One-story houses made of foam blocks have much less weight than similar buildings made of brick or precast reinforced concrete.
Therefore, it is advantageous to build houses from foam blocks and aerated concrete blocks where the soil base has weak bearing capacity on screw piles. A foundation made 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 hardening, the molds are disassembled and ready-made foam blocks are obtained. Large blocks are produced by sawing volumetric monoliths.
Foam concrete blocks
The density of foam concrete is three times less than the density of brick, and accordingly its weight is three times less. Possessing high thermal insulation, waterproofing and strength properties, foam concrete compares favorably with other types of building materials.
Considering the low load-bearing capacity and fragility of the material, foam blocks can only be used in the construction of low-rise, small residential buildings.
In terms of their quality characteristics, aerated concrete blocks 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 disadvantage of aerated concrete is its poor resistance to moisture. Therefore, masonry made of aerated concrete blocks requires enhanced waterproofing.
Masonry walls made of foam concrete and aerated concrete blocks are built in the same way as brickwork with cement mortar.
Justification for the use of screw piles
As a result of geological surveys at the construction site, the following data is obtained:
- the thickness of the soil layer with low bearing capacity (usually clayey soils subject to swelling and freezing);
- the depth of denser soil layers;
- groundwater level;
- depth of soil freezing.
Based on the obtained material, a decision is made on the advisability of using screw piles in constructing a foundation for a house made of aerated concrete blocks or foam blocks.
Screw piles
Screw foundation piles
A standard screw pile for a foundation is a metal pipe with a diameter of 90 mm, at the end of which there is a point with helical blades.
The 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 are susceptible to soil penetration into the core cavity. This may cause internal corrosion of the support.
Helical blades ensure that the pile rod enters the ground with minimal resistance using the principle of a corkscrew. A pile may have one or two blades. The length of the screw pile rod depends on the required depth of immersion in 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 house made of foam blocks, you should pay attention to the quality of the galvanized surface. Good galvanization looks like silvery stars on the metal surface.
Screw pile installation technology
Design the placement of pile supports in the corners of the building, in the centers of support of load-bearing walls with a minimum distance between piles of 1.5 to 2 meters.
One screw pile can withstand an axial load of up to 25 tons.
Installation of a screw pile
Installing screw piles is not very difficult. The head of the pile support consists of a metal heel welded to the upper end of the pile rod. This horizontal support has technological holes for fastening mounting equipment.
The mounting gate is secured through the holes. Two workers, turning the gate, plunge the pile into the ground. As the pile is screwed into the soil, it becomes compacted.
When the number of pile supports is large and their immersion depth is several meters, mechanized installations are used. The power equipment is equipped with a boom, at the end of which a rotating element is installed. It is connected with bolts to the head of a screw pile and imparts a rotational movement to it. As a result, many piles can be installed over a large area in a short period of time.
Pile tying
They build a foundation on pile supports by installing a metal frame structure, which is attached by welding to the heads of screw piles. The frame is a lattice structure made of metal profile 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 places where load-bearing walls support, a profile with a shelf width equal to the width of a block made of aerated concrete or foam concrete is placed.
Before installing the frame, be sure to check the horizontality of the pile heads at the same level.
The height of screw piles above ground level must be at least 15 cm. When the terrain surface slopes, the height of the piles will be different.
Base design
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 upward, which will cause deformation of the frame structure of the foundation of the house made of foam blocks. Any damage to the frame will inevitably put the house in emergency condition, since the structure of foam blocks and aerated concrete blocks is fragile and the walls of the house may become covered with cracks.
Basement of a house on screw piles
In order not to expose the house to the risk of destruction, the piles are lined. Along the perimeter of the house, the space under the building is covered with any suitable panel material. The fence is insulated with foam plastic, mineral wool or other material. Waterproofing is made from a polymer film. After this, siding is installed.
Expansion joints must be left between the underground fence and the bottom of the house. They are necessary to compensate for temperature deformations.
With a well-designed underground fence, when the outside air temperature is 20 degrees below zero, the internal air temperature will be 5 degrees above zero. Under such conditions, a foundation on screw piles will last for many years.
Advantages and benefits of piles for a foam block house
The construction of a 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 carried out at any time of the year;
- you can build a house on difficult soils, regardless of the terrain slope, groundwater level and soil freezing depth;
- significant savings in labor costs and finances;
- guarantee of long-term operation of the house.
Related articles:
Pile screw foundation for a house made of foam blocks
The main reasons for choosing a pile foundation are weak soils, high groundwater levels, and complex terrain of the building site. Recently, the construction of private buildings from foam concrete blocks has become very popular. The erected pile foundation for a house made of foam blocks significantly reduces construction time. The disadvantage of a house made of foam concrete on stilts is that with such a foundation design it is impossible to construct a basement. The advantage is the absence of large volumes of excavation work.
Foam blocks
Foam concrete is a relatively new building masonry material. Foam blocks are made from it for building walls. Foam blocks (PF) have gained great popularity due to their quality characteristics.
Standard sizes of foam blocks
PB is manufactured in a factory using special equipment. 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 foam mass occurs in the open air.
For the construction of external walls of buildings, PB of standard sizes 390x188x190 mm is used. Blocks 90 mm thick are used for laying partitions. There are varieties of foam blocks with side locking systems - “tenon and groove”. Sometimes the horizontal surfaces of 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 analogues. Foam blocks are used for laying external fences of multi-storey buildings, where the load-bearing function of the building is performed by the frame of the structure (columns + floors). The porous structure of the material gives the blocks high thermal insulation qualities. In winter, the masonry of the walls does not allow the cold to pass through, and in hot weather it keeps the interior cool.
The main disadvantage of the material is its low load-bearing capacity, therefore, foam block masonry is used as external enclosing structures in houses no more than 2 floors high.
Foam concrete is a fragile material, so any mechanical impact can cause damage to the integrity of the outer surface of the block.
Construction of walls made of 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 strip-pile foundation. Before this, the surface of the foundation must be covered with a layer of waterproofing.
PB is placed both on a special adhesive composition and on a regular 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 20 mm thick. It is enough to lay the expensive adhesive composition at 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.
The walls are laid in the width of the floor of the block or block. Block-thick walls are erected in northern regions, where increased thermal insulation of the external fences of buildings is required.
Scheme of dressing between rows of masonry half a block thick
Types of pile foundations
Piles, as supporting structures, are used to pass through weak soil layers and reach dense soil layers. The support structure takes on the load from the building and transfers it to a solid soil foundation, bypassing weak, unreliable soil layers. A 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 frictional forces of the side surface against the soil. Driven-in supports are manufactured in the factory. They are mainly used in industrial and civil construction for the construction of multi-storey buildings and structures.
The supports are installed using a pile driver. For buildings made of foam concrete material, 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:
- The construction site is marked for future bored supports.
- Markings are made with cord and pegs.
- In the marking areas, wells are drilled to a given depth using a hand drill or a mechanized drilling rig.
