One-story houses made of foam blocks have a much lower mass than similar buildings made of brick or precast concrete.

Therefore, building houses from foam blocks and aerated concrete blocks where a soil base with a weak bearing capacity is advantageous on screw piles. The foundation, arranged from a frame structure on screw piles, is much cheaper than a pile grillage.

Foam concrete is concrete with a cellular structure. Cement, sand and water are mixed with special foam. The mixture is poured into molding containers. After solidification, the molds are disassembled and ready-made foam blocks are obtained. Blocks of large sizes are produced by sawing volumetric monoliths.

Foam concrete blocks

The density of foam concrete is three times less than the density of brick, respectively, and its weight is three times less. Possessing high thermal insulation, waterproofing and strength qualities, foam concrete compares favorably with other types of building materials.

Given the low bearing capacity, the fragility of the material, foam blocks can only be used in the construction of low-rise, small residential buildings.

Blocks of aerated concrete in terms of their quality characteristics are not much different from foam blocks. Aerated concrete is obtained as a result of a chemical reaction of cement, sand and various fillers. A significant drawback of aerated concrete is its poor resistance to moisture. Therefore, masonry of aerated concrete blocks requires enhanced waterproofing.

Wall masonry made of foam concrete and aerated concrete blocks is built in the same way as brickwork on cement mortar.

Rationale for the use of screw piles

As a result of geological surveys at the construction site, the following data are obtained:

• the thickness of the soil layer with low bearing capacity (usually clay soils subject to swelling and freezing);
• depth of occurrence of denser layers of soil;
• ground water level;
• soil freezing depth.

Based on the material obtained, a decision is made on the advisability of using screw piles in the construction of a foundation for a house made of aerated concrete blocks or foam blocks.

Screw piles

Screw foundation piles

A standard screw pile for the foundation is a metal pipe with a diameter of 90 mm, at the end of which there is a point with helical blades.

Blades can be from 60 mm to 300 mm in size. There are piles with blades without a point. Screw piles with an open end, subject to soil penetration into the cavity of the rod. This can cause internal corrosion of the support.

Screw blades provide the entry of the pile rod with minimal resistance into the ground according to the principle of the corkscrew. The pile can have one or two blades. The length of the screw pile rod depends on the required depth of penetration into the ground and can reach from 4 to 6 meters.

Zinc coating of the surface of the rods is necessary to prevent corrosion of the metal of the piles. When choosing screw piles for a foam block house, you should pay attention to the quality of the galvanized surface. Good galvanization looks like silver stars on the metal surface.

Screw pile installation technology

They design the placement of pile supports at the corners of the building, in the centers of the support of load-bearing walls with a minimum distance between piles from 1.5 to 2 meters.

One screw pile can withstand an axial load of up to 25 tons.

Screw pile installation

Installation of screw piles is not very difficult. The head of the pile support consists of a metal nickle welded to the upper end of the pile rod. This horizontal support has technological holes for fixing mounting hardware.

Mounting gate is fixed through the holes. Two workers, rotating the gate, immerse the pile into the ground. During the screwing of the pile into the ground, it is compacted.

When the number of pile supports is large and the depth of their immersion is several meters, mechanized installations are used. Power equipment is equipped with an arrow, at the end of which a rotary body is installed. It is connected with bolts to the head of the screw pile and imparts a rotational movement to it. As a result, many piles can be installed over a large area in a short time.

Pile tying

The foundation is built on pile supports by installing a frame metal structure, which is fixed by welding to the heads of screw piles. The frame is a lattice structure of metal sections welded together. Basically, a wide profile channel is used to make the frame. Watch the video on how to avoid mistakes when tying piles.

In the places of support of the bearing walls, a profile with a shelf width equal to the width of a block of aerated concrete or foam concrete is placed.

Before installing the frame, be sure to check the horizontality of the pile heads in the same level.

The height of screw piles above ground level should be at least 15 cm. With a slope of the terrain, the height of the piles will be different.

Base device

You need to know that in the open space under the house, the piles are constantly exposed to aggressive environmental influences. In winter, frozen soil can squeeze the pile up, which will cause deformation of the frame structure of the foam block house foundation. Any damage to the frame will inevitably lead the house to an emergency state, as the structure of foam blocks and aerated concrete blocks is fragile and the walls of the house can become cracked.

The basement of the house on screw piles

In order not to expose the house to the risk of destruction, the piles are faced. Along the perimeter of the house, the space under the building is closed with any suitable shield material. The fence is insulated with foam, mineral wool or other material. Arrange waterproofing from a polymer film. After that, the siding is installed.

Expansion joints must be left between the underground fencing and the bottom of the house. They are necessary to compensate for temperature deformations.

With a well-arranged underground fencing, when the outside air temperature is 20 degrees below zero, the inside air temperature will be 5 degrees Celsius. Under such conditions, the foundation on screw piles will last for many years.

Advantages and benefits of piles for a foam block house

The device of the foundation on screw piles for a house made of foam blocks has a number of advantages:

• build the foundation in a very short time - from 1 to 2 weeks;
• foundation work can be performed at any time of the year;
• you can build a house on difficult soils, regardless of the slope of the terrain, the level of groundwater and the depth of soil freezing;
• significant savings in labor costs and finances;
• guarantee of long-term operation of the house.

Related articles:

Pile screw foundation for a foam block house

The main reasons for choosing a pile foundation are weak soils, a high level of groundwater, and the complex topography of the building site. Recently, the construction of private buildings from foam concrete blocks has become very popular. The erected pile foundation for a foam block house significantly reduces construction time. The disadvantage of a house made of foam concrete on piles is that with such a foundation design, it is impossible to build a basement. The advantage is the absence of large volumes of earthworks.

Foam blocks

Foam concrete is a relatively new building masonry material. Foam blocks are made from it for the construction of walls. Foam blocks (PB) have gained great popularity due to their quality characteristics.

Foam blocks sizes

PB is manufactured in the factory on special equipment. The foamed cement-sand mortar is treated with hot steam under high pressure. The resulting mass is poured into molds, which are sent to the drying chamber for 2 hours. Then the process of final hardening of the foamed mass takes place in the open air.

