section of the future foundation.
After this, according to the markings on the drawings, the soil is drilled at the locations of the pile. If the supports are available in ready-made form, then they can be inserted into the ground by driving them using special construction equipment.
After installing all the supports, it’s time for the formwork. In this case, removable formwork is used, or a wooden structure is made directly on site.
If you plan to install a built-in monolithic grillage, then in this case a special trench is prepared for further pouring of concrete mortar.
After preparing the concrete solution, the grillage and supports are poured.
The poured solution is left for exactly one month until it completely dries and becomes strong enough.

When performing work, you need to constantly monitor that the design that is obtained in reality corresponds to what is indicated in the drawings. For this purpose, specialists usually use building level and a level, which allow you to check the angle and evenness of all structural elements.

You can make a pile foundation for your house with your own hands. For this you may need the following materials:

Reinforced concrete supports of the required sizes, depending on the type of soil and the characteristics of the territory.
Sand or crushed stone for arranging cushions at the bottom of the drilled hole, if necessary.
Special equipment and equipment if it is planned to construct trenches and wells.
Concrete mortar for pouring the base.
Boards and nails for formwork construction.

In general, the process of constructing a pile foundation is not so complicated. If the foundation arrangement is being carried out for a small-sized future private house, then the piles, as a rule, are not too large. Therefore, they can be easily installed without the involvement of additional large equipment. In fact, the construction of a pile foundation turns out to be simpler than the construction of a strip or monolithic foundation.

Types of supports and their characteristics

In order for the foundation of the house to be as reliable and durable as possible, it is necessary to carefully select piles for the foundation. Today there are a large number of types of supports, the length of which can be from three to six meters.

Piles can differ according to the following characterizing points:

The material from which the supports are made.
Method of making a pile.
Type of section.
Method of deepening a pile into the soil.

Depending on the method of introducing piles into the ground, the following types of supports are divided:

Drill supports made of reinforced concrete, which are installed in ready-made drilled holes.
Screw supports including drill bits.
Drive-in supports, which are driven into the ground by driving or driving with a hammer and vibration.
Rammed supports, made primarily of concrete or reinforced concrete, are inserted into finished wells and then poured over the top with concrete mortar.

In addition, piles can be divided into single, row and cluster, depending on the method of placing the supports on the base area. The strength, reliability and durability of the entire structure depend on how well the piles for the foundation were selected.

Construction of buildings for various purposes on stilts significantly reduces the cost of construction. To increase the load-bearing capacity of the pile foundation, a grillage is installed.

It can be built from prefabricated reinforced concrete structures, rolled metal, and concrete.

For private construction, a pile foundation with a monolithic grillage is rightly considered the most suitable: its construction does not require the participation of heavy construction equipment.

Design features of a pile foundation with a monolithic grillage

There are two options for making a monolithic grillage:

slab - grillage that connects all piles into a single system;
tape - a grillage connecting the piles in series.

A slab grillage is installed under the entire area of the building, a strip grillage is installed only under load-bearing walls.

The most common in private construction is a strip monolithic grillage, since particularly heavy buildings are not erected in individual households, and the material consumption of a slab grillage is several times higher than a strip grillage.

In turn, the tape grillage is also divided into several varieties, characterizing its position relative to the ground:

hanging (high) – placed above the surface of the earth. The distance from its sole to the ground is at least 10-15 centimeters. This type of grillage is advisable to use on heaving soils;
ground - a grillage, the base of which lies at the level of the ground on a cushion (sand-gravel or sand). This design is acceptable only on non-heaving or slightly heaving soils. Soils subject to heaving during frosts can tear the grillage away from the piles;
low – recessed grillage. In heaving soils, it is buried to the freezing depth; on more favorable soils, the depth of immersion of the grillage into the soil can be only 200-400 mm.

Of all types of grillages, the most common in individual construction are hanging ones: they are strong enough to serve as a reliable support light buildings. Their installation does not require excavation work.

Most buildings (dachas, bathhouses, etc.) are built using a foundation on bored piles with a monolithic grillage - the cheapest and least labor-intensive option.

Construction technology

The installation of a pile foundation and a monolithic grillage can be divided into several stages:

preparatory work;
installation of piles;
grillage device.

Preparatory work

In the process of preparation, the construction site is leveled and planned (as far as possible - after all, the beauty of pile foundations is that the terrain remains practically unchanged).

