Correctly choosing and building a foundation that is optimal for a certain type and size of a house means providing the building with solid support that will last for several decades. Even a structure designed by a genius will not last even a couple of years if it is installed on an unreliable foundation. Groundwater, seasonal precipitation, changes in soil density and mobility will quickly destroy such a building.
It is advisable to shift the care of choosing and equipping a foundation to professionals who have the proper experience and know how to build a foundation for a house. This will not lead to budget overruns, installation errors and, as a consequence, poor quality of support. Qualified specialists will not only help you decide on the type of optimal foundation, which will reduce the overall costs of building a house, but are also guaranteed to do the work to the highest possible quality.
Types of foundations for low-rise construction
Choosing a suitable foundation for a house is the main task with which construction begins. The wrong type will affect the durability of the building, strength characteristics or cause unnecessary costs. Therefore, you should first decide on the type of support. To do this, a number of important parameters are taken into account.
Depth of groundwater. If they are too close to the surface, an inadequate foundation will lead to flooding and uneven settlement of the building.
Soil density and composition. Movable soils require one type of foundation, dense soils require another.
Depth of ground freezing. If you do not take this factor into account, then after each thaw there is a chance of cracks forming in the foundation, walls and ceilings.
Reinforced strip foundation with ventilation holes
In low-rise construction of residential buildings, cottages, bathhouses, sheds and other outbuildings, four main types of foundations are used.
Tape. It is a continuous structure, which is located along the perimeter of the future building. It can be poured into formwork directly on site or assembled from concrete blocks made separately.
Slab. It 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 at the top by a grillage-lintel that 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 - 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.
Columnar foundation for light outbuildings
When building any foundation, the weight of the building must be taken into account. Lightweight outbuildings do not require a monumental foundation, so columnar foundations are most widely used for them. Their choice is due to the following qualities:
speed of installation;
low cost;
ability to provide reliable support.
The columnar foundation is installed on a cushion of sand or fine gravel; in the upper part, the pillars are connected by beams, on which the base will be installed in the future. It is important to take into account the depth of soil freezing and the degree of heaving. This type of foundation is suitable for low-moving soil, otherwise the structure may shift.
On our website you can find contacts of construction companies that offer foundation design and repair services. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.
Pile foundation for frame houses
A pile foundation is several 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.
Since this technology is relatively new and not all construction companies can boast that they master it perfectly, there are still cases when, some time after construction, a house sags somewhat under some piles. But foreign experience shows that such incidents occur only when the technology is not followed, and if the installation of a pile foundation is carried out according to all the rules, then it will become a reliable support for the house. In addition, piles allow the construction of buildings even on soils with a high degree of mobility.
Foundation for wooden houses made of logs
Buildings made of rounded logs and beams have less weight than brick or concrete, but exceed frame houses, so the best option for them would be a shallow strip or pile-grillage foundation.
The first option allows you to equip a basement, has sufficient resistance to loads and is relatively low cost. To ensure its durability, it is necessary to equip it with high-quality waterproofing and pour a thick sand cushion.
For a pile-grillage foundation, you need to dig holes to the level of soil freezing and connect them with isthmuses. Then concrete is poured into the pits and ditches and a concrete strip is obtained, from which pillars emerge, resting on the soil below the freezing level.
Construction of a pile-grillage foundation
These types of foundations provide the opportunity to equip a reliable and durable foundation that can easily support the weight of a wooden house of one or two floors and will allow you to avoid unnecessary overpayment by equipping an unnecessarily expensive support designed for an impressive mass.
Slab and strip foundations for stone houses
Buildings made of brick, concrete or building blocks require a strong foundation because they have an impressive weight and are completely devoid of plasticity, which, although to a small extent, is inherent in wooden houses. The slightest movement of the base can lead to the formation of cracks in the walls and ceilings. Therefore, the best option would be a slab or buried strip foundation.
The slab base is a multi-level structure that fits into a pre-dug hole, slightly larger than the size of the building under construction. Pcastfoundation for the home consists of the following layers:
crushed stone cushion;
layer of sand;
waterproofing;
reinforced concrete slab;
second layer of waterproofing;
insulation.
This type of foundation allows you to withstand the heavy weight of the building and provides stationary support on heaving soils.
Strip foundation deep laying is mounted at a depth of more than a meter in order to be below the soil freezing level. Depending on the region and average annual temperature, this value may vary. The strip type of 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.
Which foundation for a house will cost less?
When considering how to properly build a foundation for a private house and not spend more than necessary, you should take into account the type of soil, the weight of the structure and a lot of other characteristics, then you will be able to choose the ideal option.
The lowest cost and time required are inherent in a columnar foundation. But it has two significant limitations: installation only on low-moving or stationary soils and the low weight of the structure. As a result, it is categorically unsuitable for a residential building or heavy construction.
In second place are piles, but here everything depends on their type. Screw ones are the most inexpensive of all but are suitable for light buildings, bored ones are for brick and concrete, and driven ones provide a high level of stability, but are very expensive.
Strip foundation. The non-recessed and shallow-depth type will not cost much more than the columnar type, and the deep-laying tape has the highest price due to the increased volume of work and the use of a large number 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.
What types of foundation are there? How is the foundation built and how much does it cost? See all this and much more in this issue:
As a result, it is far from a fact that a seemingly inexpensive foundation will remain so. Sometimes it happens, for example, that it is more profitable to make a monolithic foundation than to bury a strip foundation to the freezing depth. The choice of foundation should be based on a combination of factors because the price may change depending on the situation.
Slab foundation with bitumen coating for a brick house
Strip foundation - the best option
If the soil does not impose any special restrictions on the choice of foundation, then a strip foundation would be the best option. Its advantages compared to others:
ensures high stability of a building of any weight;
universal (depending on the situation, a certain type of foundation 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 the formation of condensation and extends 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, so in all other cases this type of foundation can be used.