For the construction of external walls of buildings, PBs of standard sizes 390x188x190 mm are used. Blocks with a thickness of 90 mm are used for laying partitions. There are varieties of foam blocks with side locking systems - "thorn-groove". Sometimes the horizontal surfaces of the masonry elements are also made in the form of locks, which provide an almost seamless connection of the PB.

Cutting a block with a saw

In terms of their quality characteristics, foam concrete blocks are superior to many of their counterparts. Foam blocks are used for laying external fences of multi-storey buildings, where the supporting function of the building is performed by the frame of the structure (columns + ceilings). The porous structure of the material gives the blocks high thermal insulation qualities. In winter, the masonry of the walls does not let the cold through, and in hot weather it keeps the interior cool.

The main disadvantage of the material is its low bearing capacity, therefore, as external enclosing structures, foam block masonry is made in houses with a height of no more than 2 floors.

Foam concrete is a fragile material, so any mechanical impact can cause a violation of the integrity of the outer surface of the block.

The construction of walls from foam blocks on a pile foundation

Walls are erected from foam blocks on a grillage of a pile foundation or on a monolith of a tape-pile foundation. Before this, the surface of the foundation must be covered with a layer of waterproofing.

PB is placed both on a specially adhesive composition and on a conventional cement-sand mortar. The difference in the price of masonry mortars is leveled by the thickness of the mortar layer between the rows of foam blocks. Cheap cement mortar is laid with a thickness of 20 mm. It is enough to lay an expensive adhesive composition with a thickness of 5 mm.

The first row of blocks must be installed on an adhesive mixture with a thickness of at least 30 mm. The remaining rows of masonry are laid on one or another solution.

Wall masonry is performed with a width of a block floor or a block. Block-thick walls are erected in the northern regions, where increased thermal insulation of the external fences of buildings is required.

Dressing scheme between rows of masonry floor block thick

Types of pile foundations

Piles, as supporting structures, are used to pass through weak layers of soil and reach dense layers of soil. The design of the support takes on the load from the building and transfers it to a solid soil base, bypassing weak unreliable soil layers. The pile foundation for a house made of foam blocks can consist of supports of various designs:

• driving;
• bored;
• screw.

Driven piles

Reinforced concrete piles, in addition to resting on dense soil, are held due to the forces of friction of the side surface against the soil. Drive-in supports are manufactured in the factory. They are mainly used in industrial and civil engineering for the construction of multi-storey buildings and structures.

The supports are installed using a pile driver. For buildings made of foam concrete, driven reinforced concrete piles are practically not used due to economic feasibility. Expensive and unprofitable.

Bored supports

For PB buildings, I most often use bored supports. The basis of the supports are asbestos-cement pipes. Install the supports as follows:

1. The construction site is marked out for future bored supports.
2. Marking is done with a cord and pegs.
3. In the marking places, wells of a given depth are drilled with a hand drill or a mechanized drilling rig.
4. The bottom of the holes is filled with sand with a layer of 200 - 300 mm. The sand cushion will prevent the flow of liquid concrete mortar directly into the ground.
5. Asbestos pipes are lowered into the wells.
6. Metal frames are placed in the pipes.
7. The piles are filled with concrete mortar. The pouring is done in layers with a thickness of 50 cm. Each layer of concrete is compacted.
8. Concrete in an asbestos pipe rammed with a piece of rebar of a periodic profile. If the diameter of the pipe allows, the concrete is compacted with an electric vibrator.
9. Piles are made both protruding above the ground and flush with it.

The device of the tape-pile foundation on bored supports

The tape-piled foundation differs from the pile-grillage foundation in that the load from the building is redistributed between the piles and the monolithic tape. The construction of a pile-strip foundation on bored supports for a PB house consists of several stages:

1. Between the installed piles I break through a trench for a tape monolith.
2. The moat is filled with sand and carefully rammed. The sand cushion should be 300 mm thick.
3. Install the formwork of wooden panels.
4. A reinforcing cage is placed in the formwork.
5. The reinforcement protrusions of the piles are connected to the metal frame of the formwork. The fittings are connected with wire or connected by electric welding.
6. The formwork is poured with concrete mortar with layer-by-layer compaction.
7. After 28 - 30 days, the formwork is removed. The foundation is ready for the construction of walls from foam blocks.

Foundation preparation on bored piles

Depending on the possibilities and volume of concrete work, the mortar is prepared manually or mechanized (with a concrete mixer). With large volumes of need for a solution, a concrete truck is ordered.

Screw piles

Screw foundations for houses made of foam blocks are the most optimal and economical solution. The name of screw piles (VS) comes from the type of support and the method of immersion in the ground. The screw pile is screwed into the soil like a corkscrew into a cork. The support is an all-welded metal structure, consisting of three parts:

• trunk (metal pipe);
• tip;
• blades (screw).

Screw piles for a house made of foam blocks

Trunk

The basis of the bearing part of the support is the pile shaft. The length of the pile is determined on the basis of the results of geological survey work. The metal pipe should be of such a length that would allow the screw (auger) to enter a dense layer of soil to a depth of 50 - 70 cm.

The diameter of the trunk depends on the calculated load on the support. Manufacturers produce screw piles of the following diameters, designed for maximum load: 58 mm - 0.8 tons, 89 mm - 1.4 tons, 108 mm - 3.5 tons, 133 tons - 6 tons. The wall thickness of the barrel is usually 4 mm. By special order, the plant can produce supports of other sizes.

Tip

The tip in the form of a cone is made cast or all-welded. The sharp cone ensures the fast entry of the screw into the soil. Make screw piles and without a tip. The end of the pipe is cut at an angle of 45o. The hole is welded with metal.

Sometimes trunks are left open. Such supports are used for light buildings and fences. The soil fills the pile from the inside, which can cause corrosion over time.

blades

Usually screw supports are equipped with one blade, sometimes two cutting elements are installed. The blade is the screw of the structure. When the shaft rotates, the blades are screwed into the soil, the pile plunges into the ground, reaching a dense base.

For viscous soils, the blades are sharpened. Sharpening is more convenient to do with an emery wheel installed in an angle grinder.

The blades with their rotation compact the soil around the support. This improves the bearing capacity of the pile.

