The construction of any building begins with the construction of its main part - the foundation. It is the basis of the entire house, which takes on the load from the structure, and must also resist the influences with the utmost quality environment.
Columnar- strip foundation It is customary to build in areas with sandy and heaving soil, freezing soil and on slopes.
In private construction, several types and technologies for constructing foundation structures are used, but it is worth talking in more detail about such an option as a columnar strip foundation. First we need to consider the positive and negative characteristics known designs, which will allow you to make the right choice.
Columnar foundation structure
Scheme of the installation of a columnar-strip foundation: 1 – side piles; 2 – reinforcement frame; 3 – grillage – part of the foundation; 4 – internal piles.
A columnar foundation is a lightweight strip analogue structure, where foundation pillars act as the main supports, and a reinforced concrete grillage is used as support for load-bearing walls. Determining the exact dimensions and indicators of this type of foundation depends on the developer’s existing design for the future home, as well as the result of survey work that determines the condition of the construction site. So, what do you need to know to start making a plan? construction work?
First of all, it is necessary to draw up a work plan, for which it will be necessary to test the soil for density indicators and level of occurrence groundwater. In addition, it is necessary to know the level of soil freezing in winter time years, which can cause uneven shrinkage of the house. In other words, survey work is the first stage of the beginning. You can carry out such work yourself or contact a special service that will quickly carry out all the necessary checks and surveys.
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Preparing the area and marking
The first step in the construction of a columnar foundation is preparing the construction site for work. To do this, the site itself must be cleared of foreign objects and debris that will interfere with the excavation and subsequent construction work that allows the construction of the columnar-strip load-bearing element of the building. The site chosen for building a house must be cleared of any layer of vegetation that will interfere with the work. This is done very simply - a layer of vegetation is cut off along with a small layer of soil.
The prepared construction site can be called ready for precise construction marking, which consists of several separate stages. First of all, the outer walls of the future house are marked, for which beacons and a cord stretched between them are used. Marking the inside of the walls will allow you to determine the location of the columnar foundation, for which there are separate instructions. A different number of foundation support pillars can be used, which completely depends on total weight and the load of the house, the length of the load-bearing walls and the condition of the soil layer.
The main supporting elements of a columnar foundation should be located at each corner of the house and at the intersection of load-bearing walls.
In addition, there should be no more than 3 m between the foundation pillars, which in the case of rather long walls indicates an increased number of supporting elements. The cross-section of the columnar foundation should exceed the thickness of the walls by 20-30 cm, which is simply necessary for the correct and high-quality production of the grillage. After completing the calculations and markings, you can begin full-fledged excavation work.
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Excavation and erection of formwork for a columnar foundation
Excavation work can be called one of the most labor-intensive, if special equipment is not used. This stage of work consists of preparing holes for the columnar elements of the foundation. To do this, a hole of the required size is pulled out or drilled in the marked places, into which the formwork of the support column will be subsequently installed. The depth of each hole must exceed the level of soil freezing in winter, which will allow the structure to successfully resist soil pressure.
After this, you can begin making formwork, which will allow you to produce high-quality. To make formwork, you can use various building materials, each of which has its own properties. The support type pillar can be rectangular or round, which has absolutely no effect on the strength characteristics. To make rectangular formwork, you can use a simple board, which must be coated before use. oil paint or soak in water, which will retain moisture inside the concrete solution, preventing it from losing strength.
Manufacturing will save time and effort, because as such formwork you can use a simple asbestos pipe of the required diameter. The pipe is lowered into the prepared trench and filled with concrete; there is no need to remove such formwork. As a rule, this is the option that most developers choose. The formwork must be temporarily fixed in order to remain motionless when the concrete solution is poured and dried.
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Reinforcement and pouring concrete mortar
On pillars can be considered the most important operation, because it is the reinforcing frame that provides the entire foundation with strength and reliability, without which it can be destroyed in just one year of operation. This forces the developer to take this stage of construction work very seriously. Such a frame is made from reinforcement rods with a cross-section of 10 to 12 mm. The frame for support type pillars is made on the ground, after which it is installed in a fixed formwork.
