How to make a cheap foundation. What is the best foundation to choose for the house. What it is

What type of foundation to choose

Construction is a complex and costly business that requires a scientific, rational approach. Therefore, before choosing the type of foundation, you will have to answer several important questions:

• what will the house be like? (material, number of storeys, will there be a basement)
• what are the geological conditions at the construction site?
• To what depth does the soil freeze in winter?
• at what depth is the groundwater?
• how much do you intend to pay?

Reliability and quality are not quickly executable, especially in construction, where each stage depends on the previous one, and a lot of calculations are needed to complete at least one of them in a short time.

The foundation performs a buffer function - it minimizes the possibility of soil subsidence, displacement of the walls of the house and provides. The future house depends entirely on the type of foundation, since it is its foundation and support.

How deep to lay the foundation is calculated, taking into account the climate of the area. Our country is characterized by cold winters, so waterproofing and thermal insulation are a must. Therefore, it is better to build efficiently, thoroughly, and in one season.

The wrong choice of the type of foundation and the subsequent precipitation of the building are the reasons for skewed porches, verandas, terraces, problems with opening doors, and sometimes even more large-scale disasters: breaks in communications (water supply, gas pipes, sewers),.

It is not worth saving on the basics, even if the costs for them amount to 20% of the total cost of the house, because subsequent repairs will cost an order of magnitude more expensive. The loss of finances is not yet the worst thing, sometimes it is impossible to restore or fix the structure.

The bases can be tape, slab, columnar and pile.

Slab (monolithic) type of foundation

Monolithic, also called floating, are some of the most reliable foundations for buildings of various types located on an area with poor geological conditions:

• high groundwater table
• heaving / subsiding soil
• waterloggedness

Consist of monolithic reinforced concrete slabs, located on bulk soils. Reinforcement is carried out not only along the perimeter, but also over the entire area of ​​the structure. This provides rigidity, strength of the foundation, which in turn helps in the fight against deformations. These qualities are especially important in autumn or spring, when the soils are unstable due to temperature changes.

Also, slab foundations are used in the construction of basements or basements: they protect well from moisture. Thanks to Swedish technologies and modern hydro- and heat-insulating materials, insulated slabs are becoming very popular.

If, for example, a garage is planned under the house, then it is better to use a slab foundation for this.

The construction of a monolithic base begins with digging a pit with special equipment (or manually, if the volume is small). The pit should be slightly larger than the foundation itself around the perimeter. The bottom is carefully tamped down and layers of sand and gravel are poured - making a "pillow". Each of the layers is separated by geotextiles. Then the slab is poured into the formwork: first, a thin layer is poured, then it is reinforced and the remains of concrete are added. After that, a monolithic tape is arranged on such a slab under the walls, and the slab itself can serve as a floor for basements. The thickness of such a structure rarely exceeds 0.2 m.

Advantages of a monolithic foundation:

• reinforced slab does not deform and moves with the ground, thereby ensuring the stability of the entire building
• the slab is reinforced not only outside, but also inside, which is the reason for the strength, stability and durability of the foundation
• resistance to temperature extremes, thawing and freezing, as well as high humidity
• moving soils are not scary
• can be used in places where groundwater washout is high. Provides waterproofness

Benefits of a slab foundation

Flaws:

• the cost of floating bases is high due to the large amount of earthworks and mandatory reinforcement.

Shallow tape foundation

This type of foundation is located around the perimeter of the structure. It has the same width throughout its length, and is more commonly used for stone, wood and concrete walls. If the future house is large, it is advisable to use a strip foundation.

Light one-story stone, chopped or frame buildings are best installed on shallow foundations (less freezing depth). This type is used for stable geological foundations (weakly heaving), but if you make reinforcement and prepare a "cushion" of sand, then it can be arranged on any soil.

The material for a strip foundation with shallow depth is not only concrete (monolithic or prefabricated), but even stone or brick. But it is undesirable to use a brick, since it is short-lived - it absorbs water.

Strip foundations are monolithic and prefabricated.

Under the monolithic strip foundations (in the trench), formwork is first installed, already in which the reinforcement strapping is poured with concrete. Such a foundation is strong and can withstand fairly high loads of complex-shaped buildings.

Interesting fact!
Modern trends in construction are gradually leading to the idea of ​​ending the use of wooden formwork. All construction companies are trying to achieve greater smoothness of the ends of concrete bases for greater frost resistance, and wood does not solve this problem. Yes, and all the time it is necessary to erect wooden formwork in a new way. Instead, they are now using reusable metal formwork, which makes it possible to obtain neat foundations.

The popularity of individual blocks has subsided somewhat, and in European countries they have not been used for a long time. Such blocks are produced in specialized factories. They are placed in the pit with the help of taps, and already there they are fastened together with a solution of cement. Perhaps this technology is simpler than pouring concrete into the formwork, but practice confirms that the quality of such foundations is worse. Monolithic structures are much stronger than prefabricated ones.

Advantages of strip foundations:

• even distribution of the acting load. Durability and reliability
• saving money and materials
• ease of reconstruction

Flaws:

• the need for a simple architectural layout

Screw pile foundation

The pile foundation is effective for construction on swampy soils, problem soils (for example, the city of St. Petersburg).

It is a pipe with pointed tips. Such piles are screwed into the soil layer. They will serve as a support for the reinforced concrete slab overlapping them from above.

Piles are screwed in to different depths, depending on the mobility of the soil, this distinguishes the pile foundation from the columnar type.

The pile material can be different:

• metal
• tree
• reinforced concrete

Reinforced concrete pile structures are nevertheless more durable, the possibility of their operation reaches more than 100 years.

Summing up, it turned out that this type of foundation is low-consumable in materials, effective on difficult soils, but requiring special small-sized equipment and complex engineering calculations.

It is a set of pillars installed at the main nodal points of the building with a distance of no more than 3 meters from each other. The material for columnar foundations is concrete, stone (natural), brick. The pillars are overlapped with strapping beams (made of metal or wood), which makes the base stiffer.

Also, the distances between the posts must be covered with connecting walls - (it has its own design with ventilation holes, base). It can be done from bricks, rubble masonry or concrete with a thickness of at least 0.1 - 0.2 meters.