- The bottom of the holes is filled with sand in a layer of 200 - 300 mm. The sand cushion will prevent the liquid concrete solution from leaking directly into the ground.
- Asbestos pipes are lowered into the wells.
- Metal frames are placed in the pipes.
- 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.
- I compact the concrete in the asbestos pipe with a piece of periodic profile reinforcement. If the diameter of the pipe allows, the concrete is compacted with an electric vibrator.
- Piles are made both protruding above the ground and flush with it.
Construction of a strip-pile foundation on bored supports
A strip-pile foundation differs from a pile-grillage foundation in that the load from the building is redistributed between the piles and the monolithic strip. The construction of a pile-strip foundation on bored supports for a house made of PB consists of several stages:
- Between the installed piles I dig a trench for the strip monolith.
- The ditch is filled with sand and compacted thoroughly. The sand cushion should be 300 mm thick.
- Install formwork from wooden panels.
- A reinforcement cage is placed in the formwork.
- The outlets of the pile reinforcement are connected to the metal formwork frame. The reinforcement is tied with wire or connected by electric welding.
- The formwork is filled with concrete mortar with layer-by-layer compaction.
- After 28 - 30 days, the formwork is removed. The foundation is ready for the construction of foam block walls.
Preparing the foundation on bored piles
Depending on the capabilities and volume of concrete work, the solution is prepared manually or mechanized (with a concrete mixer). If the demand for mortar is large, a concrete truck is ordered.
Screw piles
Screw foundations for houses made of foam blocks are the most optimal and economical solution. The name screw piles (SC) 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 entering a cork. The support is an all-welded metal structure consisting of three parts:
- barrel (metal pipe);
- tip;
- blades (propeller).
Screw piles for a foam block house
Trunk
The basis of the load-bearing part of the support is the shaft of the pile. The length of the pile is determined based on the results of geological survey work. The metal pipe must be of 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 thickness of the barrel wall is usually 4 mm. By special order, the plant can produce supports of other sizes.
Tip
The cone-shaped tip is made cast or all-welded. The sharp cone ensures quick penetration of the screw into the soil. They make screw piles without a tip. The end of the pipe is cut at an angle of 45°. The hole is welded with metal.
Sometimes the trunks are left open. Such supports are used for light buildings and fences. Soil fills the pile from the inside, which can cause corrosion over time.
Blades
Typically, screw supports are equipped with one blade, sometimes two cutting elements are installed. The blade is the propeller of the structure. When the trunk rotates, the blades are screwed into the soil, the pile is immersed in the ground, reaching a dense base.
For viscous soils, the blades are sharpened. It is more convenient to sharpen with an emery wheel installed in an angle grinder.
The blades, by their rotation, compact the soil around the support. This helps to increase the load-bearing capacity of the pile.
Foundation construction on screw piles
There are two methods for installing aircraft - manual installation and mechanized method. Piles with a length of no more than 2.5 m and a diameter of up to 108 mm are installed manually. Large supports are mounted using a special mechanized installation.
Installing 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:
- At the construction site, the field is marked for piles.
- At the installation points, a hand drill is used to make funnels 30 cm deep. This will facilitate the vertical installation of the rack.
- If there are no mounting holes in the upper part of the barrel, they are cut out with a gas cutter.
- Sections of water pipes are inserted into the holes on both sides.
- 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.
- A laser level is used to mark the design height of the ground part of the pile shafts.
- Using an angle machine with an abrasive wheel, remove excess parts of the supports.
- Metal caps are welded to the upper ends of the piles for installation of grillage structures.
Manual insertion of the screw support
The step between the supports should not exceed 3 m. If the distance between two aircraft is greater, an additional stand is placed in the middle.
Mechanized installation
For mechanized installation of screw piles, special equipment is used, equipped with a power unit that ensures the grip of the support head and its rotation.
During a work 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 aircraft installation will cost much more. But this drawback is compensated by the reduction in construction time for a house made of 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. Laying walls made of foam blocks involves “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 last quite a long time, from 50 to 100 years, without major repairs to the main load-bearing structures. The construction of strip-pile foundations for buildings made of PB on screw supports is the most profitable option among all types of pile foundations.
Related articles:
Pile screw foundation for a house made of foam blocks.
The foundation plays a dominant role in house construction; the strength and durability of the entire building directly depends on its reliability. Therefore, its construction must be approached with the utmost seriousness.
In the article we will talk about how to properly install a pile foundation for a house made of foam blocks, analyze its pros and cons, and also consider different types of pile structures.
Types of pile foundation
Installation of piles under a house made of foam blocks is used in the following cases:
- In the presence of weak heaving soils on the site.
- With swampy soil and proximity to 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 made of foam blocks or a private house helps to avoid a large amount of excavation work and significantly reduce construction costs.
The piles used to build a house are made of metal or reinforced concrete, connected at the top by a horizontal beam - a grillage, which evenly distributes the load from the load-bearing walls and roof over the piles. For private houses, metal or wooden grillages are usually used.
Sometimes wooden piles made from hardwood are used; they are treated with various antiseptic compounds to prevent rotting, but the service life of such piles is much shorter than that of metal or reinforced concrete. Experts recommend using foundation piles for foam block houses on poor soils; foam block is a lightweight building material and does not require a strong 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:
- Hammers.
- 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 driving machines. 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 equipment, and you can make the foundation for the foam blocks with your own hands.
Let's take a closer look at the device and methods of using each type.
Screw piles
If foam blocks are 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 having a pointed end attached to the lower end. Screw piles are screwed into the ground at their design locations.
- Broad-bladed piles do not require foundation preparation or any additional excavation work. Thanks to the pointed end, the piles are easily screwed into the ground to the required depth.
- Narrow-bladed piles used on hard, frozen soils and require preliminary preparation of wells with a diameter equal to the cross-section of the pipe, into which piles are then tightly screwed.
A pile-screw foundation for foam blocks is a reliable and durable support for a private home, which does not require large investments of time and money.
Bored piles
We are planning foam blocks for the walls; we are installing cast-in-place 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 constructing such piles is simple and accessible:
- A construction drill automatically or manually drills wells to the required depth.
- Reinforcement is done with spatial frames or individual rods.
- In case of hard soil, concrete can be poured directly into the well, having previously secured roofing material to the walls to waterproof the concrete.
- In case of weak soils, a casing pipe (asbestos-cement, plastic or metal) is installed in the well and reinforced with a frame or rods.
Important! The reinforced frame must protrude above the upper edge of the pipe (and above the concrete surface) by at least 15 cm for installation of the grillage.
- Concrete is poured with mandatory 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 remaining pipe will significantly increase the strength of the pile and at the same time serve as a waterproofing material for concrete.
Grillage arrangement
Grillage made of timber on screw piles.
A 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.
Grillages are mainly made of metal, they are welded to the top of the piles, but the use of beams made of timber, as well as monolithic or combined options, is allowed. In this case, additional steel fasteners are installed at the ends of the piles.