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 greatly limited after the building is built, which complicates repairs. His equipment must be done immediately and well, so such work can only be trusted to professionals.
The foundation is the first, most important and quite expensive stage of building a house. Sometimes this is 30% of all costs. To save money, you might consider making your own foundation. Of course, it is very difficult to pour the foundation for a multi-story mansion on your own. But for an ordinary dacha this is quite possible.
Construction of the foundation of a house
The word "foundation" comes from the Latin "fundamentum" - foundation. It is a fundamental part of any building. You can invest huge amounts of money in a house, but if the foundation is bad, then the house, even on the most solid soil, will float, crack, and collapse.
A foundation is an underground or underwater part of a structure that transfers to its soil foundation the static load created by the weight of the structure, and additional dynamic loads created by the wind or the movement of water, people, equipment or vehicles. A properly designed foundation transfers all loads to the ground in such a way that the possibility of unacceptable settlement and destruction of the structure is eliminated.
Collier's Encyclopedia
http://dic.academic.ru/
Which one is more suitable?
You can build the foundation yourself, and it’s not difficult to understand the drawings and calculations. Moreover, there are not so many types of foundations, and they are strictly tied to the types of soil and the weight of your house.
This is how a foundation of stones and concrete is built in Goa, India; photo by Jorge Royan
The foundation is bad when it is built without regard to the soil; there were violations in its design or simplifications were introduced into initially correct calculations; you tried to save on materials or violated the pouring technology. To prevent this from happening, let's consider everything in order.
Kinds
There are only four main types of foundations; they differ structurally:
- Tape.
Diagram of a strip foundation - it clearly shows the sequence of its construction and specification
- Columnar.
Diagram of a columnar foundation - it clearly shows the sequence of its construction and specification
- Slab.
Diagram of a slab foundation - it clearly shows the sequence of its construction with the laying of reinforcement and specification
- Pile.
Foundation diagram on screw piles - all specifications and principles of construction are clearly visible
But among them there are also a lot of varieties, and there are foundations combined in shape.
The construction is regulated by a number of reference books; absolutely everything is covered in them.
SNiP - building codes and regulations
- SP (Code of Rules)
- SP 24.13330.2011 (Updated edition of SNiP 2.02.03–85, 1995, as amended - 2003, text) “Pile foundations”;
- SP 50–101–2004 “Design and installation of foundations and foundations of buildings and structures”;
- SP 50–102–2003 “Design and installation of pile foundations”;
- SNiP (Building Norms and Rules)
- SNiP 2.02.04–88 “Foundations and foundations on permafrost soils”;
- SNiP 2.02.05–87 “Foundations of machines with dynamic loads”;
- SNiP 52–01–2003 “Concrete and reinforced concrete structures”;
- GOST (State standard)
- GOST 13580–85 “Reinforced concrete slabs for strip foundations. Technical conditions";
- GOST 23972–80 “Reinforced concrete foundations for parabolic trays. Technical conditions";
- GOST 24022–80 “Prefabricated reinforced concrete foundations for columns of agricultural buildings. Technical conditions";
- GOST 24476–80 “Prefabricated reinforced concrete foundations for cross-type frame columns for multi-storey buildings. Technical conditions";
- GOST 28737–90 “Reinforced concrete foundation beams for walls of buildings of industrial and agricultural enterprises. Technical conditions.
- GOST 24846–2012 Soils. Methods for measuring deformations of the foundations of buildings and structures";
- MGSN (Moscow city building codes) 2.07–01 “Foundations, foundations and underground structures”;
- Normative literature related to the topic
- SNiP 2.02.01–83* “Foundations of buildings and structures”;
- SNiP 3.02.01–87 “Earth structures, foundations and foundations”;
- “Manual for designing foundations of buildings and structures” (to SNiP 2.02.01–83);
- GOST 24379.0–2012 “Foundation bolts. General technical conditions";
- GOST 24379.1–80 “Foundation bolts. General technical conditions. Design and dimensions."
Foundation structure
All varieties have common features. These are penetration into the soil, a cushion of drainage material (crushed stone, sand, pebbles), the foundation itself and waterproofing. Only pile types do not have a cushion, and only if they do not have a recessed grillage.
Photo gallery: drawings of different types
A slab foundation (drawing) shows the principles and technology of its construction. A strip foundation (drawing) of two types: made of aerated concrete blocks and concrete: similarities and differences. Similarities and differences between a pile foundation made from different types of piles. A column foundation (drawing in two positions) shows the principles of its construction. Drawing slab foundation with insulation and full specification Drawing of a slab foundation with insulation and drainage (and full specification)
Soil mechanics
The choice of foundation primarily depends on the characteristics of the soil: its composition, depth of freezing and groundwater, and only then on the design of the house and its materials.
The type of foundation is selected depending on the soil
Soils
The contact area of the foundation with the soil must correspond to the load, taking into account the expected resistance of the soil. The maximum resistance (reactive pressure) of the soil is determined experimentally based on the principles of soil mechanics, and state building codes provide tables of permissible soil resistance for certain geographic zones.
Collier's Encyclopedia
http://dic.academic.ru/
Before designing a house, it is better to order a professional survey of the site. Moreover, you should not use the results of your neighbor: sometimes even neighboring areas differ greatly in their characteristics. But you can do it yourself: dig a hole from half a meter to a meter deep, then use a garden drill to make a hole two meters deep, studying the soil from different depths.
If the site is located in a populated village, then it is good to talk with the owners of neighboring sites and look at their sites. This will help a lot.