It can also be monolithic or prefabricated.

A monolithic construct is used provided that the groundwater is deeper than 1 meter. During its construction, holes for pillars are dug (drilled). Concrete is poured into the previously prepared formwork, and the distance from the formwork wall to the pit wall should be more than 0.1 meters. Reinforcement must also be provided, otherwise the foundation will not have the required strength.

Reinforced concrete prefabricated bases are erected on damp soils. These pillars are attached to the base plate. This type of building is not intended for moving layers, otherwise the entire building may collapse.

Benefits of the columnar type:

• material consumption and labor costs are 2 times, and in some cases 5 times cheaper, even (the most inexpensive of the above) strip foundations

The disadvantages of a columnar foundation are:

• obligatory arrangement of the basement floor
• the inability to use in areas with elevation differences is dangerous, as overturning may occur
• not used for heavy buildings on sandy (sandy-clay) rocks

What is the best foundation on clay soil?

The clay type of soil is characterized by the presence of a large amount of water in its composition (due to the fine dispersion of particles), freezing, it expands, and as a result, swells - deforms. The base breaks, under the influence of forces, and the building itself suffers.

There are several varieties of clay soils, but in all of them the choice of foundation should be in favor of:

• tape recessed
• slab
• pile

When erecting any of these foundations on clayey rocks, it is necessary to use special technologies and rules.

For example, a tape base on such soils should be laid on a thick sandy base, and itself made of insulation (foam). Often the cross-section of such structures is trapezoidal (the base is one-third wider than the top). To remove excess water from the foundation on clay, a drainage system is used.

What is the most reliable foundation?

Its grip on hard ground provides maximum stability and strength to any structure. Sometimes you have to drill deep enough.

Pile foundations properties:

• simple installation - despite the need for special small-sized equipment, it is constructed several times faster than other types of foundations. Unlike other varieties, the pile base does not require heavy construction machines and a large number of workers.
• work is carried out by 2-3 specialists
• piles are durable, not afraid of corrosive destruction and water
• versatile, as they can be used absolutely in any areas, especially with problem soils

In second place in terms of reliability is the floating type.

This type, despite its high cost, withstands the influence of poor geological conditions of the site: it retains high strength qualities. When building on clayey rocks, it requires a sandy "substrate" and high-quality reinforcement.

Is it necessary to choose a pile or slab type of foundation for the construction of private residential buildings? Of course not. Specialists will always find the best option in terms of finance and security.

It is clear even to a person who is far from the topic of construction that the top layer of soil, which turns into slurry in spring and autumn due to the abundance of moisture, cannot serve as a basis for construction. It is necessary to provide support on a more reliable surface, for which the building is equipped with a buried part - a foundation. But what should be this very foundation for the house? There are more than one or two options, let's take a closer look at this issue.

Which foundation is better

Acquaintance with the types of foundations will be more meaningful if you first determine the selection criteria for this structure. So, a good foundation should:

1. Have the lowest cost possible.
2. Provide such specific pressure on the ground, which would not exceed the bearing capacity of the latter. Obviously, the specific pressure on the ground with the same mass of the building will be the lower, the larger the area of ​​the foundation foot.
3. Have a service life not less than the resource of the building.

Realizing this, you can proceed to study the varieties of this structural element.

Types of foundations

If the solid soil is relatively shallow, columnar bases are usually used.

The cheapest option, which is an ordered group of pillars. They must be installed in the corners of the building and in other places of intersection of the load-bearing walls, and, if necessary, also along the walls with a certain step, which depends on the configuration and weight of the structure.

Columnar foundations are used on solid soils for lightweight buildings

The support area of ​​the columnar foundation is small, therefore it is erected only under light buildings: frame houses, wooden or built from foam blocks (in this case, a belt of reinforced concrete or rolled metal is laid on the pillars). With a significant mass of the structure, the specific pressure on the ground will be excessively high. It should also be borne in mind that it is impossible to arrange a basement in a house with a similar foundation.

According to the material used, columnar foundations are divided into:

• wooden;
• stone;
• brick;
• reinforced concrete.

Wooden

This is an outdated technology, but due to its low cost, it may be quite appropriate today, for example, when building a country house or a barn. The lower part of pine or oak trees with a diameter of 25 cm or more should be used, which is installed with the root part (called the butt) down. As a bioprotection that prevents decay, mining, tar and modern antiseptics are used.

Wooden posts must be treated with antiseptic impregnations

It is also helpful to burn the outside of the barrel with a gas torch or blowtorch. Then it will be much less susceptible to destruction and damage by the fungus. However, you need to understand that even with the most effective protection measures, the service life of a wooden foundation will be relatively short.

To increase the area of ​​support, under the wooden post, you can put a cross-piece made of pieces of timber 70 cm long (for reliability, it is connected to the post in a spike) or a reinforced concrete plate. It is most effective to pour the slab right on the spot and drown the column by 15 centimeters in a still liquid solution - this will ensure its reliable fixation.

Upon completion of the installation, the recess in which the post is installed is covered with sand with a layer-by-layer rammer (for good compaction, the sand is pre-moistened).

Stone

A more durable and durable option, but at the same time, again having a completely democratic cost. It is due to the use of unprocessed natural stone - rubble (limestone, dolomite, sandstone) or granite.

Fragments of 20–30 cm in size are used, which are folded into a column with filling of the gaps with crushed stone and cement mortar (rubble concrete masonry). In this case, you need to remember about the dressing of the seams.

Instead of stone, you can use another cheap material - brick fighting.

Brick

When building such a foundation, special attention should be paid to the choice of brick: it should be as moisture resistant as possible. Iron ore brick meets this requirement in the best way. In extreme cases, the use of other types is also allowed, but only under the condition of processing with reliable waterproofing.

