For unstable soils, it is better not to use classic foundations in the form of a strip of reinforced concrete. In order for a house to stand on such a support stably, the technology will have to deepen it too much. And this means an increase in the volume of excavation work and spending on concrete. It would be much more rational to create a combined pile-strip foundation with your own hands, which incorporates the best aspects of both piles and strip construction.
What is a strip foundation on piles?
In terms of structure, a pile-strip foundation is a structure made of piles dug into the ground to a depth below the freezing point, and a reinforced concrete grillage on them. It combines the advantages of two types of foundation structures. The grillage tape serves to evenly redistribute loads. And the buried pile foundation plays the role of anchors, which prevent the reinforced concrete from above from “floating away” during soil heaving and a strong rise in groundwater.
Scheme: 1-reinforced frame, 2-asbestos-cement piles, 3-concrete strip, 4-technical terminals, 5-waterproofing, 6-ventilation holes
A conventional pile-screw foundation is somewhat inferior to the type of supports for houses under consideration in terms of distribution of vertical loads. A reinforced concrete tape laid on piles is more resistant to spot raising or lowering of one of the support pillars. On the other hand, this design outperforms its purely strip counterpart in terms of construction costs, as well as stability on heaving and waterlogged soils.
Types and subtypes of foundation
A strip foundation on piles is ideal in the presence of soils with weak heaving. In such areas it can be used for the construction of two-story brick cottages. But in general, such a design is more intended for light frame or timber buildings.
However, if the site for the house has a slope, then it will be difficult to do without a pile strip foundation. It will be too expensive to pour a monolithic slab here, and other options will not be able to withstand all the loads that arise in the future.
Based on the depth of immersion of the grillage into the soil, pile foundations with it are divided into two types:
Shallow.
Not buried.
Non-recessed option
In the first case, the tape is immersed in the soil by 20–50 cm, and in the second, it hangs above the ground. Due to its greater strength, heavier buildings can be erected on a foundation with a shallow grillage. However, if the soil is heavily heaving, then the strip part of the structure on piles will simply be destroyed by heaving. It is not made too high, so it is simply not able to withstand strong loads from rising soil.
Advantages and disadvantages
Among the advantages of a pile-strip foundation are:
Sufficiently high installation speed;
Possibility to erect buildings on construction sites with a slope;
A simple technology that makes it easy to build such a foundation with your own hands;
High resistance to movement of heaving soils;
No need to use special equipment.
If the grillage is not buried, then it is not afraid of heaving and moisture in the soil. In terms of service life, this option outperforms its buried counterpart on piles and its shallow-depth strip foundation. It also beats them in terms of cost and the complexity of the work. You will have to dig several times less, the depth of immersion is the same, but you only need to remove the soil under the support pillars. Plus, all construction materials can be delivered to the site without the use of heavy cargo and lifting equipment.
When independently constructing pile-grillage foundations, bored supports made of asbestos pipes are usually used, which are reinforced and filled with concrete inside. It is this option that is discussed in the step-by-step instructions below. In terms of speed of construction, only a foundation made of FBS or screw piles made of steel can compete with such a foundation for a house.
There are only three disadvantages:
The need for additional floor insulation in the cottage;
Inability to use for arranging a basement or basement;
Building weight restrictions.
All types of pile foundations have one common problem - drafts in the underground. In the far north, piles help avoid heating the permafrost layer. At the same time, in other regions, wind freely flowing under a building is a serious problem.
Step-by-step instructions for building a foundation
When preparing to make a pile-strip foundation, you must either plan in advance for high heating costs, or immediately include insulation of the basement-foundation part of the building in the estimate and project. In the second case, you will need moisture-resistant insulation for the walls and cladding, but the home will definitely be warm.
It will be necessary to construct a false wall around the perimeter of the cottage to cover the pile pillars and prevent drafts between them. To do this, you can take facade panels for exterior finishing or corrugated sheets. If you want something more beautiful and elegant, then there are clinker tiles and decorative bricks. There are many finishing materials for the exterior of a building.
