DIY screw foundation
Have you decided to mount the screw foundation on your own? Then you need detailed information about the features of this design, as well as instructions for its installation. The work should be thought out to the smallest detail, because the stability of the entire structure depends on the foundation. This article provides relevant and useful information on how to properly equip the base of screw piles for private buildings..
Content
- Foundation on screw piles: reviews of experts on its advantages and disadvantages
- Where to install the pile-screw foundation is most appropriate?
- Foundation screw piles: design features
- What piles are used for the construction of a screw foundation?
Foundation on screw piles: reviews of experts on its advantages and disadvantages
Masters who have been working with a pile-screw foundation for a long time unanimously recommend using it. Why?
- This is a universal, strong foundation, both for low-rise buildings, and for garages, fences, lighthouses, poles, etc., tested by time. It has been used in construction for over 100 years..
- This design does not require preliminary land work. Piles are twisted into the soil using a special installation or manually.
- Construction is permissible on any difficult surface, in any climatic conditions.
- Such a foundation is appreciated by ecologists and people who care about the environment. During its construction, the roots of trees nearby and other ecosystems will not be harmed..
- Mount screw do it yourself foundation using a key or a rod will not be difficult, and it will take no more than 2 – 3 days. It is easy to dismantle and therefore suitable for temporary buildings..
- With the right selection of screw piles for cost, such a foundation will come out much cheaper than similar traditional structures.
- It is convenient to use as a basis for extensions to existing buildings.
It is possible to build a pile-screw foundation on a site with a relief of any complexity
The disadvantage of this type of foundation can be attributed to the fact that it is difficult to organize a sub-basement or basement with it, although this issue is resolved.
It is also suitable mainly for low-rise buildings (up to about 5 tons).
Where to install the pile-screw foundation is most appropriate?
- Where there is moving unstable soil. Piles pass through a section of unstable balls of soil, crashing into a solid base. These metal structures withstand lateral loads..
- In a harsh climate. In regions where the soil freezes deep and excavation is not possible, a pile screw foundation is used. It can be mounted even at the lowest freezing temperatures. A pile passes through almost any freezing layer.
- In flooded or flooded areas. If you want to build a house on the shore of a lake or river, then you only need to use a pile screw foundation – the feedback from the owners of the “lake” houses confirms that this is an ideal option. In wetlands and in humid climates, one cannot do without it either.
It turns out that it can be mounted everywhere. The only, impractical thing to do on rocky soil, since the stone foundation in itself is an ideal foundation for the building.
Foundation screw piles: design features
Screw pile design
In order to build a screw foundation with your own hands, it is necessary to present in detail the features of its design.
A screw pile is a special hollow steel pipe. On one side, she has a pointed threaded tip or drill bit. The diameter of the pile can be on average from 10 to 33 cm with a wall thickness of 8 to 12 mm, and a length of 0.25 to 2.5 m. A hat (rectangular, round, U-shaped) is located in the upper part of the pipe (ground) ), designed to mount the grillage, which is the frame for the building. A layer of a special anti-corrosion coating is applied to the inner and outer surfaces of the pipe. Its thickness significantly affects the durability of piles. The operational period of these products from a trusted, reliable manufacturer is at least 50 years..
What piles are used for the construction of a screw foundation?
- With standard thread (tip only).
- With combined thread (not only on the tip, but also on other parts of the pipe).
- With blades.
The standard ones are the cheapest, and with the blades the most expensive, since they compact the soil more efficiently than simple screws. To date, there is no standard and uniform assortment of these products. Each manufacturer develops its own model range of these products and consumables (clips, hats, adapters, etc.).
What to look for when choosing piles?
1. The first criterion is the quality of the product, which can be determined by the location and shape of the blades. The tip should be asymmetric to allow easy and gradual entry of the pile into the soil. If the pile is hardly screwed in, then the reason may be in its poor quality..
2. You should carefully study the technical data sheet of the product, check the information in it with the shape of the screws.
4. Also, it will not be superfluous to orient in choosing piles to sales leaders, to buy products from well-known and trusted companies.
5. For those who decide to install a screw foundation, customer reviews can be a great help. It is important to study the opinions of people who have bought products of a particular company.
Calculation and design
This is the starting point in the work on the foundation. The reliability of the entire structure will depend on how well the design of the “foundation” of your home is made. Therefore, for help in this matter, it is better to contact specialists who will accurately calculate the required number of poles and their technical characteristics. Many large companies that sell piles carry out such calculations for free for their customers..
When calculating the design of the foundation, it is taken into account:
- type of soil, its properties;
- groundwater level, their seasonal variations;
- freezing depth of the earth. It is necessary to know exactly the “safe” depth, that is, the one on which stable soils are located. Piles cut below frozen ground.
- weight of the future structure. It takes into account its weight with all contents, different types of possible loads on one pile and all together (for example, seasonal, wind, dynamic, etc.)
- bearing capacity of pillars;
- the margin left for trimming for leveling piles (about 15-20 cm).
Do-it-yourself pile-screw foundation construction
After you have acquired the right amount of piles of the required dimensions, you can proceed to installation. If the depth to which you want to install the pile does not exceed 1 m, then it is worth trying to carry out the installation yourself and save a lot of money on this.
Piles with a length of more than 1 m (this is the most common option, because in most regions freezing depth is 1.5 m), it is more difficult to establish. But if you have the proper skill, then you can do without specialists. The stages of work will be as follows:
1. Landmarking
The location of each pile is marked with pegs around the perimeter of the base of the structure. They are distributed evenly and with the same pitch (usually 1.5 m – 3 m). Piles must be sure to support the nodes and corners of the internal walls.
2. Screwing up piles
After marking the territory under the foundation, the piles begin to screw. If you do it manually, it is better to use a barbell. After every few turns it is necessary to check the horizontal level to avoid the curve of the column.
Important! Piles cannot twist closer than 30 cm from an existing fence or wall.
3. Alignment to one level
The piles are twisted. It may happen that they will be placed at different depths (this is due to the peculiarities of the soil cover), and their height will be different. In any case, they need to be cut to the level determined by the project in order to achieve the most even horizontal under the “box” of the structure. This is done using special equipment (laser rotating level) or a grinder. The ground height of the piles is determined by the height of the base (usually 40 to 60 cm).
4. Concreting piles
Concrete mortar (sand-cement or sand-cement-gravel) is poured into the middle of the pipe. At low temperatures, it is necessary to add anti-frost additives to it. By concreting, the internal cavity of the pile is sealed, which eliminates its corrosion from the inside. If the structure is temporary, then piles may not be concrete. But this is risky, since piles can fill with water and burst in winter when it freezes..
Important! In no case should concrete be piled outside!
5. Installation of the upper trellised part of the pile foundation (grillage)
The installation of the grillage depends on the material of this design. Under wooden houses, they usually use a cobbled bottom trim, which is attached to the heads with large screws (wood screws), and for block and brick buildings, a metal lintel, which is welded to the joints with the piles with an annular inner seam.
Options for pile-screw bases for “light” houses
Piles, if necessary, can be closed with facade panels, which are available in a wide variety on the market. Only it is necessary to leave perfumes.
As you can see, there is nothing fundamentally complicated in the installation of screw piles. It is important to do this in a quality manner, and then these structures will become a reliable support for your building for many years.
