Make a columnar foundation. Do-it-yourself columnar foundation - step-by-step instructions. Prices for masonry work

Only a professional builder can design and implement a columnar foundation with his own hands according to the recommendations of SP 50.100, 22.13330, 32.13330, 45.13330, 27.13330. These grounds are too unreliable; the results of geological surveys should be studied in as much detail as possible.

The technology for installing a grillage along pillars depends on the construction technology of the building for which the foundation is being constructed. Columnar bases are made from structural materials:

• reinforced concrete - pouring into formwork on site, installing the finished product in a 1F or 2F glass;
• wood - logs with a widening base;
• brick - clinker, solid ceramics;
• blocks - wall, only with dense fillers, hollow;
• rubble concrete - stone is introduced into the formwork after partial filling with ready-mixed concrete.

In addition to the strip grillage, a slab structure can be used. This is the only option for a columnar foundation suitable for a brick cottage on sandy soils with a groundwater level (GWL) below 1 m. In all other cases, columnar foundations are created for log houses, half-timbered buildings, buildings made of SIP panels, panel and frame buildings.

Types of columnar foundation by depth

Depending on the geological characteristics of the building site and wall materials, columnar foundations are:

• buried - below the freezing mark, groundwater level, but may not reach the bearing layer;
• shallow - 40 - 70 cm below ground level;
• non-buried - instead of the removed fertile layer, non-metallic material is filled in, the underground part is absent.

The height of the pillars above the zero mark depends on the grillage design and the technological solutions used in the project. The head is embedded into a monolithic grillage at 20 cm, the beams of the prefabricated grillage are installed on top of the piles. Therefore, the height above the surface is always individual. The construction of buried pillars is justified if there is a bearing layer at this level. This type of shallow foundation is stabilized by soil against lateral shift. Non-buried has a minimal construction budget.

Columnar foundation design

The fundamental difference between columnar foundations and piles is the occurrence of the base, as a rule, above the freezing mark, the level of groundwater level, and layers with bearing capacity. Therefore, in any case, the support-column foundation is protected from heaving forces and movements in several ways:

• a sand cushion under the base slab; if the base of the foundation is located below the freezing depth, a sand cushion is not required;
• drainage of soil by drainage system;
• insulation of the blind area and basement.

For the last two activities, open excavation of the soil in the building area is required.

Even with a small depth of the pillar itself, you will have to take into account the thickness of the widening (20 - 40 cm slab) and the underlying layer (cushion of 20 cm sand + 20 cm crushed stone). In addition, you will need a ring ditch for laying drains and access for workers to the lower level. Therefore, the size of the well and trench increases several times; it is inconvenient to carry out work from the ground at depth.

Manufacturing columnar foundations by analogy with bored piles is a gross violation of technology. It is difficult to widen the sole; there are heaving forces underneath it. The side walls without backfilling with sand are subject to tangential forces of the same processes.

Thus, correct design columnar foundation looks like:

• preparation - sand (layer thickness 20-40 cm) with layer-by-layer compaction with a vibrating plate, pouring;
• footing - serves exclusively for laying waterproofing, is a 5 cm screed;
• stepped plate (sole) – distributes loads due to the increased surface of the sole;
• pillar - a vertical post made of monolithic or precast concrete;
• grillage - reinforced concrete products, monolithic structure, timber or rolled metal (channel, I-beam).

Unlike piles, pillars do not have spatial rigidity, so the grillage beams must not just rest on their heads, but must be attached to each pillar to be connected into a single structure.

Step by step instructions

Due to the variety of operations for constructing a grillage on pillars step by step instructions necessary for an individual developer as a benefit. If you skip any stage, you will have to redo the work later or return to it, spending more effort and money.

For example, the instructions recommend laying drains at the excavation stage. If you forget about them at the beginning and remember them when landscaping the area, the trenches will have to be dug again, construction will be delayed, and the site will again be clogged with soil. The height of the pillars is selected 20 cm above the bottom of the grillage for walling in concrete.

Below we will tell you how to make a columnar foundation with your own hands correctly.

Geological surveys and calculations

The technology for constructing a columnar foundation depends on the results of geotechnical surveys, wall material, and construction technology. For example, it is prohibited to leave unloaded poles in the winter even if they are tied with a grillage.

Prefabricated loads (the weight of the building, residents, furniture, belongings, wind, snow loads) may not be enough to compensate for the extrusion forces, or the building will gradually sink into unstable soil with excess weight.