The entire process of constructing a belt on piles can be divided into two stages. First, the pile part is made from bored pipes. And then a strip structure is laid on them. You just need to remember to tie them together with reinforcement before pouring the concrete.
In general, the step-by-step instructions for a strip foundation on concrete piles are divided into five steps:
Preparatory and drawing work
Excavation of earth, installation of asbestos cement pipes and their reinforcement.
Pouring permanent asbestos-cement formwork with concrete.
Creation of strip formwork from boards and bars.
Reinforcing the tape on piles and filling it with concrete mortar.
Waterproofing reinforced concrete.
We draw on paper or in the program the future foundation - tape and piles
Marking wells with “stakes” for the piles of the future foundation
Piles must be immersed to a depth below the freezing level of the soil at the construction site. Holes for them will have to be dug 40–50 cm below this mark. The foundation must rest on a stable soil foundation.
After preparing wells with dimensions 10–15 cm wider than the outer diameter of asbestos-cement pipes, a sand cushion is poured at their bottom 30 cm thick. The pipe formwork is installed precisely on this compacted sand. The diameter of the pipes themselves is selected at the rate of 1/3 of the width of the reinforced concrete grillage.
Next, each pile is reinforced with three or four vertical steel rods with a cross-section of 10–12 mm and a length equal to the sum of the heights of the support and the tape on it. They are placed in the pipe at approximately equal distances from each other and from the asbestos-cement walls. To simplify, they can be tied with wire into the desired structure on the ground before installation.
The next stage is pouring the pipes with concrete solution. This is usually done before reinforcing the foundation strip on the piles. But the instructions given may be slightly modified. Then, first, the reinforcement is laid in the grillage and formwork is made for it, and then the whole thing is poured with concrete. The cells of the reinforcing belt are knitted with a size of 30–40 cm, depending on the width and height of the tape.
We fill the piles to the level of the tape reinforcement. The photo shows a situation where the pile was “overfilled” and had to be drilled out to install the strip frame
We dig up the “tape”, add sand, lay down roofing material and knit tape reinforcement
To perform waterproofing, it is enough to take ordinary roofing material and wrap it around the grillage. This is the cheapest option. You can also use bitumen or polymer mastic. On this, the foundation of the house in the form of a strip on stilts is made. In the future, it will only need to be covered with cladding and, if necessary, insulated.
Done - you can lay out the walls
Where to use?
When comparing the pros and cons of using a pile-strip foundation, first of all you need to focus on the material of the cottage walls and the characteristics of the soil. If a dwelling is being built from lightweight building materials and on water-logged soils, then the support discussed above with a grillage raised above the ground is an ideal option. Such a foundation will last for many years and will definitely not be damaged by heaving, and it is not difficult to make. Fortunately, the step-by-step instructions provided allow you to avoid unnecessary mistakes.
Building a house is an exciting activity that can captivate the builder’s attention for a long time. One of the most important tasks that he has to solve is the construction of foundations. The quality of the entire building will depend on the correct execution of these works. There are several types of foundations, one of which is pile-strip.
What can be distinguished in its design is that it consists of both columns and a concrete strip. This type of foundation is excellent for heaving and weak soils. In them, pile pillars are built so deep as to cover the entire freezing layer of the soil. If you are constructing in an area with difficult terrain, then this type will suit you best. Choose it as an alternative to shallow for buildings constructed using bricks and blocks. Also, pay attention to it if you are going to build on soils rich in water. Now we will analyze its device and step-by-step instructions.
Advantages and disadvantages of a pile-strip foundation
There are several points that can be called attractive in this type of foundation. They are the ones who force you to make a choice in his favor.
- They have a relatively low cost;
- You don't have to spend too much time building them. All work can be done independently, without the use of complex equipment;
- They are suitable for installation on more terrains than other types;
- They guarantee that the building will be able to withstand heaving and soil movement associated with seasonal changes, and is excellent for the climate of our country.
The disadvantages of this design should also be identified, which include:
- With it, the possibility of building a basement is completely excluded;
- The volume of excavation work that will have to be performed is much greater than when constructing other foundations;
- Usually a sand cushion is placed under the concrete layer, but since it is exposed to unstable soil, it can warp in a relatively short time, which will lead to deformation of the building.