According to the reference book “Soils. Foundations. Choosing the optimal foundation” There are three types of soils:
- rocky - massifs of homogeneous crystalline rock (rock) and sedimentary layered rock: dolomite, shale, sandstone, limestone;
- conglomerate - any soil with a large percentage (more than half) of fragments of crystalline or layered sedimentary rocks;
- non-rocky, which in turn is divided into
- bound - loams and clays;
- unbound - sands and sandy loams.
The classification of soils is clearly shown in the diagram
Soil cohesion also changes depending on humidity. Soil connectivity is independently determined visually - by the angle between the slope of the soil thrown out of the pit and the horizontal.
Our strip is characterized by non-rocky soils.
If your soil is virgin sandstone or gravel, then you are lucky (even luckier if it is rocky). Sand is a wonderful base for the home. It is quite reliable if the soil is plastic, dense and dry loam, or gravel, or even compacted construction waste. The trouble is that clays are never completely dry, and wet clay tends to swell and bulge.
Table: minimum depth of the foundation structure for construction in sandy and clayey soil
If it is easily and unevenly compressible soil - forest or garden fill soil, or, what is much worse - swampy soil, then your construction will cost you much more due to the forced compensation for these problems. In the case of quicksand (resembling dust or flour) or silt, building a house is not advisable at all.
Freezing
In addition to the composition of the soil, you need to know to what depth it freezes in winter. In our “latitudes” the freezing depth is usually from eighty to one hundred centimeters.
The base of the foundation should be below the maximum freezing depth of the soil to prevent swelling of the soil when freezing. The safe depth depends on annual temperature variations, the type and range of local soil variations, and the normal groundwater level. In addition, seasonal changes in the volume of clay soils are sometimes observed, which should not be allowed under a foundation laid on a natural foundation.
Collier's Encyclopedia
http://dic.academic.ru/
Ground water level
This is also an indicator on which not only the “model” of the foundation depends, but also the depth of its laying; it is assessed in relation to the depth of soil freezing. If in winter the water does not rise below 2 meters to the freezing depth (for brevity, let’s denote it by the letter Q), and your soil is fine and silty sand or hard clay, then the depth of the foundation will not depend on the freezing depth in principle.
Table: dependence of foundation laying depth on groundwater depth
But if the soil in the area is mixed, and there is sand or peat on top of the clay, then after precipitation, so-called “lenses” appear inside the soil - moisture seeps from above through the permeable layer and falls on the impenetrable clay. And this is very dangerous for the foundation due to its unpredictability.
Diagram of soil permeable from above, which creates internal “lenses” of water that are very dangerous for construction
Therefore, it is better to order a full survey of the site from professionals and receive a number of necessary documents about the condition of the soil. They should include the following information:
- Topographic plan with soil water curves and different types of soil.
An example of a topographic survey of a private land plot: it is too difficult to do on your own
- Mechanical properties of soils: possibility of subsidence and sliding, heaving, cohesion, ability to support the foundation without special efforts.
- Physical and chemical qualities of soils - freezing depth, wetting ability; what substances it releases when wet, and how they will affect the foundation material.
- Diagram of groundwater depth and its changes depending on the season and temperature.
A diagram of groundwater on a personal plot shows what type of foundation your future home needs
Type selection
Let's look at the types of foundations in more detail.
- One of the easiest types to implement on your own is a columnar foundation. It is suitable for light wooden house structures. Such a foundation can also be shallow, but this is more suitable for gazebos and barbecues - for a house it is too ephemeral. It is placed in pits (on a bed of drainage material) made of factory-made concrete blocks. Pros: ease of implementation, low price, suitable for any soil. Cons: not suitable for heavy house structures; The underground floor is poorly insulated.
A recessed columnar foundation made of ready-made concrete blocks is one of the simplest solutions
- Pile columnar foundation is suitable for unstable soils and slopes. It dampens movements well and is made from asbestos-cement pipes, which are concreted into pits with drainage filler. Pros: relatively simple and cheap to construct, resistant to subsidence and landslides. Cons: the same as the previous one.
A columnar foundation made of pipes is used on unreliable, floating and heaving soils, damping movements
- Pile-grillage welded foundation made of metal, from ordinary and screw piles, is ideal for unreliable soils. Pros: aesthetics and reliability, high durability. Cons: very expensive due to the cost of metal for a heavy grillage and requires welding.
The metal welded pile-grillage foundation is beautiful and reliable, but very expensive
- Slab foundation. Excellent for unstable or subsiding soil; in addition, it is often used if the house will have a very large weight. Pros: solidity, reliability. Disadvantages: labor intensive, lack of underground, high cost.
A monolithic slab foundation is almost ideal for a large house, but does not have a subfloor
- Most often, the best option is a buried or shallowly buried (for light wooden houses) strip foundation. It can be made from ready-mixed concrete, cement mortar, or concrete blocks with mortar. Pros: comparative simplicity and financial accessibility of its construction. Disadvantages: it cannot be placed on unreliable soils with close soil water, on clay and sand. But almost one hundred percent of the experts will recommend it to you, even if your site consists of unfavorable soils - but with amendments to the design: it will be necessary to make the “ribbon” of the foundation wider and deeper.
Strip concrete foundation is used more often than others due to its high functionality and not very high price.
But foundations in one form from combined materials are widespread.
Photo gallery: foundations combined in material
Strip foundation made of blocks; inside - drainage material 
Slab foundation made of blocks and concrete: the blocks here are permanent formwork 
A brick strip foundation on a concrete base is beautiful, but expensive and not very durable 
Slab foundation made of brick and concrete: here the brick wall plays the role of permanent formwork 
A strip foundation made of rubble stone and mortar will save you a lot of mortar. Options for grillages on a columnar foundation. Wooden, metal, concrete.