Then markings are made: the axes of the foundation and the installation locations of the piles are marked. It is advisable at this stage to have on hand a drawing of a pile foundation with a monolithic grillage, developed by an experienced designer.

The drawing indicates all the necessary dimensions and other information: the number of piles, their spacing, the diameter of the reinforcement and the geometric dimensions of the reinforcement cages.

Installation of piles

Wells are drilled according to the markings using a special machine or a garden drill. For most home buildings, a diameter of 200-250 mm is sufficient.

Further work is performed in the following order:

from waterproofing material(for example, from roofing felt), the pipe is twisted and lowered into the well. The purpose of this operation is to waterproof the walls of the pile. Instead of roofing felt, you can use plastic or asbestos cement pipe. Since in this case the option of installing a hanging grillage is considered, the waterproofing pipe should protrude above ground level. How much depends on the design of the foundation and the terrain. The gap between the ground and the base of the grillage can be different at each specific point - it is important that it is positioned strictly horizontally (or perpendicular to the piles);
a reinforcement cage consisting of 3-4 rods is installed in the pipe. The length of the fittings should be such that its upper end rises 200-250 mm above the end of the pipe;
the waterproofed well is filled with concrete.

The load-bearing capacity of the pile depends on the brand of concrete. For example, concrete grade 100 will withstand loads of up to 100 kg/sq. cm inclusive. That is, a pile with a diameter of 200 mm (sectional area 314 sq. cm) can withstand 31.4 tons.

However, this does not mean that such heavy structures can be erected on such piles - you should inquire about the bearing capacity of the soil on which the foundation rests.

Dry soil located below the freezing depth may have a bearing capacity of only 6 kg/sq. cm.

Installation of a monolithic grillage

The grillage is installed in several stages:

erection of formwork;
reinforcement;
pouring concrete

Formwork installation

Let's consider the most common method of constructing the formwork of a monolithic grillage:

The edges of the future formwork are marked. Along the marking lines, with a pitch of 50-90 cm, bars with a cross section of 50x50 mm are driven into the ground (strictly vertically!). You will get two rows of pegs driven in around the perimeter of the future grillage;
each pair of pegs facing each other must be connected with the same bars (on top);
For each resulting U-shaped structure made of bars, fill a board 3-4 cm wide. Its upper cut should be located at the level of the bottom of the future formwork;
horizontal boards are laid, in which holes for the piles are pre-cut;
the vertical walls of the formwork are installed and nailed to the bars standing vertically;
the assembled formwork is lined with plastic film from the inside.

Grillage reinforcement

The reinforcement cage must be completely recessed into concrete on all sides. Therefore, before proceeding with reinforcement, it is necessary to lay bars of any width, but of the same thickness - from 30 to 50 mm - on the bottom of the formwork (in the transverse direction).

The bottom row of reinforcing bars is laid on the bars and tied together. The connections must ensure the same distance between the rods.

The top row (belt) of the reinforcement cage is suspended from the transverse bars with which we connected the formwork posts. Next, the upper and lower belts are connected to each other.

The result is a frame suspended on wires.

Number of fittings

The required amount of reinforcement can be calculated based on the ratio of the cross-sectional area of the grillage and the sum of the cross-sections of all the rods. It is 1000:1. The calculation procedure is as follows:
- multiply the width of the grillage by its height and divide the result by 1000;
— divide the resulting number by the cross-sectional area of one rod.
As a result of such simple calculations, you will determine the minimum required amount fittings."

It should be taken into account that there should be no more than 150 mm between the rows of reinforcement.

Pouring the grillage

To fill the grillage, concrete grades M300 and M350 are used. When filling the formwork with a concrete mixture, it must be bayoneted in order to expel any air that may be “trapped” in the thickness of the concrete.

This can be done using a reinforcing bar. A more progressive method is to use a special vibrator. Buying it is expensive, and there is no point - it is not very often that a private homeowner deals construction work. But this equipment can be rented.

Here, in fact, is the entire list of work that a home craftsman will have to perform when installing a pile-grillage foundation. After the concrete has hardened, construction of the building can begin.

Video of the construction of a foundation on bored piles with a monolithic grillage.

The strip foundation is the most popular - it is reliable, but expensive and labor-intensive. Today, tape has been replaced as a foundation for a house by its variation - pile foundations with a monolithic grillage, which save time and money for homeowners and have the advantages of both types of foundations.

