How piles are made. Do-it-yourself device and construction of a pile foundation
A reliable support base of the house ensures its long-term operation. The design of the foundation depends on the soil on which it will be installed, and on the degree of watering of the site. Neglect of any of these circumstances leads to premature wear of the foundation up to its complete destruction. And this is due to the loss of the entire building and the costs incurred for construction.
How pile foundations are arranged
The design of the foundation is always selected depending on the nature of the soil at the construction site. In some cases, the construction on piles of various types will be the most reliable and durable.
Advantages and disadvantages of pile foundations
In real construction conditions can be applied different kinds piles. But regardless of the design of such products, a number of advantages can be distinguished that foundations on pile foundations have:
The main disadvantage of the pile foundation is the shrinkage of the supporting base. The result can be a warp of the foundation, leading to the destruction of the superstructure. The reasons often lie in the incorrect installation of piles when they are not deepened to stable solid soils. It is also possible to choose the wrong type of supports that are not suitable for the nature of the soil at the construction site. Therefore, on the selection of the type of piles, it is better to consult with an experienced specialist.
Some types of piles, such as screw piles, are quite expensive, which can also be attributed to their relative disadvantages.
Types of pile foundations and their features
Pile-driven foundations
On weakly bearing soils, it is necessary to use piles that are driven into the ground to the depth of the location of strong layers and are interconnected by a slab or grillage.
Driven piles look like square-section pillars made of concrete. At the end immersed in the ground, a sharpening is cast. Immersion is carried out by pneumatic or hydraulic hammers. Such a support base is the most durable.
Instead of reinforced concrete products, other materials can be used as piles:
- Wooden poles. They use hardwoods such as oak, ash, larch or pine. The diameter of the log under the pile must be more than 18 centimeters. The front end is equipped with a metal cap, the rear end with a metal ring to prevent splitting during driving. The disadvantage of such piles is a limited service life. But it can be increased by using protective compounds.
- Metal profiles - beams, channels and pipes. These products are easier than others to sink into the ground to the desired depth.
When driving piles, you need to control the sinking speed with each impact. The cessation of downward movement indicates that the supporting structure has reached solid ground. At this point, the deepening of the pillar can be completed. After installing all the piles according to the foundation plan, the upper ends are trimmed to one level.
A dangerous phenomenon when driving a pile is the termination of immersion when the support is stuck in a stone. Outwardly, it looks like the formation of the desired density. But subsequently the stone can move, and the pile will lose its support. A sign of such a situation may be a significant deviation in height of the driven support from the rest. In this case, the pile must be removed and the shaft drilled.
When constructing a foundation on heaving soils, piles are connected by an incomplete grillage. The lower plane of the grillage is at a distance of 15–20 centimeters from the ground. After casting, a layer of sand and gravel mixture is poured under it. Its purpose is to perceive and compensate for the load from the heaving soil.
The durability of wooden piles is achieved by processing with protective compounds.
Metal foundation supports are made from various hot rolled profiles such as beams, channels or pipes. The immersion of these piles requires significantly less labor compared to concrete piles. In addition, if it is necessary to extend the support, it can be welded by electric welding. The durability of metal supports can be greatly increased by anti-corrosion surface treatment.
When buying piles, you need to check the quality of the material by visual inspection and require the presentation of a quality certificate. Cracks, chips and other mechanical defects on the surface are not allowed.
Pile-monolithic foundation
Another name for this type of support base is "pile-slab" or SPF. It is a combination of two types of foundation - pile and slab. The reasons for using such a denouement are the following circumstances:
Construction technology
In fact, the SPF is built in two stages:
The time for complete crystallization of the foundation is 28 days, after which construction work can be continued.
In the hot season, the foundation must be covered with a film and periodically, 1-2 times a day, sprinkle it with water. Premature drying of water in concrete can lead to cracking..
It should be noted that 85% of the load is taken by the pile system, the rest falls on the slab. But this structural element gives the foundation stability.
The number of piles for the foundation is determined by the length of the foundation and the distance between the piles. Usually it is chosen equal to from 3 to 6 diameters of one support. For example, for a pipe with a diameter of 400 millimeters, it will be 1.2–2.4 meters. You can choose the average value so that the distance is the same. In this case, you need to remember about the distribution of the load.