Unlike the test screwing of screw piles in the technology of the same name to find the depth of the bearing layer, full-scale surveys are required here, costing at least 30 thousand rubles. The designer needs the following data:

• layered arrangement of layers;
• composition and characteristics of the three upper layers;
• GWL level;
• frost mark.

The cross-section of the pillars must be greater than 40 x 40 cm for concrete or brickwork, 20 x 20 cm or 20 cm in diameter for a monolithic reinforced structure.

Marking and excavation work

Unlike bored piles that reach the bearing strata, it is much more difficult to pour pillars into wells. The main problem will be the lack of sand filling in the sinuses:

• after a few years, the soil near the body of the pile will self-compact;
• will gain moisture and freeze in winter;
• heaving forces will pull the pillar out like a carrot from a garden bed;
• if there is a lower widening, the column will rise upward due to heaving forces, and soil will crumble under the base;
• the slab will not allow you to pull out the entire column, but it will no longer be able to get back into place.

We dig holes to widen the columnar foundation.

Therefore the only thing the right way There will be marking of trenches taking into account the width of the base, drainage contour, and work on the construction of formwork. Instead of a square shaft of 40 x 40 cm, you will have to remove much more soil, 1 x 1 m minimum. In this case, the thickness of all layers of the foundation pie and the height of the groundwater level are taken into account. If the last characteristic is slightly below a meter, you need to go deeper by 0.6 m, no more.

Preparation

By default, the construction of a monolithic foundation of a dwelling should provide protection from corrosion and destruction. In the absence of oxygen, the only aggressive environment underground remains moisture, which should be removed from the base with drains and stopped at the surface of concrete structures along the entire height with a waterproofing carpet.

Construction is carried out in stages:

• layer-by-layer backfilling - 20 cm of sand with moistening, vibration compaction twice (total height 40 cm);
• footing – screed height 5 cm, no reinforcement;
• waterproofing – 2-3-layer carpet of rolled material on a fiberglass base;

Reinforcement

The technology for constructing an armored belt for a column with an expanded base is as follows:

• knitting reinforcing mesh to the size of the slab, taking into account the side protective layers (40 mm from the formwork to the metal) with a cell of 15 x 15 cm or 20 x 20 cm with a thickness of 12 - 16 mm;
• joining to the mesh rods bent at right angles of 12 - 16 mm, protruding 20 - 30 cm above the base of the grillage (usually 4 pieces in the corners, one in the middle of each side);
• vertical rods are reinforced with horizontal square clamps made of 6–8 mm reinforcement;
• the structure is installed on a waterproofing carpet, which extends 10-15 cm beyond the dimensions of the sole, for subsequent bending onto the side edges of the sole.

It is prohibited to lift the reinforcement structure with metal scraps, bricks, or crushed stone to provide a protective layer.

Widening the pillar

The construction of the sole involves pouring the slab into the formwork. The widening area is twice the cross-section of the column, the height of all elements is a multiple of 30 cm. The formwork is simple - four boards fastened with screws, corners or bars at the bottom of the pit or trench.

Reinforcement of the widening and pillar.

The sides of the formwork should be slightly higher than the design level in order to properly level the concrete surface. The permissible error in the horizontal plane is 1 cm. Filling is carried out after installing the reinforcement structure.

Formwork

We install and strengthen the formwork for the columnar foundation.

Drainage and waterproofing

From the perimeter of the building it can be made at any stage, from foundation pit to backfill. To install drains, a circular trench with a uniform slope towards the underground tank is required. Dornite or geotextile is spread at the bottom, and 10 cm of crushed stone is backfilled. Perforated pipes in the filter are laid in it, and inspection wells are installed. After which, the communication is filled with another 10 cm of crushed stone and covered with the remains of geotextiles.

Waterproofing device - several technologies using different materials:

• impregnations - contain penetrating additives that change the molecular structure of concrete, making it waterproof throughout its entire depth;
• rolled materials - Bikrost, TechnoNIKOL and other fiberglass-based analogues, laid in two layers;
• coatings – epoxy and bitumen based mastics;
• paints – enamels based on bitumen resins.

Most often, combined methods are used to achieve a 50-70 year resource. Roll coating materials will have to be renewed every 15 years.

Ready-made columnar foundation with reinforced concrete grillage.