This type of base differs from a regular strip base by the presence of columns - bored foundation is equipped with a shallow reinforced concrete strip, the name of which is grillage. This band connects the tops of the piles, distributing the load of the entire house evenly on each support. This type of foundation equipment is optimally used if traditional strip foundation will big size or it will be too expensive.

There is the following classification of foundations according to the type of piles used:

driven piles are installed into the ground without removing the soil using heavy equipment (vibratory hammers, etc.); they can be made of wood, steel and reinforced concrete;
cast-in-place and bored reinforced concrete, which are poured into wells after removing soil from them;
screw.

Only bored piles can be built completely independently

The grillage happens:

monolithic;
prefabricated;
prefabricated monolithic.

Monolithic is the only type that can be made entirely with your own hands.

Piles can be placed in different ways:

single piles - arrangement of supports at angles, columns, etc.;
ribbon arrangement– piles are installed sequentially under load-bearing walls;
strip method– supports are mounted in two or more rows under a long and heavy grillage;
cluster placement– several supports are placed at points with the greatest load, under the columns;
field location- in rows or in a checkerboard pattern under large grillages.

DIY pile foundation with grillage

You can build a pile foundation with your own hands, equip a grillage, following the following technology:

carrying out calculations and drawing up drawings;
installation of piles;
filling the grillage.

First of all, the homeowner must find out the characteristics of the soil, its composition and quality, since the size, characteristics and frequency of installation of piles will depend on this. Next, the load of the building on the ground and each support is calculated. The weight (the load that the building will exert on the ground) of the structure includes:

weight of walls, ceilings, roofing material;
periodically occurring load, for example, snow falling in winter;
the weight of other objects - people, furniture, equipment.

Having calculated the total load, it is multiplied by an adjustment factor of 1.3.

The calculation of pile foundations with a grillage is carried out taking into account the number, location and bearing capacity of the supports. The standard location is every 2 meters with a depth of up to 2 meters, but in each individual case these indicators need to be calculated individually. The average height of the grillage is from 25 cm in height and from 40 cm in thickness.

The calculation of the grillage tape for bending is carried out taking into account the faces of the column in section, grillage steps and outer edges. For each section, bending calculations are made taking into account the reaction of the pile and the local load on the grillage.

Foundation construction

The construction of pile foundations requires the presence of:

piles;
reinforcing mesh;
concrete;
sand cushion;
waterproofing material.

If the underground part of the foundation is poured directly into the trench without formwork, then such a foundation is called a slotted foundation

A marking is made on the ground, according to which they first dig a recess for the grillage (if a buried tape is planned), and then a hole for each pile so that the width of the hole is greater than the width of the individual support (for finished piles).

It is convenient to dig wells with an earth drill, which can be bought at a hardware store for an average of $70. Such a drill will allow you to make a well up to 5 m in depth and up to 30 cm in diameter. A larger hole can be made with an automatic drill.

It is advisable to make an expansion at the bottom of the well, which will serve as a platform that increases the support area of each pile and gives it stability. Sand is poured into the bottom of the resulting depression, then a two-layer pipe with a diameter equal to the diameter of the pile is rolled up from roofing felt, tying it with wire. Ruberoid, which serves as waterproofing, is installed in the hole.

Next, you need to equip the frame with reinforcement. For small buildings, a mesh of three rods 0.8 cm in diameter with jumpers is suitable, the rods of which extend several cm into the future space of the grillage. The frame must be mounted so that after pouring it is hidden in the concrete on all sides. Precise instructions on the size and equipment of the foundation for a house are given by “Pile foundations” SNiP 2 02 03 85.

After installing the reinforcement, a concrete solution is poured into the well, and then passed through it with a construction vibrator so that the composition can flow into all the voids and be evenly distributed.

Next, the grillage is reinforced in the same way and filled with concrete mixture.

Secrets of arranging the grillage and foundation

Do not cross the grillage strip with pipes and other communications.
a pile that deviates from the vertical by a distance of more than 5 cm will not be reliable.
All joints remaining after installing the grillage must be additionally filled with concrete.
It is necessary to reinforce the grillage using rods about one and a half centimeters in diameter.
The grillage must be positioned strictly horizontally.