When placing the frame inside the formwork, it is worth considering the fact that the reinforcement should not reach 5 cm from the boundaries of the concrete solution. Otherwise, the strength of the foundation column will be reduced, which will lead to delamination of sections monolithic design during use. The frame bars should protrude beyond top part formwork so much that it is enough to connect the frame of the pillars with, while creating a truly strong foundation.
The final stage of manufacturing foundation pillars is pouring and compacting the concrete solution. The formwork must be poured in layers of 20-30 cm, compacting the solution itself well. This will avoid the formation of voids and air pockets due to the presence of large crushed stone elements in the solution. It is necessary to pour the support pillars at one time to avoid uneven setting of the concrete, which threatens to affect the strength of the structure after it has completely dried.
You can start making a monolithic strip grillage after a week of drying of the support pillars, which is required by the construction of the foundation. They will gain their maximum strength only in a month, but 7 days will be enough to begin continuing work. The grillage is a support for all load-bearing walls of the future house, which requires the implementation of the highest quality construction that can withstand the load not only of the future house, but also environmental influences. For this purpose, high-quality wooden formwork is made, which must be dismantled after the concrete foundation solution has dried.
Before this, it is necessary to ensure waterproofing of the grillage of the strip foundation with pillars, which may suffer from moisture rising through the capillaries of the supporting pillars. Each must be covered with a 5 cm layer of insulating material, for which heated bitumen is ideal. As soon as the waterproofing is ready for further use, it is worth starting to organize the formwork, install the reinforcing frame into it and pour the concrete solution. It is worth remembering the need to tie the reinforcing frame of the pillars to the frame of the future grillage.
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Calculation of foundation depth
There are several indicators that allow you to determine the required depth of the foundation structure:
- indicators of soil freezing;
- location of groundwater;
- characteristics of the area of soil where the foundation will be located.
An example of correct and incorrect construction of a column-strip foundation.
In cases where groundwater is located significantly lower than the freezing level of the soil thickness, freezing characteristics can be ignored. Such indicators indicate that in winter the soil will not have heaving properties, which allows the foundation to be placed higher, while saving on the construction itself. Otherwise, when groundwater almost reaches the freezing level, the foundation structure should be located deeper than this level, which will avoid compromising the stability of the entire structure.
Building codes provide for a minimum foundation level. For relatively dry types of soil, this figure is only 70 cm, while for wet soils it can increase to 1.5 m. If a basement is planned in the future house, then the supporting part of the foundation structure should be located 40 cm below the floor level of such a room.
The foundation of the building under construction must be strong and reliable, able to withstand all weight loads from building structures houses, engineering equipment, household items and snow deposits on the roof. The foundation must remain stable in the event of possible soil movements and not collapse in the event of freezing or rising groundwater. However, erecting a heavy and powerful reinforced concrete foundation is not always advisable. In certain cases, the reliability issue can be resolved using load-bearing structure columnar-ribbon type.
This is a kind of combined strip-column foundation that combines at the same time technical solutions, accepted for pile and strip monolithic systems.
Thanks to this, such foundations can be erected on weak unstable soils with a high groundwater level and a large freezing depth for one-story residential buildings and outbuildings. Ribbon pillar foundations can be built for wooden and frame buildings that do not have heavy reinforced concrete floors and stone walls.
Brief description of the design
Structurally, the columnar-strip foundation consists of several supporting stone pillars, on which rests a reinforced concrete shallow grillage, which takes all the weight loads of the building. The most commonly used pillar supports are reinforced concrete pillars, poured on site.
In general, the columnar-ribbon base combines the following main elements:
- reinforced concrete pillars, the design and number of which are determined by calculation;
- reinforcing frame filled with concrete;
- above-ground strip structure made of bricks or blocks;
- internal vertical supports for bearing loads for walls and partitions.
Upon careful examination, you will notice that the very idea of the technology was taken from multi-story city buildings with basements and semi-basements, where a pile field of the design configuration is driven in, and after that a connecting tape grillage of small depth is installed to create a single support.