Brick pillars are inferior to reinforced concrete ones in strength, but surpass wooden ones in terms of service life

Reinforced concrete

The peculiarity of reinforced concrete pillars is that for their construction it is not necessary to dig a large pit. You can make one or more holes with a garden drill, then install an asbestos-cement or plastic pipe there and pour concrete into it. At the bottom of the excavation, before installing the pipe, you need to make a sand and gravel backfill, and install a reinforcing cage in the pipe before pouring concrete (concrete does not work well in tension). The plastic pipe not only acts as a mold for concrete, but also protects it from water. Before installation, the asbestos pipe must be coated with bitumen.

In the absence of a pipe, you can use a cylindrical shell sewn from roofing material.

Due to the danger of skewing, the use of a columnar foundation is not allowed in areas with a large slope.

With a significant mass of the structure (brick house) or low bearing capacity of the soil, it is necessary to increase the support area, therefore the foundation is built in the form of continuous strips under all main walls. The cost of funds and labor increases in comparison with the columnar analogue, but it becomes possible to arrange a basement in the house - the foundation strips will become its walls. In addition, such a foundation is insured against distortions even with a significant slope of the construction site.

A strip foundation is more costly than a columnar foundation, but it will withstand a much heavier house and allow you to arrange a basement in it

There are several types of strip foundations:

• monolithic;
• made;
• rubble;
• panel.

Monolithic

It is made directly at the construction site by filling the formwork with liquid concrete. In individual construction, this type of foundation is most often used, since no special equipment is required for its construction.

Today, special foam forms are produced that can be used instead of wooden formwork. The gain from such a decision is double:

The foam must be protected as soon as possible with finishing materials from the ultraviolet radiation contained in the sunlight, which destroys it.

Made

It is built from pre-fabricated reinforced concrete blocks that are installed on a concrete slab. To combine into one whole, the foundation blocks have special grooves, which, after being installed in place, must be filled with mortar. It is easier and faster to build a foundation from blocks, but a truck and a crane are needed to deliver and install them.

For buildings with a large mass, blocks with an increased sole are produced (the product looks like an inverted letter "T"), due to which the specific pressure on the ground is significantly reduced.

Blocks with a larger sole are able to withstand very heavy weight

The joints between the blocks are susceptible to freezing, so the prefabricated foundation is not very well suited for houses with a basement.

Butovy

An inexpensive option for a strip foundation, which is built in the same way as stone pillars (see above). In terms of strength, it is inferior to the reinforced concrete analogue, therefore, it is allowed for use only with a building height of no more than two floors. Another requirement: the width of such a foundation must be at least 60 cm.

Panel

For the installation of strip foundations under light wooden houses, the owners of which want to have a basement (a columnar foundation, as already mentioned, does not provide such an opportunity), special panels are produced from aerated concrete, the pores of which are filled with insulation.

During their manufacture, water-repellent additives are added to the concrete mixture, thereby eliminating the need to carry out work on waterproofing the foundation. The thickness of the panels is 260 mm.

The most expensive type of foundation. These are no longer narrow bands built only under the load-bearing walls, but a monolithic reinforced concrete slab completely covering the building. The high cost is due not only to its size, but also to the need to use reinforced reinforcement.

Monolithic reinforced concrete slab - the most expensive of all existing types of foundations

It is necessary to resort to the device of a slab foundation when construction is carried out on weak, unpredictable soil or in conditions of high groundwater levels. The stove offers the following advantages:

1. Reduces specific ground pressure to a minimum.
2. It transforms the building into a single structure, thanks to which it maintains its integrity and does not deform with uneven soil subsidence.

If soil with sufficient bearing capacity is too deep, any of the foundations described will be prohibitively expensive. In such situations, another type is used - a pile foundation.

Piles are long, strong reinforced concrete or steel rods that are pushed into the ground to the desired depth.

The device of the pile foundation will allow you to build a house on soft soils and quicksand

There are the following types of piles:

The first two varieties are introduced into the soil by impact or indentation. Screw piles do not require the use of piling equipment, they can be installed independently. This will require a long lever and a few assistants.

Foundation design

The design phase always starts with a survey of the soil at the construction site to assess its bearing capacity, compressibility and water table. This work must be carried out by specialists of a licensed organization, who will make their decision after analyzing several samples taken with a special drill.

It is highly discouraged to build at random, even with data on soils in neighboring areas (if one of the neighbors has already ordered such a study), since the geological situation in your area may differ from that available nearby.

Soils are different, but in general they all represent different combinations of only two extreme forms:

And here are the intermediate forms:

• sandy loam: contain only 5-10% of clay impurities;
• loams: clay takes up from 10 to 30%.

Both varieties can be light, heavy and dusty. Obviously, the closer the soil is to clay, the more problematic it is from the point of view of construction.

Such an important characteristic as heaving depends on the content of clay in the soil. It is directly related to the ability to retain moisture: the more water there is in the soil before the onset of frost, the more it will increase in volume when this very water freezes. If the freezing of the soil spreads below the foot of the foundation, the latter will be subjected to an extrusion effect from below.

Thus, the depth of the foundation depends on the heaving:

The parts of the foundation located under the inner walls can be buried 0.5–0.6 m regardless of the type of soil.

When building on heaving soil, the depth of the foundation can be reduced in two ways:

1. By warming the soil, due to which the depth of its freezing will decrease. A wide strip of insulation is laid around the structure, capable of bearing the load without deformation. The best option is extruded polystyrene foam. A cheaper, but less effective analogue is expanded clay.
2. By replacing heaving soil to the depth of freezing with sandy one. The backfill width should slightly exceed the transverse dimension of the foundation.

As for the bearing capacity of the soil, it depends on many characteristics:

• the size of the particles and the strength of cohesion between them;
• the size and nature of foreign inclusions;
• coefficient of friction between particles;
• the ability of the soil to erode and dissolve;
• compressibility and loosening of the soil.

The bearing capacity of the soil is determined using specially developed methods.

All of the above applies to the most common loose soils. In addition to them, there are rocky soils, which are a very reliable foundation for construction.

Rocky soils are highly durable, therefore they are arranged with non-buried strip or pile foundations

Foundation calculation

The design and calculation of foundations should be carried out in accordance with the requirements of SNiP 3.02.01–87 "Earthworks, foundations and foundations". Before performing calculations, a number of parameters must be determined.

