What is strip foundation? A properly calculated and installed foundation of the structure is the key to a safe and high-quality construction for any building. There are several varieties of the foundation at once, but the tape is considered the most popular and convenient to use. To create it, you do not need to use additional devices. Anyone can recreate a strip foundation with their own hands, and the step-by-step instructions will help you deal with this issue quickly and easily.
Main pros and cons
What is strip foundation? Why is it called that? The strip foundation under the house got its name because of the reinforced concrete strip at the base, which is buried in the soil to a certain depth. The outer and inner walls of the building along the entire lower cavity rest on the surface of such a tape. According to the type of penetration into the ground, the strip foundation can be buried (from 1.45 to 1.65 meters), as well as with shallow penetration (no more than 1.4 meters).
The first variety is used asas a rule, for large buildings and high-rise buildings, and the second - for the construction of low-rise buildings. According to its structure, the foundation can be prefabricated and monolithic. The monolithic one is poured with a special concrete solution, and the prefabricated one is created from individual reinforced concrete blocks.
To create a monolithic regular strip foundation, the following types of materials are used:
- sand;
- rubble;
- water;
- broken brick;
- portland cement;
- fragmented rock;
- steel reinforcement.
When building a structure on your own, you can contact a construction company and order a turnkey strip foundation.
Key features
Now is it clear what a strip foundation is? It has a large number of advantages that make such a device truly popular among other types of blades:
- minimal susceptibility to high loads;
- simple creation without the use of heavy technical devices;
- fortress finished building;
- when using such a foundation, it is possible to build on soil mixtures that are heterogeneous in density;
- The walls of the structure can play the role of walls in the basement of the house.
The small width of the strip foundation is an additional advantage of such a foundation.
It is important to remember that such a system has its drawbacks:
- construction requires a lot of materials;
- it is mandatory to carry out waterproofing onplot.
What is strip foundation? With all its pros and cons, this type of foundation is considered widespread, especially when building in the private sector.
To correctly calculate the strip foundation, you should use a special concrete calculation calculator. In such a calculator, you just need to enter the parameters of the trench in order to get as much information as possible about the amount of materials required. Also, using such a device, you can easily determine the entire cost of the foundation.
Creating with your own hands
How to make a strip foundation? Due to the fact that to create such an object it is not necessary to use heavy technical equipment, anyone can easily build it on their own.
For this, a special step-by-step instruction will be presented below. A strip foundation can be erected by any man with minimal building skills.
Site preparation
Before you start creating the foundation, it is important to carefully plan the site and mark the axes. Under the layout, they mean leveling the site around the entire perimeter and building in height.
If there are strong elevation differences on the territory, then it is important to take this into account when digging a trench. In higher areas, you will have to dig much deeper, but in the lowlands, the height of the foundation will be greater.
The marking of strip foundation slabs is carried out by means of a special triangle with sides 3:4:5. Angles in this casemust be straight and all diagonals equal.
Earthworks
After preparing the site and careful planning, digging a trench to the desired depth along certain marking axes begins. Its depth will directly depend on the density of the soil, the total distance to groundwater, and the weight of the future building. For a house with a large number of floors, 1.5 meters are used, for a private building, only one meter is enough if the soil allows.
At the end of digging a trench at its bottom, it is necessary to compact the soil and drain it with layers of crushed stone and sand. Such a layer is otherwise called a pillow. The width of the resulting trench will directly depend on the material from which the walls will be created. For a private building, a width of 60 centimeters is enough.
Self-created formwork
After the creation of the trench is over, the construction of the formwork begins. Some construction companies have reusable prefabricated formwork, which is very simple and comfortable to use. Also, such a formwork for a strip foundation can be easily created with your own hands. To do this, prepare the bars and tes. Their number will depend on the scale of construction.
The formwork is a wooden box installed above the trench. Since a liquid solution will be poured into the trench, it is important to strictly follow the rules for the tightness of the building. If it is not possible to close it with some boards, then the formwork can be sheathed from the inside withusing ruberoid. The finished structure must be distinguished by its strength and rigidity, which will help it to withstand the pressure of concrete normally. To do this, the walls of the structure are fastened between each other with special jumpers every few meters. Creating a formwork for a strip foundation with your own hands is quite simple and will not be difficult.
To ensure that the lumber used to create the formwork can be used again in the future, it is important to create a structure so that not a single board is deformed during disassembly.
Choice of concrete grade
Before laying strip foundation slabs, it is important to decide which brand of concrete is best suited and can withstand heavy loads. The choice of concrete will depend on the following factors:
- weight of finished building;
- presence or absence of additional load on the base;
- soil type;
- climatic conditions in the place of residence.
The choice will also depend on the reinforcement used in the construction.
In creating a concrete pad under the base, you can use the concrete of the strip foundation of the M100 brand. Under structures of a lighter type, for example, baths, outbuildings, sheds, it is best to use the M200. The construction of a wooden house or the construction of light weight blocks requires the use of M250 concrete. For larger buildings, high quality concrete with special characteristics is used - brand M350, its strength reaches 327 kilograms per square centimeter.
Higherconcrete grades are used to create buildings that are complex in terms of geometry, as well as in areas with rather harsh climatic conditions. Given all the characteristics described, then everyone can easily choose the right brand of concrete for themselves to make a strip foundation.
Pour the foundation and lay reinforcement
After the owner has chosen the brand of concrete, he needs to prepare everything he needs for pouring. How to make a strip foundation? Some, in order to facilitate their work, pre-order ready-made concrete from special firms. The rest of the builders prefer to make their own solution. For this, it is best to use a concrete mixer. It mixes all the components. Their ratio will directly depend on the brand of concrete used, as well as on the design of the strip foundation.
