There is an opinion that it is impossible to make screw piles at home in high quality due to the high complexity of the process and responsibility for their behavior in the future.
However, if you carefully study the technology of their production and perform the necessary calculations and drawings, then to make such products yourself is quite possible.
Screw pile design
There is nothing particularly difficult to make a screw pile with your own hands, but outwardly it resembles a ship's propeller.
For the production of screw piles, a hollow steel pipe is suitable, at which a pointed tip with spiral-shaped blades is welded at one end. They have a cutting edge, thanks to which it is possible to screw the pile to the desired depth. After the installation is completed, when the pile is at the required depth, these blades play a different role - they fix the pile in the ground, not allowing it to be squeezed out when freezing in the cold season.
The pile consists of:
- hollow pipes with a wall thickness of 3.5 mm;
- shoe (bottom of the pipe);
- rotor blades.
Types of Screw Piles
The origins of screw piles date back to the 19th century, when a lighthouse on screw rods was first built in the soil of the seabed near the Thames. Later, scientists have repeatedly proved the numerous advantages of screw piles over reinforced concrete, and mainly due to the installation principle. A screwed pile is much stronger held in the ground than a hammered pile, as was done before.
Screw piles are:
- narrow-bladed;
- broad-lobed.
Accordingly, piles can be with a different number of blades and their width.
Broad-bladed piles are either single-blade or multi-blade. The first option is almost never used, considered obsolete. Single-blade piles are used only as a foundation for lightweight buildings.
The use of broad-bladed piles
Widely used in the construction of piles are broadband with several cutting blades.
The use of such piles when creating the foundations allows doubling the compression and pulling loads, and also makes it possible to increase the loads on the foundation in the future.
Thus, in the construction of foundations for the most critical buildings under construction on slopes, for multi-story buildings, multi-blade piles are used.
Narrow-bladed screw piles can be different:
- In the form of a pipe with a tip on which a blade is present. The tip is cast and welded to a steel pipe. Such a pile is great for use in creating foundations in stony soils.
- Piles used in soils with periodic freezing, or in permafrost soils. The bottom of such piles has a bevel - straight or toothed.
As in the first version of the piles, and in the second, the number of blade turns is always more than two.
Material for screw piles
When making screw piles with your own hands in an attempt to save money, you need to remember the risks that can be encountered during their operation in case of poor manufacturing.
To eliminate such negative consequences for the production of screw piles, it is necessary to choose the right material. The steel grade and the future thickness and height of the piles are of great importance. If in doubt, it is better to contact a specialist for calculations.
Another point that should not be ignored when making screw piles with your own hands is the protection of the pile from corrosion. Indeed, in the earth any iron quickly rusts, and therefore, without proper treatment, the future pile will soon rust and lose its properties.
In the factory, a zinc coating of the metal is used as such a treatment. At home, in the manufacture of self-made screw piles, the methods used at the factory are not available. And this quality cannot be achieved, or at least it will be very difficult. But it is quite possible to apply several anti-corrosion layers of a special composition to metal parts.
Production of screw piles
Another important point is the manufacture of a tip with a cutting blade. It must be not only properly welded, but also have the proper strength. Entrusting such work is recommended by a qualified welder.
Poor welding in the manufacture of screw piles leads to deformation of the metal rod and the separation of the blades from it during installation. The strength of the foundation arranged using such parts will definitely be reduced, and accordingly, the stability of the entire building will be a big question.
Thus, handicraft piles can only be used in the construction of light home buildings.
Calculation of screw piles
Before you start making screw piles with your own hands, the instruction does not hurt to study in detail. Among other things, you need to decide exactly how long they will be. In different regions in the cold season, the ground freezes to various depths, the terrain has a different relief, and, accordingly, the piles will have different lengths.
Of course, in the factory, the parameters of piles are calculated according to special formulas. When making screw piles for the foundation with your own hands, the load calculation will have to be done independently.
For the manufacture of a rod for piles, you can use a hollow metal pipe with a diameter of 10 centimeters. For blades, the blades from the construction drill are suitable, and the tip is made by welding and bending the metal, giving it the shape of a cone. Places where the parts are interconnected should be smoothed to an emery shine. In the manufacture of do-it-yourself screw piles, drawings will either have to be done independently or use existing ones.
After the end of welding, bitumen mastic or a primer for metal is allowed to be used as an anticorrosive composition.
Upon completion of the work on the manufacture of a screw pile, it is necessary to make holes for installation in the upper edge of its core. During installation, they will insert scrap or metal rods to screw the piles into the ground.
Features of the installation of screw piles
Before starting installation on the ground, it is necessary to make markings. As a rule, piles are installed in the corners of the building, and then between them after 2 meters.