Required support area

Determined by the formula: S = M / P, where M is the mass of the entire structure, including the foundation (kg); P is the bearing capacity of the soil (kg / cm 2).

Required compressive strength of the material

The same formula is applied, but in a slightly modified form: P = M / S f, where M is the mass of the over-foundation part of the structure (kg); S f - the area which the structure rests on the foundation (cm 2).

It is advisable to make the margin of safety small, since the more durable the material is, the more expensive it is.

Other initial data

When performing calculations, the depth of the foundation is determined. We have already talked about how this is done. In addition, they perform:

• calculation of reinforcement;
• calculation for possible uneven soil subsidence, etc.

The technique is rather complicated, therefore, professional civil engineers should perform such work.

What concrete should be used

Heavy concrete is used to build the foundation. When choosing, you need to pay attention to the following characteristics:

Concrete with mobility P3 and P4 are considered optimal for pouring a strip foundation. In the first case, when laying, you should definitely use a vibrating plate, in the second - its use is very desirable. Concrete with a mobility index of P5 is too fluid and is usually not used for such purposes. P2 concrete can be used only if the reinforcement is sparsely located, the use of a vibrating plate is mandatory.

Today there are a lot of enterprises engaged in the production and delivery of ready-made concrete mix (BSG). However, practice has shown that there are many unscrupulous among them, so you need to choose a supplier very carefully. Just in case, it is recommended to order concrete 1–2 steps higher in grade strength than is required by calculation.

Well, the most reliable option is to make concrete yourself. To do this, you need to scrupulously study the technology (there are many publications on this topic on the network) and rent a concrete mixer with a drive - a solution prepared in a trough by mixing with a shovel turns out to be 40% less durable.

Foundation construction

We will consider the construction process using the example of the most popular type - the strip foundation. Here are the stages it consists of:

1. Marking: the outlines of the future foundation are usually indicated with the help of pegs driven into the ground and a cord stretched between them. There are no difficulties here, but you need to remember one subtlety: the marked 4-gon must have equal not only opposite sides, but also the diagonals (a sign of equality of all angles to 90 degrees).

   The marking of the future foundation is made using a cord and pegs (or special chairs)

2. Digging a trench: excavation must be carried out to a depth below the design level of the base of the foundation, since a sand and crushed stone cushion will be laid under it.
3. Pillow device: this structural element consists of two layers: bottom - sand, top - gravel or crushed stone. The thickness of the layers is 10 cm each. The pillow excludes the flow of water to the foundation from below due to the capillary effect (crushed stone and sand are drainage materials and, due to their flowability, evenly distribute the load from the foundation to the ground).

   A foundation pillow is a combination of carefully compacted layers of sand and gravel (or crushed stone)

4. It will be more reliable to lay a preparation of lean (with an increased percentage of sand and gravel relative to cement and water) concrete 15–20 cm thick without reinforcement or 6–10 cm with reinforcement on top of the pillow.
5. Installation of formwork: it is assembled from sheet wood-shaving materials, plywood or boards. The structure must be strong enough so as not to collapse under the weight of rather heavy concrete, therefore, it is reinforced with supports throughout its entire length.

   Wooden formwork must be reinforced with side supports before pouring concrete.

6. Inside the formwork, roofing material must be laid on top of the sand-crushed stone pillow. It makes sense to wrap the wood elements from which the formwork is assembled with polyethylene. Then they will not deteriorate from contact with concrete and can subsequently be used for other tasks.
7. Reinforcement and ventilation device: the reinforcement cage is installed taking into account the fact that the greatest tensile forces during bending occur at the surface itself. That is, the working belts must be located at the upper and lower edges of the future foundation, but so that the reinforcement is protected by a layer of concrete 30–40 mm thick. When reinforcing, two important rules should be observed: the reinforcement cannot be welded - only tied: at the point of welding, it loses its strength and becomes fragile; corners and other intersections of the ribbons must be reinforced not with two straight intersecting rods, but with one L-shaped, and each part of it must have a length of at least 30 cm.

   In the corners of the reinforcing cage, solid rods are used, bent at the required angle

8. For the device of ventilation holes (air vents) in their places of location, it is necessary to attach pieces of plastic pipe to the fittings, abutting with their ends against the walls of the formwork. To prevent concrete from seeping into the pipe, it is filled with wet sand. In a similar way, holes are mounted for passing through the foundation of engineering communications.

   Special vent holes are arranged in the foundation frame. They are needed for ventilation and removal of excess moisture seeping from the soil.

9. Pouring concrete: It is highly advisable to pour all the concrete in one go. In this case, it is necessary to ensure that all air is released from the mass of the solution, otherwise voids will remain. Best of all, this is facilitated by a special tool - a vibrating plate. If it is not available, the freshly poured solution is thickly pierced with a reinforcing bar or a shovel.

Influence of weather conditions on the quality of filling

Pouring concrete is best done in moderate weather - cool and dry. It is better to postpone this operation during the period of heavy rains. But an annoying incident often happens: the filling of the formwork with a concrete mixture is in full swing, and it started pouring from the sky like a bucket. In this case, it is better not to interrupt the pouring, but the trench must be covered with plastic wrap. We open separate small areas in stages, pour concrete - and immediately return the shelter to its place.

It is especially important to exclude precipitation from entering the concrete mix in late autumn, when night frosts are quite real. If you allow the pouring of concrete with rainwater, the result will be disastrous: the monolith will turn into a fragile substance that will crumble from a slight impact.

Waterproofing

As we already know, after the installation of the formwork, the pillow is covered with roofing material. This is a horizontal waterproofing that will protect the base of the foundation from moisture. The same material or similar (roofing paper, polymer film) should be glued with mastic on the sides, not only outside, but also inside.

The inner and outer surfaces of the foundation tape must be covered with a waterproofing material

The outer side (vertical) waterproofing must be protected from mechanical damage, since it will be pressured by soil (during freezing and seasonal movements) and groundwater. In addition, it can be damaged when backfilling the trench. Such protection can be a heater or a brick wall. If for some reason they cannot be installed, you need to at least glue the waterproofing in several layers.

Instead of finishing with roll material, you can apply plastering.

