Any buildings, including suburban residential buildings, are built, of course, on the foundation. There are several types of building foundations. The main advantage of the column foundation is the cheapness and ease of filling. Also the advantage of such foundations of houses is a long service life.
Further in the article we will consider how the columnar foundation is poured step by step. In principle, the construction of such a construction is nothing complicated. However, certain technologies must be observed during its construction.
What is a
A foundation of this type can be erected either directly under residential buildings, or under household buildings or in small architectural forms. The structural elements of the columnar base are:
- supporting posts ;
- grillage.
The main load from the house in such a foundation is, of course, precisely the vertical supports. When erecting them, one should strictly adhere to all the required technologies.
The grillage in the construction of the columnar foundation is responsible for the distribution of the load from the building among the pillars. In houses of various shapes, this element can be assembled from different materials. In wooden buildings, the role of the grillage is usually played by a flange. In concrete buildings, this element most often represents a tape filled with cement mortar.
Where can be used
Column foundation is the cheapest type of building foundation . Its construction costs, in most cases, are very inexpensive. However, in terms of reliability, it is, unfortunately, somewhat inferior to other types of foundations. It is far from always possible to fill such a foundation under a house or an outbuilding.
Construct column foundations only:
- under fairly light buildings - with walls of timber or logs, or foam concrete;
- on sufficiently strong ground.
Primary requirements
When designing a building with a columnar foundation, the following important points should be considered:
- base posts must be located at all corners of the house, as well as at the intersections of walls;
- poles are placed along the length of future facades in steps of at least 1.5 m;
- above the soil surface, the pillars of the foundation should be located at a height of not less than 30 cm.
It is not necessary to deepen the column foundation into the ground too much. The bases with the supports installed below the freezing of the soil are already called pile. Columnar structures are buried, usually no more than 70-100 cm.
Do-it-yourself step-by-step instructions to build columnar foundations under the houses only on a flat surface. On steep slopes, it is supposed to flood other types of such structures.
The cross section of the supports of such a base can be either square or round. At the same time, most often on the suburban areas are poured constructions of the second variety. The calculation of the columnar foundation of a private house is carried out according to the following formula:
S = 1.3 × P / R0, where:
- S is the total cross-sectional area of the pillars;
- P is the weight of the house along with the foundation in kg;
- R0 is the resistance of the bearing soil.
The last indicator in this case is determined by special tables.
The calculation of the columnar foundation of a suburban building is, in principle, a simple matter. But, in any case, the cross section of each column of such a base should not be less than 200 mm. Most often, under private houses, piers of 30-50 cm are poured.
What tools and materials will be required
In order to build a columnar foundation with your own hands, you need to prepare:
- Portland cement grade not lower than M 400;
- well-sifted coarse river sand;
- reinforcing rod with a cross section of 8 mm;
- roofing material;
- knitting wire;
- boards for formwork grillage.
Of the tools you will need:
- concrete mixer;
- shovel and buckets;
- garden car.
Mixing cement mortar for a columnar foundation, as for any other, is best done in a concrete mixer. The reliability of the foundation of the building directly affects the period of its further service. Therefore, only the highest quality cement mortar should be used for pouring the column structure.
In a concrete mixer, the mixture intended for the construction of supports and grillage is obtained as homogeneous as possible, which allows the construction of very strong poles. However, if there is no such equipment, you can prepare a solution, of course, in a large trough with a shovel. But even in this case, the components should be mixed as thoroughly as possible.
A concrete mortar is prepared for the column foundation in the proportion of cement / sand / crushed stone as 1/3/4.
Markup
This operation is performed using pegs and a cord. First, determine where in the future will be the corners of the house. Then, using the method of the Egyptian triangle or two curves, markup is performed by driving the pegs into the ground and pulling a cord between them. At the final stage, the angles are checked by measuring the diagonals.
Stages of the construction of the column foundation
The construction of the base of a country house of this design includes several stages:
- Markup.
- Digging a hole.
- Installation of fittings and formwork.
- Pouring concrete mixture.
At each stage of the construction of such structures, of course, all the required technologies must be strictly observed.
Fill the column foundation: step by step instructions
Under residential buildings, poles of a sufficiently large cross section are usually installed. In this case, pits are dug under them using a shovel. Recesses for pouring supports of small cross section are made using a drill.