Foundation arrangement on screw piles

There are two methods of aircraft installation - manual installation and mechanized installation. Piles are manually installed with a length of no more than 2.5 m and a diameter of up to 108 mm. Large supports are mounted using a special mechanized installation.

Setting the aircraft manually

To install screw supports, you will need a hand drill, levers in the form of water pipes, a plumb line or a laser level. Install the aircraft as follows:

1. At the construction site, the field is marked for piles.
2. At the installation points, funnels 30 cm deep are made with a hand drill. This will facilitate the vertical installation of the rack.
3. In the absence of mounting holes in the upper part of the barrel, they are cut out with a gas cutter.
4. On both sides, segments of water pipes are inserted into the holes.
5. 3 people are involved in the work. Two workers use levers to rotate the barrel, a third worker controls and holds the support in a vertical position.
6. The laser level marks the design height of the ground part of the pile shafts.
7. An angle machine with an abrasive wheel removes excess parts of the supports.
8. Metal heads are welded to the upper ends of the piles for mounting grillage structures.

Immersion of the screw support manually

The step between the supports should not exceed 3 m. If the distance between two aircraft is greater, an additional rack is placed in the middle.

mechanized installation

For mechanized installation of screw piles, special equipment is used, equipped with a power plant that captures the head of the support and rotates it.

During a working shift (8 hours), this method can fill a pile field of medium size - 30x30 m. The speed of installation of supports depends on their length and soil composition.

Of course, the mechanized method of mounting the aircraft will cost much more. But this disadvantage is compensated by the reduction in the construction time of a house from foam blocks.

It is best to start building a foam block house on screw piles at the end of the winter season. This makes it possible to carry out further construction work in the summer. The laying of walls from foam blocks is associated with "wet" processes, which is advisable to do in warm weather.

Mechanized method of installing a screw pile on video:

According to experts, a house made of foam blocks on a pile foundation can stand for quite a long time from 50 to 100 years without a major overhaul of the main supporting structures. The device of tape-piled foundations of buildings made of PB on screw supports is the most profitable option of all types of pile foundations.

Related articles:

Pile screw foundation for a house made of foam blocks.

The foundation in housing construction has a dominant role, the strength and durability of the entire building directly depends on its reliability. Therefore, it is necessary to approach its construction with all seriousness.

In the article we will talk about how to properly arrange a pile foundation for a foam block house, analyze its pros and cons, and also consider various types of pile structures.

Types of pile foundation

The installation of piles under the house of foam blocks is used in the following cases:

• In the presence of weak heaving soils on the site.
• With swampy soil and the proximity of groundwater.
• When a basement is not planned.
• With difficult terrain on the site.
• To save time and reduce construction time.

Screw piles for the foundation.

A pile foundation for an extension of foam blocks or a private house helps to avoid a large amount of earthwork, significantly reduce construction costs.

The piles used for the construction of the house are made of metal or reinforced concrete, connected at the top by a horizontal beam - grillage, which evenly distributes the load from the bearing walls and roof over the piles. For private houses, metal or wooden grillages are usually used.

Sometimes wooden piles made of hardwood are used, they are treated with various antiseptic compounds from decay, but the service life of such piles is much shorter than that of metal or reinforced concrete. Experts recommend using piles for the foundation on poor soils for foam block houses, the foam block is a light building material and does not require a powerful foundation, this option will be the most optimal.

Bored piles for the foundation.

According to the method of construction, piles are divided into three types:

• Drop-in.
• Screw.
• Bored.

The first type is used mainly in industrial construction or in the construction of multi-storey buildings and requires the participation of special heavy equipment - pile drivers. We will not focus on driven piles here.

But the following two types are used when installing piles for light buildings and private houses. Moreover, they are installed without the involvement of technology, and you can make a foundation for foam blocks with your own hands.

Let us consider in more detail the device and methods of using each type.

Screw piles

If a foam block is used for the walls, the best option for the foundation would be to use screw piles.

The design is a metal pipe with a spiral attached to the lower end, which has a pointed end. Screw piles are screwed into the ground at their design locations.

• Wide-bladed piles do not require preparation of the foundation and any additional earthworks. Due to the pointed end, the piles are easily screwed into the ground to the desired depth.
• Narrow-blade piles they are used on hard, frozen soils and require preliminary preparation of wells, equal in diameter to the pipe section, into which piles are then tightly screwed.

The pile-screw foundation for foam blocks is a reliable and durable support for a private house, which does not require large investments of time and money.

Bored piles

We plan foam blocks for the walls - we arrange stuffed piles under the foundation.

This is the simplest type of pile installation. Unlike the screw method, it is done immediately at the installation site.

The technology for arranging such piles is simple and affordable:

• A construction drill automatically or manually drills wells to the desired depth.
• Reinforcement is made with spatial frames or individual rods.
• With hard ground, concrete can be poured directly into the well, having previously fixed a roofing material on the walls to waterproof the concrete.
• In case of weak soils, a casing pipe (asbestos-cement, plastic or metal) is installed in the well, reinforced with a frame or rods.

Important! The armoframe must protrude above the upper edge of the pipe (and above the concrete surface) by at least 15 cm for mounting the grillage.

• Concrete is poured with obligatory vibration compaction.
• After the concrete has set, the pipe can be removed or left in place - it depends on the desire of the owner. In addition, the left pipe will significantly increase the strength of the pile and at the same time serve as a waterproofing material for concrete.

grillage device

Grillage from a bar on screw piles.

The pile foundation for a house made of foam blocks cannot consist of piles alone, its design includes beams (grillages) that connect all the piles together into one whole and evenly distribute the load from the walls and roof over the entire surface of the foundation.

Grills are mainly made of metal, they are welded to the top of the piles, but it is allowed to use timber beams, as well as monolithic or combined options. In this case, additional steel fasteners are installed at the ends of the piles.