Design and scope of application of pile-strip foundations
Construction of a pile-strip foundation The design of such a foundation differs from the design of a strip foundation, which is simply poured with concrete. It is a combination of piles and a frame made like a regular strip frame.
However, there are varieties of it. They are determined mainly by the type of piles that will be used in its implementation. The choice of one type of pile or another determines the advantages or disadvantages of the foundation. In Soviet times, piles were often made of concrete. This was explained by the fact that concrete at that time was cheap and could be used in almost unlimited quantities. Nowadays, prices for it have risen greatly. They have reached the level of European prices, while the quality has not changed much for the better.
Meanwhile, the construction of concrete columns greatly increases the labor costs for earthworks.
Screw piles increase foundation strength After concrete piles began to be replaced with screw piles, the strength of the foundation increased with a significant reduction in costs. They are screwed in to a depth of one and a half meters. This eliminates the possibility of soil displacement due to frost heaving of the soil. In addition, channel cutting is carried out, resulting in the formation of a monolithic frame. This is a guarantee that the pile will not move. Screw piles are screwed in the same way as screws are screwed in.
To create increased strength and reliability, driven piles are installed. These are products made of reinforced concrete. They usually have the shape of rectangular rods, with one end pointed. Their reliability is several times higher than that of other types of piles.
Driven piles provide increased strength and reliability In some cases, they are made of wood, the strength of which is tested using the Brinell method. Despite the fact that driven piles have the same dimensions as screw piles, their strength is much higher.
Another type of pile-strip foundation has bored piles. These are pillars that are driven deeper than the ground freezes. This creates additional protection against shearing. They are successfully used in the construction of buildings made of brick, stone, wood, and frame. They are made during the construction of fences and baths. They are also suitable for a wide range of soils. It can be loamy soil, clay, medium, fine and dusty sands. It is possible to install them on peat soils. In this case, it is necessary that they take root in the peat-bearing soil.
Execution technology
Construction technology of pile-strip foundation To build a pile-strip foundation, the soil is first prepared. The top layer of soil is removed, after which markings are carried out. Pegs are driven in in those places where the corners of the foundation should be. Threads are pulled onto these pegs with an indentation of fifty centimeters. After this, it is necessary to mark the places where the piles will be located. To create optimal strength, they should be located at a distance of 120–150 centimeters from each other.
Marking should begin from the corners of the foundation. These marking rules are the same for all types of foundations.
If you plan to build concrete piles, then in the places where they are marked you must drill holes to a depth of 180 cm. They should have the shape of a bell with an expansion at the bottom. In this case, their diameter should be about thirty centimeters.
Ruberoid glasses are installed in the drilled holes. They should rise approximately ten centimeters above ground level. It is necessary to install reinforcing bars in these glasses, which are bent at the bottom like a hook. After this, they must be filled with concrete and compacted.
The piles will be ready after one week. Their heads will need to be covered with waterproofing. Bitumen is used as waterproofing. If you are installing other types of piles, then you must use other technologies. Special machines are used for driven and screw piles, so it will be impossible to build them yourself.
The next stage in the construction of a pile-strip foundation with concrete piles will be laying the grillage. At the beginning of installation, fill the gaps between the piles with sand and compact it. On top of this sand you must lay roofing felt and install formwork, which should rise fifty centimeters. This height must be carefully leveled using a level. Carefully reinforce the structure so that it is not destroyed during pouring.
Installation of formwork The finished foundation should exceed the width of the wall by a distance of ten centimeters.
In order to make the foundation more durable, a pre-prepared metal frame is installed inside it. It is made from rods that are tied together. In this way, the tape can be made lighter and at the same time stronger. This frame should consist of reinforcement arranged in three tiers.
At the next stage, the grillage is poured. It is carefully compacted and leveled horizontally. After this, it must be left to dry for two weeks. Then you can remove the formwork. The grillage will be ready for use after you have cleared it of debris and covered it with a waterproofing layer. This layer is made of bitumen and roofing felt.