We install a pile foundation from asbestos pipes
This design is chosen for reasons of economy for the construction of auxiliary buildings for household purposes, such as:
- barn;
- hozblok;
- summer cuisine;
- workshop;
- a garage without a viewing hole and other structures of a similar purpose.
The basis of the foundation for such buildings are piles of asbestos pipes. According to the results of exploratory drilling, their number and depth of immersion are determined. One of the weighty arguments in favor of the use of such a foundation design is the construction on a site with a slope.
Foundation installation
This operation consists in installing floor slabs on a pile foundation. For this, ribbed plates are usually used, which, with less weight, are close to solid ones in terms of bearing capacity. Installation of plates is carried out using lifting equipment. For small buildings, hollow core slabs up to 15 centimeters thick can be used.
It should be noted that for such structures, a combined foundation with a grillage is more applicable. It's more expensive, but more reliable.
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Classmates
The construction of any object begins with the construction of the foundation.
The strength and reliability of the base serve as a guarantee of long-term service of the entire building, therefore it is not customary to save on the foundation.
The cost of its arrangement usually makes up about a third of all construction costs, which is considered quite justified.
Nevertheless, research in the field of alternative construction methods has shown a number of interesting options for replacing expensive material-intensive foundations with cheaper, simpler, but no less effective and reliable types of foundations.
Let's consider one of them. How to make a pile-screw foundation with your own hands: step-by-step instructions later in the article.
known for a long time, proving their reliability in practice. However, screw piles as a foundation are a relatively recent method that has been used in military construction for a long time, although the principle of the pile device itself is quite simple.
Its essence is the principle of screwing metal piles into the ground with a tip in the form of a spiral thread, making them look like a large screw. This way saves on construction equipment: no driving with a pile driver or drilling of wells is required. At the same time, there is no need for expensive earthworks: the supports can be screwed directly into the ground without planning the site, on slopes, in depressions or other folds of the relief.
Note: It is possible to do without equipment at all, to screw the piles by hand, in the immediate vicinity of existing buildings without any harm to them.
Screw piles
Screw piles are divided into several types adapted to different types of soil and designed for a certain load.
The pile consists of a metal solid (seamless) pipe, one end of which is pointed and equipped with welded blades, and the other end is equipped with a head - a reinforced section that performs the function of contact with the tool when screwing or the anchor point of the installed pile.
Reference: in recent times products based on a welded pipe appeared on sale, which, according to manufacturers, does not affect the bearing capacity and does not create problems during installation, although initially production screw piles for foundations made of welded pipes was considered unacceptable.
There are several sizes from a pipe of various diameters from 57 mm to 325 mm, designed for different loads. The device of a pile-screw foundation provides for the use of one-, two- and three-blade types of piles designed for different types of soil.
The presence of additional blades increases stability, makes higher loads possible. The width of the blade is directly dependent on the type of soil - the softer the soil, the wider the blade. A turn is 1.25 turns. At the same time, there are multi-turn structures of the "screw" type, the tip of which is conically pointed and equipped with a multi-turn spiral with a small diameter. Used on dense clay soils.
The tip can be either welded or cast. The difference between them is that the weld is a risk factor, more prone to corrosion than other areas. During installation, the cast tip is inserted into a hollow pipe and fixed by welding, so the risk of corrosion is minimal, and the welded tip consists entirely of welded blades, being exposed to corrosion processes to a much greater extent.
Corrosion is the most dangerous enemy of metal structures. Protection against it is especially important where there is no possibility of replacing or monitoring the condition of steel parts. The metal surface has a continuous anti-corrosion coating, eliminating the risk of failure. The most reliable are galvanized piles with a cast tip with an estimated service life of up to 200 years.
Application
The use of screw piles has shown high efficiency on problematic soils:
- swampy areas, areas with a high level of groundwater;
- permafrost areas;
- areas located on heaving soils with a high level of seasonal soil movements.