Backfill

After installing drainage and a continuous waterproofing layer over the concrete surface, it is necessary to protect the side surfaces from heaving forces. The sinuses are filled with sand; compaction is necessary, since loose soils are extremely unstable. The chernozem of the fertile layer is saturated with organic matter and settles after it rots. Other soils contain clay, which swells in cold weather. Therefore, exclusively non-metallic materials are used, in which there is less heaving.

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If a private house is made using frame technology or from light building materials, then the most optimal foundation support for it is pillars with reinforced concrete strip or steel grillage. Such a base exerts minimal pressure on the ground and is quite easy to implement independently. It is not difficult to make a columnar foundation correctly according to all standards with your own hands, and such a structure is relatively inexpensive.

What is a columnar foundation?

Columnar foundations are simply ideal for light buildings (garages, garden houses, sheds, bathhouses). However, with the correct calculations, frame or foam concrete cottages can be installed on them. But for a brick house with thick walls, it is better to look for another option.

But much in this matter depends on the total weight of the building. After all, slate or ceramic roofing is much heavier than roofing felt or light metal profiles. In the design of a columnar foundation and the entire house, it is necessary to take into account all materials used in construction - from the floor and walls to the roof. And you should trust only a qualified specialist to prepare calculations.

Structurally, such a foundation is a pile field of pillars made of various materials and tied at the top with a grillage. If the soil on the site is unstable, then building a foundation for the house in the form of a buried reinforced concrete monolith is not very rational. Columnar piles have a big advantage here in terms of low cost of work. With proper design, they are not afraid of high groundwater and soil heaving.

Types of columnar foundation

The pillars of the foundation under consideration using the technology of immersion in the ground can be hanging or retaining. In the first case, short supports are held in the ground due to frictional forces, and in the second, they are made longer so that the base rests on a solid soil layer. Due to the need to carry out complex calculations and driving a large number of piles, the hanging option is practically not used in private housing construction.

According to the structural location of the grillage, they are divided into:

Not buried - the grillage part hangs on poles above the ground at a height of up to half a meter;

Shallow - the grillage is immersed in the soil by 40–60 cm;

Recessed - with the laying of reinforced concrete tape on supports below the freezing depth of the soil at the construction site.

Shallow foundation diagram

The latter option provides little benefit in terms of saving on building materials. In the construction of country houses, such a foundation is used very rarely. Most often, for cottages, builders choose a non-buried grillage, hanging along the entire length on columnar supports. This technology eliminates problems with heaving and makes it possible to make a grillage structure from a steel channel, which greatly simplifies and speeds up the process of constructing a foundation.

Advantages and disadvantages of pillar foundations

The list of advantages of a columnar foundation is quite extensive, it includes:

No need for special lifting equipment;

Possibility of constructing a pile field on slopes;

High construction speed;

No need for preparatory leveling of the construction site;

Simplicity of technology, allowing you to do it yourself;

Excellent pole heaving resistance;

Cheap design.

If it is designed and done correctly at the construction stage, then it will quietly serve for more than half a century. He is not afraid of seasonal heaving of the soil, as long as the rise of the earth does not affect the grillage. And the technology of work is so simple that it is quite possible to do everything alone, without involving third-party highly professional and expensive installers.

Among the disadvantages of pillar foundations for houses outside the city are:

Low resistance of supports to lateral loads;

Restrictions on soils (you should not choose for swampy areas).

Limitations on load-bearing load (for heavy concrete or brick houses, such a foundation is not suitable by definition);

Impossibility of building a basement.

The main disadvantage of this type of pile-strip foundation is the possible destruction of supports under strong lateral influences. If the site has highly mobile soils in the horizontal plane, then the diameter of the piles will have to be greatly increased, which will affect the cost of construction. Or you may even need to select a different type of foundation for the house being built.

Cons - side loads

Instructions - how to build the foundation yourself

Columnar foundations are erected using technology in four stages:

Excavation work involves drilling holes for support pillars and placing sand cushions at the bottom.

Installation of permanent formwork for foundation supports followed by pouring concrete or laying them out of brick or concrete blocks.

The device for this type of pile-grillage foundation is an upper load-distributing part made of reinforced concrete, steel channel or wood.

Waterproofing the entire structure and covering the supports around the perimeter of the building with siding or corrugated sheets.

Everything is quite simple, but there are a number of nuances in this process. The first of them is that, regardless of the level of the grillage, the retaining piles of the columnar version of the foundation for a private low-rise building should be immersed below the freezing point. To speed up the work, in some cases it would be best to use specialized equipment with a drill.

