The arrangement of the foundation is a serious event, because this design is the supporting structure for the whole house. The type of foundation is selected depending on the financial capabilities of the owner and the type of construction (wood, concrete, etc.). A monolithic foundation slab includes iron reinforcement and concrete. Its calculation requires an understanding of the design and knowledge of the formulas.
Scopes and features of a monolithic slab foundation
A structure of this type is classified as floating. Another feature of it is that it is located at a shallow depth in the ground. It is called monolithic due to its solid form. A plate is laid under the entire area of the future residential building.
Useful information! The rules for placing this foundation take into account not only depth, but also the presence of a special pillow, which includes two components: sand and gravel. It is needed in order to restrain and absorb the pressure of the soil when it is bloated (swelling). The expansion of the soil occurs due to the freezing of the water contained in the soil.
Arranging such a foundation is often the only possible way out. If necessary, you can order a turnkey monolithic foundation. The price of such work depends on many individual factors. Two situations are known that have no alternative to installing another base:
low stability soil;
clay with a large depth of freezing.
Such a foundation has a fairly simple design, which, however, has many nuances determined by the specific operating conditions of the foundation. The arrangement of a monolithic slab requires a large volume of concrete and metal reinforcement, as well as their correct ratio. Concrete must be of high quality – not lower than grade B30. Reinforced concrete layer over the entire area with a small margin. This allows you to increase the reliability of the plate.
Thus, the arrangement of such a foundation is quite expensive. The final price of a monolithic foundation slab is calculated depending on the area of the future structure and the density of reinforcement. In some cases, it may be lower than the cost of installing a tape structure, which is located at a greater depth.
Such a base can be used for installation of columns. A monolithic foundation in this case is very common. To determine the depth of such a structure, it is necessary to calculate the weight of a residential building and determine the type of soil in a particular area. A small deepening in the ground, prone to heaving, causes the building to rise in the winter, but this is an acceptable situation.
Advantages and disadvantages of monolithic foundation slabs
The solid type construction used as the foundation for a residential building has several advantages. In addition to the common advantages, you need to familiarize yourself with the disadvantages of such plates. The pros and cons of a monolithic foundation slab in the aggregate allow us to evaluate the feasibility of its organization.
First of all, it is worth noting that the arrangement of a monolithic foundation does not require the use of special equipment. However, there may be exceptions. For example, during the installation of a prefabricated variety, which is constructed from individual constituent elements.
The slabs of the strip foundation, as mentioned above, are laid deeper in the ground than the monolithic foundation. Therefore, the use of a slab as a base significantly reduces the volume of earthwork. To install such a foundation, it will be enough to remove the top layer of soil (fertile).
Useful information! The flat design of the monolithic base contributes to the even distribution of the loads that a residential building exerts on it.
The tiled foundation has another very important advantage: it can be used in areas with unstable soil. The tape variety in this case is not suitable.
The following advantage is very important for those who want to make such a design on their own. It lies in the simplicity of its manufacture. All the skills that a worker must possess in order to create it are the ability to mix cement and design formwork. Such a base is characterized by high strength and reliability.
Monolithic foundation slab: the main disadvantages
Almost any type of building can be built on top of the monolithic structure. To create buildings using aerated concrete blocks, wood, brick, etc. The advantages of this design are sufficient, but it also has some disadvantages. For example, in order to install a monolithic slab, you need a flat surface. In building codes and regulations (SNiP) there are certain restrictions on this indicator.
After laying a monolithic reinforced concrete slab, the possibility of arranging a basement or a cellar disappears. Also a serious minus is the problematic laying of various communications, which arises due to the continuous structure of the foundation.
To equip such a design, you will need to purchase a large number of materials. This, of course, will affect its final cost. That is why many people resort to installing a monolithic foundation with their own hands, without involving special equipment.
Communication is worth mentioning separately. Water and sewer lines must be designated in advance in the draft foundation. It is important to remember one more rule: pipes are laid before the start of pouring, after which the main work is done.
The device of a monolithic foundation: constituent elements
A monolithic base is the most expensive. Based on this, each owner wants to save on its installation. It is very important that the cost savings do not go too far, as this may affect the reliability of the foundation. In the project it is necessary to enter a plate of minimum height, at which a proper degree of strength will be ensured. There are several factors that are taken into account when calculating the width of a reinforced concrete foundation.