The use of piles can be repeated- in some cases, supports can be removed from the ground and reused. For the construction of large buildings, this method is considered unsuitable, but for low-rise construction, in conditions of limited time, it is recognized as one of the most effective.
A significant disadvantage of screw piles, like all pile foundations, is the impossibility of arranging the basement, but on problematic soils this is unlikely when using other base options.
In addition, the use of supports is limited on rocky soils due to problems with screwing. In some cases, the installation can be made in the leading well, but in general, this option is considered to be too laborious and is rarely used.
Device
The foundation on screw piles consists of a certain number of supports installed according to a certain scheme.
This so-called pile field, repeating with its outlines the plan of the future building.
So, the screw foundation: the installation of piles involves screwing the supports to a depth below the freezing of the soil, the minimum depth of immersion in the main soil is 600-800 mm, that is, with a pile length of 2.5 m, the minimum immersion depth should be 1.5 m.
It is possible to more accurately determine the depth of immersion of the pile based on the geological indicators of the site and the depth of soil freezing.
Important! After installation, the pipe cavities must be filled with concrete to increase the bearing capacity, especially with large pipe diameters.
The tops are trimmed (or extended, if necessary) to the same height and tied with a channel, which will serve as the basis for the grillage - support for load-bearing walls. A pile field with installed piles can serve as the basis for a strip or slab foundation in the case of a combined type of foundation.
Support manufacturing
To reduce costs, attempts are often made to make screw piles on their own. The opinions of experts on this issue differ. Manufacturing load-bearing structures is a responsible matter requiring certain materials, technologies and protective coatings. From another point of view, subject to the rules, independent production of screw piles is possible.
If you decide to use homemade piles, you should pay special attention to the quality of the material and welding. For a sample, it would be best to take factory model: having it before your eyes, you can clarify some details in the manufacture. An important step will be the application of an anti-corrosion coating; without it, or if the operation is performed poorly, the metal will begin to rust almost immediately after installation.
Remember: poor-quality manufacturing will necessarily entail subsidence, deformation or collapse of the building.
If you have doubts about your abilities, it is better to spend money and purchase ready-made piles made in accordance with technical requirements and have a certificate of quality. The foundation is not the case where you can try to save money - problems with it will entail much higher costs.
Calculation
The screw foundation construction technology provides for the stage of calculating the required number of supports. Based on the calculation accepted:
- The weight of the building, taking into account snow and wind loads.
- The bearing capacity of the soil.
According to the characteristics of the soil, the working load on the pile is determined, after which the weight of the building is divided by the obtained value and the number of piles is determined.
You can check with any online calculator, of which there are many on the Web. It is advisable to check using several calculators to obtain a more reliable calculation.
Do-it-yourself installation of a pile-screw foundation
How to make a pile-screw foundation with your own hands? Let's consider the device of the foundation on screw piles: technology and process steps.
1.
Do-it-yourself pile-screw foundation start with marking the site according to the design and construction plan. The screw foundation installation technology provides that the pile installation sites are marked with pegs.
2.
Do-it-yourself installation of a pile-screw foundation further involves pile driving. The procedure is performed either mechanically, or, with soft ground, manually. The piles are sunk to the calculated depth before contact with solid soil layers. In order to properly install the screw foundation with your own hands, special attention should be paid to the strictly vertical location of the pile axis. Tilt is not allowed.
3. Installed piles must be leveled to a certain height, for which they are cut (some are extended) to the desired length.
Important! To properly make a screw foundation with your own hands, in no case should you unscrew the installed pile to adjust the height. Such an action will significantly weaken the pile support and cause subsidence to its original value.
4. Installed and aligned on a horizontal plane, the supports are filled with mortar. Such an operation significantly strengthens each pile, increases the resistance to loads both vertically and in other directions.
5. Screw foundation drainage- its presence or absence does not matter, but if there is water in the off-season, excess water can be removed using a drainage groove. The easiest way would be to form a small trench around the building with a diversion outside the site so that the water can leave without problems.
6. Finished piles filled with concrete to form a grillage- belts for supporting load-bearing walls. Only a screw foundation with a grillage is allowed, which must be waterproofed.