Video
Watch a video about the nuances of constructing a pile-grillage foundation
Pile strip foundation is the most proven and popular among all types of foundations. Initially, specialists used hand-made logs for such construction purposes. This required a lot of physical effort and did not always work out perfectly. Today, not only materials have changed, but also construction techniques. In our article we will take a closer look at this type of foundation and learn everything about the process of pouring it with concrete.
Definition of this type of foundation
A strip foundation on piles is a stable and reliable composition that involves installing strips on a pile foundation, which creates a single monolith. Usually installed during the construction of massive low-rise buildings.
The connection of a pile and strip device is a pile-strip foundation. It is considered one of the best options for construction in areas with difficult soil. This design is based on a base on a sand cushion, into which piles of different cross-sections and shapes are installed. The tapes are responsible for distributing the load between them. This scheme saves the building from the destructive effects of soil instability. This system has a reinforced concrete element that can be installed at different depths.
Attention! Do not forget that this construction on heaving soils requires installing the tape above the zero mark.
Features and Distinctive Features
A strip foundation with piles is a rational solution for weak soil on the site. It will be ideal for areas near rivers and lakes. The number of floors should not be more than two so that the pressure is optimal for the structure. The feature that distinguishes this foundation is the inappropriateness of excavation work. This fact is influenced by design features.
Scope of application and design features
These structures are installed in rather difficult engineering and geological conditions. Such a foundation can cope even with soils saturated with water resources. This foundation structure helps save money on research and development of land cover. They are used not only in civil engineering, but also in the construction of industrial facilities.
The variety of structural parts depends on the following indicators:
- Type of pile;
- Pile driving method;
- Grillage design;
- Location of the pile element.
Structurally, the device has two main components:
- Tape that is mounted around the entire perimeter;
- Piles, which are responsible for the strength of the building.
A pile looks like a rod of sufficient length that is mounted into the soil. There are the following types according to the method of immersion:
- With the help of technology - these are parts pointed at one end that are manufactured at the factory;
- Types made independently can be made from various materials and have all kinds of shapes.
Another important detail of the foundation is the grillage. This is a construction design that works in a connecting system and is designed to redirect pressure to the pile area.
There are grillages:
- Monolithic;
- Prefabricated;
- Monolithic prefabricated.
Attention! For the construction of a private house, the ideal option would be a monolithic or prefabricated grillage made of reinforced concrete material.
Pile strip foundation can be mounted on the following soils:
- Loamy;
- Loess-like;
- Sandy-clayey;
- Moss;
- Vegetable.
This type of foundation is used when performing the following architectural tasks:
- Construction of a low-rise building;
- Construction of cottage buildings;
- Objects that include a basement or ground floor.
Construction materials
To make a pile strip foundation with your own hands, we will need the following materials:
- Construction shovel;
- Sand or gravel;
- Polyethylene film;
- Drilling system;
- Pipes made of metal or asbestos cement;
- Reinforcement frame;
- Bars;
- Nails;
- Various screws and dowels;
- Primer solution;
- Waterproofing materials;
- Antiseptic;
- Insulation materials.
Making the right foundation
A large number of video materials and literature, which describe step-by-step instructions, describe the initial stage of work from the marks. But, this is not true. We must begin construction work by drawing up a sketch of the building, and only then begin installing markings for the piles. Also, the following parameters should be taken into account:
- Selection of materials for the construction of the facility;
- Calculation of the maximum weight point;
- Maximum soil load level. This must be done taking into account seasonal ground movements.
- Definition with grillage. For example, for buildings of massive dimensions, a strip type is chosen.
- Selection of diameter and type of piles. But here the instructions are also very often mistaken, as they advise doing the calculation using a ready-made formula. But remember that for each site it will have its own distinctive features.
We calculate the foundation
It is very difficult to make the correct calculation using step-by-step instructions that you take from specialized literature or an amateur video lesson. This is a difficult process and it is better to entrust it to professionals. By eliminating possible errors, you can save not only money, but also extend the life cycle of the building.