A monolithic type foundation slab will cost more than other options, but will also last much longer
This type of construction consists of several layers, in addition to the main concrete part. First of all, it is necessary to determine the composition and characteristics of the soil on the site. A monolithic foundation slab for the house can be installed on almost any soil, but the geometric indicators of the design depend on its quality. A prerequisite is the removal of the top layer.
After the elimination of the fertile layer of soil, it is necessary to pour litter under the monolith into the pit. As a pillow, providing depreciation of the slab for the foundation, use sand mixed with crushed stone. The thickness of this layer varies from 40 to 60 cm, depending on how much clay the soil contains.
The next layer is the concrete, which is a small layer of concrete, which is necessary to level the foundation before pouring. And also the footing protects the carpet used as a waterproofing.
After the organization of the footings, the waterproofing material is laid. For tiled foundations, special rolls are used, which can be purchased at any hardware store.
Note! The device of a monolithic foundation slab requires laying 2-3 layers of waterproofing material.
Next, insulation is performed. It is available in two versions: rolls and plates. Thermal insulation consists of expanded polystyrene (PPS), characterized by a high density index. Then comes the main layer – concrete, inside of which are two reinforced grids. They are intended to increase the integrity and strength characteristics of the structure. For example, a monolithic foundation for columns must be very strong.
It is important to remember that the upper part of the plate is necessarily located above the soil level. This is explained quite simply: when laying wall materials they, as a rule, sag to a certain depth in the ground.
What types of monolithic concrete slabs exist
The main criterion by which monolithic concrete foundations are classified is their internal structure. Depending on this, two varieties of such foundations can be distinguished:
In the first case, the styling technology includes the traditional sequence of actions, without any changes. Classical filling of the slab with internal reinforcement is done on a sand and gravel lining.
Installation of a precast monolithic foundation differs from the classic version. This method involves the use of finished reinforced concrete products. They are stacked on a pillow of sand and gravel. Then concrete mortar is poured over them (with a less wide layer), that is, in this case, the factory elements perform the function of the base.
What kind of monolith is better? Both the first and second options for organizing the foundation for the house are distinguished by their reliability and strength characteristics. Thus, according to these signs, they are equivalent.
The main advantage of the prefabricated variety is a more affordable price. A turnkey monolithic foundation slab will cost 28-42$ more. for 1 m². Prefabricated slabs have another small advantage: with their help, the arrangement of the foundation is accelerated, since they are produced in finished form.
What types of monolithic concrete foundations exist
To date, there are 3 main types of monolithic plates. All of them have their own structural and installation features. Before proceeding with the procurement of materials and subsequent installation, it is recommended that you familiarize yourself with each type of design in more detail.
Classic stove. It consists of concrete and a reinforced mesh, which is located inside the base. The technology of its installation is quite simple. The design is placed on a pillow consisting of sand and gravel. Warming is not always a prerequisite for installation. The thickness of the monolithic reinforced concrete foundation depends on the soil and the mass of the building. The minimum figure in this case is 20, and the maximum is 60 cm.
Note! The thickness of the pillow layer depends on how deep the upper fertile soil layer lies. It is completely removed, and the resulting foundation pit is filled up with sand and gravel.
The Warmed Swedish Plate (WSP). It is a technological monolithic design, which includes not only fittings, but also a warm floor system. Accordingly, the cost of a monolithic foundation of this type is the highest.
There are other differences between WSP and classical design. The first of them is the fact that it is equipped with a special formwork, the shape of which corresponds to the Latin letter “L”. This formwork is not removable, and its function is to prevent leakage of thermal energy, which reduces the cost of operation of the plate.
Another feature of WSP is that the concrete layer located on top of the underfloor heating pipes and reinforcement has a thickness of 10 cm. In the manufacture of this design, high-quality materials that have a long service life are used. This is due to the difficulty of repair work in the event of a failure of a system passing or embedded in the slab.
The disadvantage of such a foundation is the complexity of its arrangement. This is due to the fact that the installation of stiffeners requires a separate time. However, the bearing capacity of the solid structure is increasing. The thickness of such a plate varies from 10 to 15 cm.
Calculation of a monolithic foundation slab: procedure
For a competent calculation of the thickness of all elements of the foundation for a residential building, you need to follow a certain sequence of actions. Violation of this regularity will ruin the design and make it unusable. The first thing that needs to be calculated is the size of the sand and gravel cushion. It is important to consider that all dimensions are reflected in the final cost of a slab of a monolithic foundation.
