FBS blocks are a solid structure made in the form of a parallelepiped and equipped with mounting loops. The end faces of the product have special recesses, which are filled with liquid during the construction process. So in a simple way the strength and integrity of the foundation structure made of FBS blocks is ensured.
The overall dimensions of the FBS are regulated by the state standard. Standard sizes differ in length and width, but the height of all modifications is constant and equal to 600 mm. True, some manufacturers produce blocks 300 mm high.
The weight of the FBS does not allow the work to be done manually. Trying to install them using a winch is fraught with enormous labor costs. So you can’t do it without a crane. This very significant drawback explains why FBS foundations for individual houses are very rarely built.
The disadvantages include the lack of reinforcing elements inside the FBS. To strengthen the foundation, the blocks are laid on reinforced concrete foundation slabs - pillows.
Construction of a foundation from FBS blocks: step-by-step instructions
The block foundation for a house is a simple structure consisting of:
- reinforced concrete pad;
- walls made of FBS;
- waterproofing.
In some cases, the structure is supplemented with an upper armored belt.
The construction of a foundation from FBS blocks is carried out in several stages.
Stage one - preparatory work
At this stage, design documentation is being developed. There are now many computer programs available that can lay out blocks. But if you don’t know how to use them, draw the masonry on paper, just do it not arbitrarily, but to scale.
Based on the drawing, it will be easy to understand the order of installation of FBS and their dressing.
At this stage, the entry points for utility lines are determined. There are masonry elements on sale in which passage holes are created. If you miss this moment, you will have to drill them into the body of the concrete block. This will lead to additional time, financial and labor costs.
The width of the foundation depends on the thickness of the walls of the above-ground part of the building. For wooden buildings, 300 mm is sufficient. The width of a foundation made of FBS blocks for a brick house is usually taken to be 600 mm.
Stage two - excavation work
Inspect the construction site for the organization of access roads for special equipment. Remove everything that will interfere with further actions: bushes, trees, debris, etc.
After this, remove the fertile layer 150-200 mm thick at the building construction site. It can be carefully folded away from the pit: in the future, the turf will be useful when arranging a garden or vegetable garden.
Before making a foundation from FBS blocks, it is necessary to mark it on the ground (). This is done using pegs and cords.
The following are brought to the area:
- external and internal contour of the foundation.
A trench is dug according to the markings. Its depth should exceed the freezing depth of the soil by 200-250 mm. There are regions in Russia where the soil freezes up to two meters deep. It is not economically feasible to build a foundation using FBS blocks for a house in such places. Typically, a block base is used where this parameter does not exceed 0.8-1 m.
Stage three - arrangement of the sole
When you start laying the blocks with your own hands, you will need to choose the type of base for the foundation.
There are two options to solve this issue:
- build a sand cushion;
- pour the concrete base.
The second option is used in the case of unstable soils. It costs a lot of money, significantly slowing down the speed of construction. Therefore, in the absence of objective reasons, it is better to refuse it. In most cases, it is enough to equip a sand cushion.
Work at this stage is carried out in the following order:
- the walls of the pit or trench are leveled;
- a 10-15 cm layer of sand is poured into the bottom of the pit;
- the sand is spilled with water and thoroughly compacted;
- crushed stone is poured over the sand layer (layer thickness - 100 mm) and also compacted.
These operations are the same for both options for arranging the pillow. If there is a need for a base, it is mounted on top of the crushed stone, and a reinforcing mesh is placed inside it. Then the concrete mixture is poured ().
On soft soils, you can increase the area of the foundation base using FL reinforced concrete foundation slabs. they are laid on the sand-crushed stone preparation either completely or at intervals of up to 70 cm. In the latter case, the space between the individual elements must be filled with soil, carefully compacted.
How to put a foundation of blocks on pillows? The first row of FBS must be laid in such a way that their vertical joints (or seams) are located on the slabs. Based on this condition during design, the maximum permissible gap between concrete pads is determined.
Stage six - laying blocks
At this stage, we proceed directly to creating a foundation from FBS blocks: how to lay the blocks:
- The laying of each row begins with the installation of beacon blocks. They are placed in corners and intersections of walls. Vertical seams are filled with mortar. If the overall size of the foundation is not a multiple of the length of the blocks, a gap will form at the end of laying the row. It must be filled with concrete, after installing the formwork;
- all subsequent rows of the foundation made of FBS blocks for a house must be laid on a layer of mortar. Its thickness is 1.5 cm. Be sure to bandage the vertical joints at 250-600 mm. If this rule cannot be followed, use masonry mesh or reinforcing bars;
- The quality of work is regularly checked using a building level.