When installing screw piles with your own hands in hard-to-reach places, or in the absence of special equipment, installation is carried out manually with the involvement of several people.
The manual screwdriving technique is as follows:
- In special holes in the upper part of the pile, a device must be inserted to help tighten the piles. It can be any metal rod or pipe, or scrap. This device is held by two workers from different sides and screwed into the ground, pressing on it. The pile should be rotated in the direction of the screw thread.
- When screwing a pile, it is necessary to observe the verticality of its position. To do this, every 25-30 centimeters of deepening, you need to stop work and using a plumb line or building level to check how vertically the pile is.
- When the last pile is twisted, it remains to set the height of the foundation using a laser level. For this, the protruding ends of the pipes are cut off with a grinder, which is then poured inside with concrete. This will increase the strength of the entire foundation and create an obstacle to corrosion of the pipes from the inside.
- Metal plates (or platforms) are welded to the pile heads . They will subsequently be installed on the foundation strapping. For strapping, both a steel channel and a wooden beam are used.
The process of manufacturing and installing piles without involving production facilities and highly qualified specialists is quite possible, and with a competent approach is not so complicated. Unlike the construction of a concrete foundation, a screw foundation does not require much time and finance, since the installation of screw piles with their own hands occurs without the use of special equipment.
- each pile must be twisted strictly vertically, in no case installing it in a pre-dug hole;
- piles are installed not only at the corners of the future building, but also at all intersections of internal and external walls;
- dig the pile into the ground so that its tip is at a depth of at least 60 centimeters;
- if piles are used to create a foundation for easy construction, then you can not fill their inside with concrete, especially if the wall thickness is more than six millimeters;
- if the height of the pipe when leveling the foundation was insufficient, you can increase it with a head.
Foundation on stilts for fence
If it is necessary to build a protective structure, it is advisable to produce screw piles at home. The main thing is to follow the basic rules and instructions that explain how to make screw piles for the foundation.
Due to the annual seasonal variations of the soil, any foundation undergoes destruction. Unlike screw piles, a conventional foundation is pushed out by frozen soil to the outside and deformed. Almost none of the developers does not deepen the classic foundation for the fence as much as it is possible to make a screw. And this, no less, no more than one and a half - two meters in depth!
Screw piles are firmly held in the ground, thanks to the properties of their tip with blades. The efforts of the soil can not cope with such a foundation, and the fences on the pile-screw foundation are long and not destroyed for decades.
Conventional foundations that do not have a tip or blades, whether metal or concrete poles, are pushed out by frosty heaving of soil outward, the fence warps and loses its integrity.
The advantages of a screw foundation for a fence
When installing screw piles with your own hands, you do not need to spend time and energy on clearing the territory and digging a trench. It is enough, using the beacon cord, to mark the places of screwing the piles.
70-80 centimeters lower than the ground freezes in this particular region are usually taken as the depth of penetration of piles.
When twisting piles in soft soils, they are buried from the surface until they come into contact with their dense layers. In the case when it is impossible to determine the required screwing depth, it is allowed to lengthen the piles and increase them with additional sections.
When tightening screw piles with thick walls, drilling rigs can be used instead of manual installation.
Screw piles for the foundation of the house
When erecting the foundation of a building, it is not recommended to use home-made piles, since it is unsafe for life. It is better to purchase factory-made piles, which are made in compliance with all norms and rules, and also have a much longer service life.
When deciding to make do-it-yourself screw piles when choosing pipes, you should follow simple rules:
- brick houses, buildings of stone or blocks are erected on foundations constructed using piles having a diameter of 13.5 centimeters;
- chopped and frame-shield structures, hangars and similar structures are built on the basis of piles with a diameter of about 10.5 centimeters;
- light structures can be installed on pile foundations from piles with a diameter of 8.9 centimeters.
The nuances of the pile-screw foundation for the building
Although at first glance it might seem that the production of screw piles is a simple process and does not require special skills, it should be borne in mind:
- Even a small error in the calculation of the diameter or pitch of the blade, when calculating the angle of inclination of the blade to the pile plane, will inevitably lead to a change in the required force for twisting the pile. Sometimes this leads to the complete impossibility of the installation.
- In any case, the do-it-yourself screw pile production process is long and time-consuming.
- Only piles of small diameter can be made independently. This is due to the fact that it is difficult to choose components for large piles, as well as to perform their high-quality connection between themselves.
Thus, it is important to understand that making screw piles with your own hands is quite possible, but hardly economically feasible. As a rule, manufacturers of screw piles offer the consumer comprehensive services for developing the foundation of a building, and it is often more profitable to turn to them.