Components of the structure
After we have chosen the type of foundation, we need to choose what we will use: concrete or cement mortar; and - ready-made or self-made.
Concrete or cement mortar
Many people confuse these concepts and often call all poured structures concrete.
- Cement mortar is made from cement, sand and water, and sometimes from cement, lime or clay, sand and water, in the ratio determined by SNiP. Often additives are added to it to increase strength, water and frost resistance; plasticizers that increase setting speed and viscosity.
- Concrete is also created by mixing cement, water and fillers in a certain ratio. Instead of sand or together with sand, crushed stone, gravel, and pebbles are included in concrete. This solution produces the strongest artificial stone. Concrete is also used in the form of ready-made blocks and panels.
Components of good concrete: high-grade Portland cement, non-clayey fine river sand, fine crushed stone
You can order ready-made concrete, or you can make cement or concrete mortar yourself.
An electric cement mixer for preparing mortar will greatly facilitate the life of any craftsman.
The cement for mixing must bind the composition well, so heavy Portland cement grades M300–400 are used. The mixing ratio according to SNiP depends on the brand of cement, soil characteristics and foundation depth. Here is a useful table.
Table: ratio of cement and sand for laying foundations
Formwork
Formwork is a structure made of boards (sometimes panels) and stops, necessary for fixing the form when pouring concrete and cement structures.
Formwork for strip foundations made from edged boards is the most common solution for us
There are two types:
- Removable - disassembled after the concrete/cement has set; formwork made of boards and chipboards can be used up to 8 times. Industrial formwork - up to several hundred times.
The principle of constructing removable formwork from boards is the simplest
- Non-removable remains on the concrete. This is a recent invention, they are made from polystyrene and connected with special locks. It is quite expensive, but serves as insulation, which is very practical.
Fixed polystyrene foam formwork is connected with special locks and then serves as insulation
Permanent formwork also includes hollow concrete blocks of various shapes, which are placed on a sand bed in a trench, connected with a metal rod and filled with concrete.
Fixed formwork made of hollow blocks is also very convenient, although difficult to implement
Products
They are absolutely necessary to ensure that the subfloor or space under the house is ventilated, and that excess dampness, fungi and mold do not grow there. The soil releases moisture and must dry. The vents are especially relevant for the log house we have chosen, as well as for any wooden structures, but only if there is an underground space in the case of a sealed monolithic strip foundation. If the floors are laid on a slab, or the foundation is piled, there is simply no need for them.
According to SNiP 31–01–2003 (updated as SP 54.13330.2011) “Residential multi-apartment buildings” (clause 9.10), the total area of vents should be 1 to 400 of the basement area, but be at least 0.8 square meters. One hole should be no less than 15x15 centimeters. If it is larger, it will require special reinforcement when pouring, so we will make smaller vents. There must be an even number of them, and they must be located opposite each other. They should be 90 centimeters or less from the corners.
The vents should be 90 centimeters or less from the corners
If there are internal foundation strips, then they should also have vents so that there are no sealed chambers left.
There should also be vents in the internal foundation strips so that there are no sealed chambers left
It is not necessary to close the vents for the winter, according to SNiP 11-3-79 “Construction Heat Engineering”, which regulate the ratio of temperatures in the underground and outdoors. It is better to insulate the floor well.
If for some reason you did not make holes when pouring the foundation, you can punch them later with a grinder or hammer drill. But this violates the integrity of the foundation and poses a difficult task.
If the vents are not made when pouring the foundation, you can punch them later with a grinder or hammer drill
You can close the vents from mice and other small animals with special grilles.
A cushion of sand, crushed stone or gravel is necessary for drainage, thermal insulation, and better placement of the mortar. For a typical strip foundation, a thickness of about 30 centimeters is sufficient.
The pillow under the foundation is clearly visible in this diagram
Waterproofing
Waterproofing can be:
- with film, lining the boards until they harden - so that the boards can then be used for other purposes (optional);
Waterproofing formwork boards during the construction of a grillage for a pile foundation
- roofing material (on top) and bitumen mortar (the entire base can be used) after hardening - to prevent moisture from penetrating into the walls (it is strictly necessary, and it is better to use both materials).
Waterproofing the foundation with bitumen and roofing felt is an absolutely necessary thing in construction.
Concrete is quite fragile and is unable to resist bending under uneven deformations. Reinforcement is a guarantee of the strength of the foundation, saving it from cracking and shifting.
The reinforcement diagram shows its principle and necessity
There are simple rules:
- It is better to avoid welding or use it selectively, giving preference to tying reinforcement.
Tying reinforcement contributes to greater flexibility of the foundation
- The diameter of the reinforcement is 0.1% of the cross-sectional area of the tape, taking into account its length. It is accepted that if the length of the tape is more than three meters, then the cross-section of the rod is 12 mm.
Foundation reinforcement is the key to the strength of the house
- There are also rules for determining the distance between vertical and horizontal rods and their number per linear meter.
Determining the distance between vertical and horizontal bars
Insulation and finishing
You should not neglect the insulation of the foundation at all - you will greatly save money on heating the house and basement, and protect the house from dampness. Moreover, you can do this while pouring it, or you can do it after it has hardened. You may be pouring with polyurethane foam formwork, but you can also lay polymer panels in regular formwork. Or sheathe the finished foundation with such panels and cladding on top.
Insulation for the Penoplex foundation - polystyrene foam PSB-C 25 2000x1000x100mm - laid on a waterproofing film
The foundation itself can be finished with any material. There is endless scope for creativity here!
Blind area
Around the foundation, after building the house, it is imperative to make a blind area - a strip impenetrable to water, wider than the overhang of the eaves of the house, ideally with a well-thought-out storm drainage system and good drainage. Its main purpose is to prevent water from penetrating the foundation. Water that has saturated the ground can cause heaving of the soil and cracking of the foundation. Water can get inside the basement and cause the wooden house to rot from below.