When all the piles are installed, installation of the grillage begins:
- If it is planned in a monolithic version, then formwork is installed and reinforcement is made with frames, which are connected to the reinforcement protruding from the piles.
- Concrete is poured into the formwork, the surface is vibrated and thoroughly smoothed.
- Beams made of timber are installed in fasteners pre-welded to the ends of the reinforced frame (usually cuttings of a wide-flange angle, plate or channel, with a flange width equal to the cross-section of the beam). The grillage is secured to the 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 built on a slope.
A pile foundation for a foam block has many advantages:
- The device can be installed on soils of any type and complexity.
- Requires a minimum of excavation work.
- The costs of concrete and reinforcement are reduced due to a significant reduction in the volume of the foundation, and accordingly, the cost of the entire construction will be an order of magnitude lower.
- Work can be carried out year-round and at any temperature.
- The design is reliable and durable.
- A pile foundation for a foam block is resistant to floods, groundwater, seasonal soil heaving, temperature changes, and various mechanical and chemical influences.
- There is 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.
- Has high seismic resistance.
- The different heights of the piles above the ground avoid the threat of flooding of the house in dangerous flood areas.
House on the water with a foundation made of reinforced concrete piles.
If we talk about the disadvantages, they include:
- With a pile foundation it is impossible to build a basement or subfloor.
- 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 advantages than disadvantages, but this is only true if the site has poor, weak soil. And if you need a basement in your 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 soil composition, order a project from a specialized organization with calculations of the location and depth of the piles.
The house is made of foam concrete on stilts and a metal grillage, which is used as a channel.
Experts do not advise doing this yourself, unless, of course, you are a design engineer, since an error in the calculations can lead to negative consequences that threaten the collapse of the building.
When installing piles, the instructions for installing such a foundation must be strictly followed, which contain the necessary tolerances and describe all the subtleties and nuances of this work. If the soil in the area 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 of installing pile foundations; photos and videos in this article will give a more complete understanding of this topic.
Choosing the best base option for the house
The construction of country houses using piece materials is becoming more and more widespread. There are a number of reasons for this: the aesthetic appearance of structures, the properties of materials (for example, thermal insulation and noise reduction coefficients), and the costs of construction work.
Most developers, already at the initial stage, are faced with the most important question of which foundation is best suited for building a house made of foam blocks. It would be incorrect to answer unequivocally “monolithic”, “pile” or “tape”. This article discusses three types of foundations for foam block houses. The choice will depend on the specific construction conditions.
The decision to choose the type of foundation for a house made of foam blocks is made taking into account the following features:
- properties of the soil layer(composition, level of freezing, occurrence of groundwater);
- pressure from the rebuilt structure(weight of the house, together with the foundation and above-ground part, load from the internal filling of the house: furniture, residents, etc.; exposure to wind, precipitation);
- costs for the construction of the entire facility and construction timing, including the viability of a particular type of design.
Problematic soil
Geological study of the soil layer costs a lot of money if you order the service from specialists. For this reason, many private developers do not conduct such surveys. You have to study the geology of the soil yourself.
You can also seek advice from the owners of houses living nearby. However, you shouldn’t rely entirely on the recommendations of neighbors on the site, because the soil can have significant differences both in composition and in changes throughout the calendar year.
To determine the degree of problem of the soil, it is necessary to dig a well to a depth of approximately 250 cm and select pieces of soil every 20 cm in depth. In order for the result to be reliable, it is better to make several such wells in 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 logical solution is to build a shallow strip foundation.
The main indicator for the strip foundation will be the groundwater level. If they are very close to the surface, then such a foundation will lose its relevance and 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 unstable. Stable and reliable layers are found deeper than 200 cm. Pile foundations are well suited for problematic soils. They are widely used for light structures, for example, wooden log houses.
If we consider steel screw piles, their stability limit ranges from 4 to 8 tons. If a house is built from foam concrete, the minimum distance between piles should not be more than 1 meter. All piles must be surrounded by a monolithic reinforced concrete strip.
In the case of heaving soil, a columnar concrete foundation is also used, but first it is worth calculating the pressure on each support and correlating the obtained value with the bearing capacity of the pillars.
Loads
If we take into account that foam concrete blocks consist of a porous material, then buildings made from foam blocks will be lighter than buildings built using brick.
For example, the weight of one square meter consisting of red brick will be 1.8 tons.
The same volume of white brick will be even heavier - 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 approximately twice as heavy as wooden structures.
For the type of building material under consideration, there are three foundations:
- pile,
- tape,
- monolithic.
In practice, recessed or monolithic tape is often used. Pile types of foundations are suitable for one-story houses made of foam blocks.
In each specific 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 labor-intensive task that requires careful calculations.
Pile type foundation
This type of foundation uses a pile as one load-bearing unit. To ensure that the structure has stable support, the piles are placed at 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 that does not touch the ground surface, or it may be made without a grillage. The construction method 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 that 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 labor-intensive calculations and difficulties in predicting changes in such a foundation.
The method of constructing such foundations involves installing a large number of piles, which are held in place by friction. The supports do not rest entirely on solid layers of soil, which is why they are called hanging piles. - Retaining piles. These supports reach hard soil layers. Due to their reliability, retaining piles are able to bear enormous loads and not change their performance over time.
This technology is often used by private developers to build houses and garages.
It is allowed for implementation after soil research and careful calculations.
The shape of piles can be rounded, rectangular, or pointed. According to the manufacturing method, they can be steel, reinforced concrete or wood, driven or screw.
The technology for building foundations for foam block houses is divided into pile-grillage and pile-screw types of foundations.
Pile-grillage foundation for a house made of foam blocks
Most widely used by private developers. The load-bearing elements are piles, and a reinforced concrete grillage ties the structure together.
The decision will depend on a number of factors:
- Desires to save money. Savings in this case can amount to 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 strip foundation.
- Construction period. If the soil is problematic (heaving, groundwater level), then the construction time for a pile foundation may be delayed for a long period. In this case, a screw foundation on piles or a strip foundation would be optimal. will be a significant argument in favor of the pile type. Although this does not exclude 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 foundation itself may crack. A pile-screw foundation eliminates such difficulties, since the piles are screwed deep enough.
The advantages of a foundation on screw piles are the following:
- construction takes little time;
- independent performance of work;
- high load-bearing properties;
- cost savings;
- the construction of the foundation is not limited to seasonality;
- no waste or debris remains;
- used for uneven terrain.
Tape base
Strip foundations are characterized by stability, versatility, and simple design. This type of foundation is considered the most popular among developers. It is used for houses, fences, garages and bathhouses.
The strip foundation is a reinforced concrete structure laid out along the contour of the building. The load from the construction site is evenly distributed over the entire foundation, creating virtually no internal stresses.
However, the construction process is quite labor-intensive, requiring a lot of time, strict adherence to construction technology and thoughtful calculations.
There are three varieties of this type:
- Shallow base. It is successfully used 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 under the condition that the soil does not heave during the cold season, otherwise such a foundation will crack.