Advantages and disadvantages of column-and-ribbon structures
The construction of a foundation of this type is less labor-intensive than in the case of any other type of monolithic reinforced concrete, and also requires lower costs building materials. Having design solutions in hand, professional construction knowledge and extensive experience are not required to complete the work. Even a beginner can cope with this, having one or two assistants with him.
The structural advantages of columnar-tape foundations include:
- good protection from vibration effects and possible ground movements;
- special design of support pillars, which increases strength and stability;
- the use of mixed types of materials when installing the grillage;
- increased thermal insulation properties due to the lack of contact of the underground floor with the soil;
- the possibility of construction in areas with difficult terrain without preliminary planning;
- reduction in the volume of earthworks;
- the opportunity to make a columnar strip foundation with your own hands.
In addition to obvious advantages, such support structures also have disadvantages that can somewhat complicate the organization and implementation of work:
- complex engineering calculations that take into account a combination of soil characteristics and the total weight load;
- possible differences in the cross-section of the support along the height and perimeter of the building;
- the practical impossibility of determining the influence of soil heaving, which requires a safety margin;
- impossibility of making a basement.
Therefore, it is recommended to entrust the calculations and project development to professionals who will determine the necessary data and make decisions with the minimum possible, but necessary margin of safety and reliability.
Selection of support pillar material
The reliability of the foundation structure largely depends on the right choice support strut material. At this stage of construction, you should not try to save money. If at the moment the purchase of inexpensive materials will allow you to save certain cash, then in the future you will have to spend very significant sums on repairs and correcting defects.
For the construction of a columnar strip foundation with monolithic slab ceilings can be used:
- wood;
- rubble stone;
- solid red brick;
- aerated concrete, foam blocks, slag concrete or concrete blocks;
- asbestos-cement, concrete, plastic or metal pipes;
- concrete pillars;
- pre-fabricated and bored columns.
Each material has its own characteristics, which are described below.
Wood
The main reason for low popularity wooden foundations lies in their fragility. Even additional treatment to protect against moisture, rot and insects increases the service life for a short time. However wooden beams can be used to install grillages raised above the ground during the construction of light utility and domestic buildings.
Rubble stone
This material has long been known to builders and has been widely used for the construction of foundation structures. It is distinguished by great strength and durability. However, its laying requires highly skilled mason skills to fit individual stones to each other. Therefore, only a professional builder can lay reliable rubble stone pillars.
Types of columnar foundations: a. brick pillar on a rubble base; b. solid brick pillar; V. brick pillar on concrete base; d. burnt wooden chair (oak or pine); d. metal stand; e. rubble pillar. Bricks and blocks
For the underground part of the foundation structure, only high-grade clinker or solid clay bricks can be used. In columnar strip foundations made of bricks and blocks, the above-ground part of the grillage is laid out, located on a concrete monolith.
Considering the hygroscopicity of these materials, a surface coating with bitumen waterproofing in several layers is required.
Pipes
The use of asbestos-cement, concrete, plastic or metal pipes It is advisable as permanent formwork, inside which a reinforcement cage is installed and concrete is poured. As a result, you can quickly obtain reinforced concrete pillars of high quality. Metal materials must be provided with a waterproofing coating to protect against corrosion.
Concrete pillars
Vertical pillar supports made of reinforced concrete are made on site after drilling or excavating wells. The structures are poured inside removable or permanent formwork after installing the reinforcement cage. In addition, individual poles or prefabricated piles can be purchased. They are installed at points with the greatest weight load and then tied with a grillage.
Rammed and bored posts
They are purchased ready-made on the building materials market. Installation is carried out using special driving equipment directly at the installation sites. Structurally, these are hollow reinforced concrete supports, inside of which a metal frame is installed and concrete is poured. Columns of both structures may be used together.
Technological principles of construction
The entire foundation construction process must be carried out step by step, in the following order:
- installation or installation of support pillars;
- installation of reinforced concrete monolithic screed, metal or wooden grillage;
- brick or block masonry.
