If the groundwater is close or on a heaving type of soil, there is a need for a more stable type of foundation for the house. In this case, the best option would be to install a pile-screw foundation. Then you can not be afraid that in the spring there will be an uneven shrinkage of the building. This is both a practical and inexpensive way to make a solid foundation. But in order to extend its service life, it is necessary to observe the installation technology, especially if construction work is carried out in the cold season.
This type of foundation is a set of piles that are screwed into the ground. You can do it yourself or use a special technique. Above is made grillage - binding of screw piles, which are located separately, in an integral structure. It can be made of wood or metal.
Each pile looks like a metal pipe with thick walls - 40 to 120 mm .
It has a tip in the form of a blade with a large thread, which helps to screw the piles into the ground and at the same time acts as a support on the ground. The diameter of the blades is different - from 20 to 85 cm .
To facilitate the installation process, screw piles with a length of 2-2.5 m are most often used. Due to the ideal shape of the blades, they are easily screwed to the required depth by the efforts of 3-4 workers.
Attention! If there are differences in height or if there is another lateral load , piles with two blades are used. Due to this, the foundation and the building standing on it become even more stable.
Piles are hollow and solid . For the foundation, hollow is most often used, so that it is possible to pour concrete into the middle. The pile blades are perpendicular, so the screw will not loosen the soil.
Their bearing capacity is within 5-25 t . When building a foundation, you can choose from several project options. The choice will be influenced by soil type and architectural features of the building .
Table 1. Foundation projects.
|What it looks like||When used|
|Single piles||Serves to support individual elements. Often used when you need to add something to a finished building|
|Standard foundation||Suitable for columns, the main elements of the building|
|Pile tapes||Located under the walls of the house|
|Pile field||Used when erecting heavy structures|
The protective coating of piles requires special attention. The most reliable building materials are made with polyurethane resin spraying and galvanized piles. The latter are obtained by hot-dip galvanizing.They have a protective coating both on the inside and on the outside.
Interesting to know! To check the quality of the piles, you can ask the building materials store for a test tightening. If the metal is heavily exposed, the protection will be poor, and if the coating is reliable, it will remain intact.
If you choose high-quality building materials, the foundation erected from them will have the following advantages:
The installation of such a foundation takes from 1 to 3 days , if you do everything manually, without the use of technical means.
To its few disadvantages include the following:
In order not to face these shortcomings, it is recommended to investigate the soil at the site in advance, choose high-quality materials and follow the recommendations for installing piles.
Its mounted in places that are not suitable for a strip base. Such areas include:
Piles are also suitable for foundation replacement or reconstruction. The installation process takes place in several stages.
Before starting construction work, you need to make accurate calculations.Here you need to pay attention to the following points:
Next, the number of supports and the gap between them are calculated. You also need to know the installation depth. All values must be taken with a margin.
To find out the exact parameters, it is better to involve a specialist who, based on the project of the house, will make the necessary calculations. It should be borne in mind that if the soil is weak and mobile, the load on one pile should be small. Then more material will be needed.
Piles are distributed and laid out throughout the length of the base of the house or outline the places for their installation. This is done in order to check how much the amount of material corresponds to preliminary calculations.
Then there will be no extra elements and there will be no situation with their shortage.
The gap between them should be commensurate with the number of piles so that they are evenly distributed throughout the site. For houses made of foam block or wood, it is enough to adhere to a distance of 1-2 m , and for heavier structures it is reduced by at least half.
Next, the angles are set. A cord is pulled between them.
When it comes to installing the next pile, the cord is removed in this place. This is necessary for safety reasons, so as not to stumble over it and not be injured during the deepening of the pile.
Pay attention! During installation, serious deviations from a straight line must not be allowed. The maximum allowable deviation is 2-3 cm . If it is larger, it will be difficult to smooth out and this will complicate the tying process.
To facilitate the installation of the foundation, it is necessary to remove the top layer of soil covered with vegetation at the pile installation sites. For this, a drill with a diameter smaller than the blade itself is used. Then the pile is easier to screw into the ground.
If it is not possible to get the drill, these manipulations can be done with a bayonet shovel. You can prepare the soil after completing the layout or simultaneously with it.
When installing them with your own hands, it is recommended to do it three or four. 2-3 people can be directly responsible for screwing in, and one can see that the pile enters the ground in a strictly vertical position.
At the top of the pile there are holes into which iron pipes are inserted. They act as levers when several workers walk around the pile, screwing the element into the ground. To control the position of the pile, special levels with magnetic bases are used.
They are attached in two places directly to the pile.
When the depth of laying the foundation exceeds the length of the pile, it is increased. To do this, use a clutch whose diameter is greater than the diameter of the pile itself.
This is done in a certain order:
If there are still deviations, the piles are leveled.