Instruction:
Step number 1. At the bottom of the pits sand is preliminarily poured with a layer of 15 cm. The resulting shock-absorbing cushion is rammed with water from a hose. A layer of crushed stone of 20 cm is poured over the sand and also compacted.
Step number 2. Formwork is installed in the pits. For massive pillars of square section, at the same time, boards and plywood are used. The formwork for round supports is made in most cases from roofing material.
Step number 3. Next, fittings are installed in each pit. Pillars cannot be poured without it. Otherwise, in the future they will not last long. Reinforcement for foundation pillars is made using four 8 mm rods, by intercepting them with thick steel wire clamps.
Step number 4. Pillars are poured with concrete mixture. To ensure that the supports subsequently turn out to be reliable, the solution, when laying in the formwork, is pierced from time to time with a shovel or rod to remove air bubbles.
Grillage filling
The columnar foundation instruction prescribes to erect with reinforcement not only supports, but also a grillage. To connect all the frames in a single design, simple technology is used.
At the end of pouring work, the reinforcing rods of supports should rise above their surface by 20 cm. This is necessary for connecting the frame of the pillars with the grill reinforcement. This element itself is poured into a pre-knocked down wooden formwork. Also sometimes a form for grillage is equipped with a slightly different technology.
In this case, the walls of the formwork are also made of wooden panels. The bottom is not stuffed at the same time. Instead, a mound of earth is poured under the formwork, which after pouring is simply scattered. But to use such a technology, of course, is advisable only if the foundation supports do not rise too high above the surface of the earth.
Fill the grillage of the columnar base of the house as follows:
Step number 1. In the formwork, a reinforcing frame is installed on blocks of 5 cm thick.
Step number 2. Link it to the frame of the pillars.
Step number 3. Lay the concrete mixture into the mold.
The metal frame for grillages of columnar foundations is usually used two-row. With the reinforcement of the pillars, it is connected with the use of wire. Install the frame so that it is located at a distance of 5 cm from the walls of the formwork and from the top of the future tape.
Features of the installation of the column-tape design
Such a base is usually equipped in areas with a significant depth of freezing of the soil. The construction of a strip foundation in this case is considered impractical. After all, material for pouring the structure to great depth will have to use unreasonably much.
Structurally, the column-strip foundation consists of:
- supports buried in the ground, usually of square section;
- concrete tape buried in the soil by 30-40 cm.
A foundation of this type is being built using practically the same technology as the base with grillage:
- marking is carried out and a trench is dug under the tape;
- in the corners of the trench and along its length in increments of 1.5-2 m, holes are dug under the pillars;
- a sand cushion is poured and formwork is installed;
- reinforcing cages are installed in pits and poles and are connected to each other;
At the final stage, the concrete mixture is poured. After a couple of days, the formwork is removed from the finished column-base foundation.
Other types of columnar bases
Most often, structures of this type are poured, of course, from concrete. However, columnar foundations can be constructed using other materials. For example, under various kinds of buildings, such bases are often equipped using pipes.
Under small structures, such as arbors or verandas, brick column foundations are also sometimes erected. With proper installation, both of these varieties of substrates can also be quite reliable.
Erection of brick pillars
Thus, the most inexpensive and at the same time reliable supporting structure is considered a concrete columnar foundation. The step-by-step technology for pouring such a foundation was considered by us in detail above. But what are the rules for the construction of brick column foundations? Such designs are also assembled using a fairly simple technology.
In this case, at the bottom of the pits dug under the supports, in this case, first pour a concrete pillow about 20 cm thick. Then they proceed to the masonry itself. Use for the erection of supports of such a foundation is allowed only ceramic solid brick. Silicate for this purpose can not be used.
One row of pillars of such a base is laid out of 4 bricks. Every 4-5 rows, the support is blocked from above by a reinforcing mesh. At the center of the laid out column, a rod is first inserted, and then concrete is poured.
Foundation of pipes
The construction of such a foundation is also a fairly simple procedure. The assembly of a columnar foundation from pipes looks like this:
- With the help of a drill, holes are made in the ground;
- sand is poured on their bottom;
- install pipes in the pits;
- pour them with concrete from the outside in order to give them stability;
- pour concrete into the pipes.
At the final stage, plates of sheet metal are welded onto the pipes, on which the grillage will subsequently rely.
Now you know how to build a column foundation with your own hands. Step-by-step instructions are presented in the article.