Such a pillow performs several functions at once. The first of these is depreciation. And also worth noting the waterproofing function. Under the influence of the gravity of the monolithic structure, the pillow is compressed and creates reliable protection against groundwater. There are several features of determining the thickness of this layer, which is an important component of the device of the slab foundation.
This indicator varies from 15 to 60 cm, and there is a direct dependence of the thickness of the pillow on the depth of freezing of the soil. The amount of groundwater also plays a very important role.
Useful information! Experts advise to place a small layer of fine gravel on top of the sand. Its thickness is determined individually, but it should not exceed 5-10 cm from the total height of the sand and gravel cushion.
If the site is located on the ground, the freezing depth of which exceeds 1 m, then it is recommended to lay the pillow in a thick layer (60 cm). The same applies to those sites that are located on unstable soils. The pillow is a very important part of the design and protects the monolithic slab under the foundation from moisture. And finally, the maximum pillow size must be selected if the ground contains an excess of groundwater.
In areas with a soil freezing depth of up to 1 m, it is possible to equip a pillow with a thickness of 20-30 cm. These dimensions require the presence of dense soil and the absence of groundwater. Thus, having determined the characteristics of the soil, it is easy to make the necessary calculation of the thickness of the pillow. Having determined this value, it is possible to calculate how many materials will be required for its organization.
At the next stage of calculating the monolithic foundation, the number of necessary reinforcement is required, which will be required to give rigidity to the concrete slab. It is important to remember that the reinforcing mesh is laid in 2 layers. The distance between them should not exceed 5 cm.
After determining the amount of reinforcement, the plate itself is calculated. Its minimum thickness is 15 cm. The depth of soil freezing is the main characteristic that you need to focus on when choosing this indicator. There is one important rule: the supply of concrete located at the edges of the reinforcing mesh should be at least 5 cm.
Calculation of the thickness of the monolithic foundation slab
For an optimal calculation of the thickness of a plate of this type, it will be necessary to calculate several indicators. First of all, it is worth determining the distance between the first and second reinforcing mesh. Their location directly affects this geometric indicator. Next, you need to determine which layer of concrete should be above the reinforcement, as well as under it. In this case, it is worth taking into account the thickness of the rods from which the mesh will be made.
The standard thickness of the foundation slab is approximately 20-30 cm. However, with such dimensions, the structure negatively affects the composition of the soil, since its layers shift in the place where the monolith is installed.
The calculation also takes into account how much the plate will protrude above the top line of soil on the site. In this case, the following pattern can be traced: the more the bearing walls are spaced, the thicker the monolith should be. Material for such a foundation will require quite a lot. If necessary, you can make a tape monolithic foundation. Reinforced concrete structure of this type is solid, but is installed in a horizontal plane in the ground.
It is worth noting that there are certain regulatory documents by which the foundation is calculated. If you independently perform the foundation for a residential building, you must definitely familiarize yourself with them before starting work. These documents take into account the calculation of the thickness of the foundation in two stages:
load bearing calculation.
Note! The reliability of the entire residential building depends on the thickness of the slab foundation. Any design errors can lead to the formation of cracks in the walls and their subsequent destruction.
At the first stage, the total mass of the building is calculated. The final figure should take into account not only the materials from which the house will be made, but also the weight of snow on the roof (in winter), interior items inside the house, as well as all residents. There are special tables by which you can determine the value of the load for a particular material. For example, for 510 mm brick walls this figure is 920 kg / m².
When performing calculations of other types of monolithic bases (for example, a columnar monolithic foundation), additional measurements are required. In this case, it all depends on the structural elements.
To calculate the mass, you need to take a numerical value from the table corresponding to the material of your walls. This indicator already takes into account their thickness, therefore, to determine the weight of the building, you just need to multiply this value by the area.
Definition and use of the coefficient of reliability
The reliability coefficient is needed in order to determine the margin of bearing capacity of a concrete structure. As a rule, this indicator can easily be taken in the tables, which indicate the load parameters for a particular material. When organizing a monolithic slab with your own hands, it is recommended to collect as much data as possible and perform appropriate calculations.
The coefficient of reliability determines the margin of bearing capacity. To do this, it should be multiplied by the load indicator. This parameter is very important, since when changing the purpose of the building, it is necessary in order to determine the feasibility of this solution.