Places for laying utility lines through the foundation must be sealed with liquid glass or mastic.

Today, special silicone-based compounds are produced that make the concrete surface non-wettable. They eliminate the capillary effect in the pores, due to which water is absorbed. They are called water repellents. Water-soluble varieties can be added to the composition of concrete, producing volumetric hydrophobization.

Materials based on organic solvents are applied to the surface, while they impregnate concrete by 1 - 2 cm. True, it must be borne in mind that hydrophobized concrete has low adhesion, so it will be impossible to stick anything on it.

Warming

All building structures, except for the roof, should be insulated outside, otherwise, being isolated from the warm interior space, they will often freeze and thaw. In the case of the foundation, it is necessary to select such a heater that could withstand the pressure from the side of the soil when it freezes or moves. These requirements are met:

• extruded polystyrene foam (has the best thermal insulation properties);
• expanded clay;
• sawdust concrete.

Expanded polystyrene sheets are installed very simply: they are glued to the waterproofing, and then they are also screwed on with disc dowels (the cap has an increased diameter). Special sheets should be used with an end configuration that allows seamless installation. If ordinary sheets are used, the seams between them must be sealed with polyurethane foam.

Extruded polystyrene foam sheets retain heat well and reliably protect the waterproofing layer from destruction

Blind area device

To prevent atmospheric moisture from penetrating into the soil adjacent to the foundation, a concrete strip 1 m wide is arranged around the house.It is done as follows:

Finishing the foundation of the house

For finishing the above-ground part of the foundation, special materials are produced that differ from the wall ones with increased strength. The most popular are:

Plinth panels and siding are screwed to the lathing, stone slabs are fixed with mortar or glue.

Video: building a strip reinforced concrete foundation with your own hands

It must be remembered that the foundation is one of the most critical parts of the building. Therefore, it is highly desirable that specialists be engaged in its design and construction. If you do intend to do it yourself, follow each step with the utmost diligence and thoroughness, paying special attention to the concrete preparation technology.

Starting a private construction project, the owner of the future building most often wants to save money and at the same time get a reliable building. And we are talking here not only about the selected building materials for the house itself, but also about the type of foundation that will be the basis for the construction. How to choose the best cheap foundation, what type of foundation is suitable for the specific soil on the site, and how to save money on the work, we understand the material below.

Important: the cost of building a frame is 30% of the total cost of building a house as a whole. Therefore, it is worth carefully weighing all the parameters and nuances of installing the base with the help of competent specialists.

Parameters for determining the cost of the foundation

In order to understand how much money will be spent on installing the base of the house, they take into account such important criteria as:

• Remuneration of labor for the designer of the house. It is this person who is able to make for you the most profitable structure on the specified site.
• Geological analysis of the soil.
• The sum of the costs of all building materials for the foundation.
• Excavation costs including backfilling of the base.
• The cost of installing a reinforcing belt and installing formwork.
• Wages to workers, if any, will be involved in construction work.

Important: it is definitely impossible to save on the performance of geological analysis of the soil and the work of the designer. After all, a competent approach to soil research allows you to make an optimal project of a house with a foundation, which will have a good bearing capacity specifically for your building.

In addition to these two important components of the subsequent savings in construction, it is necessary to take care of high-quality insulation, waterproofing of the base of the house, as well as a reliable drainage system.

The effect of hiring competent specialists

If there is some bewilderment on the topic “why pay specialists, designers and geologists,” then we hasten to dispel all doubts. The work of such professionals will bring the following advantages to the implementation of installation work:

• So, a competent geologist will determine the optimal place on the site for building a house. Optimality here means the lowest possible level of groundwater and the same level of soil freezing. This means that the depth of the foundation can be safely reduced. The savings in building materials and payment for earthworks are obvious in this case.
• A competent professional designer will help you make a reliable building from optimal building materials. Indeed, for example, cement of the M-500 brand has a high bearing capacity, but it also costs several times more than cement of the M-300 brand. Or maybe, according to the project, your house will require the use of cement of the M-300 brand. That is, it will be enough for your design. And here the savings are obvious. Needless to say, there are a lot of such nuances when designing a building. And only an experienced architect-designer can cope with them.
• In addition, it is the designer who is able to correctly deduce the optimal width of the foundation tape or grillage. After all, construction is not always about creating maximum opportunities for the foundation. The architect will be able to determine the optimal load-bearing capacity of the frame just for your house. This means that building materials will then be purchased not according to the maximum quantity and bearing capacity, but according to the optimal parameters.

In addition to saving on construction by attracting experienced professionals, an important role is played by such points as:

• Drainage system design. After all, competent drainage of water from the site reduces the level of groundwater, which means that the level of freezing of the soil will be reduced. Therefore, the foundation can be made shallow. Another savings point.
• The design of the waterproofing system also allows you to make a shallow frame even on a soil with a high GWL. And this is an additional point of savings during construction.
• The device of a high-quality heat insulator also allows you to reduce the cost of building a foundation. Due to good insulation, the base strip can be narrowed down to optimal load-bearing capacity.
• It is worth noting that both the geologist and the architect are able, in accordance with the obtained site studies, to choose the most efficient and economical type of foundation for the desired building.

Cheapest types of foundations

The price for installing the foundation is formed not only from the amount spent on the purchase of building materials, but also from the total weight of the finished house. It is for this reason that a light and economical frame on pillars or piles can be made for a frame or wooden house. Below we consider options for foundations that will be economical options in each case for a particular building.

Foundation for a wooden house

For such a house, it is quite possible to mount a shallow columnar frame with a wooden grillage. The financial benefit in this case will be in the following parameters:

• No need to dig a full-fledged pit;
• Possibility of using improvised means (blocks, bricks, wood) as a building material for foundation supports;
• Minimum labor costs during installation, that is, the base can be built even with your own hands without the involvement of professional craftsmen.
• The cost of such a columnar frame on average in Russia is from 40 USD. for one pillar.

Important: such a foundation is considered the cheapest, however, it is only suitable for light houses and buildings on sandy soils.