The base supports themselves can be made of:

Filled in asbestos cement pipe reinforced concrete;

• FBS (factory-made reinforced concrete blocks for foundations);

  Natural stone.

Below is step-by-step photo instructions columnar foundation on foam blocks:

We transfer the foundation plan to the area - we mark future boundaries with pegs

Digging holes

Using a hydraulic level, we measure the zero level of the foundation - its height

We set the following levels of blocks of our foundation

We make all the other pillars according to the level

We lay roofing felt on the posts for waterproofing

It is also possible to use steel screw piles. But this will already be one of the variations of the pile-screw foundation. Previously, supports were even made from moisture-resistant larch. However, today most private developers prefer to install something more durable and concrete under their house.

The supports are placed at intervals of 1.5–2.5 meters so that they are located at the corners of the building, at the intersection points interior walls and laying load-bearing beams, as well as under stoves and fireplaces. These are the main load points. The grillage is quite capable of distributing some of them throughout the entire structure. But ideally, the main weight should fall precisely on the support piles on which the columnar-strip foundation rests.

When choosing a brick, you should immediately exclude the silicate variety. And ceramic should be taken with the highest possible frost resistance. In general, if you don’t want to mix and pour concrete, then it is best to choose FBS. These blocks were originally intended for the construction of foundations for various buildings.

By design, the concrete grillage on top of the pillars is a small strip foundation. A separate formwork is assembled for it with reinforcement made of 10–12 mm steel rods placed in it. After tying them together, the finished reinforcing belt will only need to be filled with concrete mortar with a grade of at least M-300. Moreover, for wooden buildings The grillage part is often made entirely from timber. In many cases, it is quite enough to redistribute loads.

To waterproof the elements of a columnar base, you can use roofing material or liquid bitumen mastic. Even soft tiles are suitable if they were left unused when covering the roof of an already constructed building.

Where is it better to use a pillar foundation?

It is not difficult to build a columnar foundation with a grillage on top of the supports yourself. The step-by-step instructions given above and the nuances of making such a support described above will help even a novice builder cope with the task. Everything is completed in just a few days. True, you will have to wait up to a month until the concrete in the grillage hardens, but there is no other way.

Example of a house

If you plan to build a lightweight structure, then making a similar foundation for it will be the most profitable in terms of cost and time of work. You can even prepare the project yourself. But it is better to order calculations for the foundation under a massive cottage from a professional.

If you know how to build a columnar foundation with your own hands, you can safely start building any building on your country plot, from a small greenhouse or gazebo to a huge wooden house.

Columnar foundation - features and varieties

When you plan to build a residential house made of wood, any outbuilding, bathhouse or garage, the question arises of what type of foundation to choose for them. Anyone wants to spend less money on such an event and at the same time get a truly reliable foundation for future construction. The best option in this case is to install a columnar foundation. It is the simplest to implement and relatively inexpensive.

The foundation we are interested in is suitable for another object that does not exert strong pressure on the ground and does not have basements.

It is not recommended to erect heavy concrete or brick structures on such a foundation.

The structure of this foundation is quite simple - a number of support pillars are placed on the ground in places where the main load will be directed upon completion of the construction of a house or other object. Such places include:

• piers;
• corners of the structure;
• sections of wall intersections;
• heavy load-bearing beams.

Columnar foundation It is allowed to make with your own hands from natural stone and wood, rubble concrete, brick, concrete, steel and asbestos pipes, bored piles. It can be prefabricated or monolithic. In the first case, the raw material for its construction is a “mixture” of stones, bricks and reinforced concrete blocks. The monolithic base is made of reinforced concrete, which ensures increased strength of the foundation.

Columnar structures are also usually divided into two types, taking into account the degree of freezing of the ground on which it is installed and the type of soil itself. From this point of view, the foundation is:

• Shallow - the pillars are mounted 0.4–0.7 m deep into the ground. Experts advise using such a foundation when constructing buildings on rocky or sandy soil.
• Recessed - laying of supports is carried out to a depth that is 0.5–1 m below the freezing mark of the soil in a particular area. Pouring and installing such a foundation is recommended for watery and clayey soils, where there is always a danger of the foundation being washed out.

Note that a columnar foundation is built with your own hands using the same technology. Next, we will look at how to make a columnar base yourself using various materials.