This value varies from 1.05 to 1.4, depending on materials and load indicators. It is worth noting that for a reinforced concrete monolithic structure, the coefficient will be 1.3. It is a constant indicator that fully complies with the properties of this material.
Determining the thickness of a monolithic foundation using the formula
In order to determine the total mass of a residential building, it is necessary to make a fairly simple calculation. First, you need to multiply the total area of the structure by the load indicator, and then by the reliability coefficient. Then the resulting numbers are added up. Thus, the total weight is determined.
After preparatory calculations, you can begin to calculate the most important thing – the thickness of the future foundation. To do this, you can use the calculator of a monolithic foundation or carry out calculations using formulas. In the second case, you need to be careful, because it is very simple to make a mistake in a particular value or to write the number incorrectly. First of all, you need to determine the specific load. Consider the formula:
P1 = M1 / S, where:
P1 – the specific load exerted on the soil is presented in the table (excluding the foundation);
M1 – total load (mass) from the building, which is determined during the collection of loads;
S is the area of the reinforced concrete slab.
Note! To continue the calculations, you need to find the difference between the specific load and the tabular value of this value. This is quite simple: the second is subtracted from the first.
Next, you need to determine the mass of the foundation, which is optimal for this situation. To do this, multiply the load difference obtained above by the area of the concrete slab. And finally, having at hand all the necessary values, you can easily calculate the thickness of the future monolithic foundation for the house. The calculation is carried out according to the following formula:
T = (M2 / 2500) / S, where:
T is the thickness of the foundation;
M2 – the required weight of the building;
2500 – density of 1 cubic meter of reinforced concrete slab;
S is the plate area calculated in m³.
In this way, the thickness of the concrete slab is calculated. The resulting figure is rarely round, so it is recommended to round it to the nearest value (0 or 5). In case of difficulties in determining these parameters, it is recommended to contact professionals and think about the advisability of ordering a turnkey monolithic foundation.
When determining the thickness of the slab of the base of a residential building, it is advisable to use several methods at the same time. There are other formulas, as well as online calculators, with which you can also get the required value.
How to calculate a concrete slab using a foundation calculator
An online calculator is a special program that is used to carry out calculations of all the necessary sizes of a future design. Using it, the thickness of the monolithic plate is calculated, as well as the size of its formwork and the number of reinforcement. The cross-sectional index of the reinforcement can also be determined using this program. Such a method which has some advantages over formula calculations:
the presence of 2D and 3D visualization.
The latter advantage is considered one of the most useful, as it allows you to evaluate in real time the feasibility of a particular design. Having a preliminary model of the foundation of the slab, it is much easier to find errors that were made during data entry.
Note! Thus, using the 3D model, if necessary, you can immediately correct the flaws and check the resulting option again.
Using an online calculator, it is quite simple to calculate the amount of reinforcement and its diameter. If necessary, you can determine the allowable distance between the individual elements, as well as their mass. An online calculator of a monolithic foundation (slab) is able to make comparisons between the data obtained and the optimal values indicated in SNiP.
These programs have other additional features. For example, you can determine the thickness of the boards that will be used for the construction of wooden formwork. It is also worth noting that the online calculator allows you to calculate the amount of insulation and the optimal proportions of concrete.
Foundation plate reinforcement: process value
Concrete material copes with compressive loads. However, it also has a weak point – low bending resistance. For this, the use of special metal nets made of reinforcement is recommended in the construction of monolithic plates. They can significantly increase the strength and endurance of the plate to the adverse effects of any kind.
The reinforcement of the slab foundation contributes to its resistance to external loads. Such effects occur in the cold season, when the soil freezes to a certain depth. Thanks to hardening, the base of the building is able to withstand the short-term influence of moisture (for example, during leakage). Without a metal mesh, when wet, concrete significantly loses its strength.
Reinforcement is a necessary step in the construction of the foundation slab. Monolithic technology is based on the use of metal grids. In order to perform the reinforcement of the foundation correctly, it is necessary to calculate the number of elements. And it is also very important to accurately determine the geometric characteristics of the individual components from which the metal mesh will be constructed.
Note! If your house belongs to the category of standard, then the project can not be done independently, but simply download the finished construction scheme on the Internet. However, experts recommend that you check it before using it, as it sometimes contains errors. The implementation of such a scheme can be entrusted to a qualified organization, but it will cost quite a lot of money.
How to choose the right fittings for the tile foundation?