This division is based on the possibility of continuous production of work at each of these stages.
Installation of support pillars
Calculation of the cross-section, quantity, locations and depth of pillar supports. When choosing the type of structure, it is recommended to use a shallow monolithic grillage strip located along the pillars to a depth of about 500 mm.
This allows the weight load from the building to be more evenly distributed on the foundation. A grillage structure raised above the ground should be done in the presence of complex terrain, in places of strong soil heaving and in permafrost areas.
The base needs to be buried 300-400 mm below the possible freezing point of the soil, taken from SNiP “Climatology”. Based on the results of engineering calculations, depending on the selected material and terrain features, the technical characteristics of the pillars are determined, such as diameters, locations and installation method.
Reinforcing frames must contain at least 4 vertical strings. The technological process of installing supports can also be divided into several sequential works, which include:
- removal of existing vegetation and leveling of the work site;
- marking the locations of pillars and grillage configurations;
- drilling or digging wells;
- installing a sand cushion and pouring concrete only to the height of the lower base plate;
- ensuring waterproofing protection of elements;
- installation of permanent formwork or bored columns;
- assembly and installation of reinforcement cages;
- pouring concrete into formwork or columns.
When pouring, one should take into account the mandatory expansion of the base to a size twice the diameter of the column itself, but not less than 400 mm. Therefore, pouring concrete should be done in two stages. Initially, you should fill the base, wait 2-3 days, and only then begin installing the formwork for the installation of supports.
Grillage installation
With a shallow grillage design, this stage of work should begin with digging a trench from the very beginning. The depth of the concrete strip should be more than 400 mm.
After this, the formwork of the design configuration is installed. To do this, you can use boards or standard factory-made shields. Inside the assembled formwork it is necessary to lay a layer of plastic film or roofing felt. This will ensure the tightness of the structure and prevent water leakage from the cement mixture.
Metal frames are manufactured according to the calculated design diagram for the installation of a horizontal reinforcing belt. All reinforcement structures are placed inside the formwork and, during installation, are connected in conjunction with the vertical strings of the pillars, which must protrude to a height of at least 300 mm.
Correct and incorrect device. Next, you can start pouring concrete. The mixture must be laid in layers, and the work is planned in such a way that the laying of the concrete mixture is completed in a day. The above-ground part of the foundation can be made of bricks or blocks. This will ensure the presence of a horizontal waterproofing layer between the underground part and the supporting tape of the layer of construction of the walls of the house.
The formwork can be removed a few days after the concrete has gained strength.
At the final stage, all outer surfaces of the grillage are covered with three layers or roll materials are used. Protecting stone structures from moisture at each stage of work will ensure long-term operation and prevent the formation of destruction.
Installation sequence. Foundation Construction Guide
Let's summarize. Step-by-step instructions for installing a columnar strip foundation with your own hands provide for the following stages of work:
- Clearing the site of trees, bushes and low vegetation. Leveling the ground surface if necessary.
- Marking the installation locations of pillars and grillage contours along the axes of the house. The pillars must be in all corners of the building and at a distance of no more than 2.0 meters from each other.
- For brick, rubble or square monolithic pillars, you need to dig holes. For permanent cylindrical formwork in the form of pipes or hollow columns, holes should be drilled. The depth of pits or wells is 300 mm deeper than the possible freezing point.
- Pour and compact sand or crushed stone-sand cushion into the open cavities. Install formwork elements or bored posts. Raise them above the bottom of the pit to the height of the support cushion.
- After this, install the reinforcement frame of the columns, resting on the bottom, and pour concrete to the height of the support pad. Wait 2-3 days for the concrete mixture to set.
- Pour concrete into the column formwork and compact it well using a vibrating tool. After hardening the concrete mixture with removable formwork or masonry, treat the surfaces with a triple layer of bitumen coating insulation. This work can be performed after installing the grillage.
- Install the formwork in such a way that the reinforcement protruding from the pillars fits into its internal space. Next, begin assembling the formwork for the horizontal belt. After its installation, cover the walls and bottom with plastic film or roofing felt.