The blind area can simply be made of asphalt, concrete or cement mortar (necessarily with reinforcement to prevent cracking, on a sand or gravel bed), it can be tiled, or it can be finished with the same material as the foundation itself. Its thinnest part should be at least 5–7 centimeters thick, and it must have a slope away from the house for better drainage of water.
The thinnest part of the blind area should be at least 5–7 centimeters thick, and it must have a slope away from the house for better water drainage
Sometimes the blind area is also insulated for better effect.
Insulating the foundation and blind area will completely protect the house from the cold
Photo gallery: options for blind areas and foundation linings
The foundation is faced with colored pebbles. Rubble stone and tiles are used here. Pebble cladding is a cheap, but very beautiful option. Cladding with rubble stone is very beautiful. The blind area and foundation can be finished with granite. Concrete blind area and stone-trimmed foundation - a competent approach. Concrete blind area and stone-trimmed foundation - very elegant solution Blind area finished with tiles on concrete Asphalt blind area is also an excellent and very simple solution Blind area trimmed with pebbles in concrete
Weather conditions during pouring
It is especially necessary to specify favorable weather conditions when pouring the foundation, since there are a lot of pitfalls when working in low temperatures.
- Regular cement mortar will not set if the outside temperature is below 5 0 C, and your foundation will immediately begin to crumble.
- Digging in frozen ground is always unpleasant. It's just very difficult to do it manually, and when using machinery there is a risk of damaging the equipment.
- The sand and gravel cushion will be filled in poorly, because in winter both sand, pebbles, and crushed stone are in a frozen state, and it is extremely difficult to compact them well. When they thaw, the pillow will not have the required density and elasticity.
- If you want to use waterproofing of the formwork, then the film is brittle in winter, and it will be extremely difficult to do it carefully.
- The fittings have a high coefficient of thermal expansion. A reinforcement structure welded in the cold will certainly increase in size with warming.
- In addition, there is always a danger that when the temperature rises and the ground thaws, the soil will move, and this will certainly lead to shifts in the foundation and can also lead to its rapid destruction.
Pouring a foundation in winter is a dangerous undertaking
But if you are itching and you are ready to work at low temperatures, or the nature of your soil (sand) is such that winter is the only way to avoid crumbling during excavation work, then you need to fulfill some conditions so that troubles do not arise later.
Table of concrete setting at different temperatures
The figure clearly shows that the optimal temperature for pouring the solution into the formwork will be in the range of 15–25 0 C.
Foundation calculation
Of course, we have already chosen a place for the house. The humorous picture determines all the permitted places for construction on your garden plot according to SNiP.
Drawing of choosing a location for a house, taking into account all the buildings and trees on the site and the neighbor’s fence
First, which is completely natural, we make a house project, relying on expert opinions or previously known data on soils and waters on the site. Choosing material for the house. We must not forget that a slab foundation occupies the entire area of the house, and a strip foundation and all types of pile foundation grillages must be under every wall of the house, even the inner one. Taking into account all the factors, we chose a one-story wooden house made of rounded logs with an area of 122 m2.
A one-story wooden house is the best project for unreliable soils, and a strip foundation that is not very deep is well suited for it.
For the house we have chosen, a non-buried monolithic concrete strip foundation is perfect, which is most often used for light wooden and frame houses. Under such a foundation, trenches for water supply and sewerage can then be laid. It is a continuous monolithic tape, buried 50–70 centimeters and protruding above the ground by 50 centimeters, the same in cross-section in all its places. Its protruding part serves as a base.
Calculator
Do not forget that all external dimensions of the house and veranda are indicated in the center of the foundation strip, and not along its edges, and internal dimensions - according to the internal dimensions of the walls. If the number of internal walls indicated is insufficient for your project, their lengths can simply be summed up, which is what we did. The thickness of the foundation strip is set depending on our soil or our preferences.
Table: entering the necessary numbers in accordance with the house project
| Position | ||
| 1 | Main parameters (house dimensions, m) | |
| Length | 8,33 | |
| Width | 10,5 | |
| 2 | Additional parameters (lengths of internal walls, m) | |
| 1 additional wall | 21 | |
| 2 additional wall | 2,85 | |
| 3 additional wall | 11 | |
| 4 additional wall | 3,14 | |
| Length of the largest wall of the veranda | 10,5 | |
| Length of the smallest wall of the veranda | 2,84 | |
| 3 | Desired belt power | |
| Width (m) | 0,4 | |
| Depth into the ground (m) | 0,5 | |
| Base height above ground level (m) | 0,5 | |
| Thickness of sand cushion (m) | 0,3 | |
| Number of reinforcement bars per level | 3 | |
| Number of reinforcement levels per 1 meter of tape height | 2 | |
| Distance between vertical posts of reinforcement (m) | 1,5 | |
| 4 | Average prices for materials (RUB) | |
| Concrete M-250 (per 1 m 3) | 3500 | |
| Sand for pillows (per 1 m 3) | 500 | |
| Metal fittings D=12mm (per 1 linear meter) | 35 | |
| Edged board for formwork (40x150x6000mm, per 1 m 3) | 6000 | |
After entering all the initial data, the calculator gives us an accurate calculation of the materials we need and their cost, based on current average prices.