Foundation for a brick or block house

Heavier structures require a more powerful base with a high load-bearing capacity. In this case, the most economically viable option would be a shallow or medium-depth columnar monolithic foundation with the same reinforced concrete or beam grillage. Ideally, a tape frame should be built under a stone house. Especially if the soil on the site is complex. When building a tape frame, you can save on building materials if there are deposits of buta (natural stone) near the site. The rubble strip foundation is strong and reliable enough and has a high bearing capacity.

Important: the mass of one m3 of blocks is approximately 600-700 kg, while the mass of bricks in the same volume is already about 1.5 tons. A strip foundation made of concrete with reinforcement will cost about 7 thousand rubles / linear meter. A columnar frame made of concrete with reinforcement and with a monolithic grillage will cost $ 65. for one pillar plus grillage.

Foundation for a monolithic house 1-2 floors

In this case, a full-fledged strip base or a concrete monolithic slab is arranged. The latter option is especially good for moving soils with high groundwater levels. Moreover, if it is planned to install a strip foundation, then in the case of moving soils on the site, it is necessary to mount a support sole under the frame tape. The expansion will reduce the mass of the house on the base and increase the bearing capacity of the foundation.

You can save on the construction of a strip base if you assemble it from concrete blocks. This will reduce the cost of work by about 30%. The cost of a strip monolithic base will cost about 111-126 USD / running meter. A monolithic concrete slab will cost from 48 USD / m2. But depending on the depth of the base.

Pile foundation

The most economical and at the same time durable type of frame. The base on metal screw piles can be arranged on difficult moving soils, in rocks, with a high level of groundwater. The only condition for a pile foundation is a structure that is lightweight. This can be a frame or panel house, a garage or a utility room such as a barn.

The savings here are as follows:

• No need for complex earthworks;
• Do-it-yourself installation without the involvement of professionals;
• Relatively low cost of building materials (piles and channels for grillage).
• The price of a pile foundation is on average from 72 USD. for one pillar.

Important: the pile foundation can be mounted directly at water bodies. And the term of installation work with a certain skill will take only 1-2 days.

TISE technology foundation

This is a type of pillar or pile foundation, the supports of which have a cross section of 25 cm. At the same time, a special expansion with a cross section of 60 cm is arranged under the pillars of the base. It is called a shoe or a sole. Such a pillow is capable of significantly reducing the pressure of the mass of the house on the columns of the frame, which means it can prevent the soil from sinking under its weight.

The TISE technology foundation is good for any house (brick, block, frame, stone). In addition, it is this type of foundation that can be arranged on almost any soil, such as sand, clay, loam, high GWL, etc.

An important link in the construction of the base using TISE technology is a strong grillage - a frame encircling the posts. It is most often made of rolled metal or monolithic concrete. The cost of such a foundation (including work) will be from 64 USD / running meter.

Foundation slab

It is also called a floating base. Such a monolithic concrete pad goes into the depth of the soil by 1.5-1.7 meters. In this case, the concrete fill is reinforced with a rigid frame.

A slab foundation can hardly be called an economical base arrangement, but such a frame will withstand any load on the most difficult soils. The slab foundation is not afraid of seasonal heaving of the soil, or a high GWL, or moving layers or difficult terrain.

Important: when starting construction with your own hands, carefully weigh all its nuances in order to avoid deplorable mistakes in work.

There are many types of foundations for the construction of private low-rise buildings. But most often, under domestic cottages, an option is set up in the form of a reinforced concrete tape under load-bearing walls. After all, in order to make a strip foundation with your own hands, you only need to have minimal concrete mixing skills and follow the instructions. The technology of the device of such a basis is simple, which is why it is chosen so often for independent execution.

What it is?

Structurally, a strip foundation is a reinforced concrete structure created along the perimeter of the future structure to redistribute the load on the ground. A similar support is used for the construction of residential buildings, garages, outbuildings, baths, garages and even fences. It is not difficult to make it yourself.

This is how it looks

However, when building such a foundation, it is extremely important to adhere to certain rules and recommendations. If the technology for manufacturing the strip foundation is not followed, it will be possible to forget about the durability of the supporting structure itself and the building on it. They will not stand for a long time.

Seasonal swelling of soils, the effect of moisture on concrete without waterproofing, incorrectly calculated loads - there are many reasons for the destruction of the strip base on which the house already stands. All of them must be foreseen and taken into account in advance, otherwise the damaged or completely destroyed structure will have to be rebuilt.

Types and types of foundations

In terms of depth, it is MZLF (shallow) and simply buried. In the first case, a concrete belt under a low-rise building is buried only 200-400 mm into the ground, and in the second, it is buried up to one and a half meters (below the level of freezing of the ground).

If the soil at the construction site is rocky, and the groundwater is deep, then it is better to choose a shallow, cheap and small-volume concrete option. On heaving, high groundwater level and sandy areas for the house, you will have to make a more powerful and expensive support. Often, the estimate for a similar basis for a dwelling comes out such that it is necessary to choose a different type of basis altogether.

Scheme of walls with MZLF

Structurally, a tape reinforced concrete base is:

Monolithic;

The first type is performed by pouring a reinforced concrete belt. The second option is laid out from special factory-made foundation blocks (FBS) or bricks.

Pros and cons of strip foundation

He has three undoubted merits

Extreme simplicity of the device - any novice builder will cope with pouring concrete and laying blocks (there is a step-by-step instruction - to build everything correctly, you just need to follow it step by step);

The ability to withstand heavy loads both from below from the ground and from above from the weight of the cottage and everything in it.

A strip base made of reinforced concrete will last for many years, even if not light aerated concrete blocks were taken for the construction of the walls of the house, but heavy solid bricks. In terms of cost, it is second only to screw piles, but in most cases it surpasses them in reliability.

Among the disadvantages of such a foundation are:

The obligation to thoroughly analyze the soil at the construction site;

The need to use lifting equipment (in the case of using FBS);

Long-term concrete curing of at least 3 weeks (when choosing a monolithic option);

Impossibility of laying on highly heaving and watered soils.