In order to make a rational calculation, you need to have the following information:
- Geological results of the study, which include data on soil structure, groundwater levels and ground freezing, and features of the relief map;
- Estimate and project;
- Estimated data on the load on the foundation;
- Dimensions of the planned area for construction work;
- Crisis plan for possible land deformations;
- Data on the dimensions of the tape base.
Attention! In addition to all of the above, you need to decide on the characteristics of the piles, the type of reinforcement and waterproofing.
Stages of construction work
- We apply markings and prepare trenches, which should be no more than half a meter thick. The perimeter of the foundation is marked according to the project standards.
- We determine the location for the piles and carry out drilling.
- Next we carry out waterproofing. This is one of the most important processes for the strength of a building.
- Create a 30 cm sand cushion;
- We reinforce piles with metal rods;
- We fill all holes for piles with concrete solutions;
- We make formwork for the strips and also fill it with concrete.
Attention! If you cannot fill it yourself, then it is better to hire specialists for this.
All about pouring the foundation
There are some rules for obtaining the highest results from these works. Their step-by-step implementation is encouraged:
- It is necessary to use cement of at least grade M 200;
- It is preferable to make a solution of medium density;
- Filling is performed with the shortest time interval for all wells;
- After its completion, reinforcement can be performed;
- It is better to first fill the load-bearing elements and leave them to dry for two days;
- After this, you can fill the grillage, also at the same time.
- After concreting, the grillage must be left to dry for three days.
Attention! After completing the process of pouring all components, check the horizontal and vertical alignment of the building.
Nuances when performing work
When performing this work, the following nuances may appear, without which it will be impossible to fill:
- First, we fill the piles, and only then can we proceed to the area of the foundation made of strips;
- The fittings must be completely filled;
- The thickness of the solution should be of medium consistency;
- It is prohibited to fill the foundation in wet weather, because the foundation will lose a percentage of its strength.
So, when creating this type of foundation, the choice of technology plays a major role. We do not recommend using the type of piles with filler; this can be allowed in a base made of tapes. Remember that only compliance with all construction standards and the correct composition of the mortar can build a strong and stable structure.
Comments:
Today, laying a pile strip foundation with your own hands is not difficult. Of all the existing types, this foundation is the most popular, due to its low cost, the possibility of laying in areas with uneven ground, the speed of construction, the absence of the need to use special equipment, as well as a high degree of stability during seasonal movements and soil heaving. But there is one drawback to using it - the inability to build a basement.
A pile-strip foundation should be laid when the soil on the site is constantly changing its location.
This type of foundation is best used when building block or brick houses.
Funds required for the construction of a pile-strip foundation
In the process of laying a pile strip foundation, the following tools will be needed:
- winch or truck crane;
- pipes made of steel and asbestos cement, the minimum diameter of which is 30 cm;
- 10-12 mm metal rods;
- sand;
- crushed stone
- concrete solution;
- sheet or strip roofing felt;
- bitumen waterproofing;
- concrete mixing apparatus;
- vibrating lathe for concrete;
- welding machine;
- shovel;
- chisel;
- boards and wooden panels for formwork construction;
- construction nails;
- hammer;
- construction mixer;
- wire;
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Marking the location of the foundation
A pile strip foundation is a solid reinforced concrete structure formed by a so-called reinforced concrete belt and concrete piles located underground. This support prevents subsidence and movement of the foundation. Before you start building a pile strip foundation with your own hands, you need to mark the place where it will be located.
At the initial stage of marking, it is necessary to decide on the width of the tape used. To build a house, it is recommended to use a tape at least 40 cm wide and 60 cm deep or more.
Then, using fishing line or twine, the place for the future ditch is marked. After this, the installation location of the piles is determined. It is recommended to install the piles at a distance of about 2 m from each other.
The installation of the first piles takes place in the corners of the branches in the tape, as well as in their center, the rest - along the perimeter. For a more uniform distribution of elements, the distance between the corner piles is divided equally. The resulting value will become a guideline for installing the next pile.
