The strip foundation is most often used in the construction of a variety of buildings. In addition to its simplicity and reliability, it is distinguished by the simplicity of transformation into monolithic foundationwhich is considered even more durable.
- What is a strip foundation ↓
- Description ↓
- Scope of application ↓
- Styling technology ↓
- Estimated Cost ↓
- Payment ↓
- Online calculator ↓
- Self-calculation according to the formulas ↓
- Calculation Example ↓
What is a strip foundation
The foundation of the tape type is a frame structure made of concrete and reinforcement. This design has a rectangular shape, is solid and intersects in the corners with itself.
Such a foundation is located along the entire house, given the load-bearing walls inside. Usually, part of the foundation stands about 10 centimeters high above the ground. The rest of this element of the house is underground in a previously dug trench. It is important that the surface of the foundation exceeds the width of the walls in size, only then the foundation of the building will be reliable.
Despite its popularity, such a foundation requires voluminous and labor-intensive land work. In addition, the arrangement of the tape base can not be called economical in the use of materials. But this option is suitable for heavy houses, for example, of brick, and is very simple to build.
The foundation of the tape type and on soils with the possibility of uneven shrinkage shows itself perfectly. If necessary, equipment of the basement - the foundation walls can also serve as the walls of the basement at the same time (do not forget to check the possibility of arranging the underground basement by level groundwater).
On average, the service life of such a foundation varies from 30 to 80 years, depending on the materials used and the quality of the construction work.
Scope of application
Among the main areas of application of strip foundations, it is worth highlighting separately:
- Houses with heavy walls made of stone or brick (with a density of more than 1300 kilograms per cubic meter).
- Houses with heavy reinforced concrete or metal floors.
- In the case of construction on soil predisposed to uneven draft. With the help of the strip foundation, the load will be redistributed, and the walls will not crack and collapse.
- If there is an underground floor or basement in the construction plan.
As a rule, for the construction of the foundation of the strip type, the main building materials are reinforced concrete and but concrete. The technology of building the foundation itself involves the following steps:
- The preparatory phase of construction, which consists in marking the site for the future construction, vacancy of a place on a building site and acquisition (delivery) of all required construction materials. Particular attention should be paid to the layout of the site, and the quality of the entire foundation will depend on its quality. On the construction site cleared of extraneous debris and objects, it is necessary to mark the axis of the construction and fix the angles with beacons. Particular attention must be paid to the perpendicularity of all marked sides. The dimensions of the construction site must exceed the final dimensions of the house by several meters.
- Digging a trench. The trench itself can be dug manually or using an excavator. If you use the technique, it’s important to level and tamp the bottom of the trench manually. Without fail, all trash is removed from the trench.
- A foundation pit fence is installed.
- The bottom of the trench is covered with a layer of sand or gravel (12-20 cm).
- The future foundation is waterproofed by laying waterproofing material.
- From boards about 40 mm wide foundation formwork (you can use collapsible metal structures).
- Reliable formwork fixing (using spacers). In this case, it is necessary to achieve a strictly vertical arrangement of this element.
- In parallel with the installation of the formwork, the foundation reinforcement is laid (the reinforcement parameters are indicated in the construction project, taking into account what loads must be maintained).
- The foundation is poured with concrete. It is advisable to perform this operation from a height of not more than one and a half meters. Concrete is poured in successive layers up to 20 cm high, with each layer being rammed before pouring the next.
- One week after pouring concrete, formwork is removed.
- Work is underway on foundation waterproofing (via bituminous mastic glued roofing material).
- The final stage at which backfilling of the sinuses of the foundation takes place with sand.
The foundation of the tape type is a reliable foundation of any building. Therefore, there are times when its value can be more than half the cost of the entire construction as a whole. Among the factors affecting the cost, there are:
- soil quality at the construction site;
- groundwater level;
- building area;
- material used for walls and building structure;
- requirements for additional reinforcement.
The cost of the strip foundation is the sum of the costs of the entire spectrum of work and the cost of the materials used (volume of concrete and reinforcement). If you count all the work required by the technology of arranging such a foundation, and the estimated cost of materials, on average, a running meter of a strip type foundation will cost 6000 rubles.
To calculate the strip foundation, it is necessary to take into account all the features of the soil and the building itself. Based on these data, possible loads and required volumes of materials are calculated. Based on the volume of materials and the approximate cost of work, the price of the foundation is formed. For the calculation, you can use online calculators or independently calculate everything according to formulas and tables.
One of the popular sites for calculating the strip foundation is http://stroy-calc.ru/raschet-lentochnogo-fundamenta.
Using this site, where it is enough to indicate the dimensions of the house and the expected materials for the construction, you can easily calculate parameters such as:
- length and width of the foundation;
- the area of the foundation support to determine the required amount of materials for waterproofing;
- lateral area of the foundation, to determine the amount of materials for thermal insulation;
- volume of concrete for pouring the foundation;
- concrete weight and the load created by the structure on the soil;
- diameter of reinforcement rods;
- number of rows laying reinforcement;
- total length and weight of fittings (you may like it option with fiberglass reinforcement);
- formwork thickness and the required number of boards;
About how to calculate the cubic area of the foundation in the next article.
Self-calculation according to the formulas
In order to start an independent calculation of the foundation of the tape type, it is necessary to determine the initial data: the terrain, the size of the house, etc. First you need to calculate the depth of the base of the building.
To determine the depth of the foundation, you need to know the characteristics of the soil on the construction site and the characteristics of the house itself. When building massive houses with heavy brick walls, it is necessary to deepen the foundation 30 cm more than the freezing boundary of the soil.
Thus, the total height of the foundation with the outside will be the freezing limit of the soil plus 60 cm. If the building is not very massive, it will be enough to deepen the foundation by 50 cm. The width of the strip is usually taken standard (equal to 40 cm).
To complete the calculation, it is necessary to calculate the footprint of the foundation so that the building can withstand all the loads. For this, you can use the following formula:
S> k (n) * F / k (c) * R
k (n) is the safety factor, which is 20% (k = 1.2); F is the estimated load from the house and foundation on the soil, plus the load from snowfall in winter, ceilings, etc .;
k (c) is the working coefficient, which is looked at in the table depending on the conditions and materials of work (for example, for clay soil and hard structures equal to 1); R - soil resistance indicated in the tables in accordance with the type soil.
All tables are compiled according to the requirements of sanitary standards. You can find them both in the standards themselves and building requirements, and on the Internet. The only calculated parameter will be the total load.
We give an example of calculation. In the case of depth, no questions will arise. For example, take a terrain with a freezing boundary of 130 cm, then the depth of the foundation is 160 cm.
In the case of calculating the area we take:
k (n) = 1.2; F –150000 kg (defined as the total value of the data from the tables of pressure of the materials of walls and foundations, snow pressure for the region);
k (c) = 1.1; R = 2.5.
In this case, according to the formula, we get an area equal to 6, 5454 square meters. We round up and get 6.6 square meters.
The cost of the strip foundation can be more than half the cost of the whole house, but it will be a reliable foundation. The main cost item for such a foundation is materials. You can use formulas or online calculators to calculate materials. If you are unsure of your abilities when calculating and want to save time, it is better to use online services.