When all the piles are installed, the installation of the grillage begins:

• If it is planned in a monolithic version, then formwork is installed and reinforcement is made with frames that are connected to the reinforcement protruding from the piles.
• Concrete is poured into the formwork, vibrated and the surface is carefully smoothed.
• Beams from a bar are installed in fasteners pre-welded to the ends of the reinforcement cage (usually these are trimmings of a wide-shelf angle, plate or channel, with a shelf width equal to the beam cross section). The grillage is fixed with piles using bolts or studs.
• A gap of at least 15 cm is left between the ground and the grillage to prevent deformation of the beams as a result of seasonal heaving of the soil.

Pros and cons of a pile foundation

Pile foundation on a slope.

The pile foundation for the foam block has many advantages:

• Perhaps the device on soils of any kind and complexity.
• Requires a minimum of earthworks.
• The cost of concrete and reinforcement is reduced due to a significant reduction in the volume of the foundation, respectively, and the price of the entire construction will be an order of magnitude lower.
• Work can be carried out all year round and at any temperature.
• The design is reliable and durable.
• The pile foundation for the foam block is resistant to floods, groundwater, seasonal heaving of the soil, temperature extremes, various mechanical and chemical influences.
• The almost complete absence of precipitation, in order to start finishing the house, you do not need to wait a year, fearing seasonal deformation of the walls or roof.
• It has high seismic resistance.
• Different pile heights above the ground avoid the threat of flooding the house in dangerous flood areas.

House on the water with a foundation of reinforced concrete piles.

If we talk about the minuses, then they include:

• With a pile foundation, it is impossible to build a basement or underground.
• Installation of piles in hard or frozen soils may require the use of special equipment.
• Low quality of elements in independent or handicraft production.

As you can see, such a foundation has more pluses than minuses, but this is so only if the site has poor, weak soil. And if you need a basement in the house, then it is better to make a strip foundation.

Conclusion

If you decide to install a pile foundation on your site, it is recommended to conduct a study of the composition of the soil, order a project from a specialized organization with calculations of the location and depth of the piles.

A house made of foam concrete on piles and a metal grillage, which is used as a channel.

Experts do not advise doing this on your own, unless, of course, you are a design engineer, as an error in the calculations can lead to negative consequences that threaten the collapse of the building.

When installing piles, the installation instructions for such a foundation must be strictly followed, which contains the necessary tolerances, describes all the subtleties and nuances of this work. If the soil on the site is soft and weak, then it is necessary to deepen the piles until they reach solid ground.

In the article, we talked about some of the stages in the installation of pile foundations, photos and videos in this article will give a more complete understanding of this topic.

Choosing the best option for the basis for the house

The construction of country houses using piece materials is becoming more and more massive. There are a number of reasons for this: the aesthetic appearance of buildings, the properties of materials (for example, thermal insulation and noise reduction coefficients), construction costs.

Most developers, already at the initial stage, are faced with the most important question of which foundation is best suited for building a house from foam blocks. It will be incorrect to answer unambiguously “monolithic”, “pile” or “tape”. This article discusses three types of foundations for foam block houses. The choice will depend on the specific conditions of construction.

The decision on choosing the type of foundation for a foam block house is made taking into account the following features:

• soil layer properties(composition, freezing level, occurrence of groundwater);
• built-up pressure(mass of the house, together with the foundation and the above-ground part, the load from the internal filling of the house: furniture, residents, etc.; the impact of wind, precipitation);
• construction costs of the entire facility and timing of construction, including the feasibility of a particular type of structure.

Problem soil

The geological study of the soil layer costs a lot of money if you order a service from specialists. For this reason, many private developers do not conduct such surveys. You have to study the geology of the soil on your own.

You can also ask for advice from the owners of houses living nearby. However, you should not fully rely on the recommendations of neighbors in the area, because the soil can have significant differences both in composition and in changes throughout the calendar year.

To determine the degree of soil problematicity, it is necessary to dig a well to a depth of approximately 250 cm and select pieces of soil every 20 cm of depth. In order for the result to be reliable, it is better to make several such wells at different places on the site.

If in the end it turns out that the soil is resistant to seasonal changes (does not heave in winter), the freezing level does not exceed 100 cm, and the groundwater level is deeper than 200 cm, then the construction of a strip shallow foundation is a logical solution.

The main indicator for the tape base will be the level of groundwater. If they are very close to the surface, then such a foundation will lose its relevance, become an unreliable foundation. Therefore, when underground currents lie at a depth of 50 to 100 cm, a strip foundation should not be erected.

Subsequently, such a foundation will require the construction of a drainage system. For such soil, monolithic non-buried types of reinforced concrete foundations will be suitable.

Often a situation arises when the ground is very unsteady. Stable and reliable layers are deeper than 200 cm. Pile foundations are well suited for problematic soils. They are widely used for lightweight structures, such as wooden log cabins.

If we consider screw piles made of steel, then their stability limit ranges from 4 to 8 tons. In the case of building a house from foam concrete, the minimum distance between the piles should not be more than 1 meter. All piles must be surrounded by a monolithic reinforced concrete tape.

In the case of heaving soil, a concrete column foundation is also used, but first it is worth calculating the pressure on each support and correlating the resulting value with the bearing capacity of the pillars.

Loads

If we take into account that foam concrete blocks consist of porous material, then buildings made of foam blocks will be lighter than buildings built using bricks.

For example, the weight of one square meter, consisting of red brick, will be 1.8 tons.

The same amount of white brick will be even more significant - about 2 tons.

Foam blocks, laid out per square meter, will have a mass of approximately 900 kg.

Consequently, foam block structures are 2 times lighter than brick ones. Nevertheless, houses made of foam blocks are also about twice as heavy as wooden structures.

For the type of building material under consideration, there are three foundations:

• pile,
• tape,
• monolithic.

In practice, tape buried or monolithic is often used. Pile types of foundations are suitable for single-storey houses made of foam blocks.

In each case, it is necessary to carry out calculations and take into account various secondary factors. For this reason, it would be incorrect to offer general recommendations, because the preparatory stage of construction is a laborious task that requires careful calculations.

Pile type foundation

This type of foundation uses a pile as one bearing unit. In order for the structure to have a stable support, piles are placed at the points of greatest pressure - these are load-bearing walls along the perimeter of the building and inside it.

The upper part of the foundation may have a high grillage, which does not touch the ground surface, or is performed without a grillage. The construction technique provides for some free space between the ground and the house itself in order to prevent the structure from being affected by seasonal changes in soil and groundwater.