- Strip-pile foundation is a combination of two types. Refers to the most durable foundations. Used for difficult soil and fairly heavy structures.
- Band-column type. Such a foundation belongs to an intermediate type between buried and shallow. It is suitable for private construction. It is recommended to use in areas located on slopes. When groundwater is close enough to the surface of the earth, a pile foundation will be preferable.
Monolith
The monolithic foundation is a solid reinforced concrete structure. Most often, special reinforced concrete slabs, which come in various shapes and sizes, are used to lay the base. This type of foundation is used not only in private construction, but also in the construction of large objects. It requires special equipment for high-quality work.
The integrity of the reinforced concrete structure ensures high reliability and durability. Depending on the depth of laying of monolithic slabs, there are superficial, shallow and deep laying (the base is below the freezing level).
Conclusion
Advantages of a pile foundation for houses made of foam blocks:
- Cost-effectiveness due to reduction of land work and building materials.
- Quite fast construction time compared to strip and monolithic foundations.
- Excellent reliability and stability even in difficult soil conditions.
- Suitable for private development.
The disadvantages of piles include their suitability for fairly lightweight foam block structures and the complexity of calculations. To eliminate negative aspects and avoid possible mistakes, it is worth entrusting the design work to professionals.
Which foundation is better for a house made of timber on loamy soil?![](https://i0.wp.com/beton-stroyka.ru/wp-content/uploads/2018/08/fundament-dlya-zabora-lentochnyy-svoimi-rukami-s-perepadom-grunta-1.jpg)
For a house made of foam blocks, you should first of all remember the nature of the material itself and the type of soil on which the structure will be built.
This type of blocks has many advantages: strength, durability, relatively low weight, good thermal insulation, low cost and high speed of construction. But there is one drawback. Houses made of foam concrete are more fragile than houses made of aerated concrete. If the foundation is tilted, a crack will appear that will ruin the entire structure. It is because of this that many developers prefer to build a house on stilts. This is the main, but not the only reason.
Let's look at the advantages of a pile-screw foundation for a house made of foam blocks compared to strip and column foundations:
- Reliability on unstable soils. The shallow foundation for foam blocks, which is so popular today, can become askew and crack as a result of soil movement, which inevitably entails cracks in the walls. The situation is similar with a columnar foundation. Screw piles are installed at the desired depth, so they are insensitive to ground movement.
- Ability to withstand high loads. Radoswai specialists will select piles of optimal thickness and draw up the project correctly.
- Quick installation. Here, pile structures clearly outperform strip and column structures. And this advantage is very consistent with the prefabricated nature of houses made of foam blocks.
- Low cost. Prices for screw piles for foundations will allow you to save a lot of money without harming the quality and reliability of the structure.
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High-quality execution of the foundation for any building is the key to the reliability of the entire structure and the length of the building’s operational period. When choosing the optimal foundation, a large number of factors should be taken into account, such as:
- type of soil and its condition;
- number of floors, design features of the building;
- terrain;
- material used for building walls, which determines the intensity of operational loads.
What kind of foundation is needed for a house made of foam blocks?
The main advantages of foam blocks are considered to be excellent heat and sound insulation characteristics, high speed of wall construction and low weight. The last factor determines the type of foundation that should be used for a foam block house. The optimal solution for such buildings is a pile-screw foundation that can withstand the load created by a low-rise building. In addition, this type of foundation is characterized by the fastest possible construction time and low cost.
Pile-screw foundation for a house made of foam blocks is essentially a set of metal piles that are screwed into the soil. The upper parts of these piles are combined into a single structure using grillages. Such schemes are applicable on almost any type of soil. With the help of foundations of this variation it is possible to achieve uniform distribution of the load on each support.
Important!
If you neglect some of the features of foam block and gas silicate buildings, you may not achieve the desired result - a strong, durable building. The negative characteristics of these building materials include extremely low ductility, which entails high fragility rates. Therefore, if the configuration of the base is violated due to its shrinkage after the binder blocks of mortar or adhesive mixture harden, the erected walls may receive significant damage and cracks.
For this reason pile foundation for a foam block house It is not recommended to build it yourself. The same applies to attempts to save money by turning to the services of non-professional performers.
How to build a foundation for a foam block house
Classic variation - strip foundation
To calculate the configuration of such a foundation, it is necessary to take into account various characteristics of the future structure:
- features of individual planning;
- type of facing material, its weight;
- operational loads;
- type of floors, their weight, installation points for floor joists.
In addition, the design of a strip foundation depends on the load-bearing qualities of the soil at the point of construction, the maximum possible snow load determined by climatic conditions, the configuration of the roof of the building and many other factors.
It is very difficult to independently carry out accurate calculations without having minimal skills and knowledge.
Modern prefabricated modification - pile-screw
Foundation for the construction of a house made of foam blocks, based on metal screw piles, can be calculated much more simply. In any case, much cheaper than the total costs of manufacturing a strip-type base will be a deliberate increase in the number of individual supports - screw piles. And if you combine these two types of foundation, making the buried part using pile-screw technology, and the above-ground grillage is made of concrete, you can get the most practical, strong, reliable and durable structure. Such a foundation will combine all the positive characteristics of both foundation variations - it will be completely immune to low-temperature influences, to which metal piles are somewhat sensitive, and durable and rigid. The only drawback of the hybrid design described above is the increase in cost, but sometimes this option is the only possible one.
However, even despite the apparent simplicity of the process of calculating this type of foundation for a building, it is recommended that this operation be entrusted to professional engineers specializing in work of this kind and knowledgeable, what kind of foundation for a house made of foam blocks should be preferred in each individual situation.
One of the specializations of our company is the production of foundations of pile-screw modification. We are able to carry out all stages of the construction of such structures as quickly as possible, with consistent quality and a long warranty period, from survey activities, design estimates, preparatory operations and ending with the direct installation of the foundation. Houses of the foam block or gas silicate variety, built on our foundations, will be protected for many decades from cracks in the walls that form due to shrinkage of any section of the foundation.
What is the best foundation for a house made of foam blocks?
The foundation for a house made of foam blocks should be as rigid as possible, not changing its configuration over time. Foundations made of screw piles have these qualities.
Installation of screw piles under a foam block house
One-story houses made of foam blocks have much less weight than similar buildings made of brick or precast reinforced concrete.
Therefore, it is advantageous to build houses from foam blocks and aerated concrete blocks where the soil base has weak bearing capacity on screw piles. A foundation made from a frame structure on screw piles is much cheaper than a pile grillage.
Advantages of foam concrete and aerated concrete blocks
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 hardening, the molds are disassembled and ready-made foam blocks are obtained. Large blocks are produced by sawing volumetric monoliths.
Foam concrete blocks
The density of foam concrete is three times less than the density of brick, and accordingly its weight is three times less. Possessing high thermal insulation, waterproofing and strength properties, foam concrete compares favorably with other types of building materials.
Considering the low load-bearing capacity and fragility of the material, foam blocks can only be used in the construction of low-rise, small residential buildings.