Monolithic foundations are very popular in the construction of country houses, as well as cottages. These residential buildings have one thing in common: they do not require the organization of a basement or a cellar. For private houses, a monolithic reinforced concrete base is used less often.
To form a slab foundation with your own hands, you need to understand its design. This is a concrete slab, inside which iron rods are laid (in perpendicular directions). It is important to remember that the reinforcing mesh can be one if the thickness of the cement base is less than 20 cm.
Before proceeding with the calculation of the number and dimensions of reinforcing elements, it is necessary to choose a suitable brand of rods. It is determined depending on the operating conditions of the foundation. For example, if the soil on the site is quite dense, then reinforcing bars that belong to the class AI can be purchased. They have ribbing and are used in conditions of low probability of horizontal shifts. The diameter of such rods should be at least 10 mm.
In the case of the construction of a slab foundation on unstable soil, a reinforced rod with an increased diameter is used. The cross section must be at least 14 mm. It is worth noting that the use of such elements is also recommended if the house is being built on a slope.
When selecting rods, it is also necessary to consider what material the walls are made of. A monolithic foundation may not withstand the pressure exerted by the frame of the house if the fittings were not selected correctly.
For light buildings (wooden or frame), it is recommended to use metal rods with a diameter of 10 to 12 mm. For more massive buildings made of brick or aerated concrete, it will be necessary to purchase reinforcement in the size of 14-16 mm.
Useful information! On the drawing of a monolithic foundation, a metal network is mandatory. The standard distance between individual metal elements in this design is 20 cm. This indicator is equally suitable for both longitudinal and transverse rods. Thus, it can be quickly calculated that for 1 m of the length of a residential building, 5 elements will be required.
Foundation foundation preparation: step by step instructions
The dimensions of the pit dug under a monolithic base should be larger than the dimensions of a residential building. It is recommended to increase its length by 1 m. For the organization of the pit, it is necessary to carry out preliminary marking in accordance with the required dimensions (taking into account the stock). Further, the fertile soil layer is completely removed from this territory. The upper layer of soil may have a different thickness depending on the region (20-50 cm).
Then, preparation for the construction of the foundation slab is made in accordance with the instructions. Drain pipes fit into the finished pit. They must be laid along the edge in pre-prepared grooves so that they are located below the bottom. This will ensure the removal of atmospheric water into the drainage wells and protect the foundation from their harmful effects.
The precast-monolithic foundation also requires the organization of outlet communications. Level the bottom of the pit and compact the soil as much as possible. Then the geotextile is laid. It is important to remember that this material should cover not only the bottom, but also the walls of the pit.
Separate canvases overlap each other, after which their edges are glued together with reinforced tape. Geotextile has a very important function – it prevents the germination of plant roots in concrete. In addition, it does not allow sand to be washed out, which is a damper substrate.
At the next stage, sand filling is carried out in a pit covered with a geotextile cloth. It is desirable that it be of medium grain size. The thickness of this layer depends on the characteristics of the soil and ranges from 20 to 30 cm. This value of such a basis determines the final cost of the work. The price of a monolithic foundation depends on the amount of materials used to equip it.
You can not immediately fill all the sand in the pit. This process is carried out in stages, layer by layer. Each previous layer is compacted, and only after that the next one is performed. The recommended thickness of one layer is 8-10 cm.
The next step is backfilling of gravel. All gravel is distributed immediately, after which it is necessary to level it out as much as possible and compact it just like sand. Then organized work on laying the water supply and sewer lines. To do this, in the rubble, it is necessary to perform trenches into which pipes will be laid. After laying the pipes, the ditches are covered with sand, which is subsequently carefully compacted.
Foundation slab construction technology: concrete substrate
At the preparatory stage of the construction of the foundation, another action is performed. For maximum reliability of the future substrate under a monolithic slab, a concrete layer is used. Its application allows not only to ensure the strength of the bottom of the pit, but also to level it.
The process of forming a concrete substrate (or monolithic overlapping of the foundation) is quite simple. First of all, formwork is performed. It should be thick enough to resist concrete pressure. As a rule, it is constructed from a board whose thickness is 40 mm.
Useful information! If plywood was taken as the material for the formwork, then 18 mm can be limited.
The construction of a monolithic foundation is a rather complicated process. Care must be taken in assembling the formwork for the concrete substrate. The height of this structure is calculated very simply: it is necessary to measure the conditional height of the remaining layers following it.