7. The foundation on screw piles with your own hands is almost ready. brick, siding, corrugated board, etc.
The choice of material is based on the properties of the soil - how much it "walks" in the spring and autumn periods, whether the movement of the soil will cause the destruction of the base.
In difficult cases, it is recommended to leave a small gap between the base of the base and the soil surface. It will compensate for ground movements and provide ventilation, allowing the lower surface of the floor to dry out. Installation of the foundation on screw piles does not end there.
8. Insulation of the pile-screw foundation- a difficult question, since the technology for installing screw piles for the foundation does not always provide for it. The specifics of the use of thermal insulation does not provide unambiguous methods.
But one of the most effective simple ways is backfilling a mixture of lime and sawdust about 0.5 meters thick (or as far as the height of the base allows). Such a backfill solves not only the problem of insulation, it reduces soil heaving and does not allow water vapor to penetrate into structural elements. The installation of the foundation on screw piles has been successfully completed.
Useful video
Additionally, you can visually see about the screw foundation: the installation rules and the screw foundation device technology are discussed in the video below.
conclusions
Pile-screw foundation is a reliable way out on complex and problematic soils. Saving time and money, possibility self-fulfillment works, the simple technology of screw pile foundations and the absence of the need for complex site preparation are the arguments decisive in favor of choosing such a foundation, reliable and profitable.
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Usually the construction of pile foundations is carried out on weak soil foundations. In some cases they do pile foundation with their hands on dense soils. The fact is that the foundation made for a house on stilts will cost much less than a building on a monolithic strip base.
The construction of a pile foundation does not require large volumes of earthworks. Great time savings, independence from the seasons - all this attracts developers to use piles in the construction of their houses. How to make a pile foundation with your own hands, we will tell in this article.
Piles immersed in the soil are tied with a grillage
The foundation of buildings of this type is a grillage, which combines the upper parts of the piles into a single supporting structure. Supports and grillage can be made from various materials.
The choice of the type of these structures is influenced by factors such as the bearing capacity of soil layers, the level of groundwater, the depth of soil freezing and the actual load from the weight of the structure.
How to choose the right type of piles? Consider the types of pile supports that the developer can install on their own.
Supports made of wooden logs are erected for the house with their own hands. Recently, this is not the most popular material for pile foundations.
The installation of wooden supports is carried out in places where the occurrence of clay, peat and other weak soils mainly prevails.
The support should be of such length that the end of the pile can rest against the dense soil.
A vertical survey taken at the local architecture department will show how deep a do-it-yourself pile foundation needs to be. You can also determine the depth of dense soil by test drilling.
One end of a wooden pile is sharpened with an ax
Logs are sharpened with an ax in such a way that, under hammer blows, they can reach a dense base without much difficulty.
The wood is planed to obtain a smooth surface. Racks are impregnated with antiseptics. Processed piles will stand in the ground for more than a dozen years.
The upper ends of the piles are cut to one level. Installation of a grillage from thick boards, logs or timber will create a reliable foundation for wooden and panel houses. Walls of foam blocks are also erected on such a pile foundation.
To know how to build a house on bored poles, you need to carefully study the structure ground base and calculate the weight of the future structure. This will make it possible to select the desired type of piles. Bored piles are of several types:
- frameless poles;
- removable casing pipes;
- fixed casing frames;
- piles with extended heel;
Frameless poles
Piles mounted without a frame are the cheapest
One of the cheapest ways to build a pile foundation with your own hands is to build the foundation of a structure on frameless bored piles.
Drill holes in the soil with a hand drill. Reinforced frames are lowered into the wells. The holes are then filled with concrete.
The reinforced frame is prepared from several vertical bars of reinforcement with a diameter of 10 to 20 mm. The rods are knitted with wire with transverse steel pieces of reinforcement. The height of the reinforced frame should be such that its upper part can serve as a link with a metal grillage.
The outlets of the reinforcement are welded to the metal elements of the grillage. After that, the well is poured with a concrete mixture with a layer-by-layer rammer.
The thickness of each layer of concrete should be no more than 200 - 250 mm. The liquid mixture is rammed with a manual electric vibrator. If the diameter of the well is small, then the concrete is bayoneted with a piece of reinforcement.