At the bottom along the perimeter of the structure, steel material is placed from reinforcement bars. The greater the number of such rods and the greater their thickness, the stronger the foundation.
The created concrete is poured into the trench and formwork to the level mark and carefully leveled so that its surface becomes more even and horizontal.
More experienced builders recommend using specialized vibrators when pouring a large foundation, which go deep into the thickness of the concrete itself. They help to eliminate air bubbles, making the foundation more uniform in consistency and stronger.
After the foundationcompletely hardens and will be ready, it is important to waterproof its walls with specialized coating materials. A properly created foundation will help ensure the safe and long-term operation of the building.
How long can it be used?
The service life of the strip foundation will directly depend on the material used in the work. For example:
- monolithic concrete and rubble tapes on cement mortar continue to remain intact for 150 years;
- brick ribbons - 30 to 50 years;
- precast concrete - 50-75 years.
If we consider the design of the finished foundation, then it can be divided into:
- Monolithic - used on the construction site itself.
- Prefabricated - when creating, reinforced concrete standard blocks are used, created at the factory and mounted on the construction site by means of a crane. The prefabricated foundation is made of reinforced concrete slabs - concrete blocks and pillows.
Distinctive features of each type
Depending on the strength of the load, builders divide the strip foundation into deep and shallow. The shallow and deepened monolithic foundation is a strong reinforced concrete frame that runs over the entire area of the future building, which helps to provide houses with good stability when built on slightly heaving and heaving soils. In this case, one should be guided by the principle of "price-strength". The cost of such a foundation will be low - only 15-18 percent of the entire building.
The buried type of strip foundation is used when building a house with heavy walls or coatings, as well as with heaving soil. It is also important to use a recessed foundation in the case when the owner plans to finish the garage or basement in the house in the future. The depth of laying the foundation will reach 20-30 centimeters below the freezing depth of the soil. Such a base needs to use more material. Under the walls located in the building, you can make a foundation of less depth - 40-60 centimeters.
A buried foundation, when compared with a shallow foundation, is distinguished by its strength and special stability due to the fact that its lower part is located below the groundwater freezing level and is not subjected to a deforming process. But it is important to remember that when creating it, the amount of consumables and labor intensity increase significantly.
The described types of foundations are usually laid in the summer. When creating them, it is not necessary to use expensive devices, a concrete mixer and a little mechanization will be enough for the builder.
On sandy or dry soils, strip foundations are allowed to be laid above the freezing level of the soil, but not less than 50-60 centimeters from the soil level.
On deep freezing soil, a strip-type foundation is used extremely rarely due to its poor resistance to low temperatures.
Pros and cons of precast foundation
Prefabricated strip foundations are often used not only in industry, but also increation of private houses and cottages.
The main advantages of such a foundation for a house include quick construction and the ability to load the finished structure after mounting after a certain amount of time. It is important to remember that the cost of this type of foundation will be much higher. During its construction, you will have to use the help of professional builders and lifting equipment.
The main disadvantages include the following factors: the strength characteristics of the prefabricated material (with the same thickness) are 20-30 percent lower than that of a monolithic one. The foundation created using prefabricated blocks is not as rigid as monolithic, as it includes many separate parts. The prefabricated foundation cannot be strengthened with additional reinforcement, since the blocks will be located according to a standard design. It is possible to strengthen the prefabricated foundation only by means of grids laid between the rows of sides, but this will not provide the desired effect.
It is possible to reduce the cost of materials for a foundation of this type by laying foundation wall blocks and pillows not in a continuous row, but with a certain distance - an intermittent foundation. A base of this type will save about 25 percent of the blocks, which will reduce the cost of the entire building.
Any builder should remember that if there is peaty, silty soil with a weak bearing capacity on his site, then it is forbidden to use an intermittent foundation as the foundation for the building.
Strip foundation, consisting of prefabricated materials, loses in its own waystrength and performance characteristics of monolithic.
What kind of errors can occur?
The errors described below can adversely affect the quality of construction of absolutely any foundation, including tape:
- When carrying out survey work, the characteristics of the soil were not considered - its subsidence and heaving. The level of groundwater and the depth of freezing of the earth were inaccurately identified. Due to the mistakes made in the project, mistakes are made from the very beginning that negatively affect the state of the finished building - the foundation begins to crack, sags heavily over time.
- Poor quality building materials were used during the work.
When considering poor quality work, special attention should be paid to:
- incorrectly placed axis - the angle of the building is less or more than 90 degrees;
- skew foundation;
- the pit was not dug to the required level;
- the thickness of the pillow in the trench was not taken into account;
- during the hardening of concrete in cold weather, the builders did not maintain the optimum temperature - the concrete did not warm up, which led to a decrease in its strength and strength.
Communications device
Some people who want to build the foundation for their future home on their own often encounter engineering communications when working. Underground utilities - linear installations with technological devices that are needed for the transportation of gas and liquid, as well as the transmission of energy. They include piping for hot and cold water, gas, telephone lines and electrical wires.
To understand what communications of this type are, it is important to contact the state institution at the place of residence and get a topographic survey of your site, which will indicate all the main underground utilities.
In the event that the house to be rebuilt falls on such communications, the builder will have to transfer or use another technology to link the house to the site. It is important to remember that the construction of a private facility nearby or above underground utilities leads to an additional load on the structure, which can provoke a man-made accident and lead to tragic consequences.
Most often, communications of this kind pass through the site when it is located in a village or on the outskirts of a city. If the construction project was created by a specialist in this matter, then all possible methods for solving the problem will be discussed in advance.