Table: final calculation of necessary materials and approximate calculation of finances
| Position | ||
| 1 | Necessary materials | |
| Concrete M-250 | 36.7 m 3 | |
| Sand | 11 m 3 | |
| Metal fittings | 1030.1 m | |
| Edged board for formwork | 6.7 m 3 | |
| Self-tapping screws | As needed | |
| Twine and pegs for marking | From improvised means | |
| 2 | Financial costs (RUB) | |
| Concrete M-250 | 128562 RUR | |
| Sand | RUB 5509.8 | |
| Metal fittings | RUB 36,054.8 | |
| Edged board for formwork | 40016.2 RUR | |
| Total total cost (excluding screws) | ||
| RUB 210,142.8 | ||
We will need tools:
- Bayonet and shovel shovels
- Wheelbarrow
- Manual rammer or vibratory rammer for compacting soil and sand
- Construction mixer for mixing cement (container for manual mixing)
- Welding machine for welding fittings
- Hammers
- Grinder for cutting reinforcement
- Nail puller
- Mount
- Hydraulic level or level
- Roulette
- Carpenter's meter
- Pliers
- Stitchers for finishing
- Circular saw for boards
- Electric drill for boards
- Board screwdriver
- Goats for cutting boards
Marking and excavation work
We prepare the site: mow the grass, level the ground, uproot trees and stumps at the construction site. The construction site should be larger than the area of the house by at least a couple of meters in each direction.
We mark the trenches for the foundation strip with twine and pegs, not forgetting about the trenches for water supply and sewerage communications. The pegs must be driven in indented from the corners of the foundation so that the corners are marked by the intersection of the strings.
The height of the pegs should be equal to the base of the foundation - that is, the height to which the foundation strip protrudes above the ground.
Marking the foundation - parallel lines formed by strings are visible
The sand or pebble cushion under the strip foundation is compacted with a vibrating rammer
The cement will reach its maximum strength only in a month
We begin to assemble the house on the finished foundation
Video: creating a strip foundation with your own hands
You are convinced that pouring the foundation yourself is quite simple in technology, but complex in terms of time and labor costs. But you will save a lot of money and get satisfaction from the fact that you did it!
The importance of the foundation for any building is difficult to overestimate, because a reliable foundation of a building is the primary condition for its long-term trouble-free operation. You can build any, no matter how strong and beautiful walls, a well-designed and installed roofing system, reliable floors, and carry out expensive finishing. But all this can “go to waste” if errors were made when calculating the foundation, and during its construction, negligence was shown, unacceptable simplifications were made, low-quality materials were used, and the established technology was violated.
So, the foundation is a key stage of any construction, which sometimes takes up to a third of the total budget. In an effort to save some money, some potential homeowners are seriously thinking about the problem: is it possible to build a foundation with their own hands? The answer to this question, unfortunately, is not obvious. It’s one thing to create the foundation for a small country house, garage or outbuilding, and quite another thing to create a full-fledged country mansion with several levels, and even with adjacent extensions.
This article will discuss the main types of foundations, but the main emphasis will be on its strip variety. We hope that after reading the article, many visitors to the site will become more clear whether they should undertake the construction of the foundation themselves, or whether it would be better to use the services of specialists.
Main types of foundations
There are quite a lot of varieties of foundations used in individual construction, but mainly four basic schemes are used, as well as their various combinations. And the main types include strip, columnar, slab and pile foundations.
Strip foundations
This is the most commonly used scheme, as it is suitable for almost all construction conditions, with the exception, perhaps, of regions with close permafrost or for buildings built literally “on the water.”
Despite a certain difference in the technologies for constructing strip foundations of various types, they all have a common feature - this is a continuous, closed strip-base along the entire perimeter of the house being built and under the internal load-bearing structures. The tape itself is buried in the ground to the required calculated value, and protrudes from above with its base part. The width of the tape is maintained the same throughout the entire foundation - this parameter should also be based on the calculations performed.
There are many types of foundations for the construction of private low-rise buildings. But most often, under domestic cottages, an option is installed in the form of a reinforced concrete strip under load-bearing walls. After all, to make a strip foundation with your own hands, you only need to have minimal skills in mixing concrete and follow the instructions. The technology for constructing such a base is simple, which is why it is so often chosen for independent implementation.
What it is?
Structurally, a strip foundation is a reinforced concrete structure created around 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, bathhouses, garages and even fences. It's not difficult to make it yourself.
This is what he looks like
However, when building such a foundation, it is extremely important to adhere to certain rules and recommendations. If the strip foundation manufacturing technology is not followed, the durability of the supporting structure itself and the building on it can be forgotten. They won't last long.
Seasonal swelling of soil, exposure to moisture on concrete without waterproofing, incorrectly calculated loads - there are many reasons for the destruction of the strip foundation 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 foundation
According to its depth, it can be either MZLF (shallow) or simply recessed. In the first case, the 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 freezing level of the ground).
If the soil at the construction site is rocky and the groundwater is deep, then it is better to choose a cheap and shallow concrete option that is small in volume. On heaving, high groundwater and sandy areas for the house you will have to make a more powerful and expensive support. Often the estimate for such a foundation for a home is such that it is necessary to choose a different type of foundation altogether.
Scheme of walls with MZLF
Structurally, a reinforced concrete strip base can be:
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 foundations
It has three undoubted advantages
The device is extremely simple - any novice builder can handle pouring concrete and laying blocks (there are step-by-step instructions - 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 foundation made of reinforced concrete will last for many years, even if heavy solid bricks, rather than light aerated concrete blocks, are used to build the walls of the house. 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:
Mandatory thorough soil analysis at the construction site;
The need to use lifting equipment (in case of using FBS);
Long concrete curing period of at least 3 weeks (if choosing a monolithic option);
Impossibility of laying on highly heaving and water-logged soils.
Step-by-step instructions - do-it-yourself foundation
The thickness and height of the tape of the base under consideration, as well as the depth of its placement, are selected based on soil analysis, climatic conditions of the area and the number of storeys of the building 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 using a ready-made project yourself. But in order to avoid mistakes, it is best to make the strip foundation yourself with the step-by-step instructions given below. It describes all the intricacies of building such a structure for a typical one-story cottage.