Removable casing pipes
To increase the bearing capacity, stuffed supports are formed from concrete in removable casing pipes. The frame of the piles is made from metal pipes. Before installation, the inner surface of the removable shell is coated with a lubricant that will prevent the cured concrete from sticking.
Piles are concreted and reinforced in the same way as frameless supports. Two weeks after pouring liquid concrete, the casing pipes are taken out of the wells. The earth around the pillars is heavily rammed.
Fixed casing frames
In very weak soils, it is advisable to make the pile shell from asbestos-cement pipes. This will protect against the penetration of earth particles into the mass of liquid concrete. For details on the manufacture of bored piles, see this video:
The penetration of foreign bodies and moisture into the structure of concrete can weaken the bearing capacity of the bored support.
An asbestos-cement pipe lowered into the well becomes part of the support structure. A reinforced frame is installed inside the asbestos shell. Concrete is poured and the mixture layers are compacted in the same way as when forming piles with removable formwork.
Piles with an extended heel will be more stable than conventional ones.
The bottom of the well is expanded with a special device
Drilled bearings with an extended heel have a high bearing capacity. Foundations made of piles of this type can withstand the load of low-rise buildings. If the developer plans to build a two-story country house on soft ground, then supports with a wide heel will be the most suitable solution to the question of how to make a foundation.
The base of the well is expanded with a special device that has a cutting blade at the end of the barrel.
By rotational movements of the blade at the base of the pit, the pile support area is expanded.
The resulting space is filled with concrete. Then the complete installation of the bored support is carried out.
In addition, there are other ways to widen the heel of the pile, but they can be done at the bottom of the pit only with the help of special equipment.
The use of the explosive method is possible only with the involvement of specialists who have permission to carry out such work.
The use of such methods for the independent construction of a pile foundation with your own hands is impossible. Such methods of widening the heel of the support are used in the construction of industrial or civil facilities. For more information about the extension tool, see this video:
Screw piles
Screw piles are one of the cheapest ways to build the foundation of a house.
Recently, screw piles have gained wide popularity among the population. A house built on a pile foundation of screw supports will cost the developer much less than building a dwelling on any other foundation.
Given the high cost-effectiveness, ease of installation in any soil, except for rocky foundations, screw piles are increasingly used in private construction.
The screw rack is made in the factory. The support consists of several steel elements:
- support pipe;
- tip;
- screw.
support pipe
The main part of the support is steel pipe. Its diameter depends on what load the screw pile is designed for. This table shows where and how screw supports of a certain diameter are used:
№ | Support diameter | Ground base | Application area | |
---|---|---|---|---|
1 | 57 mm | up to 800 kg | Waterlogged soil | One-story houses, light buildings. |
2 | 89 mm | up to 1.4 t | Waterlogged, clay and peaty soils | Country houses, garages. |
3 | 108 mm | up to 3.5 t | Everything except rocky soils | Log, panel frame houses. Buildings from foam blocks. |
4 | 133 mm | up to 6 t | Everything except rocky soils | Brick and monolithic houses. |
support tip
The tip of the support is a cast or all-welded steel cone.
The speed of its immersion into the soil to the design mark depends on how well the end of the screw support is made.
A poorly welded cone may break when the screw strut is immersed.
As a result, the support has to be changed to another pile.
In the construction of small structures and fences, piles with a beveled end are used. The end of the rack cut at an angle of 45 degrees is welded with an oval-shaped steel sheet.
Screw
Usually screw piles have two blades at the pointed end.
The barrel screw consists of 2 blades. The size of the blades is directly proportional to the diameter of the trunk. In some cases, 3 blades are welded to the pipe. This, of course, causes some difficulties in driving the pile, but significantly increases its bearing capacity.
For the quick construction of a pile foundation with your own hands, the edges of the blades are turned with a grinder. The pointed edges of the screw greatly facilitate the entry of the support into the ground.