The construction of a pile foundation with a monolithic grillage is shown in stages in the video:

The grillage is the upper part of the foundation on pile supports. It is its design that allows the mass to be distributed from the load-bearing structures of the building. The grillage is a massive frame made of reinforced concrete, which is located under the walls. It is installed on driven or screw piles.

A pile foundation with a grillage is in demand in low-rise construction. The tape, made in monolithic form, is capable of reliably connecting the pile heads. This design is used in areas where it is impractical to install other foundations.

Types of grillage on piles

Loads from a house on unstable soil are transferred through the grillage to the deeper layers. They are dense enough to withstand heavy loads. A pile foundation with a grillage is erected in regions with soil freezing depths of up to half a meter. If a house is being built in an area with difficult terrain, this type of foundation is the only possible one.

Grillages placed on piles are divided into groups taking into account production technology:

Monolithic. They are reinforced tapes. They are built according to the principle of simple strip base. However, sometimes they can be made in the form of a slab. In this case, more money and time are spent on filling. The pile caps are tied with a tape grillage around the perimeter and in the locations of the load-bearing walls. It is important to understand that a pile-strip foundation is erected only in cases where this is permissible according to the calculated strength indicators.
Prefabricated. They are built from reinforced concrete beams. You can create a full-fledged grillage by combining several ready-made elements. Subsequently, they are monolithic.
Prefabricated monolithic- combined designs.

The dimensions of the grillage on a pile foundation are determined in accordance with the design. The width of the tape usually exceeds 40 cm and exceeds the width of the wall by several centimeters. You can understand what a pile foundation grillage is by studying the differences between such structures:

Each of these types of grillage is chosen depending on the characteristics of the site and the future home.

Advantages of pile foundations with grillage

The advantages of a foundation on piles with a grillage include increased structural strength. The house built on it will be durable and stable. Other advantages of such foundations:

Minimum excavation work.
Low consumption of materials. Less concrete will be required than when constructing a traditional strip foundation.
Possibility to work in winter. Piles are installed even at a temperature of -10 degrees.
The soil does not sag during flooding or during frost heaving.
Reduced heat loss - the contact area between the foundation and the ground is small.
Reducing the cost of building a foundation by 20%.
Speeding up work.

A bored foundation with a grillage takes its rightful place among other types of foundations. It is a reliable structure with a large margin of safety. Since the endurance of a monolithic structure is significantly higher, the grillage should be equipped as a single strip. Such a foundation on reinforced concrete piles is reliable, easy to construct and inexpensive.

Sequence of construction of a pile foundation with a grillage

A pile structure with a grillage is created by professional builders in accordance with certain stages. Sequencing:

Clear the area. It is necessary to remove fertile soil to prevent grass from growing under the base.
Create a pile field.
Assemble and install the grillage reinforcement frame. It must have at least two rows of reinforcing bars, fastened with vertical elements every 30-40 cm.
Secure the frame to the stilts, paying special attention to the corners of the base. Here the reinforcing bars should be bent in different directions. The frame contour is completely closed around the entire perimeter.
Build formwork. Concrete for the tape will be poured into it. When installing a hanging grillage, additional support elements are installed between the piles. This applies to both strip and monolithic slab grillages.
At the final stage of constructing a pile foundation, it is necessary to mix concrete and pour it into the formwork.

This sequence is understandable to everyone, but the subtleties of some operations are accessible only to experienced builders.

Creating a pile field

At this stage, you will also have to follow a certain order of actions. First, mark the area for pile field. At the points where the piles will be driven, reinforcement bars are immersed in the ground. A string is pulled between them and the accuracy of the base geometry is checked.

Then do the following:

Unloading the piling rig. Bored piles and a machine for driving them into the ground are brought to the site. The installation is small in size and equipped with a swamp chassis. This allows you to keep the coverage of the area intact.
Transportation of piles around the territory. Reinforced concrete elements unloaded in one place, and a pile driving machine delivers them to the installation point. Often the piles are moved around the site on a trolley.
Preparing for installation. First, the piles are lowered and fixed to the ground, and then the boom is raised. The piles are lifted with a winch.
Driving piles. Piles are placed into the ground using the impact method. One element is immersed to the required depth in a few minutes. Installation control reinforced concrete structures carried out using a level.
Cutting off the ends of piles. The piles are partially trimmed until the reinforcing bars are exposed. The work is performed with a hammer drill.

During operational work, a pile field is created in a few hours.