Experienced builders try to choose longer products to build a foundation from FBS blocks. Thus, they reduce the number of vertical seams, thereby increasing the strength of the structure and its reliability.
Stage seven - waterproofing
In the step-by-step instructions for a foundation made of FBS blocks, this stage is the simplest. It is necessary to coat the surfaces of the structure with liquid mastic - internal and external, paying special attention to the seams.
If the construction site is located in a region with frequent and heavy rainfall, it makes sense to cover the foundation with roofing material after coating.
Stage eight - armored belt
How to make a foundation from FBS blocks with your own hands to eliminate the risk of its destruction? It can be reinforced with a reinforced concrete belt cast along the top row. In the future, floor slabs will rest on it.
Many professional builders consider this step unnecessary, but practice shows that when building a block foundation with your own hands (most often, inexperienced ones), such a step is completely justified.
The reinforcing belt is constructed in the following order:
- Formwork () is installed along the perimeter of the foundation (on the outer and inner sides of the walls). To prevent the panels from moving apart from below under the pressure of the concrete mixture, they are tied together with wire. They are fastened at the top with clamps or pins;
- a reinforcing frame or mesh is lowered into the formwork;
- concrete mixture is poured ().
The formwork is dismantled after the concrete has hardened (). To facilitate this operation and prevent leakage of the solution at the time of pouring, it is advisable to cover the internal surfaces of the boards with polyethylene film before installing the reinforcing mesh.
Conclusion
In this article, we tried to answer the question: how to build a foundation from FBS blocks, highlighting the most important points of this process. This technology is highly labor-intensive, but does not present any particular complexity.
If you carefully carry out all operations, even those that may seem not particularly important, the result will be a foundation for a house that is built according to all the rules and can last for decades.
Video on how to properly make a foundation from FBS blocks.
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Knowing how to strengthen the foundation, it is possible to update the old foundation and repair it. Strengthening your foundation is a good alternative to replacing it, which can be very expensive. In order to strengthen the foundation of the house well and quickly, you must first understand the emerging factors that affect its damage.
Strengthening the foundation is necessary when increasing the number of storeys and the weight load on the base of the building.
Inspection of reinforced concrete base before reinforcement
Knowing how to strengthen an old foundation can significantly improve its condition and thereby avoid its replacement. To strengthen the foundation, you need to first assess its condition by conducting an inspection.
A study needs to be carried out to assess the general condition of all structures. This examination will help determine the load acting directly on the reinforced concrete structure, identify all distortions and existing cracks that indicate problems with the foundation.
It is also necessary to conduct an underground survey to help determine the material from which the structure is made.
There are situations when a damaged structure needs certain reinforcement, namely such as:
- increasing the load placed on the foundation;
- building settlement;
- increased vibration near the building.
Before you begin to strengthen the damaged structure, you need to determine whether its shrinkage has completely ended. To do this, you need to install certain beacons made of plaster across the formed cracks, and then watch them for a whole month. If there are no changes, then you can start working.
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Unloading before strengthening
Before strengthening the foundation, it is necessary to unload it, which will help avoid destruction during strengthening activities.
Removing the load on the foundation of the house can be complete or partial. For partial unloading, wooden supports and struts are used, which can be wooden or metal.
To carry out unloading, supports are installed directly in the basement. The same supports must be installed on each floor of the building being strengthened. It is worth remembering that the support posts must be installed strictly one above the other.
Complete unloading involves the installation of metal supports directly in the walls of the house.
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Strengthening the foundation
Many people are interested in how to strengthen the old foundation so that it can be replaced. You can strengthen the old foundation of a house in various ways, the choice of which depends on the type of reinforced concrete structure and the degree of its destruction.
It is possible to strengthen the damaged structure using a certain iron clip, installed on either side of the base of the house. The supports installed along the entire perimeter of the building to be strengthened look like steps. This method is only suitable for multi-storey buildings that do not have a basement.