The height of the piles themselves is determined by the distance at which dense layers of soil rest, which can withstand the pressure of the structure. The totality of all installed piles is called the base of the foundation.

There are two types of pile structures:

• Hanging piles. The foundation on such piles in individual housing construction is used quite rarely due to the complexity of the calculations and the difficulties in predicting changes in such a sole.
  The method of building such foundations involves the installation of a large number of piles that are held due to friction. The supports are not fully supported by solid layers of soil, which is why they are called hanging piles.
• Support piles. These supports reach hard ground layers. Due to their reliability, retaining piles are able to carry huge loads and not change their performance over time.
  This technology is often used by private developers for the construction of houses, garages.
  It is allowed for implementation after a study of the soil and careful calculations.

In their shape, piles are rounded, rectangular, pointed. According to the manufacturing method, they can be steel, reinforced concrete or wood, driven or screw.

The technology for building a foundation for foam block houses is divided into pile-grillage and pile-screw types of foundations.

Pile-grillage foundation for a house of foam blocks

Most widely used by private developers. Piles act as load-bearing elements, and a reinforced concrete grillage ties the structure together.

The decision will depend on a number of factors:

• Desire to save. Savings in this case can be up to 30% of the resources allocated for the construction of the foundation. If, as a result of the calculations, it turns out that more than a dozen piles need to be installed, then it will be easier to choose a monolithic or tape base.
• Construction period. If the soil is problematic (heaving, groundwater level), then the construction time of the pile foundation can be delayed for a long period. In this case, the screw foundation on piles or strip foundation will be optimal.
will be a significant argument in favor of the pile type. Although this does not exclude the carrying out of design work.

Pile-screw foundation for a house made of foam blocks

A shallow foundation with problematic soil is dangerous because in the spring there may be difficulties with doors and windows. The very same foundation can crack. The pile-screw foundation eliminates such difficulties, since the piles are screwed deep enough.

The advantages of the foundation on screw piles will be the following features:

• construction takes little time;
• independent performance of work;
• high bearing properties;
• cost savings;
• the construction of the foundation is not limited to seasonality;
• there is no waste and garbage;
• used for uneven terrain.

Tape base

The strip foundation is characterized by stability, versatility, simple design. This type of foundation is considered the most popular among developers. It is used for houses, fences, garages and baths.

The strip foundation is a reinforced concrete structure laid out along the contour of the building. The load from the construction object is evenly distributed over the entire base, practically without creating internal stresses.

However, the construction process is quite labor-intensive, it requires a lot of time, strict adherence to the construction technology and thoughtful calculation.

There are three varieties of this type:

1. Shallow base. It is successfully applied in the case of good soil with hard layers capable of bearing the load. The groundwater level should be low. Massive brick buildings are erected on the condition that the soil does not heave during the cold season, otherwise such a foundation will crack.
2. Strip pile foundation is a combination of two types. Refers to the most durable foundations. It is used for complex soil and rather heavy structures.
3. Strip-column type. Such a foundation belongs to an intermediate type between buried and shallow. It is suitable for private construction. It is recommended to apply on sites which are placed on slopes. When groundwater is close enough to the surface of the earth, then a pile foundation will be preferred.

Monolith

The monolithic foundation is a solid reinforced concrete structure. Most often, special reinforced concrete slabs are used for laying the base, which come in various shapes and sizes. This type of foundation is used not only in private construction, but also in the construction of large objects. It requires special equipment for quality work.

The integrity of the reinforced concrete structure ensures high reliability and durability. Depending on the depth of laying monolithic slabs, surface, shallow and deep laying are distinguished (the sole is below the freezing level).

Conclusion

Advantages of a pile foundation for houses made of foam blocks:

1. Profitability due to reduction of land works and building materials.
2. Sufficiently operational terms of construction in comparison with strip and monolithic foundations.
3. Excellent reliability and stability even in problematic soils.
4. Suitable for private development.

The disadvantages of piles include suitable for fairly light structures made of foam blocks, the complexity of the calculations. To eliminate negative points, to avoid possible mistakes, it is worth entrusting the design work to professionals.

What is the best foundation for a house made of timber on loamy soil? Do-it-yourself tape foundation for a fence with a difference in ground

The foundation in housing construction has a dominant role, the strength and durability of the entire building directly depends on its reliability. Therefore, it is necessary to approach its construction with all seriousness.

In the article we will talk about how to properly arrange a pile foundation for a foam block house, analyze its pros and cons, and also consider various types of pile structures.

Types of pile foundation

The installation of piles under the house of foam blocks is used in the following cases:

• In the presence of weak heaving soils on the site.
• With swampy soil and the proximity of groundwater.
• When a basement is not planned.
• With difficult terrain on the site.
• To save time and reduce construction time.

A pile foundation for an extension of foam blocks or a private house helps to avoid a large amount of earthwork, significantly reduce construction costs.

The piles used for the construction of the house are made of metal or reinforced concrete, connected at the top by a horizontal beam - grillage, which evenly distributes the load from the bearing walls and roof over the piles. For private houses, metal or wooden grillages are usually used.

Sometimes wooden piles made of hardwood are used, they are treated with various antiseptic compounds from decay, but the service life of such piles is much shorter than that of metal or reinforced concrete. Experts recommend using piles for the foundation on poor soils for foam block houses, the foam block is a light building material and does not require a powerful foundation, this option will be the most optimal.

According to the method of construction, piles are divided into three types:

• Drop-in.
• Screw.
• Bored.

The first type is used mainly in industrial construction or in the construction of multi-storey buildings and requires the participation of special heavy equipment - pile drivers. We will not focus on driven piles here.

But the following two types are used when installing piles for light buildings and private houses. Moreover, they are installed without the involvement of technology, and you can make a foundation for foam blocks with your own hands.

Let us consider in more detail the device and methods of using each type.

Screw piles

The design is a metal pipe with a spiral attached to the lower end, which has a pointed end. Screw piles are screwed into the ground at their design locations.