In terms of their quality characteristics, aerated concrete blocks 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 disadvantage of aerated concrete is its poor resistance to moisture. Therefore, masonry made of aerated concrete blocks requires enhanced waterproofing.
Masonry walls made of foam concrete and aerated concrete blocks are built in the same way as brickwork with cement mortar.
Justification for the use of screw piles
As a result of geological surveys at the construction site, the following data is obtained:
- the thickness of the soil layer with low bearing capacity (usually clayey soils subject to swelling and freezing);
- the depth of denser soil layers;
- groundwater level;
- depth of soil freezing.
Based on the obtained material, a decision is made on the advisability of using screw piles in constructing a foundation for a house made of aerated concrete blocks or foam blocks.
Screw piles
A standard screw pile for a foundation is a metal pipe with a diameter of 90 mm, at the end of which there is a point with helical blades.
The 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 are susceptible to soil penetration into the core cavity. This may cause internal corrosion of the support.
Helical blades ensure that the pile rod enters the ground with minimal resistance using the principle of a corkscrew. A pile may have one or two blades. The length of the screw pile rod depends on the required depth of immersion in 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 house made of foam blocks, you should pay attention to the quality of the galvanized surface. Good galvanization looks like silvery stars on the metal surface.
Screw pile installation technology
Design the placement of pile supports in the corners of the building, in the centers of support of load-bearing walls with a minimum distance between piles of 1.5 to 2 meters.
One screw pile can withstand an axial load of up to 25 tons.
Installation of a screw pile
Installing screw piles is not very difficult. The head of the pile support consists of a metal heel welded to the upper end of the pile rod. This horizontal support has technological holes for fastening mounting equipment.
The mounting gate is secured through the holes. Two workers, turning the gate, plunge the pile into the ground. As the pile is screwed into the soil, it becomes compacted.
When the number of pile supports is large and their immersion depth is several meters, mechanized installations are used. The power equipment is equipped with a boom, at the end of which a rotating element is installed. It is connected with bolts to the head of a screw pile and imparts a rotational movement to it. As a result, many piles can be installed over a large area in a short period of time.
Pile tying
They build a foundation on pile supports by installing a metal frame structure, which is attached by welding to the heads of screw piles. The frame is a lattice structure made of metal profile 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 places where load-bearing walls support, a profile with a shelf width equal to the width of a block made of aerated concrete or foam concrete is placed.
Before installing the frame, be sure to check the horizontality of the pile heads at the same level.
The height of screw piles above ground level must be at least 15 cm. When the terrain surface slopes, the height of the piles will be different.
Base design
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 upward, which will cause deformation of the frame structure of the foundation of the house made of foam blocks. Any damage to the frame will inevitably put the house in emergency condition, since the structure of foam blocks and aerated concrete blocks is fragile and the walls of the house may become covered with cracks.
Basement of a house on screw piles
In order not to expose the house to the risk of destruction, the piles are lined. Along the perimeter of the house, the space under the building is covered with any suitable panel material. The fence is insulated with foam plastic, mineral wool or other material. Waterproofing is made from a polymer film. After this, siding is installed.
Expansion joints must be left between the underground fence and the bottom of the house. They are necessary to compensate for temperature deformations.
With a well-designed underground fence, when the outside air temperature is 20 degrees below zero, the internal air temperature will be 5 degrees above zero. Under such conditions, a foundation on screw piles will last for many years.
Advantages and benefits of piles for a foam block house
The construction of a 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 carried out at any time of the year;
- you can build a house on difficult soils, regardless of the terrain slope, groundwater level and soil freezing depth;
- significant savings in labor costs and finances;
- guarantee of long-term operation of the house.
How to build a house from foam blocks on screw piles
How to properly build a house from foam blocks on screw piles. How to tie piles under a foam block and at what height to place it.
Pile foundation for a house made of foam blocks
One or two-story houses made of foam blocks have a reduced weight compared to buildings made of other materials, so buildings can be built on fairly weak soils. It is especially important to choose the right supporting base so that construction is not only practical, but also saves money.
If the bearing capacity of the soil is low, the most profitable option is piles, namely screw piles, because such a foundation is much cheaper than a pile grillage.
Material advantages
Foam concrete is a product obtained from the composition of sand, water, cement foam and plasticizers, which has a porous structure. The variety of size range of block elements allows you to build any structure quite quickly and without special financial costs.
The density of foam concrete is three times lower than the density of brick, which means the weight is also much less. At the same time, other indicators, such as: heat, waterproofing, strength, remain at the level of the most durable and expensive materials. However, given the fragility of foam concrete, it is not worth constructing multi-story structures; it is recommended to construct one- or two-story buildings, possibly with an attic.
Foam concrete blocks are often compared to aerated concrete, but the latter reacts much more to humidity. Therefore, if your site is located in an area where the soil is oversaturated with water, the construction of a foam concrete structure on screw piles is an ideal option for building a practical and very warm house.
Advice! Masonry walls made of foam concrete are built in the same way as brickwork using a mortar of cement and additives.
Justification for the use of screw-type piles
A preliminary soil analysis at a construction site gives the following indicators:
- The thickness of the layer with low bearing capacity. Often these are clays, loams, sands - soils prone to heaving and freezing;
- Level of occurrence of a denser soil layer;
- The height of the groundwater flow;
- Soil freezing point.
Based on the analysis, one or another type of foundation is built.
Screw piles for a foam concrete house
A standard screw-type pile element is a metal pipe with a diameter of 90 mm, equipped with blades at the end. The size of the blades is 30-60 cm; it is best that the equipment has pointed edges to simplify work in the ground.
Important! Screw piles with an open end are more susceptible to corrosion due to the possibility of soil getting inside the trunk.
The screws at the end of the pile act like a corkscrew, driving into the ground with minimal soil resistance to the desired depth. The length of the trunk is determined by the freezing point and can be 4-6 meters or more. Finished products must be coated with a special zinc-based composition to reduce the threat of metal corrosion.
Pile installation technology
After marking the construction site, pile elements are placed in the corners, under load-bearing walls in increments of 1.5-2 meters. A properly installed pile-screw foundation can withstand a load of up to 25 tons per element. But installation is not difficult, and we can do it with our own hands:
- The head of the finished element is equipped with a metal heel firmly welded to the rod. The nickel has holes for attaching equipment, where the gate is secured;
- Rotation of the gate deepens the pile into the ground, and during the screwing process, soil compaction occurs;
- The foundation requires the installation of a metal frame structure, attached to the pile heads by welding. This is a lattice base, made either from rods or from channel scraps.
Advice! Preliminary horizontal alignment of the piles is mandatory!
Before starting tying, it is worth checking the level of the piles above the ground - an indicator of 15 cm is considered the norm. If the landscape has slopes, the height of the piles will vary. In places where load-bearing wall panels are supposed to be installed, a profile is placed, the width of the shelf of which is identical to the width of the block element.