The grillage on metal screw racks is mounted from various materials, depending on the type of structure. These can be connecting elements from a bar, a metal channel or a corner. Reinforced concrete beams, welded with their embedded parts to the screw piles, form a reliable foundation for two-storey houses. For more information on the use of screw piles, see this video:
The device of the high ground part of the foundation will make it possible to make a high base. This will protect the house from seasonal flooding of the area and the penetration of dampness into the premises.
Do-it-yourself installation of a pile foundation on screw supports
Screw piles are installed by a team of 3 people. Mounting holes are made in the upper part of the supports, through which steel pipes are threaded. Two workers use these levers to screw a screw post into the ground. The third worker with a plumb or theodolite controls the vertical position of the support
After the installation of the pile field, the upper ends of the racks are cut to one level. Then they install the headrests, which, by their design, provide reliable fastening of the elements of the grillage.
The durability of steel racks depends on the quality of the anti-corrosion coating. Since the cavity of the supports is filled with concrete, the inner surface of the pile is not coated with an anti-corrosion compound.
At the base of a house being built on a site with weak soil, it is advisable to make pile- strip foundation with your own hands. The choice of this option is due to the negative impact on the concrete tape, the presence of clay, peat, humus, groundwater in the area in the upper layer of the earth, creating quicksand.
Under a concrete structure in the form of a tape (grillage), three types of piles are used: ready-made concrete piles, screw piles and bored piles.
Soil category, impact on concrete base
In summer, weak soil in some places under the foundation is washed out, subsidence occurs, and then the foundation is destroyed. With the advent of cold weather, wet soil freezes and swells, pressure is created on the foundation, which also leads to its destruction.
The problem is solved with the help of piles buried below the soil freezing line, resting on a solid layer of earth.
A shallow strip foundation is cast on piles and does not depend on the changing state of the upper soil layer. The number and dimensions of piles, the dimensions of the tape depend on the load and location of the building under construction.
Piles under the tape are made in a bored version, forming a single monolithic structure. The choice of foundation for the house depends on the category of soil. At heaving soil it is advisable to use a pile-tape base.
Concrete foundation technology on piles under the house
The foundation for a house on stilts can be made on your own, knowing how to make a pile-tape foundation with your own hands in order to avoid mistakes during independent work.
It is important to study the technology and step-by-step instructions for making the foundation. To get acquainted with previously built similar structures and ask the performers about possible problems during the construction of the foundation. Examine all the component materials required for construction.
The device of the strip foundation with piles
The production of a strip pile foundation can be carried out without the involvement of expensive equipment, renting the necessary equipment.
The concrete base, depending on the purpose of the building being erected, provides for the insulation of piles and tape or is limited to waterproofing. The technological process is reflected in the executive project and, taking into account preparatory work includes operations performed sequentially. AT step by step instructions for the manufacture of a pile-strip foundation with their own hands, these operations are reflected:
The house for permanent residence must have a warm base, as heat loss will be 30%. Compliance with the instructions will allow you to perform high-quality work in a short time.
Do-it-yourself base for a house
To make a pile-strip foundation with your own hands, it is advisable to have practical experience or work together with a professional.
Before starting work, it is necessary to provide the construction site with electricity and water (no centralized - local).
Prepare hand and measuring tools, rent the necessary equipment. Bring materials and accessories to the site:
- formwork for piles asbestos-cement pipes;
- sand gravel mixture;
- cement;
- reinforcement d = 12 mm and d = 6 mm;
- edged lumber t = 50 mm;
- fixed formwork from cement chipboard with accessories t = 35 mm;
- insulation from expanded polystyrene boards t = 50 mm;
- expanded clay insulation;
- ruberoid;
- built-up waterproofing;
- hardware.
M400 cement is suitable for the production of concrete mix
Do-it-yourself construction of a pile-strip foundation will save money, but it will require you to conscientiously study and consistently perform all technological operations.
Work begins with cleaning the site, removing the vegetation layer, leveling the site for your house.
They also plan a ditch to drain groundwater and rainwater from the base of the house.
In addition, a trench is laid out for the tape, its depth is determined, taking into account the bearing capacity of the soil.
Before starting work, it is necessary to study the top layer of the earth on the site, determine the level of soil freezing and the presence of groundwater. Make an accurate calculation of the size and number of piles for the foundation.