- Assemble the reinforcement cage in accordance with the design and lay it inside the formwork structure. After this, tie or weld a horizontal belt with the vertical strings of the pillars.
- Concrete is poured into the grillage formwork in one day. Concrete is laid in layers and the mixture is compacted to remove air bubbles.
- If masonry is used in the construction of the foundation grillage, then 2 layers of roofing felt should be laid on the surface of the concrete to create a waterproofing layer. Every 3-5 rows brickwork needs to be reinforced metal mesh with a cell no more than 100x100 mm made of 5-6 mm wire.
5-7 days after completion of the work, you can begin installing the walls or frame structure of the building. In the case of a raised grillage structure, all sand located under the building must be removed. In this case, the house will remain supported only by columns.
Video on the topic
In modern private housing construction, the construction of monolithic strip foundations predominates. This type of foundation ensures the achievement of optimal technical and operational characteristics for buildings different types. In most situations, this option provides the necessary strength and performance characteristics of the structure. The load-bearing capacity is very high. But sometimes its use is limited or unacceptable, then you have to resort to alternative options, among which the columnar strip foundation stands out.
Limitations of using strip base
One of the key determining parameters of construction is the geological situation at the site. The strip foundation will have to be laid to a significant depth or various types of changes will have to be made, which are inconvenient and unprofitable. Among those limiting the use of the foundation, the following geological characteristics can be identified:
- The upper horizons of the underlying soil may have a high coefficient of frost heaving, which leads to seasonal destruction of the foundation.
- If in the construction region there is a large depth of soil freezing in winter, then you will have to go through this mark with a powerful concrete belt, which is very expensive.
- Deep occurrence of strong and stable horizons.
- The presence of a significant terrain slope on the site requires the adoption of an alternative solution so as not to equip the enormous height of the belt base.
With a thorough analysis of the current situation at the site and study of available data pre-design surveys The architect will help you choose the best base design option.
If it is important for the building owner to have a basement or underground garage, then laying the foundation to a significant depth is inevitable. But if you do not need such a design, then it is enough to limit yourself to optimally selected columnar bases.
This type of base allows excellent base characteristics to be achieved by uniform distribution load at minimum costs for passing soils.
Combined foundation - when to use and possible options
A strip foundation with pillars combines the advantages of two popular and actively used foundations. This is how you can competently apply the advantages to achieve the best result.
The combined strip-column foundation is a simple hybrid of well-known design options. Main principle, which is the basis of this type of foundation, is to go through soft soils and reach the load-bearing horizon not with the entire base strip, but only with load-bearing supports, which support the building, guaranteeing its stability and strength.
After reaching the surface, the supports are connected with a monolithic tape, which allows you to create a single structure in which the weight is evenly transferred to the created pillars. Such a connecting screed is called, which does not rest on the ground, as in the standard form, but on the created foundation pillars.
At a general glance, a columnar-strip foundation is a type of pile-strip foundation, which is erected on.
Using the described type of foundation for construction various types buildings and structures allows you to achieve the following advantages:
- Reducing the volume of work and the use of building materials, which leads to a reduction in the cost of work and a drop in the estimated cost of the entire construction.
- Acceleration of work, which contributes to the speedy achievement of the required result.
- Carrying out work at all stages of foundation construction does not pose any particular technical difficulty and allows you to achieve the task on your own.
Combined foundation
The strip-and-pillar foundation serves as an excellent example of a successful combination of several popular types of foundation.
Types of pillars for columnar-strip foundations
You can build a column-and-strip foundation with your own hands in the shortest possible time if you carry out the design preparation correctly and follow the construction rules. At the design stage of a columnar-strip foundation, the distance between the pillars and the parameters of the supports themselves are determined with maximum accuracy - after all, these are the future supports of the entire structure.
A wide selection of pile types, which are used as supports for the foundation, determines the varieties of this combined foundation. The supports can be manufactured both in the factory and directly on site. The bored type of construction is optimal for the construction of such a foundation.
Sometimes single support structures are used, which allow the main load to be distributed as accurately and efficiently as possible.