• Wide-bladed piles do not require preparation of the foundation and any additional earthworks. Due to the pointed end, the piles are easily screwed into the ground to the desired depth.
• Narrow-blade piles they are used on hard, frozen soils and require preliminary preparation of wells, equal in diameter to the pipe section, into which piles are then tightly screwed.

The pile-screw foundation for foam blocks is a reliable and durable support for a private house, which does not require large investments of time and money.

Bored piles

This is the simplest type of pile installation. Unlike the screw method, it is done immediately at the installation site.

The technology for arranging such piles is simple and affordable:

• A construction drill automatically or manually drills wells to the desired depth.
• Reinforcement is made with spatial frames or individual rods.
• With hard ground, concrete can be poured directly into the well, having previously fixed a roofing material on the walls to waterproof the concrete.
• In case of weak soils, a casing pipe (asbestos-cement, plastic or metal) is installed in the well, reinforced with a frame or rods.

Important! The armoframe must protrude above the upper edge of the pipe (and above the concrete surface) by at least 15 cm for mounting the grillage.

• Concrete is poured with obligatory vibration compaction.
• After the concrete has set, the pipe can be removed or left in place - it depends on the desire of the owner. In addition, the left pipe will significantly increase the strength of the pile and at the same time serve as a waterproofing material for concrete.

grillage device

The pile foundation for a house made of foam blocks cannot consist of piles alone, its design includes beams (grillages) that connect all the piles together into one whole and evenly distribute the load from the walls and roof over the entire surface of the foundation.

Grills are mainly made of metal, they are welded to the top of the piles, but it is allowed to use timber beams, as well as monolithic or combined options. In this case, additional steel fasteners are installed at the ends of the piles.

When all the piles are installed, the installation of the grillage begins:

• If it is planned in a monolithic version, then formwork is installed and reinforcement is made with frames that are connected to the reinforcement protruding from the piles.
• Concrete is poured into the formwork, vibrated and the surface is carefully smoothed.
• Beams from a bar are installed in fasteners pre-welded to the ends of the reinforcement cage (usually these are trimmings of a wide-shelf angle, plate or channel, with a shelf width equal to the beam cross section). The grillage is fixed with piles using bolts or studs.
• A gap of at least 15 cm is left between the ground and the grillage to prevent deformation of the beams as a result of seasonal heaving of the soil.

Pros and cons of a pile foundation

The pile foundation for the foam block has many advantages:

• Perhaps the device on soils of any kind and complexity.
• Requires a minimum of earthworks.
• The cost of concrete and reinforcement is reduced due to a significant reduction in the volume of the foundation, respectively, and the price of the entire construction will be an order of magnitude lower.
• Work can be carried out all year round and at any temperature.
• The design is reliable and durable.
• The pile foundation for the foam block is resistant to floods, groundwater, seasonal heaving of the soil, temperature extremes, various mechanical and chemical influences.
• The almost complete absence of precipitation, in order to start finishing the house, you do not need to wait a year, fearing seasonal deformation of the walls or roof.
• It has high seismic resistance.
• Different pile heights above the ground avoid the threat of flooding the house in dangerous flood areas.

If we talk about the minuses, then they include:

• With a pile foundation, it is impossible to build a basement or underground.
• Installation of piles in hard or frozen soils may require the use of special equipment.
• Low quality of elements in independent or handicraft production.

As you can see, such a foundation has more pluses than minuses, but this is so only if the site has poor, weak soil. And if you need a basement in the house, then it is better to make a strip foundation.

Conclusion

If you decide to install a pile foundation on your site, it is recommended to conduct a study of the composition of the soil, order a project from a specialized organization with calculations of the location and depth of the piles.

Experts do not advise doing this on your own, unless, of course, you are a design engineer, as an error in the calculations can lead to negative consequences that threaten the collapse of the building.

When installing piles, the installation instructions for such a foundation must be strictly followed, which contains the necessary tolerances, describes all the subtleties and nuances of this work. If the soil on the site is soft and weak, then it is necessary to deepen the piles until they reach solid ground.

In the article, we talked about some of the stages in the installation of pile foundations, photos and videos in this article will give a more complete understanding of this topic.

A pile foundation for a block house is provided on problem soils (heaving clay or loam), if a combination of factors does not allow the construction of a different type of support base. When using screw or bored supports, it is easy to do the construction of a foundation base for a foam block house with your own hands.

Types of pile foundations

If soils with weak bearing capacity lie on the building site, groundwater rises close to the soil surface, and the soil itself freezes to a considerable depth, it is worth considering using a pile foundation as a foundation for a house.

For foam block houses, screw or bored piles are most often used.

It is not advisable to build a small residential building from foam blocks on driven reinforced concrete piles for the following reasons:

• Reinforced concrete products are of high cost, which will affect the increase in the cost of building a house.
• The technological process of driving piles into the ground will require the use of special equipment, the rental of which is quite expensive. Piling equipment has a significant mass, therefore, for its delivery to the construction site, equipped roads and driveways are required.

A foam block house is best built on screw or bored piles, each type of support is used in certain conditions. Usually, the foundation of bored piles is erected in deeply freezing soils, in other cases, a residential building of foam concrete blocks is mounted on screw supports.

Pile foundation: screw supports

Due to the ease of erection, a block house on screw piles can be built in a couple of weeks.

Consider the option of building a residential building from foam concrete on screw pile supports. For the construction of this type of foundation, specialized equipment and tools are not required; 3 workers can do the job.

Screw supports represent a metal hollow rod with a pointed end. At the bottom of the supporting elements, blades are welded, which, when the pile rotates, help it sink into the ground. There are two types of blades: welded and cast.

Cast structures have higher strength and reliability, in the places of the weld, especially with insufficient insulation, there is the development of corrosion foci, which significantly weaken the support, and eventually make it completely unusable.

The supports are inserted into specially prepared pits, their vertical position is checked, after which screwing into the ground begins.

The rotation is clockwise until the pile stops, the work is done by 2 workers who immerse the pile using a special device. At the upper end of the screw supports there is a special hole, it is through it that a rotational mechanism is passed, which helps the piles to sink into the soil. Private developers often use scrap, which is passed through a hole in the pile. Segments of pipes are put on scrap, when exposed to them, the support is screwed in.