Advice! If it is necessary to screw a large number of piles under a foam concrete house, as well as with significant depth (several meters), it is recommended to use mechanical installations: connect with bolts to the head of the pile and, imparting a rotational movement, deepen the elements to the desired level.
The arrangement of the basement also requires attention. Piles are constantly exposed to aggressive environments, so all elements need to be protected. It is especially important to prevent deformation of the structure in the cold season, otherwise damage to the frame will increase the risk of destruction of the structure.
Facing the piles does not take much time: the house is covered around the perimeter with panel sheets, then insulated with any available material and waterproofed with film. The entire structure can be covered with siding, but it is important to leave small expansion joints between the fence and the bottom of the house; they will protect the structure from temperature deformations.
Important! If the underground is well equipped, then even with frosts of minus 25 degrees, the internal temperature will be +5 degrees, in such conditions the pile-screw foundation will last for a very long time.
Advantages and benefits of a pile foundation for a foam concrete house
The simplicity of arranging a load-bearing base does not detract from the strength and practical qualities of the foundation. So, this type has a lot of advantages:
- Efficiency of arrangement. The whole process takes 3-8 days;
- The work is carried out regardless of the time of year, however, it is better to build a house from foam blocks on screw piles at a stable above-zero temperature;
- The foundation makes it possible to build a house on very weak soils, difficult landscapes and next to ancient monuments, parks, relict trees - in the case of a pile foundation, there is no need to clear the construction site of roots, topsoil and no excavation work is carried out at all.
An equally important advantage is the low cost of the supporting base and the fact that two people can carry out the work. And careful protection of the elements guarantees a long service life of both the foundation and the entire building as a whole.
Installation of a pile foundation for a house made of foam blocks
The main reasons for choosing a pile foundation are weak soils, high groundwater levels, and complex terrain of the building site. Recently, the construction of private buildings from foam concrete blocks has become very popular. The erected pile foundation for a house made of foam blocks significantly reduces construction time. The disadvantage of a house made of foam concrete on stilts is that with such a foundation design it is impossible to construct a basement. The advantage is the absence of large volumes of excavation work.
Foam concrete is a relatively new building masonry material. Foam blocks are made from it for building walls. Foam blocks (PF) have gained great popularity due to their quality characteristics.
Standard sizes of foam blocks
PB is manufactured in a factory using special equipment. 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 foam mass occurs in the open air.
For the construction of external walls of buildings, PB of standard sizes 390x188x190 mm is used. Blocks 90 mm thick are used for laying partitions. There are varieties of foam blocks with side locking systems - “tenon and groove”. Sometimes the horizontal surfaces of 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 analogues. Foam blocks are used for laying external fences of multi-storey buildings, where the load-bearing function of the building is performed by the frame of the structure (columns + floors). The porous structure of the material gives the blocks high thermal insulation qualities. In winter, the masonry of the walls does not allow the cold to pass through, and in hot weather it keeps the interior cool.
The main disadvantage of the material is its low load-bearing capacity, therefore, foam block masonry is used as external enclosing structures in houses no more than 2 floors high.
Foam concrete is a fragile material, so any mechanical impact can cause damage to the integrity of the outer surface of the block.
Construction of walls made of 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 strip-pile foundation. Before this, the surface of the foundation must be covered with a layer of waterproofing.
PB is placed both on a special adhesive composition and on a regular 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 20 mm thick. It is enough to lay the expensive adhesive composition at 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.
The walls are laid in the width of the floor of the block or block. Block-thick walls are erected in northern regions, where increased thermal insulation of the external fences of buildings is required.
Scheme of dressing between rows of masonry half a block thick
Types of pile foundations
Piles, as supporting structures, are used to pass through weak soil layers and reach dense soil layers. The support structure takes on the load from the building and transfers it to a solid soil foundation, bypassing weak, unreliable soil layers. A pile foundation for a house made of foam blocks can consist of supports of various designs:
Driven piles
Reinforced concrete piles, in addition to resting on dense soil, are held due to the frictional forces of the side surface against the soil. Driven-in supports are manufactured in the factory. They are mainly used in industrial and civil construction for the construction of multi-storey buildings and structures.
The supports are installed using a pile driver. For buildings made of foam concrete material, 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:
- The construction site is marked for future bored supports.
- Markings are made with cord and pegs.
- In the marking areas, wells are drilled to a given depth using a hand drill or a mechanized drilling rig.
- The bottom of the holes is filled with sand in a layer of 200 - 300 mm. The sand cushion will prevent the liquid concrete solution from leaking directly into the ground.
- Asbestos pipes are lowered into the wells.
- Metal frames are placed in the pipes.
- 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.
- I compact the concrete in the asbestos pipe with a piece of periodic profile reinforcement. If the diameter of the pipe allows, the concrete is compacted with an electric vibrator.
- Piles are made both protruding above the ground and flush with it.
Construction of a strip-pile foundation on bored supports
A strip-pile foundation differs from a pile-grillage foundation in that the load from the building is redistributed between the piles and the monolithic strip. The construction of a pile-strip foundation on bored supports for a house made of PB consists of several stages:
- Between the installed piles I dig a trench for the strip monolith.
- The ditch is filled with sand and compacted thoroughly. The sand cushion should be 300 mm thick.
- Install formwork from wooden panels.
- A reinforcement cage is placed in the formwork.
- The outlets of the pile reinforcement are connected to the metal formwork frame. The reinforcement is tied with wire or connected by electric welding.
- The formwork is filled with concrete mortar with layer-by-layer compaction.
- After 28 - 30 days, the formwork is removed. The foundation is ready for the construction of foam block walls.
Preparing the foundation on bored piles
Depending on the capabilities and volume of concrete work, the solution is prepared manually or mechanized (with a concrete mixer). If the demand for mortar is large, a concrete truck is ordered.
Screw piles
Screw foundations for houses made of foam blocks are the most optimal and economical solution. The name screw piles (SC) 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 entering a cork. The support is an all-welded metal structure consisting of three parts:
- barrel (metal pipe);
- tip;
- blades (propeller).
Screw piles for a foam block house
The basis of the load-bearing part of the support is the shaft of the pile. The length of the pile is determined based on the results of geological survey work. The metal pipe must be of 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 thickness of the barrel wall is usually 4 mm. By special order, the plant can produce supports of other sizes.
Tip
The cone-shaped tip is made cast or all-welded. The sharp cone ensures quick penetration of the screw into the soil. They make screw piles without a tip. The end of the pipe is cut at an angle of 45 degrees. The hole is welded with metal.
Sometimes the trunks are left open. Such supports are used for light buildings and fences. Soil fills the pile from the inside, which can cause corrosion over time.
Typically, screw supports are equipped with one blade, sometimes two cutting elements are installed. The blade is the propeller of the structure. When the trunk rotates, the blades are screwed into the soil, the pile is immersed in the ground, reaching a dense base.
For viscous soils, the blades are sharpened. It is more convenient to sharpen with an emery wheel installed in an angle grinder.