The edge of the formwork must be even, as this will allow you to control the height of the concrete pouring.Thus, it is not recommended to use an unedged board in this case: it will not work to make an even monolithic foundation. The work on the design of the formwork involves the installation of spacers, which make it possible to provide the necessary rigidity of the wooden structure.
After installing the formwork, you can begin to fill the concrete substrate. The layer thickness of such a litter is 10 cm. For its formation, it is allowed to use concrete of lower quality grades (from B7.5 to B10). The concrete substrate is a reliable and durable base. After laying it, you can begin to waterproof the foundation, as well as its insulation.
How to waterproof a foundation slab
The location of the monolithic base makes it vulnerable to moisture. In order to protect the foundation from the effects of precipitation, you will need to take care of its reliable waterproofness. Today, there are two common varieties of waterproofing:
For waterproofing the slab foundation, it is customary to use both of these types. Their combination significantly increases the protection of the monolith from moisture. Before starting work, it is recommended that you carefully study the sequence of actions.
First of all, the foundation foundation should be prepared for waterproofing. To do this, you need to clean it from dust and dirt. After that, you can start applying liquid waterproofing. It is important to remember that the finished undiluted mixture has a rather high viscosity, therefore it is customary to use special solvents to dilute it. If necessary, liquid waterproofing can be diluted with ordinary kerosene.
The prepared mixture is applied to the walls of the foundation and wait a while for it to penetrate deep into the concrete. This will strengthen the material and increase its hydrophobicity. At the next stage, roll material is installed on a monolithic foundation. The laying technology takes into account that the hydroinsulator should protrude approximately 10-15 cm beyond the structure.
Useful information! It is worth noting that the waterproofing material is overlapped.
In this case, bitumen mastic is required to be applied to the joints. It is very important that the material lies evenly – there should be no waves on the canvas. After laying the first layer, you can proceed with the installation of the second.
Foundation plate insulation: a step-by-step guide
Warming of concrete is a necessary measure, which is aimed at protecting the monolithic structure from the effects of low temperatures. The arrangement of competent insulation allows you to increase the operational life of the slab. Traditionally, polystyrene foam is used for insulation. It is very important to choose the right material: polystyrene must be extruded.
The thickness of the insulation depends on climatic conditions. This indicator varies from 10 to 15 cm. During insulation, you must be careful to correctly perform this work on the foundation plate. The technology of this process is quite simple.
It is important to remember that you cannot use only one layer of polystyrene for insulation. At a minimum, two layers are recommended. In some cases, this number is increased by another point. The exception is polystyrene plates, which have locks in the form of the Latin letter “L” – they can be put in 1 layer. The number of layers is reflected in the final price of a monolithic slab foundation.
During installation, do not forget that the seams formed during operation require overlapping. This is due to the fact that cold bridges are formed in such places. Of course, this procedure takes extra time, but its implementation will save on heating the house. After installing the polystyrene, a plastic film (necessarily tight) is laid on top of it, on which heat-insulating material will be installed.
DIY foundation plate reinforcement – what you need to know
After waterproofing, as well as the organization of thermal protection of the future monolith, the reinforced frame is assembled. Perhaps this is the most problematic stage of work for beginners. It is quite difficult for an untrained person to master the technology of fastening individual elements in a grid. Before you start assembling the frame, it is recommended that you study the video materials on this topic.
To assemble the frame, as a rule, ribbed bars are used that correspond to class AIII. The cross-sectional index of such reinforcement is 12-14 mm. Its laying is carried out as follows: along and across in increments of 15 to 30 cm. As already mentioned above, depending on the thickness of the base plate, there can be 1 or 2 layers of reinforcement.
In order for the monolithic foundation slab to acquire the necessary strength with its own hands, it is necessary to correctly calculate the number and size of bars at the design stage. The distance from the edge of the plate to the metal elements must be at least 5 cm.
Note! In order to ensure the desired distance, the fittings are assembled on special supports.
During the installation of the reinforcement, a checkered pattern is obtained. The intersection of the longitudinal and transverse rods is fastened by a soft wire made of steel. To twist the wire, you need to purchase a special hook. With it, the process will accelerate significantly. There is another option for connecting rods in a grid of a monolithic foundation. The technology involves the use of special plastic clamps. However, this method of connection is not as widespread as the previous one.
It is important to remember that experts categorically do not recommend using welding to connect reinforcing bars . The thing is that the weld has a very low resistance to rust.