Well device and tape
We dig, we plan the bottom of the trench, controlling the horizontal position with the help of a level. On the compacted bottom of the trench, we outline and drill wells for the piles. The depth of the well should exceed the depth of soil freezing and go into dense soil by 0.5 - 0.6 m.
We insert the formwork into the drilled wells, which should be made of asbestos-cement pipes protruding 0.3 m above the bottom of the trench. At the bottom of the trench, pressing against the outside, we lay a drainage pipe around the perimeter and lead it into a ditch to drain water.
The pipe is pulled out of the well by 15 cm so that a pillow forms during pouring
We fill the bottom of the wells and trenches with a drainage layer of sand and gravel, plan and tamp, spilling water.
We pull out pipes from the wells by 0.15 m, so that when pouring concrete under the pipes, gravel is saturated with a solution, and a pillow is formed to support and hold the piles.
We line the bottom of the trench with a layer of roofing material so that when pouring the concrete does not mix with the drainage layer.
We cut out the roofing material above the wells, leaving holes open for filling with concrete.
Mounting the formwork
Having prepared wells and a trench for a pile strip foundation, we proceed to the installation of reinforcing frames for piles and strips. We install connected frames of reinforcement in the wells, which should protrude from the bottom of the trench to the height of the reinforcing frame of the tape.
Along the axis of the walls of the house, we mount a reinforcing mesh frame on the roofing material and the drainage layer in the trench. The meshes are connected to the protruding pile frames and create a single structure.
On both sides of the reinforcing frame, we mount a fixed formwork made of moisture-resistant cement-bonded particle board. Inside the outer wall of the formwork, we install a heater made of polystyrene foam boards. The sides of the formwork are interconnected by special bonds that determine the width of the foundation strip and hold the formwork walls and insulation in the structure. For more information about pouring the foundation, see this video:
After the formwork has been assembled, the entire structure is reinforced on both sides with edged board stops. With a leveling tool, we check the exposed formwork for the verticality of the walls and the horizontality of the upper edge.
The foundation tape, as the basis for the house, rests only on piles, is not supported by soil, so it is important that the structure is monolithic. We fill the formwork with M300 concrete in one go. First, we fill the wells with concrete, then fill the tape.
We compact the concrete in the wells with a deep vibrator, remove air bubbles. After the concrete mixture has hardened, we dismantle the reinforcement of the formwork and apply welded waterproofing on the upper part of the foundation. For the house, the pile-strip foundation is insulated, for which the earth under the building is covered with a layer of expanded clay with a thickness of 0.2 m.
A well-insulated foundation will reduce home heating costs by 30%.
Self-construction of a strip foundation on piles will save money and build a reliable, durable foundation for your home.
Do-it-yourself pile-tape foundation: step by step instructions
At the base of a house being built on a site with weak soil, it is advisable to make a pile-strip foundation with your own hands.
Independent production of screw piles is a serious matter, and we have taken on the difficult task of describing the technology of this process. Detailed drawings and photos of the stages of work are attached, since without this it will be impossible to master the technology. In addition, at the end of the second section, you can watch a video instruction from a specialist with detailed explanations of all the nuances of the technique.
Most builders do not recommend making screw piles on their own, emphasizing the complexity of the process and great responsibility. But, despite this, we can confidently say that having become acquainted with the manufacturing technology and having the drawings of screw piles at hand, it is quite possible to make these products with your own hands.
Screw pile design
The screw pile in its appearance resembles a ship's propeller. It is a hollow steel pipe, which on the one hand is equipped with a sharp tip, equipped with a cutting spiral blade.
The drawing above shows the constituent components of a screw pile:
- The barrel, which is made of a pipe, with a wall thickness of at least 3.5 mm.
- Shoe, that is, directly the lower part of the pipe.
- Tip.
- A helical blade, the shape of which and the angle of inclination determine the twisting force into the ground.
Thanks to the spiral blade, the pile is screwed into the ground to the required depth. On the other hand, when screwing stops, the blade will prevent the pile from being pushed outward and reliably fixed in the ground. This design of screw piles in the arrangement of the foundation allows you to do without the use of lifting mechanisms.