The blades, by their rotation, compact the soil around the support. This helps to increase the load-bearing capacity of the pile.
Foundation construction on screw piles
There are two methods for installing aircraft - manual installation and mechanized method. Piles with a length of no more than 2.5 m and a diameter of up to 108 mm are installed manually. Large supports are mounted using a special mechanized installation.
Installing 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:
- At the construction site, the field is marked for piles.
- At the installation points, a hand drill is used to make funnels 30 cm deep. This will facilitate the vertical installation of the rack.
- If there are no mounting holes in the upper part of the barrel, they are cut out with a gas cutter.
- Sections of water pipes are inserted into the holes on both sides.
- 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.
- A laser level is used to mark the design height of the ground part of the pile shafts.
- Using an angle machine with an abrasive wheel, remove excess parts of the supports.
- Metal caps are welded to the upper ends of the piles for installation of grillage structures.
Manual insertion of the screw support
The step between the supports should not exceed 3 m. If the distance between two aircraft is greater, an additional stand is placed in the middle.
Mechanized installation
For mechanized installation of screw piles, special equipment is used, equipped with a power unit that ensures the grip of the support head and its rotation.
During a work shift (8 hours), this method can fill a medium-sized pile field - 30x30 m. The speed of installation of supports depends on their length and soil composition.
Of course, the mechanized method of aircraft installation will cost much more. But this drawback is compensated by the reduction in construction time for a house made of 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. Laying walls made of foam blocks involves “wet” processes, which is advisable to do in warm weather.
Pile foundation for a house made of foam blocks: technology
A self-built pile foundation for a house made of foam blocks significantly reduces construction time and saves money.
One or two-story houses made of foam blocks have a reduced weight compared to buildings made of other materials, so buildings can be built on fairly weak soils. It is especially important to choose the right supporting base so that construction is not only practical, but also saves money.
If the bearing capacity of the soil is low, the most profitable option is piles, namely screw piles, because such a foundation is much cheaper than a pile grillage.
Material advantages
Foam concrete is a product obtained from the composition of sand, water, cement foam and plasticizers, which has a porous structure. The variety of size range of block elements allows you to build any structure quite quickly and without special financial costs.
The density of foam concrete is three times lower than the density of brick, which means the weight is also much less. At the same time, other indicators, such as: heat, waterproofing, strength, remain at the level of the most durable and expensive materials. However, given the fragility of foam concrete, it is not worth constructing multi-story structures; it is recommended to construct one- or two-story buildings, possibly with an attic.
Foam concrete blocks are often compared to aerated concrete, but the latter reacts much more to humidity. Therefore, if your site is located in an area where the soil is oversaturated with water, the construction of a foam concrete structure on screw piles is an ideal option for building a practical and very warm house.
Advice! Masonry walls made of foam concrete are built in the same way as brickwork using a mortar of cement and additives.
Justification for the use of screw-type piles
A preliminary soil analysis at a construction site gives the following indicators:
- The thickness of the layer with low bearing capacity. Often these are clays, loams, sands - soils prone to heaving and freezing;
- Level of occurrence of a denser soil layer;
- The height of the groundwater flow;
- Soil freezing point.
Based on the analysis, one or another type of foundation is built.
Screw piles for a foam concrete house
A standard screw-type pile element is a metal pipe with a diameter of 90 mm, equipped with blades at the end. The size of the blades is 30-60 cm; it is best that the equipment has pointed edges to simplify work in the ground.
Important! Screw piles with an open end are more susceptible to corrosion due to the possibility of soil getting inside the trunk.
The screws at the end of the pile act like a corkscrew, driving into the ground with minimal soil resistance to the desired depth. The length of the trunk is determined by the freezing point and can be 4-6 meters or more. Finished products must be coated with a special zinc-based composition to reduce the threat of metal corrosion.
Pile installation technology
After marking the construction site, pile elements are placed in the corners, under load-bearing walls in increments of 1.5-2 meters. A properly installed pile-screw foundation can withstand a load of up to 25 tons per element. But installation is not difficult, and we can do it with our own hands:
- The head of the finished element is equipped with a metal heel firmly welded to the rod. The nickel has holes for attaching equipment, where the gate is secured;
- Rotation of the gate deepens the pile into the ground, and during the screwing process, soil compaction occurs;
- The foundation requires the installation of a metal frame structure, attached to the pile heads by welding. This is a lattice base, made either from rods or from channel scraps.
Advice! Preliminary horizontal alignment of the piles is mandatory!
Before starting tying, it is worth checking the level of the piles above the ground - an indicator of 15 cm is considered the norm. If the landscape has slopes, the height of the piles will vary. In places where load-bearing wall panels are supposed to be installed, a profile is placed, the width of the shelf of which is identical to the width of the block element.
Advice! If it is necessary to screw a large number of piles under a foam concrete house, as well as with significant depth (several meters), it is recommended to use mechanical installations: connect with bolts to the head of the pile and, imparting a rotational movement, deepen the elements to the desired level.
The arrangement of the basement also requires attention. Piles are constantly exposed to aggressive environments, so all elements need to be protected. It is especially important to prevent deformation of the structure in the cold season, otherwise damage to the frame will increase the risk of destruction of the structure.
Facing the piles does not take much time: the house is covered around the perimeter with panel sheets, then insulated with any available material and waterproofed with film. The entire structure can be covered with siding, but it is important to leave small expansion joints between the fence and the bottom of the house; they will protect the structure from temperature deformations.
Important! If the underground is well equipped, then even with frosts of minus 25 degrees, the internal temperature will be +5 degrees, in such conditions the pile-screw foundation will last for a very long time.
Advantages and benefits of a pile foundation for a foam concrete house
The simplicity of arranging a load-bearing base does not detract from the strength and practical qualities of the foundation. So, this type has a lot of advantages:
- Efficiency of arrangement. The whole process takes 3-8 days;
- The work is carried out regardless of the time of year, however, it is better to build a house from foam blocks on screw piles at a stable above-zero temperature;
- The foundation makes it possible to build a house on very weak soils, difficult landscapes and next to ancient monuments, parks, relict trees - in the case of a pile foundation, there is no need to clear the construction site of roots, topsoil and no excavation work is carried out at all.
An equally important advantage is the low cost of the supporting base and the fact that two people can carry out the work. And careful protection of the elements guarantees a long service life of both the foundation and the entire building as a whole.
Houses on screw piles made of aerated concrete
The flourishing of private housing construction in our time has reached large proportions. This is also facilitated by the growth in the turnover of land plots due to their transfer from one category to another, as well as the development of technology for the production of prefabricated building elements. A special place is occupied by houses made of aerated concrete. Let's consider the main types of foundations for such buildings, their features, disadvantages and advantages.
Types of foundations for aerated concrete houses
Building wall blocks are individual elements that have the correct geometric shape of a parallelepiped. The linear dimensions of the parts may be different, since there are separate materials for the construction of external and internal walls. The generally recognized advantages of aerated concrete blocks are their comparatively lower weight with fairly high strength characteristics.