If the reinforced concrete structure of the base of the house is made of brick, then such clips cannot be used to strengthen it. This type of strengthening is suitable for buildings only with a strip foundation made of stone. Also, this type of strengthening is best used if the house is built of blocks.
To strengthen the tape version of the structure with a reinforced concrete clip, you need to take:
- cement-sand mortar;
- roofing felt;
- perforator;
- hydraulic level;
- fittings;
- concrete;
- reinforced concrete supports.
If the foundation is curved, then it must first be leveled and only then proceed to strengthening.
Scheme of strengthening the foundation with a double-sided bench.
After taking measures to level the foundation to the required condition, you need to carefully inspect it for the presence of various types of cracks. All cracks should be sealed using a cement-sand mortar, which must be made in a ratio of 1:3.
When the concrete has hardened, it is necessary to prepare the walls of the tape itself, for which small notches are made with a puncher to help better interact with the screed. If the foundation is of a pile type, then this must be done with each support being strengthened.
The soil around the base of the house needs to be removed. The width of the resulting trench must completely match the width of the tape used. This is approximately twenty centimeters. The bottom of the resulting ditch must be leveled using a hydraulic level. Then it needs to be watered and compacted well.
Then you need to pour sand, the layer should be at least five centimeters thick, pour water on it and compact it well. The next layer should be roofing felt, which acts as a waterproofing material.
When everything is ready, you need to install the formwork exactly along the entire perimeter of the building being strengthened. The height of the formwork must be in full compliance with the overall height of the poured tape that strengthens the base. The next step is the assembly of the metal structure. To make it, you need to take reinforcement rods with a cross-section of 8-13 mm.
In places where this is stipulated by the existing building design, vents are installed. Then concrete is poured in layers, which must be compacted using a metal rod.
The last layer of the solution must be made quite liquid so that the tape can be leveled.
To strengthen a damaged foundation, you can reinforce the soil using certain chemicals. Using such materials, the soil structure can be transformed into a more dense one, and at the same time it will acquire good water resistance. The process of soil reinforcement consists of several stages, namely:
- preparing the solution;
- mixing it with soil;
- soil compaction.
To prepare a solution to strengthen the foundation, the following components can be used:
- bitumen;
- tar;
- organic waste;
- liquid glass;
- lime.
If, when using liquid glass required to strengthen the foundation, additional electrosilicatization is carried out, that is, an electric current is passed between two electrodes, then the strengthening effect can be increased several times.
Have you found cracks in the walls, the windows don’t close well, and the doors are leaking? You need to be wary and take a closer look at the foundation of the building before the floors stand on end and the house goes downhill. Most likely, you need qualified foundation repairs made from FBS blocks. Experience, coupled with the quality of building materials, will save you from big problems in the future!
Defects discovered in a timely manner are often local in nature, and therefore solutions will be local and inexpensive.
Repair of the foundation from FBS blocks: all about the reconstruction strategy!
Physical destruction of a foundation made of building blocks can occur in a number of ways 
reasons:
- Savings on hydrogeological studies of the site;
- Poor quality installation of blocks;
- Errors in waterproofing.
The absence of large cracks does not mean that a major reconstruction of the foundation will not be needed, sometimes even with the replacement of the entire structure. Specialists from the Construction Factory company will conduct a detailed study of the strength characteristics of the foundation, determine the groundwater level and freezing depth. Based on this data, an optimal work plan is selected, aimed at:
- strengthening the soil under the foundation;
- strengthening the foundation itself;
- waterproofing and installation of foundation drainage.
It is quite difficult not to notice catastrophic damage, but even in such cases, the professionals of our company will have a qualified answer, since a wide range of construction services allows us to equip a facility of any complexity on a turnkey basis.
Repairing the foundation from FBS blocks, which way should we go?
Effective repair of a foundation made of FBS blocks includes all three directions, since the strengthened soil and foundation will repeatedly collapse under the influence of water.
When most people hear the word “foundation,” they think of either a solid reinforced concrete base or a base on pillars or piles. At the same time, they forget about the existence of another option - FBS construction, which is actively gaining popularity among professional builders and amateurs. It is worth taking a closer look at the foundation made of FBS blocks, step-by-step instruction The implementation of which is so simple that even a beginner can figure it out.