Strip-column foundation can be erected in the shortest possible time with your own hands, while ensuring sufficient strength and aesthetics of the structure.
The process of constructing a columnar strip foundation
Combined foundations for a house allow you to get excellent results. In practice, simple pillars for a strip foundation provide high technical characteristics. You can build the foundation yourself; to do this, you must follow several stages of construction:
Construction stages
- Preparing the building site. At this stage, you should thoroughly clean the area, level the soil and mark the base of the area. This is done either independently or with the involvement of surveyors. The exact position of each support on the site is determined.
- for future supports. Performed using special hand drills or additional equipment - depending on the parameters of the wells being created and technical characteristics soils. The well usually widens at the bottom, which allows for additional support and strength. Drilling is carried out strictly according to the project, maintaining the calculated spacing between the supports.
- Waterproofing of each created well. To ensure the safety of the supports, it is important to ensure the strength and protection of the posts. They experience constant pressure from groundwater, which leads to destruction of the base structure. Therefore, or other hydrophilic materials, to prevent destruction of the base.
- The bottom of the well is covered with a sand-gravel mixture, after which the necessary work is done. The reinforcement is installed vertically and usually 4 rods are enough.
- The formwork is installed, which becomes the support body.
- After completing the installation of wells for each pillar, they proceed to similar work for arranging a connecting grillage. Here they also make the underlying cushion, waterproofing, formwork - the resulting structure is simply poured with concrete.
The combined foundation is easy to construct and efficient in operation. A simple columnar-strip foundation with a monolithic screed has the following practically valuable advantages:
- Low cost of production of work and purchase of materials. Ultimately, this choice of base allows you to reduce the cost of creating a solid base several times.
- Easy installation of supports and grillage, which allows you not only to complete the work in a short time, but also to perform most of the work yourself, without the involvement of additional workers and specialists.
- The construction of the foundation can be completed entirely by a team of 2-3 people.
Thus, the combined type of base allows achieving excellent performance characteristics at limited costs. This approach is the best solution in some situations, allowing you to optimize the entire process of building a house.
The foundation is the foundation of the entire building, so it is very important that it is strong and durable. A strip-and-column foundation is a monolithic type of foundation, which is ideal for erecting it on heaving, swampy or sandy soil. This type of structure is suitable for private houses with wooden or timber-frame walls. It is quite durable and does not require significant costs. This article will talk about how to make a strip-column foundation with your own hands, without using special equipment and without hiring highly qualified workers.
This type of foundation consists of two main components - supporting structures and grillage. The supporting structures are pillars, and the grillage is a system in the form of a tape.
The tape element allows you to cover the subfloor of the building with a reliable structure that can withstand excess moisture. In addition, the grillage tape creates a surface that is very convenient to use for laying wall materials such as foam blocks and bricks.
Advantages of a column-strip foundation
The advantage of this type of foundation is the presence of vibration protection. The structural support is equipped with side sections that are tightly fastened to the tape element, which creates a “vibration isolating system.” The main purpose of this system is to reduce the effects of vibration generated by roads or railways located next to the building.
Basics positive quality This type of foundation is characterized by low labor intensity. Even non-professionals can manipulate the preparation of a site for construction and pouring the structure with concrete, so it’s quite easy to make a columnar strip foundation with your own hands. The strip element of the foundation structure is placed above the ground, so the amount of concrete mixture used is reduced, which allows for significant savings on the construction budget.
In addition, another advantage of this design is low heat loss. This quality is explained by the fact that the main part of the structure will not have contact with frozen soil, which will reduce heat loss by approximately half.
Components of a columnar strip foundation:
- The supporting structure is pillars. The number of pillars depends on the weight of the building.
- Reinforcing frame.
- Tape design.
- Internal piles.
Types of pillars for columnar-strip foundations
Precast pillars are produced directly at the construction site and installed in special wells into which concrete mortar is poured. Bored posts are especially popular. This can be explained by the fact that this design does not require special costs and has good load-bearing capacity. This type of structure can be concreted without casing.