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Calculations when working with pile-strip foundations
When laying a pile strip foundation, it is necessary to take into account the instability of the soil at the construction site. Therefore, it is best to use ready-mixed concrete grade M300. To lay the foundation in areas with a higher degree of soil moisture, it would be advisable to use M350 grade cement.
To determine the required amount of concrete, it is necessary to multiply the width and depth of the tape by its length. To determine the required amount of concrete for pouring piles, it is necessary to first measure their height and radius. Then the resulting sizes must be multiplied by each other. This is followed by multiplying the obtained value by the estimated number of piles.
Thus, it is possible to determine the amount of concrete required for a pile-laid strip foundation structure after calculating the dimensions of the strip itself with the total volume of concrete required for individual elements.
As a rule, piles with a 20 cm diameter and a meter length are used in laying the foundation. Typically, one such pile is covered with 0.125 m³ of concrete. This indicator is used as a starting point when calculating the pouring of piles with a different length.
After determining the required amount of concrete, special frames will be required, for the manufacture of which class A3 reinforcement or metal is used.
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The process of constructing a pile strip foundation
After the work on marking the site has been completed and all calculations have been made on the amount of concrete required to lay the foundation, you can begin to begin excavation work, during which, after removing the soil, a monolithic strip is poured.
To do this, dig a ditch 30 cm wide and 60 cm deep. It should pass 10 cm below the place where the tape was laid. After the ditch is completely dug in, its bottom is compacted and covered with a 30 cm layer of sand. Then the bottom is compacted again.
The next stage involves drilling holes for installing piles. Holes for piles are drilled along the entire perimeter and in the corners of the future foundation at a distance of at least 2 m from each other. With a hand drill used for this purpose, holes 1.5 m deep can be easily drilled. As a rule, the width of each hole for piles is no more than a third of the width of the foundation strip. In the case of drilling deeper holes, the use of special equipment and technology will be required for this purpose. Most often, a tractor with a drilling mechanism is used for this.
The use of rectangular piles will require additional financial costs, since their installation requires special equipment.
A 10 cm layer of sand or gravel is poured into the bottom of a drilled hole of the required depth, from which a kind of cushion is created. If there is a threat of collapse of the walls of the hole due to moving soil, hollow asbestos-cement pipes are placed in it, the diameter of which must be the same as the diameter of the hole itself.
After preparing all the holes for the piles, they proceed to strengthening the future foundation. This stage is one of the most important in the process of laying it. To do this, frames made of 12 mm reinforcement are installed in the drilled holes. They are installed in such a way that the vertical frame coincides with the upper level of the strip of the future foundation.
After this, using frames that are laid horizontally, the thickness of the tape is strengthened. A special feature of this stage is the connection of the tape frame and the pile frame. To do this, the wire is burned, with the help of which the frames are tied together. Thanks to this connection, the resistance of the pile strip foundation to such natural phenomena as an earthquake or landslide increases.
Upon completion of strengthening the foundation, it is necessary to install formwork of the required height. As a rule, it is assembled and secured with nails. The formwork is strengthened at the edges using bars. The formwork is strengthened using special ties. The formwork is installed on both sides of the strip frame. Metal rods are placed in its middle, the diameter of which, depending on the weight of the building, varies from 80 to 160 mm. To strengthen the building, pile reinforcement must be connected to the foundation strip.
Pile-strip foundation is a type for heaving and weak soils. Its peculiarity is that the walls of the building rest on a solid perimeter, and strong adhesion to hard layers of soil is ensured by piles buried below the freezing depth. This design allows, on the one hand, to reduce construction costs, and on the other, to ensure the strength and high load characteristics of the building.
Advantages of a pile-strip foundation
- Low price;
- It is carried out quickly, you can make a pile-strip foundation with your own hands without the use of special equipment;
- Can be installed in areas with any terrain;
- Excellent resistance to heaving and seasonal soil movements.
Among the disadvantages, one can note the impossibility of constructing a full-fledged basement.