Step-by-step instructions - DIY foundation

The thickness and height of the tape of the base under consideration, as well as the depth of its laying, are selected based on the analysis of the soil, climatic conditions of the area and the number of storeys of the house being built. Without knowledge in this area, it is better to entrust this design stage to a professional. There are many nuances and requirements of GOSTs that must be observed.

But it is quite possible to create a support for your house according to a ready-made project on your own. But in order to avoid mistakes, it is best to make the strip foundation yourself with step-by-step instructions, which are given below. It describes all the subtleties of building a similar structure for a typical one-story cottage.

Stages of work

The first stage is marking and earthwork. Regardless of the depth, the sole must rest on solid layers of soil. It can be clay, sandy loam, stony layers or loam. They are usually hidden under turf and layers of ordinary earth. All this will have to be torn down and removed before starting to build the foundation of the house.



We prepare the site, distribute the basic materials: artmatura, insulation, formwork boards

To mark the site, you will need pegs, a tape measure and twine. If the soil is dense, then an excellent formwork will be obtained from the walls of the dug trench. It will only be necessary to build it up later from above. If the soil is loose and constantly crumbles, then the trench will have to be dug a little wider in width so that shuttering boards can be placed inside the pit.

The second stage is the preparation of the pillow. The bottom of the excavated trench is leveled with sand and fine gravel. This sand and gravel layer should be thoroughly tamped, sprinkling with water as it is poured. In height, it should be in the range of 10-30 cm. This pillow serves to redistribute and reduce point loads on the strip foundation from below during seasonal swelling of the soil.



Insulation can be placed on top of the pillow - this will avoid heaving from freezing of the soil

The third stage is the placement of the formwork. Here you will need bars with a cross section of 30 to 40 mm and boards 15–20 mm thick or laminated chipboard. The formwork created for the concrete base of the house will subsequently have to withstand a considerable mass of concrete poured into it. It should be made durable and reliable. If, after filling with concrete mixture, it collapses, then everything will have to start over.



We expose the formwork from the boards

If the groundwater at the construction site is high, then the reinforced concrete will need waterproofing. From above, at the level of the basement of the house, it is usually done with a coating. And to protect that part of the base that remains in the ground, roofing material should be laid in the trench on the sides and on the bottom. It will reliably protect concrete from excess moisture in the soil at the stage of hardening and after.

The fourth stage is the laying of reinforcement. For reinforcement, steel rods of 14-16 mm cross-section and a thin binding wire are usually used. You can also fasten the fittings with electric welding. But in this case, experience with the welding machine is required and he himself. Plus, when performing welding, one must be prepared for the appearance of metal corrosion in the future.



We knit reinforcement






As a result, a frame of reinforcement with cells of 25-30 cm should be formed inside the trench. Moreover, it is laid so that the steel is covered with concrete poured on all sides. Otherwise, the metal will inevitably begin to rust, then the house will definitely not stand for a long time.








The fifth stage is concrete pouring or FBS laying. If it is decided to equip the foundation for the house being built using block technology, then this greatly speeds up the process of its construction. Here you do not have to do the formwork and wait almost a month before the completion of the concrete setting.

However, support on foundation blocks will cost more than a monolithic counterpart. Plus, they will have to dig a larger trench in width. To distribute the loads for the lower row of masonry, FBS are made with an expanding base.

If a monolithic option is chosen for the support device, concrete should be poured immediately over the entire surface. No gaps in length and no layers in height. A monolith is a monolith. The house must be on a solid foundation.



Nails can be used to mark the pouring border in the formwork

When self-preparing the concrete mixture, it is necessary to mix cement, sand and crushed stone in proportions of 1: 3: 3. But it is better to initially order a ready-made solution with the M300 brand and higher.



Fill in











When pouring concrete, it is extremely important to ensure that no voids form inside it. There are special vibrating machines for compaction. However, you can also use a piece of reinforcement to pierce the filled mass and release air from it.








The sixth stage is waterproofing and blind area. It is allowed to start waterproofing works 3-4 days after the concrete is poured. It takes about three weeks to fully set. But you can already start to process the mastic, even if not completely frozen strip foundation for the house.



We are waiting for solidification

Also, along the entire perimeter of the structure, you will need to make a blind area to drain rainwater away from its walls.



Ready-made foundation with basement rows of bricks

Use for building a house

Such a support can easily withstand private houses with a height of two or three floors. For the construction of a cottage on it, you can choose glued beams, logs, foam blocks or ceramic blocks. You just need to competently investigate the soil and correctly calculate all the loads. At the end, it will not hurt to veneer the foundation for additional protection from the weather. For this, natural stone or clinker façade tiles are ideal. But you can choose an easier-to-install and inexpensive corrugated board or siding.

To correctly choose and build a foundation that is optimal for a certain type and size of a house means providing the building with a solid support that will last for several decades. Even a structure designed by a genius will not stand for a couple of years if it is installed on an unreliable foundation. Groundwater, seasonal rainfall, changes in soil density and mobility will quickly destroy such a structure.

It is advisable to shift the care of the selection and equipment of the foundation onto the shoulders of professionals who have the necessary experience and know how to build a foundation for a house. This will not lead to budget overruns, errors in laying and, as a result, poor support quality. Qualified specialists will not only help you decide on the type of the optimal foundation, which will reduce the overall cost of building a house, but also guarantee that they will do the work as efficiently as possible.

Sectional foundation

Varieties of foundations for low-rise construction

Choosing a suitable foundation for a house is the main task with which construction begins. The wrong look will affect the durability of the building, the strength characteristics or cause unnecessary costs. Therefore, you must first decide on the type of support. For this, a number of important parameters are taken into account.

• The depth of the groundwater table. If they are too close to the surface, then an inappropriate foundation will lead to flooding and uneven settlement of the building.
• Density and composition of the soil. Moving soils require one type of base, dense soils another.
• The depth of freezing of the earth. If this factor is not taken into account, then after each thaw there is a chance of cracking in the foundation, walls and ceilings.

Reinforced strip foundation with ventilation holes

In the low-rise construction of residential buildings, cottages, baths, sheds and other outbuildings, four main types of foundations are used.