Making screw piles for a fence with your own hands
As you know, the arrangement of a screw foundation is a relatively simple undertaking, so many are interested in the question of how to make screw piles on their own, because this will significantly save financial resources.
Most often, piles for the construction of fences are made with their own hands. For self-manufacturing piles, you first need to prepare the following individual components:
- Pipes with the required diameter.
- Screw part, with a step of about 5 cm.
- Tip, at least 15 cm long.
- Heads, for fastening a bar or beams.
The length and diameter of pipes are the main technical parameters of screw piles. The length of the product is determined depending on the type of soil. Its value should be such as to ensure that the pile is immersed to the level of stable soil.
The choice of pile diameter depends on the magnitude of the forces created directly by the building structure. According to the type of fence, it is recommended to use pipes for the manufacture of screw piles of the following diameters:
- 55 mm - for the installation of light fences, for example, from a chain-link mesh.
- 76 mm - for mounting a fence made of metal corrugated board or slate.
- 89 mm - for arranging a massive fence made of bricks or light blocks.
It is recommended to purchase special blanks with a cast tip for the production of screw piles. But if this is not possible, then it is made independently directly from the pipe used. For this:
- The ends of the pipe are cut into separate sectors of a certain size according to the pattern.
- They are welded into a cone.
- The seams are being straightened.
The screw part can be made of steel with a thickness of 5-6 mm. Today you can buy special blanks for screws, but their cost will be higher. The outer diameter of the screw to be installed must be selected depending on the characteristics of the soil, namely, the deeper the pile must be screwed, the smaller the screw diameter should be.
A cap should be installed as a base for fixing a channel or beam on top of the screw pile. A properly made product looks like the photo below:
All prepared components are interconnected by welding. It is very important to monitor the quality of the weld in order to exclude possible destruction of the structure during installation.
A detailed video instruction from the master with comments will help you visually see the process of creating a pile with your own hands.
Video review: Homemade screw piles for a fence
Homemade screw piles for the fence
Screw piles for the foundation of the house
The process of manufacturing a screw pile for the construction of a building foundation is similar to that described above. But with the slightest uncertainty about the quality of manufacturing and doubts about the correctness of the calculations of the bearing capacity in accordance with the types of soil and load, experts do not recommend using home-made products for arranging foundations. That is, for the production of screw piles, it is necessary to have experience and relevant knowledge.
Video review: Installation of a pile-screw foundation
Installation of a pile-screw foundation
If, nevertheless, a decision is made to make screw piles with your own hands for the foundation, then you should be responsible for choosing the diameter of the pipes:
- For the construction of light structures, such as gazebos or terraces, pipes with a diameter of 89 mm are suitable.
- Frame-panel and log buildings, as well as hangars and similar structures, should be erected on foundations of screw piles with a diameter of 108 mm.
- Houses made of brick, stone or blocks are built on foundations equipped with screw piles with a diameter of 133 mm.
Despite the apparent simplicity of the production of screw piles, the following should be remembered:
- It is only possible to make piles of small diameter on your own, since it is very difficult to select components for massive samples and connect them qualitatively at home.
- Any mistake or error in choosing the pitch and diameter of the blade, as well as an incorrectly selected angle of inclination to the plane will increase the screw pile tightening force, and in some cases will lead to the impossibility of installation as a whole.
- Independent production of screw piles is a laborious process that takes a lot of time.
Based on the foregoing, it is important to understand that it is not difficult and quite possible to make screw piles with your own hands, but it is hardly economically feasible. At the same time, it should be taken into account that, as a rule, screw pile manufacturers provide comprehensive services for the development of a building foundation project.
The installation of screw-type piles is usually carried out using special equipment. But if it was decided to manufacture these products on their own in order to save money, then it would be more rational to use simple devices for manual installation. To do this, special holes are made in the upper part of the pile, into which special levers are inserted. As a rule, screwing a screw pile requires the efforts of 2-4 people. During installation, you should strictly monitor the vertical level of immersion of screw piles into the ground.