How to fill a monolithic foundation slab with concrete
Pouring is the key to creating a slab foundation for your home. This process should be performed as correctly as possible, in compliance with the technologies and rules that are indicated in the relevant construction documentation. For pouring, only high-quality concrete must be used. The following brands are suitable: M-300 and M-400. In any case, concrete below the M-200 grade cannot be used.
Filling the foundation plate with your own hands is not recommended, since concrete should be loaded into the prepared foundation in such a way as to fill it at a time. Today it is easy to rent special equipment (concrete mixer) without difficulty. Of course, you can fill it yourself, but the strength of the finished structure in this case may decrease.
A very important point is the compaction of concrete during pouring. For this, a special tool is used – a vibrator, which eliminates bubbles inside the concrete mortar, thereby compacting it. After pouring concrete into the pit, limited by the formwork, it is necessary to carefully level it.
Another point that you should pay attention to when filling the foundation plate with your own hands: during operation, no joints should be formed. They arise if one part of the concrete poured into the pit has already frozen, and pouring is still ongoing. And finally, it is necessary to carefully level the surface of the solution. Subject to all these rules, the foundation plate will turn out to be solid and of high quality and will last for more than one year.
Pile-monolithic foundation: features of the organization
The foundation, which is installed on piles, differs from monolithic not only in installation technology, but also in cost. The price of such a foundation of construction is more reasonable. Thus, the pile foundation allows you to save on the construction of a residential building.
Note! Piles or poles in this case do not have sufficient strength. In order to increase their rigidity, they are strapped (connection to each other).
There are several technologies for connecting individual columns. The grillage foundation is very popular. A monolithic pile foundation of this type can be performed using two technologies: docking of the connecting tape underground and above it. The choice of pile-monolithic type of foundation is advisable in the following cases:
if on a site on which construction work is underway, problem soil;
in the case when the house is being built in the coastal zone;
if the building is on a slope;
to save money.
Monolithic supports can be equipped with your own hands without the use of special equipment. This makes them very popular. The monolithic foundation with grillage is versatile and affordable.
Before starting installation of such a design, it is recommended that you familiarize yourself with video materials on this topic. It is worth noting that pile-monolithic structures are distinguished by a long operational period.
Recommendations for the care of concrete for self-installation of a monolithic slab
In order for concrete to harden safely, a high humidity level of 90-100% and a temperature above 5 ° C should be ensured. It is recommended to wait for warm weather, starting from 20 ° C, to fill the stove. It is this temperature regime that is ideal for hardening. Caring for a monolithic concrete slab is straightforward: you need to protect it from damage and maintain the required level of humidity. If necessary, you can entrust the creation and maintenance of the foundation to professionals by ordering a turnkey monolithic foundation slab.
Having finished laying, concrete needs to be closed with a film. This will provide him with protection from heat and wind. The film itself should be converted into large-sized panels. Then lay the resulting strips with a run of 10-15 cm and glue with tape. It is important to minimize the number of connected sections so that the tarpaulin or film consists of 1-2 parts. Separate elements of the panel should cover each other at least half a meter.
You will need a film of this size so that it can close the side of the formwork, and you can install a load on the edges of this coating – wind protection. In addition, with this load, whether it be boards or something else, you need to squeeze the intersection of the parts of the tarpaulin or film. This will reduce windage. For the same purpose, boards can be laid out over the entire surface of a monolithic foundation for a home.
At an air temperature of more than 5 ° C, 8 hours after pouring, it is necessary to pour concrete with water. This must be done by drip, and not by inkjet. In order to prevent the surface from being damaged by drops, you can lay a burlap on top and cover with a film. According to this technology, only the material with which the plate is covered is watered, and it, in turn, helps to maintain the necessary humidity.
Useful information! If you know that frosts are expected, concrete needs to be additionally insulated. For this purpose, any materials that allow you to keep warm are suitable: from those presented in construction stores to a variety of improvised means (sawdust, straw, etc.).
When is it worth removing the formwork? If you have a monolithic slab, experts recommend removing it after the concrete has acquired 70% strength. The exact period depends on the temperature at which the hardening takes place.
The monolithic structure used as the foundation for residential buildings is a very reliable and durable construction. However, it has a rather high cost and requires a flat surface. In the case of self-installation of such a reinforced concrete slab, it is recommended to study video materials on this topic.