As soon as the installation of the piles is completed, you can begin to align them along the horizontal line. To do this, use hydrolevel or level. The corners of the base are beaten off to them, and then the rope is pulled along these landmarks. The excess is sawn off with a grinder, focusing on the markings.
Tip! The horizons of the future foundation of the house can be outlined in advance so that they can be immediately mounted with the same height.
But if there are irregularities, it is easier to cut off the extra pile section than to increase the missing distance.
After leveling the structure, it is recommended to strengthen it - fill each element with a mixture of heavy concrete. This will provide additional protection against corrosion within the pile and make the foundation more rigid.
Tops made of metal are put on the piles from above and fixed by welding. They come in different shapes:
They are welded strictly according to the marking. After that, the weld seams are treated with special agents to prevent corrosion.
Pay attention! If a metal strapping is planned, the piles themselves are screwed straight into the piles themselves, you can do without heads. Then the strapping is welded directly to the piles.
This structure acts as a connecting element between the piles.
It also supports the load-bearing walls and helps to evenly distribute the pressure on the foundation. There are several material options available for this purpose.
Table 2. Materials for grillage and the nuances of their use.
|Wooden planks|| Fixed with special wood screws. |
Additionally, you can use metal brackets, then they are deepened so that they are not longer than the pile itself
| Bars are treated with a bitumen-based varnish before starting construction work in order to reduce the aggressive influence of the external environment. |
Waterproofing must be installed under the bars.The simplest option is roofing material
|Metal channels||Welded to piles or tops around the structure perimeter||Need to be treated with anti-corrosion agents|
The smoother to make the grillage, the easier it is to build walls later. Therefore, its installation is done strictly according to the markup. A metal grillage will cost more than a wooden one, but it is stronger and more reliable.
When the cold lasts 3-5 months , it is not always possible to suspend construction work before the onset of heat. Thanks to pile technology, building a foundation no longer looks like an impossible task.
This is the only type of base that can be installed in all weather conditions. At the same time, the quality of the supports will be high, but no special efforts are required.
And in the construction of some buildings, installation of the foundation is possible only in severe cold.
This applies to piers, baths and berths located on the shore of the reservoir. In the summer, it is impossible to carry out construction work there, and in the winter they are done right on the ice.
Important! If you carry out the installation of piles in the winter, you need to follow a certain technology, otherwise there is a risk of injury, and the foundation itself will be unreliable.
The process of installing piles in the cold has its own characteristics:
But, despite these nuances, there are several reasons why it is more expedient to screw piles in the cold season than in summer.
These include the following:
Then the only solution is to install piles at low temperatures.
In order to properly install the piles under the foundation and provide it with good bearing capacity, it is better to do design in the summer. Then it is possible to carefully study the soil on the site, to predict its behavior when interacting with the piles. Warm weather also allows for pole markings.
In winter, this will be problematic, especially if there is a layer of snow.
If the marking could not be completed in the summer, then you can make it in the cold. Then the soil is preliminarily cleaned of snowdrifts and ice. But here it is important not to overdo it, because the snow floor plays the role of a natural heat insulator, due to this, the depth of freezing of the earth decreases.
The technology of their installation is as follows:
Preparation of soil for drilling - sampling the soil to the depth of its freezing. At this stage of construction work, thick gloves will be needed.
Step 2. Warming up the ground. For this, a fire is made on the site where the pile will be installed.
This is a very time consuming and time consuming process, but it prevents material and tool breakage.
Step 3. Screwing in the supports is performed. If the soil is very frozen, it will not be easy to screw in the piles. Then it is advisable to do this work not manually, but using a motor-drill.
Pay attention! When screwing in the supports, the first 1.5-2 m of the earth are considered the most dangerous. Once this mark is passed, the drilling process will go easier.
After installing the piles according to marking them need to be filled with concrete. Then, during the freezing of the soil and its subsequent freezing, the pipes will not be subject to deformation and will continue to fully perform their functions.
Pouring concrete in frost is not an easy process. But the problem of water crystallization can be solved in several ways:
If you are interested in the reconstruction of the finished foundation, we advise you to read the article - How much is the foundation for a standing house.
The best option is the use of impurities and additives. Without them, ice crystals in the concrete can cause the pile to break.
Then the support will be defective, it will have to be replaced. Additives are expensive, but the amount of solution required is small, so it is better not to save on materials so that the foundation is reliable.
Important! It is not recommended to ignore the technology of filling piles with concrete mix. Empty supports will be unstable.
Pile-screw foundation is the optimal solution in a situation where you need to install a solid foundation in the shortest possible time.
This option is suitable for moving and uneven ground. It can be installed even in winter. The pile structure does not require further repair, because its elements are reliably fixed in the ground.
Posted By: Work Style |08, Nov 2020
Posted By: Work Style |08, Nov 2020
Posted By: Work Style |03, Nov 2020
Posted By: Work Style |10, Nov 2020
Posted By: Work Style |03, Nov 2020