It is the low weight of the structure being erected that makes it possible to produce lightweight foundations of one type or another for houses made of hydrogen-saturated elements. The most widespread of them are the following types of foundations:
- Reinforced concrete strip;
- Pile foundation:
Type of foundation for houses made of aerated concrete
- cast-in-place reinforced concrete;
- on driven piles;
- on screw piles;
- pile-grillage.
A fairly common type that requires a lengthy manufacturing process is a strip-type foundation with varying degrees of depth. To manufacture it, it is necessary to perform many separate construction operations - marking, excavation of soil inside the tape, production of formwork, production of a reinforcing belt, production of concrete and pouring it into a cavity in the ground, long-term exposure of the base without load until it acquires maximum strength.
Strip foundation for a house made of aerated concrete
Installation technology requires a large number of man-hours and money. It is much more expensive to build any building on a strip foundation than to build a house from blocks on stilts. In terms of time, it takes several times longer to build a reinforced concrete base. At the same time, if you follow simple rules and installation technology, a house made of blocks on screw piles will last no less than on a strip foundation, especially if there are problematic heaving or wet soils in the construction area.
What types of piles are there?
To install houses made of blocks, all three types of piles are used - driven, bored and screw. The first require the use of specialized construction equipment and the absence of constructed buildings near the work site. These aspects significantly limit their use in private housing construction.
Bored pile foundations for aerated concrete houses are also made using various mechanisms. In addition, large volumes of soil must be removed to dig holes. To strengthen concrete piles, it is necessary to produce formwork, a reinforcing frame, and concrete, which also does not contribute to the widespread use of this type of support.
Pile foundation for a house made of aerated concrete
Unlike previous types, screw piles can be installed in one working day by three to four workers. When installing a screw foundation for a house made of aerated concrete on difficult soils, it is sometimes necessary to use special drilling rigs to screw in the supports. To strengthen the base of the building, a common frame called a grillage is mounted on the tops of the racks. Let us dwell in more detail on the description of the technology for installing steel supports.
Calculating the number of screw piles using a calculator
Pile calculator
Number of piles:
Pile diameter:
Pile length:
If you need to calculate the number of screw piles that will be required to build a foundation at your site, you can do this without leaving your home. You only need to know the primary parameters. It is necessary to calculate the number of corners and joints of external walls with load-bearing partitions. The piles should be located in the indicated places; they should go along the perimeter in increments of no more than three meters. If you plan to install a fireplace, then, depending on its weight, you will need to install from one to four piles under it.
Use the online calculator for calculating the number of piles on our website. In addition to the required quantity, you can also find out their preliminary diameter and length.
Calculating a pile field online is quite simple; you only need to enter data in the appropriate fields:
- Indicate the length of the sides of your building.
- Indicate the type of building - gazebo, bathhouse, house, garage, household building, etc.
- Specify the number of floors if necessary. Note: a house with an attic will be considered a 1.5-story building.
- Select the building material for your structure.
- Indicate the type of soil on the site.
- Indicate the number of corners of the planned house.
- Specify the height of the basement floor from the proposed options.
- Please indicate whether you are going to install a fireplace/stove.
- Click on the "Calculate" button.
Of course, this calculation is preliminary; it will serve as a guide when planning the budget and further orders.
If you decide to build a house from aerated concrete on screw piles, you should start by marking the site. Along the perimeter of future walls, the installation locations for supports are determined. They are placed under external and internal vertical structures in increments of 1.5-2 meters.
Screw piles can be purchased at specialized construction markets or made independently. To determine the length of the supports, it is necessary to conduct geological research in the work area or use information from specialized organizations. Neighbors who have already completed the construction of a house can also provide great help.
After delivery, installation of screw piles can begin. They are installed vertically with the blades down and buried by rotation into the ground. It is necessary to constantly monitor the correct position using a building magnetic level or plumb line. When installing a screw foundation, usually two people rotate the pipe with blades, and one or two control and guide it. For control, cuttings of profile rectangular or round steel pipes 2-3 meters long are used.
In order for an installed aerated concrete house on a pile foundation to please its owners for a long time and not cause any problems, the base of the building must be made in compliance with technology. Even the slightest deviation from the required vertical can lead to improper operation of the base of the structure. Screw the screw piles to such a depth that they reliably go deep into a solid layer of soil.
After installing all the supports of the pile foundation, it is necessary to cut them at the same horizontal level. For this purpose, you need a laser level and an angle grinder, popularly called an angle grinder. Having turned on the level, set its beams at the required height from the soil and mark them with a marker on each pipe of the pile. Next, apply a ring line, wrapping it with a sheet of thick paper and aligning its upper edge.
Using a grinder with a metal disc installed, cut the pipe along the markings to a depth of 1 mm. After this, the metal is cut through its full thickness until the excess part of the head is separated. This is done with all supports of a screw foundation. After bringing them to the general level, it is necessary to carry out work on additional strengthening and anti-corrosion protection of the internal surface of the piles. To do this, they are filled to the top with liquid concrete.
Aerated concrete on screw piles cannot be installed without additional work with them. It consists of welding special platforms on the upper edges of the racks, made from scraps of pipes of larger diameter and sheet steel 10 mm thick. These heads are pre-fabricated according to the number of screw piles purchased or manufactured.
Installation of screw piles with grillage
Since block aerated concrete on screw piles requires a continuous linear base, it will also have to be manufactured additionally. The grillage is mounted on the heads of the supports and consists of steel or reinforced concrete elements. The former are more preferable, since they involve the use of finished rolled products with an I-beam or U-shaped section. It is convenient to attach them to the heads with a welded seam.
Making a reinforced concrete grillage on screw piles is more difficult. According to its location, it can be buried, above-ground and airy, raised above the soil level. The last type is the most difficult to manufacture. The technology for installing a reinforced concrete grillage is as follows:
- after cutting the screw piles along the perimeter of future walls and partitions, a trench is dug or panel formwork is installed immediately after preliminary leveling;
- for the air grillage, additional supports are installed on which the bottom of the future tape and side walls are attached;
- a frame of steel rods with a diameter of 8-10 mm connected to each other with annealed wire is installed in the prepared formwork;
- Next, the concrete mixture is poured, compacted and left to cure for 2-3 weeks. In the first seven days, the mixture is covered with canvas, which is periodically moistened.
Pile-grillage foundation
The use of a grillage greatly simplifies the process of building a house on screw piles. Unlike a traditional strip foundation, a pile-grillage foundation allows you to connect the entire structure of the house with the strongest and most reliable layer of soil, located quite deep. In addition, piles serve as the only possible solution in the case of construction on the slopes of hills, gentle ravines, river banks, lakes and ponds.
Not all users know whether it is possible to build a house from aerated concrete on screw piles. This article not only gives an affirmative answer to this question, but also recommends using such a base when working with such a relatively light and durable material. Probably, aerated concrete on screw piles is the future of private housing construction in our country.