Features of the material
Difference between FBS and other blocks
Foundation building blocks, abbreviated FBS, are monolithic rectangular concrete bricks of large size, reinforced with a frame of reinforcing bars.
The demand for the material is determined by the special stability provided by the reinforcement.
There are two methods for connecting FBS to each other:
- Application of cement mixture. Laying building blocks is done using the same technology as laying bricks. In this case, proper bandaging of the joints is necessary, in addition, the location of each new block relative to the previously installed ones should be adjusted.
- The use of a specially designed dry adhesive composition, when diluting which it is very important to maintain the correct proportions. This method does not require special physical and time resources, however, from a financial point of view it is unprofitable: the cost of the mixture is higher than the price of cement mortar.
Advantages and disadvantages
Before building a foundation from FBS blocks, the pros and cons of the planned structure must be taken into account and worked out, otherwise there is a risk of being disappointed in the finished foundation.
The block base has many advantages over other foundation options. It is worth highlighting the following:
- Possibility of independent device. The laying technology is quite simple; even an amateur can handle the installation;
- Small time investment. Due to the fact that the construction of the foundation involves the use of large building elements installed in a checkerboard pattern, the work can be completed in one day;
- Durability and sustainability. The blocks have a high load-bearing force and are not afraid of mechanical influences;
- Convenience. Manufacturers provide all the subtleties that may affect the work with FBS. To simplify the construction procedure, each particularly large product is equipped with hooks, with which you can easily move the blocks;
- Strength. Additional strengthening of the base is provided by special grooves, which FBS almost always have;
- Possibility of installation on unstable and frozen soils. If construction is carried out in regions where a cold climate predominates, or in areas with weak soils, then this option will be a real salvation.
In addition to impressive advantages, foundations made from FBS blocks, like all existing foundations, also have negative qualities:
- Solid value. The raw materials themselves are not cheap, and besides, it may be necessary to hire construction equipment, which will also negatively affect the budget;
- Possibility of uneven shrinkage. This is due to the fact that the base is not a monolith.
Naturally, basic designs of this type are not without drawbacks, but their positive characteristics fully compensate for all the disadvantages.
Design of a basis from FBS
In order to competently build a prefabricated block base that will serve for decades, it is necessary to design it responsibly. What should you consider when creating a project? Please note:
- Type of soil in the building area;
- Path of soil waters;
- Soil freezing level;
- All possible loads;
- Number of floors of the future building;
- Dimensional characteristics of the base and basement (if provided).
The first three points determine the depth of the structure and the level of its waterproofing.
If the design is completed, you can begin the foundation, the installation of which is carried out in several stages. All stages have their own nuances, and therefore should be considered in more detail.
Stage 1. Marking and working with soil
Before marking is carried out, the area is cleared of debris.
Following the design, pegs (wooden pins or scraps of reinforcement) are installed in places that correspond to the corners of the future building. A strong twine is pulled between the pins. Similarly, mark the locations of the load-bearing walls under which the foundation will lie.
After this, the upper fertile layer of soil is removed and a trench is dug for the FBS structure. The minimum width of the trench should be equal to the FBS block, plus 20 cm - this will simplify installation and waterproofing work.
Stage 2. Laying the pillow
If the project involves the construction of a basement, then it is impossible to do without installing a base made of concrete mixture (or slabs). If there is no basement to be built, a sand and crushed stone cushion is laid at the bottom of the trench. Sand is poured (layer thickness is up to 15 cm), watered and compacted. Next, crushed stone (10 cm) is poured, which is also compacted.
If the site has clay soil, it is worth filling up, moistening and compacting the sand again.
Stage 3. Arrangement of formwork and reinforcement cage
The formwork is installed along the walls of the trench. It is made of wood (the minimum thickness of the boards is 2.5 cm), connected with self-tapping screws. The height of the formwork should be similar to the height of the reinforcing belt and equal to 10-15 cm.
The metal belt is made of D12 or D14 rods, fixed with knitting wire. The mesh size of the “mesh” is 10 by 10 cm or 15 by 15 cm. The width of the belt should be equal to the width of the FBS.
The finished mesh is placed on the pillow.
Stage 4. Pouring concrete
The resulting structure is slowly filled with concrete mixture. To prevent air bubbles from forming in the thickness of the solution, the mixture is pierced with a steel rod or a vibrator is used. To make the structure more stable, the reinforced frame should be poured in one go.