Preparing for arranging a columnar foundation - important tips

First, you need to decide on the type of soil that is available on your site where construction work is planned. After analyzing it, you can choose the type of base and installation depth of the support pillars (see above). For a light gazebo, it will be enough to deepen the foundation by 0.4–0.5 m and make it from wood or asbestos pipe products. But a relatively large wooden house will need to be placed on a deeper (about 1 m) and powerful foundation, for example, made of concrete.

After this, you need to calculate the number of pillars that will go to construct the foundation. They must be present in the center and at all corners of any building (even if, in your opinion, it is very small). You will be guaranteed a truly reliable foundation for the building if you place pillars every 2 m (vertically and horizontally) of the structure. The height of the supports is usually taken 0.3–0.5 m above the soil level. It can be increased when there is a possibility large quantity precipitation and flooding.

Next, we begin to clean the area of ​​land where the foundation is planned to be poured. We carry out these works as carefully as possible - we remove all unevenness in the ground, remove debris, add gravel to the clay soil. Then we create a point plan of the planned foundation and mark on it the locations of all the pillars.

You should also move 2 m away from the perimeter of the future building on four sides to mark the area from which you need to completely remove the surface earthen layer (20–30 centimeters). This is done to eliminate the danger of vegetation growing under the structure. And at the place chosen for construction, it is necessary to pour gravel or, after which you can start digging holes for installing the supports of the columnar foundation.

Formwork for the foundation - how to do it quickly and correctly?

The most common and economical is roofing felt formwork. This is what is most often installed on private farmsteads during the construction of various structures. It's done simply:

1. We take a piece of roofing felt of the required length (we focus on the length of the post, and also add a little length to the scraps according to the level) and twist it in two layers into a tube. It is best to wind the material onto a template, for example, onto a metal pipe (its cross-section should be about 20 cm).
2. We securely fasten the resulting twist with wide packing tape. Sometimes, before this, the roofing material blank is additionally wrapped with stretch film, which increases the amount of rigidity that the formwork will have.
3. We take out the template from the resulting tube. In fact, the roofing felt formwork is ready!

Instead of roofing felt, you can use glassine. The sequence of operations in this case will be similar to that described above. Also, formwork is often made from wooden panels consisting of boards 15 cm wide and 4 cm thick. It turns out to be reliable and of high quality, but its cost, of course, is much higher than a structure made from roofing felt. Permanent formwork can be made of asbestos-cement or steel pipes. Their diameter should be 10–20 cm.

After this, we begin the process of strengthening the columnar base. For reinforcement, you need to use reinforcement with a diameter of 1.2–1.4 cm. It must be installed longitudinally. The function of horizontal jumpers will be performed by metal wire.

If the foundation is made with a grillage (special slabs or beams - the supports of the future building), about 20 cm of reinforcing bars are left above the pillars. With their help, after pouring the concrete mixture, you can easily connect the grillage to the columnar supports.

We make a columnar foundation from asbestos or steel pipes - you can do it!

In this case, permanent formwork made from pipe products of a suitable cross-section is required. The construction of such a foundation is recommended for any buildings, including wooden houses. For the work, you will need pipes with a cross-section of about 200 mm or more if the building is heavily loaded (several floors, large area).

Step-by-step instructions for building a foundation are as follows:

1. We clear the site.
2. We prepare cylindrical pits in which we install a reinforcement cage or pipes and fill them with earth, ensuring the fixation of the supports.
3. We fill the pipe structures used with concrete solution to one third of their length. This procedure is mandatory; it creates the required hydraulic cushion for the base.
4. We raise the pipes to a third of the height and pour the concrete mixture again, leaving about 15 cm of empty space at the top.
5. We completely remove the pipes, and compact the concrete solution that remains in the hole and place a reinforced rod in its center.
6. We are waiting for the concrete to harden.

The connection between the base and the erected walls of the structure is carried out using metal anchors. They should be attached to the lower wall beams and immersed in the 15 cm cavity left. You have made a reliable and durable foundation out of pipes. All that is required is to finally concrete the structure.

Construction of a foundation made of concrete blocks and wood - instructions

For frame private houses, various gazebos in suburban areas, saunas and outbuildings, you can make a base from blocks. In this case, the support-column foundation is made with your own hands from concrete elements with geometric parameters of 20x20x40 cm.

The block base device includes the following stages:

1. Site preparation.
2. Digging holes, covering them with crushed stone and creating a sand cushion at the bottom.
3. Installation (using cement-based mortar) of concrete blocks.
4. Carrying out waterproofing measures (using ordinary roofing felt laid on the surface of concrete pillars).
5. Plastering the surface of the blocks.