Before starting the immersion of screw elements, it is worth treating them with special protective compounds against corrosion.

The thing is that the pile coating is injured, passing through the thickness of the soil. Scratches form on the metal surface, which serve as open gates for the occurrence of corrosion, piles are destroyed especially quickly in wet soil (for example, clayey), so additional processing of the elements will never be superfluous.

grillage device

The screwing of individual pile foundation rods is provided along the perimeter of the building, as well as under internal load-bearing walls and partitions. The distance between the supports is usually from 1.2 to 1.5 meters.

When all the piles are screwed into the ground, you can start trimming the protruding parts of the supports. It is very important to observe a single level of foundation pillars that rise above the ground. When trimming, they try to remove that part of the trunk in which there was an eye for screwing the elements into the ground.

After cutting the piles, the hollow part of the pipes is filled with concrete mortar, after which it is covered with a metal head. The headband is welded to the pile support rod, reliably blocking the access of dampness and atmospheric precipitation.

To combine all the supports into a single foundation belt, it is necessary to build a special structure - a grillage.

Watch the video on how to build a grillage with your own hands without the help of professionals.

The foundation grillage is made of wood, monolith or rolled metal (beams, channel bars), for a foam block house built on clay soil, the ideal grillage is obtained from a channel laid along the heads in the position with the shelves down.

The upper platform of rolled metal has a flat surface, on which it is easy to lay waterproofing and the first row of foam blocks. The quality of the walls of the dwelling, the stability of the structure and its strength depend on how evenly the first row of block masonry is laid out.

Plinth and blind area

A house on stilts usually requires a plinth cladding that will protect the space under the house from winds, precipitation and low temperatures. The equipped plinth helps to keep heat on the ground floor of the foam block house, improves the appearance of the building itself and serves to reliably protect the structure from adverse factors.

The pile foundation for a house made of blocks can be hidden behind a fence made of brick or monolithic reinforced concrete. The space between the piles can be closed with siding, choosing a color in the style of finishing the exterior facade of the building. There are many options for installing a basement, you can always find the most acceptable option for each building.

A blind area is necessary just like for any other building.

The blind area is usually performed with a slope from the wall, which helps protect foundations and basements from precipitation. The insulated blind area helps to keep warm, the device of such a design is especially important in the presence of a basement or technical underground.

Houses made of foam blocks are widely popular among developers - primarily because of the convenience of laying foam blocks and the speed of their construction. However, foam block houses have special requirements for building a foundation for them. An optimal and promising foundation for foam block structures can be called a foundation on screw piles.

1. Foam block as a building material

The foam block is a fairly new building material. It is obtained by adding foaming additives to cement mixtures - as a result, builders have a qualitatively new material that is durable, light and porous. The foam block is produced under industrial conditions using special equipment. The dimensions of the blocks exceed the dimensions of bricks and may exceed the dimensions of ordinary cinder blocks. The porous structure of foam blocks gives them qualities that exceed those of other wall materials. First of all - the specific gravity and the ability to retain heat.

This material appeared relatively recently due to the development of building materials technology. The foam block has a number of similar parameters with traditional wall materials - brick and cinder block:

• Solidity of the material
• Masonry with cement compounds
• Correct geometric shape

At the same time, foam blocks have a significant difference from brick and cinder block:

1. Significantly lighter weight
2. Easy to cut to desired size
3. Greater moisture resistance compared to slag blocks
4. The dimensions exceed those for a brick, and it is much faster to build houses from it than brick ones.
5. The weight of foam blocks is much lower than that of cinder blocks, which reduces the complexity of masonry

However, the advantages of the foam block turn into disadvantages:

• Increased brittleness
• Insufficient strength

In connection with these features of foam blocks, it is not recommended to build houses from them above 2 floors.

2. Features of the foundation for foam block houses

The structure of foam blocks predetermines its properties - such as insufficient strength and fragility (compared to brick and cinder block) - therefore, they must be taken into account when building a foundation. Any errors in the calculations of the foundation and its installation can lead to increased stresses on the wall material, in particular, individual foam blocks. If a brick or cinder block can easily cope with them, then the foam block may collapse.

Thus, increased requirements are imposed on the foundation for foam block buildings, and not always they can be completely met.

3. Types of foundations for foam block houses

Traditionally, under any houses made of monolithic materials, powerful foundations are installed that can easily withstand the multi-ton weight of the structure. First of all, these are reinforced concrete foundations of three types:

1. Plinye, when the house is installed on a monolithic slab
2. Strip foundations installed along the perimeter of the building and under load-bearing walls
3. Columnar foundations accepting a distributed load, including from especially loaded points

However, there is not always a need for such foundations in the case of building houses from foam blocks. This is primarily due to the weight of houses, which is significantly inferior to the weight of houses made of brick or cinder block.

In addition, difficulties arise with the construction of the foundation of foam block houses when:

• The house is being built on weak, unstable soils
• High groundwater level
• With increased heaving of soils
• When building houses on difficult terrain, on slopes

It is often impossible to establish a high-quality foundation in such cases, and, as we mentioned above, any errors in the construction of the foundation can affect the durability of such material as a foam block.

In addition, a big problem is the rather long time frame for laying the foundation - for all its laboriousness, as well as the need for strict exposure to it for forty to forty-five days. As a result, it is problematic to build a house from a foam block in one summer construction season - half of it will be spent only on the construction of the foundation, because in the case of concrete foundations, this is also seasonal work.

An excellent way out in such situations is the construction of a foundation on screw piles.

4. Advantages of a pile-screw foundation for a foam block

We list the advantages of the foundation on screw piles for foam block houses:

1. The speed of construction - you can start building a house immediately after laying the foundation
2. The ability to install piles in weak, mobile, heaving soils
3. The ability to establish a foundation on the ground with uneven terrain, even with significant slopes
4. Support of screw piles on stronger soil layers, which increases the stability of the foundation to loads
5. Easy foundation calculation
6. Relative ease of installation compared to monolithic strip or slab foundations

Significant cost savings

The disadvantages of a pile-screw foundation for houses made of foam blocks include:

1. The impossibility of building a basement or basement
2. Weight restrictions for a house under construction

However, the last point can be crossed out - the houses made of foam blocks themselves should not have a lot of weight due to the structural features of the wall material, as mentioned above.