After laying, the concrete is leveled and allowed to harden. The maturation of the material will end after 28 days, after which you can proceed to the next stage.
Stage 5. Laying FBS
Work with the FBS itself requires the presence of a truck crane or several assistants, since the blocks are quite massive.
First, a cement mixture is prepared, for which raw materials of at least M100 are used. One block requires from 10 liters to 15 liters of mixture.
The block laying scheme is quite simple:
- Products are laid on the corners of the building;
- Ropes are stretched between the blocks;
- FBS are set by level;
- The gaps between the elements are filled with cement mixture.
The finished row is coated with a 1.5 cm layer of cement mixture. Each new row is installed in the opposite direction to the previous row with a shift of 50%.
Stage 6. Hydro- and thermal insulation
Moisture has a very detrimental effect on concrete, which is why high-quality waterproofing is simply necessary for a FBS base. It is performed using roofing felt sheets and bitumen mastic, which is used to treat the base from the outside and inside.
For thermal insulation, polystyrene foam is used, the sheets of which are glued over the waterproofing with special glue.
At the end, the free space between the walls of the trench and the base is filled with soil and sand in several stages. Each new layer is conscientiously compacted.
The foundation hardens within a month. After this period, you can begin building the walls.
Video about laying FBS blocks:
Foundation building blocks (FBS) are worthy products for arranging reliable foundations for various buildings. They, having a number of operational and installation advantages, have recently been often used by private developers.
FBS - specifically for foundation construction
The blocks in question are reinforced concrete elements made from high-grade heavy concrete. They are reinforced with metal rods (due to this they can withstand serious loads) and look like rectangular parallelepipeds. FBS are often equipped with special eyes that facilitate the process of loading them at the factory and unloading them at the construction site. In addition, special recesses are provided at the ends of the products. During installation, a liquid concrete solution is supplied into them, which connects the individual blocks to each other as tightly as possible.
The service life of a foundation made of FBS blocks is more than 100 years. Minimize construction time - order FBS blocks and concrete of any grade on the Beton 174 website
Basic tech. The characteristics of foundation products are as follows:
- water resistance of concrete – W2;
- compressive strength – B12.5;
- frost resistance – F200;
- density – within 2400 kg per cubic meter;
- strength – about 110 kg/cm.
The geometric sizes of blocks vary. This allows consumers to select the optimal products for the construction of any foundation. The most popular standard sizes of FBS are as follows: height and width – 0.3–0.6 m, length – 2.4; 1.2; 0.9 m. But if necessary, it is easy to order products with other parameters.
The starting raw material for the described blocks is most often expanded clay concrete. The technology for manufacturing FBS is quite complex and labor-intensive. It involves the use of special equipment - forced concrete mixers and large deep vibrators. The process of obtaining a block with specified technical parameters takes more than 30 days. Since FBS is usually used for the construction of foundations, manufacturers additionally treat the surface of the products with composite compounds (water repellent plus bitumen). Such coatings perform the function of effective waterproofing, which well protects the blocks from the influence of atmospheric, melt and groundwater.
Is it possible to build a good foundation quickly and inexpensively?
The key advantage of the products we are interested in is the guaranteed speed of arranging foundations for various buildings. Moreover, a foundation made of FBS blocks can be built in any weather. Neither heavy snowfall nor rain is an obstacle to such construction work. Other advantages of foundation blocks:
- Easy and simple do-it-yourself installation. Problems can only arise when lifting blocks of large mass. You can’t handle this task yourself; you’ll have to order a crane.
- Flexibility of the resulting foundation. Non-monolithic foundations are built from FBS. There are joints between individual products. Due to its flexibility, the foundation can be built on sandy and many other problematic soils. It is not recommended to build foundations using building blocks only on very soft soils. In this case, there is a possibility of it bending due to strong heaving of the earth.
- Minimum construction costs. The affordable cost of the blocks reduces the cost of work. Cost reductions are also achieved due to the fact that almost all foundation construction operations can be performed independently.
- High moisture resistance, low thermal conductivity, increased frost resistance.
- Unique durability. Buildings on FBS stand without accidents for up to 160 years!
Let us immediately note that all foundation products are required to be supplied with certificates. They provide technical block descriptions. Before purchasing products for building a foundation for a house or other structure, we strongly recommend that you read the data in the certificate. Purchasing low-quality blocks will not allow you to take advantage of the benefits that are inherent in high-quality FBS.