In some cases, single support structures are used. Such poles are suitable for places that will bear the main load.
Choosing the right material for constructing the pillars of the structure
When constructing a strip-column foundation, you first need to pay attention to what materials will be used in the construction of the supports. For this purpose, you can use brick, concrete blocks, metal or asbestos cement pipes, as well as wood.
Peculiarities: 
- Wooden supports. This type of pole is not particularly popular due to the fact that wood is a short-lived material. But still, wooden supports are used to build wooden terraces. The pillars for this purpose should have a diameter of 0.15 -0.2 m. In addition, it is better to treat the wood with impregnations that will prevent destruction.
- Pillars made of pipes made of asbestos concrete or metal. Monolithic columnar-strip foundations are often made from these elements, since such pipes are well suited for permanent formwork.
- Brick pillars. Supports made of this material are used if the columnar foundation is to be made unburdened. The width of the brick structures should be half a meter.
- Concrete pillars. This type of support is considered the most reliable, therefore they are most often used in self-construction columnar strip foundation. There are monolithic concrete pillars and those made from ready-made blocks. The width of this structure should not be less than half a meter.
The process of constructing a columnar strip foundation
This process consists of two main stages:
- Creating a support structure from pillars.
The first step is to choose the right foundation depth. This must be done taking into account the structure of the soil, the degree of freezing of the ground and the depth of groundwater. As the foundation sinks, it is divided into two types: shallow and buried. The buried column-and-strip foundation is immersed approximately half a meter below the freezing level of the soil.
You need to pay attention to the fact that the pillars need to be installed at a distance of one to two meters from each other. A larger distance may result in a structure that is not very strong.
The installation of foundation supports must begin with the preparatory stage, which consists of preparing the site for construction. First of all, remove the excess layer of soil, making the area level. If the soil at the construction site is clayey, then you need to remove most of it and fill the area with sand.
Then we mark out our construction site. To do this, you need to use a special thread used in construction. Let's stretch it in the form of two non-intersecting strips, the distance between which is equal to the thickness of our strip foundation.
Do not forget to monitor the angle of intersection of the threads, it should be equal to 90⁰. Also, we must not forget to mark the intersections of wall surfaces and the corners of the building.
The next step is to dig trenches in the places where the strip structure of our foundation lies. The depth of the trenches should be approximately 40 cm, and the width should be made in such a way that there is still about 10 cm left for placing the formwork.
To install the pillars we use a concrete mixture, but do not forget about creating a waterproofing layer. For it, using roofing felt rolled into a couple of layers, we make a pipe. We connect it with tape and insert this structure into the ground until it stops.
Before making a columnar strip foundation, you need to take care of creating a frame from reinforcement and wire, and then insert it into the drilled hole so that the reinforcement protrudes outward by approximately 15-20 cm.
Next, we will begin pouring the resulting support with concrete. To begin, we will pour a layer of concrete mixture about 20 cm thick into the well. Then we will lift the roofing felt pipe to allow the mixture to form a base. The next step is to fill the well completely and leave the concrete to dry.
- Creation of the strip part of the foundation.
First of all, we knit the reinforcing frame again. Then we weld it and attach it to the reinforcement protruding from the concrete-filled pillars.
Having completed all the above-described stages of constructing a columnar-strip foundation, we will begin installing the formwork, which is part of the strip foundation. To do this, take several boards, the width of which is 10 cm, and assemble formwork from them. Then lay waterproofing inside the formwork, which can be polyethylene film.
After carrying out these manipulations, we will fill the formwork with concrete. You can do this manually, or you can use a special mixer machine. The formwork can be removed after three weeks, when the concrete becomes strong.
After the concrete has hardened, you need to apply a coating layer of waterproofing to the foundation. The side parts of the strip structure need to be processed. For this purpose, heated bitumen can be used. It is best to do this procedure a couple of times.
It is better to remove the sand poured under the strip element, since otherwise the building will stand on a non-buried structure. The result should be a trench about two centimeters deep. After pouring the concrete, the mixture that falls into this trench will create a protrusion that will help securely fix the structure.