Construction of a foundation on piles with a grillage

You can build a screw foundation with a grillage yourself. To do this you will need to do the following:

calculation of piles and grillage;
installation of piles;
creating a grillage;
arrangement of the basement.

First you need to decide what the composition, type and quality of the soil is. This will allow you to find out the required depth of the pile foundation grillage. It is especially important to find out about the layer on which the foundation will rest. The data obtained depends on:

pile length;
the size of the gap between the supports;
bearing capacity of each pile.

own weight of walls, roofing and ceilings;
variable loads;
payloads (engineering systems, furniture, household appliances).

The resulting amount should be multiplied by 1.3. This value is a correction factor.

Calculation of piles and grillage

What will be the distance between the piles, their load-bearing capacity and installation depth depends on preliminary calculations. If you correctly determine the number of supports and the method of their location, you can make the foundation strong and durable. A gap of 1-1.5 m is traditionally left between the piles. The immersion depth of the supports is 1.5-2 m.

Particular attention is paid to the calculation of the grillage. It is he who determines the reliability of the foundation. Usually the height of this element does not exceed 25 cm. The width is determined by the width of the base or thickness outer wall. The minimum value is 40 cm.

Separately, you should calculate the tape for bending. It is made along the edges of the support in sections, the outer edges of the armrest. The formula used for this is:

For all sections, the total bending moment is calculated. In this case, the moments from the reactions of the piles and local loads on the overhang of the grillage are taken into account.

The calculation of foundations on piles should be entrusted to an experienced civil engineer. You can't do it yourself. Only after receiving the necessary data can you begin installation.

Self-production of piles

When creating piles with your own hands, earthworks are performed using an earth drill. If it is necessary to drill holes more than 0.3 m in diameter and 5 m in depth, a motorized apparatus is used.

You can make piles yourself in the following sequence:

Build “glasses” from roofing felt, the width of which will be equal to the diameter of the wells. They are made 25 cm longer than the immersion depth of the supports. Several layers are made on top and tightened with wire. The result is formwork. The pipe will be installed in it.
After installing the pipe, a reinforced frame is made. It is placed inside the support. Three rods with a diameter of 8 mm are enough. They are connected to each other by jumpers. Vertical rods should be placed 4 cm above the edge of the grillage.
Concrete is poured into the pipes, compacting it with a vibrator.
Set up a grillage.

When creating a feed, several recommendations are taken into account. For example, the grillage should not cross pipeline lines. The piles are installed strictly vertically. The permissible deviation is 5 cm. Each seam and joint that was formed when creating the grillage is filled with concrete.

The grillage must be reinforced. For this, rods with a diameter of 1.4 cm are used. They must have a length equal to the length of the walls. In the absence of such rolled metal, rods of at least 60 cm are selected. Their number is determined by diameter:

1 cm - 8 rods will be required;
1.2 cm - 6;
1.4 cm - 5.

Before installing walls, make sure that the surface of the grillage is horizontal. Defects are corrected with concrete mortar.

After completing the construction of the foundation on piles with a grillage, the base is finished. The upper edge of the finishing elements is attached to the lower part of the building wall. The top edge is covered with ebb. From below, the finishing does not reach the ground surface by several centimeters. This allows you to avoid deformation of the base during frost heaving.

Important! Drainage should be installed to remove precipitation. They will also equip a blind area 70 cm wide. It is better to lay it paving slabs.

Insulation of a columnar foundation

After the columnar foundation with a grillage has been erected, backfilling should be done. It is a replacement for the base. The fence protects the space between the surface of the earth and the base of the house from snow drifts and drafts.

Wooden fencing is an affordable and easy-to-install option for cladding the plinth. It is made from boards that are placed vertically or horizontally. The work process includes:

a trench 40 cm deep is dug between the supports;
one third of the depth is covered with sand and fine gravel;
wooden blocks with a groove 40-60 mm wide are attached to the base pillars;
the boards are fastened to each other with grooves;
The bottom of the fence is covered with expanded clay.

With the boards in a vertical position, the first beam is laid on the cushion in the trench. The second is fixed at the bottom of the building. Boards are inserted vertically into the grooves made on the bars.

To make a brick or stone fence between the supports, you should also dig a trench into which the pillow will be poured. The thickness of the fence in this case will be 1.5 bricks. Stone walls should not be more than 30 cm.