Thus, the foundation on screw piles can be considered optimal for the construction of foundations for houses from foam blocks.

5. Features of mounting the foundation on screw piles for foam block houses

In general, laying a pile-screw foundation for foam block houses is similar to that for any buildings and includes:

• Foundation planning considering loads
• Site preparation for the foundation
• Driving screw piles
• Pile concreting, cutting by level
• Installation of grillage on piles

We have already mentioned the features of the foam block as a building material. They need to be taken into account in laying the foundation.

Since foam block houses can be much heavier than houses made of timber or frame houses made of wood, an appropriate margin of safety must be included in the calculation of the pile-screw foundation. In most cases, for a standard two-story foam block house, piles with a diameter of at least 108 mm and a wall thickness of 4-5 mm are chosen. The calculation of the bearing capacity of each pile shows that their number should be greater than for a frame house of the same size.

Often, to give additional strength to the foundation, not an ordinary wooden grillage is installed on the piles, but a concrete one, up to the laying of a monolithic slab on the piles. Thus, there is a qualitative combination of the properties of the pile-screw and monolithic foundation. Using such foundations, you can build quite massive houses on them.

Deepening of piles also requires relatively more than in foundations for lighter buildings.

As for the installation of screw piles, then, of course, a mechanized method is preferable, the developer needs to prepare for this. This is due to both the high standard number of piles in the pile field, and the parameters of the piles, as well as the depth of their screwing. Manually laying the foundation for a fairly large foam block house is a laborious task, and it will take more time than using a pile drill. This will save money on paying for heavy equipment, but will increase the wage share of builders if the installation is done manually. However, for light buildings, options are possible.

6. Conclusion

The construction of a house from foam blocks can be done in the shortest possible time - this is due to its features. But in order to quickly build a house, it is necessary to use the technology of a prefabricated foundation. The use of screw piles will be optimal in this case.

The firm "K-DOM" specializes in laying foundations on screw piles, as well as the production of screw piles. Our specialists can assist developers at any stage of the construction of a pile-screw foundation, taking into account all the features of the future building, including the built and foam blocks.

In the article we will tell you what to remember if you want to build a house from foam blocks on screw piles.

Foam block - a building material that is made from a variety of cellular concrete - foam concrete. Foam concrete is made from cement, sand and water with the addition of a foaming agent. This technology is considered very promising due to the following material properties:

• good thermal insulation;
• high sound insulation;
• durability;
• low weight with high strength.

We will talk about some features of the design and installation of a pile-screw foundation for a house made of foam blocks.

Determination of the ground conditions of the construction site

When choosing a foundation, it is very important to understand that it only serves to transfer loads from the structure to the base of the soils below it. Consequently, it is the soil conditions of the construction site that will determine the parameters of the foundation structure.

Thus, building without knowledge of soils is not only reckless, but also dangerous. Moreover, even within one small area, different conditions of soil occurrence, dangerous geological objects or processes (suffusion, karst, quicksand) can occur.

In the case of a pile-screw foundation, based on soil data, the following is selected:

• barrel length;
• distance between the blades, pitch, angle of inclination of the blades (for modifications with two or more blades);
• configuration of the blades (not to be confused with the diameter), which ensures installation with minimal disturbance of the soil structure, which guarantees the proper perception of design loads (read more "Key principles for selecting the parameters of screw pile blades"), etc.

The corrosive aggressiveness of soils (CAG) must be taken into account when assigning the steel grade, the wall thickness of the shaft and the blade. This makes it possible to achieve compliance of the service life of the structure with the requirements of GOST 27751-2014 “Interstate Standard. Reliability of building structures and foundations. Basic Provisions". To clarify the correctness of these parameters, after performing the calculation of the service life, the residual wall thickness of the shaft is checked for compliance with the design loads.

In order to give its customers the opportunity to obtain all the necessary data without carrying out expensive geological surveys, GlavFundament has developed and implemented as mandatory procedures adapted for individual housing construction - geological and lithological surveys (express geology) and measurements of soil corrosiveness (for more details, "Express- geology and measurements of soil corrosiveness”). CAG measurements were recognized as mandatory, since most of the territory of the Russian Federation is represented by medium and highly aggressive soils.

To confirm the bearing capacity of screw piles after immersion, mandatory control measurements of the torque value (VKM) are performed. Often a similar procedure (trial screwing) is considered as an independent study. But this is not entirely correct, since the results, firstly, will depend on the time of year, and secondly, immersion to the design depth does not provide information about the properties of the soil under the pile.

To check the correctness of data on soil conditions, we recommend using the map of completed objects containing information on:

• types of buildings;
• corrosive aggressiveness of soils;
• blade configurations;
• torque value.

The presence of a height difference on the site requires not only the use of screw piles of various lengths, but also in a different combination of modifications than in the case of construction on a flat surface. This is due to the increase in the horizontal impact on the foundation.

Collection of loads from the structure

Since foam blocks are a fairly lightweight building material, the loads from the structure are often underestimated.

How to arrange piles taking into account the impact on the foundation of different loads

Different parts of the structure transfer loads of different sizes to the foundation:

• under the responsible nodes of the structure;
• under load-bearing walls;
• under non-load-bearing walls, floor joists.

The ability of screw piles to perceive design loads depends on the soil conditions of the construction site, as well as on the number, diameter and configuration of the blades. Wall thickness and barrel diameter, first of all, ensure compliance with the requirements for rigidity, strength, durability.

Therefore, under nodal loads, it is recommended to install piles with two blades of the maximum diameter for this modification. This design makes it possible to achieve the inclusion in their work of the maximum volume of the near-pile soil massif and prevents the “stall” when transferring critical loads. However, if the distance between the blades, the pitch and the angle of inclination of the blades of such piles are calculated without taking into account the specific soil conditions of the site, a "reverse effect" may occur - a decrease in the bearing capacity even with respect to deaxial varieties (more "").

Thus, the foundation for a foam block house is always calculated individually. So that we can calculate its cost for you, provide geological survey data or sign up for a visit by a geologist.