Stages of work
The first stage is marking and excavation work. Regardless of the depth of the foundation, the sole must rest on solid layers of soil. It can be clay, sandy loam, rocky layers or loam. They are usually hidden under turf and layers of ordinary soil. 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 main materials: fittings, insulation, boards for formwork
To mark the area you will need pegs, tape measure and twine. If the soil is dense, then the walls of the dug trench will make excellent formwork. It will only be necessary to build it up from above. If the soil is loose and constantly crumbling, then the trench will have to be dug somewhat wider so that formwork boards can be placed inside the hole.
The second stage is preparing the pillow. The bottom of the dug trench is leveled with sand and fine gravel. This sand and gravel layer should be thoroughly compacted, pouring water as it is poured. It should be between 10–30 cm in height. This cushion serves to redistribute and reduce point loads on the strip foundation from below during seasonal heaving of the soil.
You can put insulation on top of the pillow - this will prevent heaving from freezing the ground
The third stage is placing the formwork. Here you will need bars with a cross section of 30 to 40 mm and boards with a thickness of 15–20 mm or laminated chipboard. The formwork created for the concrete foundation of a house will subsequently be required to withstand a considerable mass of concrete poured into it. It should be made strong and reliable. If, after filling with the concrete mixture, it collapses, then everything will have to start again.
We install formwork from boards
If the groundwater at a construction site is high, then reinforced concrete will require waterproofing. From above, at the level of the base of the house, it is usually done as 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 its hardening and after.
The fourth stage is laying the reinforcement. For reinforcement, steel rods with a cross-section of 14–16 mm and thin dressing wire are usually used. The reinforcement can also be fastened using electric welding. But in this case, you need experience working with a welding machine and yourself. Plus, when performing welding, you must be prepared for the occurrence of metal corrosion in the future.
We knit reinforcement
Inside the trench, a frame of reinforcement with cells of 25–30 cm should eventually be formed. Moreover, it is laid so that the steel is covered on all sides by the poured concrete. Otherwise, the metal will inevitably begin to rust, and the house will definitely not last long.
The fifth stage is pouring concrete or laying out FBS. If it is decided to equip the foundation for a house being built using block technology, then this greatly speeds up the process of its construction. Here you don’t have to make formwork and wait almost a month for the concrete to set.
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 bottom row, FBS masonry is made with an expanding base.
If a monolithic option is chosen for the support structure, concrete should be poured immediately over the entire surface. No breaks in length and no layers in height. A monolith is just a monolith. The house must stand on a reliable foundation.
Nails can be used to mark the pouring boundary in the formwork.
When preparing the concrete mixture yourself, you need to mix cement, sand and crushed stone in proportions 1: 3: 3. But it is better to initially order a ready-made solution with a grade of M300 or higher.
Fill in
When pouring concrete, it is extremely important to ensure that no voids form inside it. There are special vibrating machines to perform compaction. However, you can also use a piece of reinforcement to pierce the poured mass and release air from it.
The sixth stage is waterproofing and blind area. It is allowed to begin waterproofing work 3-4 days after pouring concrete. It takes about three weeks for it to fully set. But you can already begin treating the strip foundation for the house with mastic, even though it has not yet completely hardened.
Waiting for it to harden
Also, along the entire perimeter of the building, you will need to make a blind area to drain rainwater away from its walls.
Ready foundation with basement rows of bricks
Use for building a house
Such a support can easily support private houses two to three floors high. To build a cottage on it, you can choose laminated veneer lumber, logs, foam blocks or ceramic blocks. You just need to properly examine the soil and correctly calculate all the loads. Finally, it wouldn’t hurt to cover the foundation for additional protection from the weather. Natural stone or clinker tiles for the facade are ideal for this. But you can choose easier-to-install and inexpensive corrugated sheeting or siding.
The foundation is the basis of any structure. Its main purpose is to ensure the strength and reliability of the erected structure. Building the foundation is a key point in the overall construction of a house. If you want to build a foundation with your own hands, then do it as efficiently as possible! A well-laid foundation will extend the life of the building and protect it from the negative effects of the environment. The type of foundation is of great importance, the choice of which largely depends on the type of soil at the construction site and the type of structure.
Types of foundations and their features
You can build a house on any foundation; it is only important to take into account the natural conditions of the area where the construction site is located. The following types of foundations are used in modern construction:
- A columnar base is erected for wooden or light frame buildings, as well as for houses in which it is not planned to arrange a basement. Pillar bases are ideal for sloping areas. From an economic point of view, it is more profitable to build such a foundation at a large depth of soil freezing or in wetlands.
- A base in the form of a concrete strip is the most common option. Strip foundations can be erected under brick houses and fences. However, it is not recommended to erect heavy stone structures on a strip foundation. The strip base allows you to equip a basement in the house. The best place for the construction of the belt is considered to be an area with deep groundwater and an insignificant amount of soil freezing.
- A slab foundation is an ideal foundation option for questionable soil characteristics. This is a reliable, solid foundation. The slab is one of the most expensive construction processes that requires precise calculations. Therefore, you should only choose as a last resort.
- The pile-screw foundation is very popular due to its high load-bearing capacity, low price and high installation speed. The weak point of such a foundation is . A pile foundation can be erected on all types of soil with the exception of rocky soil.
You can order high-quality concrete mortar for pouring all types of foundations with delivery on the website beton174.ru.
Self-construction of the foundation for a house
In order for the foundation of the house to be strong and reliable, it is necessary to treat each stage of its construction very responsibly.
Stage 1. Marking the foundation.