When the height of the supports is from 0.7 m, the scaffolding is made of heat-insulating boards. They create it in the following sequence:

a structure in the form of a frame, which is made of a steel profile, is fixed to the supports;
thermal insulation - polystyrene foam - is fixed on the inside;
on the street side, corrugated sheeting is fixed with self-tapping screws;
the resulting gap between the corrugated sheet elements and the ground level is sealed with thermal insulation material.

With any option for creating a fence, you should remember about the ventilation windows through which the space under the house will be ventilated. The diameter of such holes ranges from 100 to 150 mm. In winter, the vents are covered with rags.

Monolithic slab with grillage

Pile foundations with a monolithic grillage are columnar structures with a reinforced upper part. The pile heads are united by a single element. There are several types of such bases, which can be divided according to different criteria. This classification depends on the method of creation, material of manufacture and method of installation.

The main task of creating a grillage is the optimal distribution of loads on the base. Since the piles are installed at a certain distance from each other, in order to fix their heads at the same level, a connecting structure is created. Thanks to this, the load on the supports is distributed.

Thanks to the grillage structure, the foundation can be well insulated. This allows you to extend the life of the entire structure. The possibility of pile movement is excluded.

Monolithic slab refers to traditional foundations. It is made in two types - shallow or shallow. When choosing the latter option, it is immersed in the ground to a depth of 45 cm. Reinforcement of the pile foundation grillage over the entire area is mandatory. Thanks to this, the monolithic foundation is able to withstand significant loads during soil movements. This is relevant for areas with problem soils.

Materials used

Grillages are divided into light and heavy. Depending on this criterion, source materials are selected. If you need to build a small house, the grillage is made of wood. When a massive building is being erected, the use of a reinforced concrete grillage is justified.

Sometimes the best solution is to use solid metal products. However, this rarely happens as it requires regular treatment. In addition, it is difficult to install.

The technology used to create wooden grillages on columnar foundation, involves protecting the material from water and various pests. Metal structure rusts over time. For this reason, its installation is justified in a small number of cases.

More often, the foundation on piles with a grillage is built from concrete. It is made directly at the site where the house is built. This type of work is more labor-intensive, but it saves money in the long run.

Height classification

The grillage, together with the piles that are located under it, can be located in different ways. Taking into account the position relative to the ground level, a monolithic grillage can be of the following types:

High. In this case, the top of the slab is high above the ground.
Elevated - the slab is slightly buried in the soil.
Recessed - a monolithic base is completely immersed in the ground.

Each of these types has its pros and cons. However, the most common is the high base. This is the easiest one to install. Foundations on bored piles with a monolithic grillage do not experience soil pressure.

Highly located slabs also have their disadvantages. Among them is the need to thermally insulate the first floor. When installing such structures, it will not be possible to create a basement. If this utility room is necessary, it is created in conditions of a ruined or elevated base.

The piles under the grillage must also have a certain location. This depends on the expected pressure on the slab. They can be placed as a continuous “forest”, or installed in stripes.

Advantages of a grillage made from a monolithic slab

Before constructing a foundation with a slab grillage, it is important to become familiar with certain intricacies of the work. For example, a certain type of grillage is chosen taking into account the type of soil. You should find out how friable or hard it is, and determine the degree of its saturation with moisture.

Among the positive aspects of installing a foundation with a grillage made of a monolithic slab are:

Wide range of applications. Such foundations are erected on any soil, even unstable ones.
High reliability.
Long service life. If you use high-quality materials, the operation guarantee of this design is 70 years.
There is no need to take into account the terrain of the site.

A foundation with a grillage made of a monolithic slab can be constructed using simple technology. This allows you to make a reliable foundation for your home with your own hands.

Features of foundation construction with a monolithic grillage

If we compare the installation of a monolithic grillage with the installation of piles, the first process turns out to be more complicated. Such work will require a lot of effort from builders. This is explained by the need to create formwork. And install a reinforcing frame over the entire base area.

When arranging a grillage, there are several secrets that can simplify the task. For example, today horizontal formwork is often replaced with foam boards. This material fills the 10-centimeter space between the lower surface of the ceiling and the ground.

If you need to make a reliable frame equipped with an underground level, you should choose a monolithic base or a recessed strip foundation. In other cases, it is worth paying attention to pile supports. They are easy to install, and the cost of such work is low. Piles are ideal for low-rise buildings.