• Tape. It is a solid structure, which is located along the perimeter of the future structure. Can be poured into formwork directly on site or assembled from separately manufactured concrete blocks.
• Plate. Consists of several layers, each of which performs a specific function. The top layer is a solid reinforced concrete slab.
• Pile-grillage. It is assembled from pillars buried deep in the ground, which are connected in the upper part by a grillage-lintel, which evenly distributes the load on the structure.
• Pile. It is erected from supports that are located evenly under the entire area of ​​the house or under places with the greatest load - the corners of the house, walls, lintels.

Depending on the above factors, the building material and its dimensions, the final result is determined, and a foundation project for the house is created.

Column foundation in section

Column foundation for light farm buildings

When building any foundation, the weight of the building must be taken into account. Lightweight outbuildings do not require a monumental foundation, therefore, columnar foundations are most common for them. Their choice is due to the following qualities:

• quick installation;
• low cost;
• the ability to provide reliable support.

The columnar foundation is installed on a cushion of sand or fine gravel, in the upper part, the columns are connected by beams, on which the basement will be installed in the future. It is important to take into account the depth of soil freezing and the degree of its heaving. This type of base is suitable for inactive soil, otherwise the structure may shift.

Column foundation

On our website you can find contacts of construction companies that offer the service of designing and repairing the foundation. You can communicate directly with representatives by visiting the Low-Rise Country exhibition of houses.

Pile foundation for frame houses

The pile foundation is a few piles screwed or driven into the ground (thick metal pipes with an anti-corrosion coating), on which the piping is mounted and the house is built.

Video description

What are the features of concrete driven piles? We will talk about the pile foundation in our video:

Since this technology is relatively new and not all construction companies can boast that they are fluent in it, there are still cases when, some time after construction, a house sags somewhat under some piles. But foreign experience shows that such incidents occur exclusively when the technology is not followed, and if the installation of the pile foundation is done according to all the rules, then it will become a reliable support for the house. In addition, piles make it possible to erect buildings even on soils with a high degree of mobility.

Foundations for wooden houses made of logs

Buildings made of rounded logs and beams are lighter than brick or concrete ones, but they exceed frame houses, so a shallow strip or pile-grillage foundation would be the best option for them.

The first option allows you to equip a basement, has sufficient resistance to loads and a relatively low cost. To ensure its durability, it is necessary to equip with high-quality waterproofing and fill in a thick sand cushion.

For the pile-grillage foundation, it is necessary to dig holes to the level of freezing of the soil and connect them with isthmuses. Then concrete is poured into pits and ditches and a concrete tape is obtained, from which pillars come out, resting on the soil below the freezing level.

Pile-grillage foundation

These types of foundations provide an opportunity to equip a reliable and durable base that can easily withstand the weight of a wooden house of one or two floors and will avoid unnecessary overpayment by equipping an unnecessarily expensive support designed for an impressive mass.

Slab and strip foundations for stone houses

Buildings made of bricks, concrete or building blocks require a solid foundation, because they have an impressive weight and are completely devoid of plasticity, which, albeit to a small degree, is inherent in wooden houses. The slightest movement of the base can lead to the formation of cracks in walls and ceilings. Therefore, the best option would be a slab or recessed strip foundation.

Multi-layer slab foundation

The slab base is a multi-level structure that fits into a pre-dug hole slightly larger than the building under construction. Pcastfoundation for the home consists of the following layers:

• crushed stone pillow;
• a layer of sand;
• waterproofing;
• reinforced concrete slab;
• second layer of waterproofing;
• insulation.

This type of foundation allows you to withstand the large weight of the building and provides a fixed support on heaving soils.

Strip foundation deep-laid is mounted at a depth of more than a meter in order to be below the level of soil freezing. This value may vary depending on the region and the average annual temperature. The tape view of the base performs a double function, in addition to providing reliable support for stone walls, it allows you to equip a basement, but in this case, you will need to spend money on waterproofing and insulation.

Deeply buried strip foundation

Online foundation calculator

To find out the approximate cost of various types of foundations, use the following calculator:

What foundation for a house is cheaper

Considering how to properly build the foundation for a private house and not spend more than necessary, one should take into account the type of soil, the weight of the structure and a lot of other characteristics, then it will be possible to choose the ideal option.

• The lowest cost and time consumption is inherent in the columnar foundation. But it has two significant limitations: installation only on sedentary or stationary soils and a low weight of the structure. As a result, it is categorically unsuitable for a residential building or heavy construction.
• Piles are in second place, but here it all depends on their variety. Screws are the most inexpensive of all but are suitable for light structures, bored - for bricks and concrete, and driven ones provide a high level of stability, but are very expensive.
• Strip foundation. A shallow and shallow-buried view will not cost much more than a columnar one, and a deep-laid tape has the highest price, due to the increased volume of work and the use of a large amount of materials.
• A monolithic slab is the most expensive type of foundation, but provides maximum reliability on heaving soils. In some cases, such a foundation is the only option suitable for the soil.

Video description

What types of foundations are there? How does the construction of the foundation take place and how much does it cost? All this and much more, see this issue:

As a result, it is far from the fact that the seemingly inexpensive foundation will remain so. Sometimes it happens, for example, that it is more profitable to make a monolithic foundation than to bury the tape to the depth of freezing. The choice of the foundation should be based on a combination of factors, because the price can change depending on the situation.

Slab foundation with bituminous coating for a brick house

Strip foundation - the best option

If the soils do not impose special restrictions on the choice of the foundation, then the tape one will be the best option. Its advantages over others:

• provides high stability of a building of any weight;
• universal (depending on the situation, a certain type of basis is used, which allows you to spend the budget within strictly defined limits);
• arrangement of hydro and thermal insulation ensures resistance to soil freezing, protects against condensation and prolongs the service life of the support.

The only limitation for installing a strip foundation is high soil moisture, but there are few areas with such soils in our country, therefore, in all other cases, this type of foundation can be used.

Finished shallow strip foundation

Conclusion

The foundation is one of the most important parts of a building. It is stupid to save on it, it cannot be made of low quality, access to it will be severely limited after the construction of the building, which complicates the repair. Its equipment needs to be done immediately and well, so such work can only be trusted by professionals.