Making markings for the foundation
The markings indicate the position of the future house, so the strength of the entire structure depends on its correct execution. The main tools for this stage are wooden pegs and thick threads. The following actions are performed:
- Pegs are driven in along the expected line of the building's façade and a thread is pulled between them. The distance between the stakes should exceed the length of the house by 0.5 m.
- On a thread, mark the places where the corners of the house will be located, and draw lines perpendicular to the lines of the facade through these marks. Their length should slightly exceed the planned width of the house.
Advice! To check the perpendicularity of the corners, you need to measure 3 m along one thread, and 4 m along the other. If the distance between these points is 5 m, then the angles are right.
- Along these threads a distance equal to the length of the side walls is measured and marks are made using pegs.
- A thread is pulled between the marks, parallel to the line of the house facade.
Advice! To check the accuracy of the angles, you need to measure the diagonals of the resulting rectangle. If these parameters are equal, then the marking is done correctly.
- After all control measurements are taken, the internal lines of the foundation are marked. To do this, it is necessary to make a retreat of 0.4 m inside the perimeter. To more accurately mark the corners, the pegs are placed outside the perimeter.
Stage 2. Excavation work.
Earthworks during construction
You can do the work at this stage manually using a shovel. You can use special equipment that will speed up the process several times. depends on the type of foundation chosen: for a shallow-depth strip - 0.6-0.7 m, for a regular foundation - about 1.8 m. To arrange a sand and gravel cushion, an additional 20 cm is dug.
The walls of the trench must be strictly vertical; a building level is used to check. To prevent the soil from crumbling, you can install supports.
The bottom of the trench is carefully leveled, also using a building level to check horizontality.
The gravel-sand cushion is arranged in the following order:
- Sand is poured into the bottom in a layer of 10-15 cm, moistened and compacted.
- Sand is poured back in and thoroughly compacted again.
- A layer of gravel up to 15 cm high is laid on top of the sand, which is also carefully compacted.
Advice! To avoid erosion or silting of the shallow foundation cushion, the bottom of the trench can be covered with geotextiles.
Stage 3. Installation of formwork for the foundation.
Making formwork
Arranging the strip base formwork is a very important stage. His main task is to choose the right material. After all, the formwork must withstand the load of a huge mass of concrete mortar. Most often, edged boards with a thickness of more than 20 mm or sheets of moisture-resistant plywood are used to make formwork. These materials are low cost and more accessible compared to other options.
Installation of formwork is carried out in the following order:
- Rectangular boards are constructed from boards, fastening them with transverse bars. It is better to use self-tapping screws as fasteners. This will make it easier to dismantle the formwork system in the future.
- The installation of shields is carried out on both sides of the trench with reinforcement after 50-70 cm with wooden spacers. Using spacers of the same length, you can achieve the same distance between opposite sides of the formwork.
- Outside, the formwork is secured with wooden supports. One side of the bars should be cut at 45 0. It is with this end that the block rests on the formwork panels. This design will make the mold more durable.
- Next, the formwork and the bottom of the trench are covered with waterproofing material, which will prevent the wood from absorbing milk from the concrete solution. For this purpose you can use .
Stage 4. Creation of a reinforcing frame.
The reinforcing frame embedded in the foundation serves to strengthen the foundation and extend its service life. Most often, the frame for the foundation is made of steel rods with a diameter of 10-16 mm, and soft knitting wire is used to bind them together. The frame is created in the following way:
- The reinforcement is cut into rods along the length and width of the trench.
- Longitudinal rods, laid at a certain distance, are fastened with transverse elements every 25-30 cm. The result is a horizontal lattice.
- To create a three-dimensional shape, horizontal gratings are laid in several rows, also fastened with transverse rods.
At the corners of the foundation and at the intersection of the main tape with the load-bearing partitions, it is necessary to additionally tie the frame.
Stage 5. Pouring concrete.
To pour the foundation, you need to use high-quality factory-made concrete. It will be delivered to the site using specialized equipment. But to save money, you can prepare the mixture yourself on the site. For this you will need M400 grade cement, fine crushed stone and coarse sand. Compliance with the mixing proportions is a very important condition that guarantees a high-quality solution. The mixture is prepared using the following technology:
- Sift 3 parts of sand and combine them with 5 parts of crushed stone.
- Mix everything thoroughly and add 1 part of water. In this case, the liquid is introduced in small portions until a solution of medium thickness is obtained.
- The solution is stirred until a homogeneous consistency is obtained.
The resulting composition must be poured in layers of no more than 20 cm. It is very important that the solution fills all the voids in the reinforcement frame. To compact, you can use small reinforcement bars, piercing the poured mixture with them. This will also remove any air bubbles that may have formed when mixing the solution. If you use a special vibrator, you can increase the strength of the poured base several times.
The next layers should be poured according to a similar pattern until the concrete is even with the stretched line. The top of the concrete mixture is leveled using a trowel.
Dismantling of the formwork can be done after two weeks, and further construction is recommended to begin only after a month.
Important! During the entire period of strengthening the foundation, it is necessary to monitor its surface. From rain and sun rays it is necessary to cover the foundation with plastic film. To avoid cracking, maintain constant moisture.
How to build a foundation for an extension to a house
Sometimes, after the main construction is completed, the need arises to build an extension to the house. To avoid troubles during the operation of this part, it is necessary to build it on a high-quality foundation. To do this, you must follow the established rules:
- The foundation of the house and the extension must be exactly the same.
- For rigid fastening of the additional base, the reinforcement frame of the main building is connected to the reinforcement of the extension.
The process of pouring the foundation for an extension is carried out using the same technology as the main tape.
Creating a foundation for a house with your own hands is a very responsible and time-consuming process. However, if you follow all the rules and regulations, you can make a high-quality and reliable foundation with your crayfish.