Design and scope of application of pile-strip foundations
A pile-strip foundation transfers the building's load to the ground using two structural parts: a foundation strip installed around the perimeter of the building and under load-bearing partitions, and piles that ensure the strength of the foundation during seasonal ground movements. The piles and foundation strip are reinforced with reinforcement. Piles can be made either using the bored method or using asbestos-cement pipes filled with concrete. Recently, metal screw piles with drill blades at the lower end have become very popular. The foundation strip is made by pouring concrete.
Pile-strip foundations are used for private low-rise construction of houses, cottages, and other buildings with a semi-basement. They can be installed on soils prone to heaving, as well as in areas with large elevation differences. Such a foundation is much cheaper and is completed faster than a buried one.
Execution technology
- Site preparation comes down to clearing debris, leveling and marking. A shallow trench is dug under the foundation strip, up to half a meter. The bottom of the trench is covered with sand or gravel, which ensures water drainage from the foundation and reduces heaving of adjacent soil layers. In the corners, at the intersections of load-bearing structures, as well as along the perimeter of the walls, holes for piles are drilled with a drill approximately 2 meters apart. The depth of the wells is 0.3-0.5 m greater than the depth of soil freezing. The diameter of the wells is chosen so that the piles fit freely into the well.
- River sand is poured into the wells, forming a cushion 15-20 cm thick. The sand is spilled with water and compacted. Afterwards, asbestos-cement or metal pipes are installed, filled with 30-40 cm of concrete and raised by 20 cm. Concrete, flowing into the space under the pile, forms an expansion, the so-called sole. It provides stronger adhesion of piles to hard layers of soil. Until the concrete has set, level the vertical position of the supports. After the concrete hardens, a reinforcement cage made of several metal rods connected with wire and forming a lattice is inserted into the pipe. The height of the reinforcement should be such that it extends out of the pipe and reaches almost to the top of the foundation strip.
- Wooden formwork of the required height is placed above the ground surface. The formwork is assembled using nails or self-tapping screws, and reinforced with bars in the corners. All protruding structures are located on the outside of the formwork. The walls are reinforced with struts and ties. Reinforcement is placed inside the formwork: a rod with a diameter of 8-16 cm, depending on the design load, is laid in all three directions, forming a three-dimensional mesh. At the intersection points, the rods are tied with wire using a hook for tying reinforcement. Be sure to connect the reinforcement of the piles and the foundation strips - this connection ensures the strength of the structure.
- First the piles are poured with concrete, and then the entire foundation strip. Be sure to remove remaining air from the structure using a deep vibrator or a regular reinforcing bar, piercing the thickness of the solution in several places on each section of the foundation. The foundation mirror is leveled, smoothed with a rule and isolated from precipitation with covering material or plastic film. During the process of drying the foundation, its moisture content is checked and it is not allowed to dry out; to do this, in too hot weather it must be slightly moistened.
- After the concrete has hardened and gained the necessary strength, you can begin waterproofing and. Concrete is a hygroscopic and thermally conductive material. Wet concrete cracks when it freezes, leading to the destruction of the foundation. Therefore, it is recommended to waterproof it immediately after constructing the foundation. Typically, bitumen or polymer mastics or roll materials are used for this purpose: roofing felt or self-adhesive membrane films. Before waterproofing, the concrete surface must be primed with a special solution, as well as an antiseptic. After the primer has dried, the walls are covered with waterproofing.
- Insulating the foundation of a house is an important step towards creating a warm and stable microclimate. The use of modern materials and techniques will allow you to raise the temperature in the semi-basement space to positive values, even in the midst of frost. The most popular methods of thermal insulation are insulation using polystyrene or polyurethane foam. Polystyrene is a new modification of the well-known foam plastic, resistant to mechanical stress and providing good thermal insulation. The slabs are glued with special glue, and after it dries, they are additionally secured with dowels.
- Polyurethane foam is a sprayed coating similar in principle to polyurethane foam, but its thermal insulation characteristics are much higher. To apply it you need a special installation.
- A pile-strip foundation is an excellent solution for constructing an inexpensive and reliable foundation for a house; if constructed correctly, its service life is more than a hundred years.