The downside of the products in question is that when building a foundation, they need to be protected from moisture and also thermally insulated. These operations are not that complicated. But, nevertheless, they increase the cost of money, time and physical effort. And don’t forget that you will have to spend extra money on ordering a crane to lift heavy blocks.
Let's start arranging the structure - let's start with digging
In private construction, FBS is recommended for arranging strip-type foundations. Such prefabricated foundations are suitable for houses with several floors, and for garages, and for any outbuildings. buildings Before starting the main work, it is necessary to draw up a construction plan, calculate how many blocks and what sizes are needed for the walls of the foundation being built. We also determine the method of knitting the products and the areas of the foundation through which utilities will be laid (you need to order FBS with holes). After this, you can purchase the required amount of materials.
The first step of arranging the foundation is standard. Digging a pit. To determine its exact depth, we recommend ordering a simple geological survey. It describes the properties of the soil and the characteristics of the flow of soil water. The cost of such research is low. And the benefits from it are enormous. We recommend taking the trench depth 20-25 higher than the soil water level.
Then we level the bottom of the hole and place a two-layer cushion on it - 10 cm of crushed stone plus 5 cm of sand. We spill the resulting cake with water and compact it as thoroughly as possible. As a result, we should get a dense and even pillow. Fill its surface with concrete mortar (two-centimeter layer). We are waiting for the last one to dry. In some cases, a solution for pouring a sand-crushed stone cushion is not made. Instead, a regular masonry mesh is mounted on it. It eliminates the risk of gaps and holes appearing between the individual blocks that will make up our prefabricated foundation.
How can a self-taught craftsman create a solid foundation?
Laying the foundation from the block products in question has some features. We definitely need to make an additional foundation that will not allow the FBS to sag during the operation of the building. It makes the most sense to make such a special sole in the form of a concrete flat slab. Its construction requires materials and time. If there is a light structure on the foundation, the slab may not be poured. It is successfully replaced by a number of FBS. But in this case, their height is considered as width. In other words, we will simply need to lay the products on their sides. This technique is not used if the foundation for a house is being created.
Step-by-step instructions for pouring the slab are as follows:
- 1. We make formwork from edged boards, controlling its position with a hydraulic level.
- 2. We knit reinforcement (F12).
- 3. We fill the slab.
After the sole has hardened, you can begin laying the blocks. We begin the procedure with the installation of corner FBS. We join the products as tightly as possible. We coat the seams with a composition of. Using this method, the first row of the foundation structure is installed. It is very important to ensure that it is perfectly level horizontally.
Next, we proceed to the installation of the second and subsequent rows of the foundation being built. They should be placed in a sling. This means that the seam (vertical) of each product from the top row must fall strictly in the middle of the FBS from the bottom line. All gaps between the blocks are filled with cement. We do not spare material! There should be no gaps between the blocks.
At the corners of the building, it is advisable to install block products with an overlap. How to do it? Not difficult. It is necessary that the corner of the first row falls on the edge of the building block from the right wall, and the corner of the second row from the left, and then in turn. When installing each FBS, we check the accuracy of installation (both vertically and horizontally). The outer walls are always laid out first, the inner walls are built after them.
As you can see, the process of laying a strip foundation cannot be called complicated. Any novice builder can handle it. The following tips will help facilitate the construction of the structure:
- 1. In cases where the calculation of the base was not carried out in the most accurate way, and the foundation blocks do not coincide with it, it is allowed to install them with a slight plumb line at the corners (100 mm from one edge or 50 mm from both).
- 2. If during the laying process there is a place in the row where the whole FBS does not fit, there is no need to cut out a suitable size piece from the whole block product. It is much more convenient and smarter to fill the hole with cement or simple building bricks.
- 3. Decide in advance on the date for which you will order a crane for lifting and installing blocks. Then the work process will not be delayed.
Last tip. If a private house is being built without a basement, and the soil on the site has a high load-bearing potential, the base can be made intermittent rather than continuous. In this case, the blocks are placed at 50–70 cm intervals. The latter are covered with earth and pressed. Construction costs for intermittent structures are reduced by 10–15% due to the fact that fewer blocks need to be purchased.