Block foundations cannot be constructed on horizontally moving soils, water-saturated and peaty soils. It is also undesirable to place overly massive buildings and structures on them.

You can also do wooden foundation. But the service life of such a foundation will be objectively short. It can be increased by impregnating the wood with special antiseptic solutions. But even in this case, the foundation will last a maximum of a couple of decades.

For such a foundation, it would be correct to use coniferous wood or oak piles. The pillars are immersed in the soil by 0.5–1.5 m. The cross-section of the piles should be chosen larger - from 20 cm. Construction is carried out according to a simple scheme:

1. We clear the area for laying the foundation.
2. We dig holes. Their cross-section is taken to be 1.5 times the diameter of the wood supports used.
3. We install wooden poles at the corners of the planned building, along its perimeter (every 2 meters) and at the points of intersection of the walls of the structure.
4. Place a layer (15–20 cm) of sand on the bottom and compact it as thoroughly as possible.
5. We carry out waterproofing of the lower part of the wooden supports (impregnation with oil, “wrapping” in 2-3 layers of roofing felt or ordinary roofing felt, which it is advisable to glue with bitumen-based mastic).
6. We mount and align the pillars vertically (use a building level).
7. We fill the voids between the pit and the pillar with broken bricks, large crushed stone and sand. These materials should be poured in layers and compacted constantly. The thickness of each layer is at least 10 cm.
8. We level (now in height) the installed supports - we cut off their tops to achieve a completely horizontal plane. This procedure is easy to do if you stretch a cord over the posts.
9. We apply roofing material or a special waterproofing film to the ends of the columnar supports.

Your wooden foundation is ready! Feel free to install a wooden structure on it.

The secret to the popularity of a columnar foundation is that it is quite cheap and suitable for many types of buildings. It is quite easy to build a columnar foundation with your own hands.

This article tells you how to make a columnar foundation, the pros and cons of the foundation, which is better for a veranda, other wooden buildings or a house made of foam blocks.

More about columnar foundation

The basis of the house is the foundation, so you need to take the choice of its type very seriously. The pile foundation is one of the most popular.

Firstly, making a columnar foundation with your own hands is easier than any other type of foundation, and secondly, it is a less expensive option.

The support is made of concrete or wooden piles. They can be made of any material, depending on the weight of the house.

But you need to remember that the structure should not weigh very much, because the pile foundation is still not as strong as a monolithic or simple strip one. It is often built for wooden houses made of timber, since wood is a lightweight material.

This type may also be suitable for buildings made of foam blocks, but to a lesser extent, since this material is quite heavy.

But for a veranda and other small buildings, such a foundation is almost always suitable, you just need to check the type of soil - you cannot build a pile foundation on heaving soil.

Despite the fact that a pile foundation is suitable for almost all types of buildings, in some cases it is not recommended to use it.

For example, if the land on the site is very mobile and there is a lot of groundwater. It is still impossible to use these types of foundations if the total weight of the house is very large (if it is reinforced concrete).

If the site is located in a mountainous area, then the use of such a foundation is also impossible. A multi-storey building should not be built on such a foundation.

For all other types of buildings and soil, the construction of pile types of foundation is completely justified. It is especially good to use a pile foundation if a wooden building is planned.

When designing a building using a columnar base, the most important point is to determine the exact weight of the entire house (it includes furniture, residents, etc.) and the total load (pressure from the weight of the building, wind and snow).

It is also very important to know whether the support can withstand such pressure - then building a columnar foundation with your own hands will not be difficult. Calculation of a columnar foundation is a very important part of the design.

Pile foundations can be built from anything. For example, supports made of plastic pipes for sewerage are often used.

To build a columnar foundation with your own hands, step-by-step instructions are a necessary thing that it is advisable to have with you.

Conventional pile and support-column foundations

A simple pile type of foundation looks like several piles that stand in those places where the greatest load occurs (in the corners of the house, under load-bearing beams, etc.).

Columnar-type foundations are built for structures that do not have basements or cellars. This type of base is especially often made for wooden buildings made of timber. The supporting beams for such a foundation are laid on supports - piles or pillars.

The structure of such a base can be made of wood or stone. To build such a foundation for a house, use the butt part of a tree pillar (the part next to the root). Typically, the diameter of the butt part varies from 18 to 25 cm.

For verandas and houses made of timber, a wooden foundation is most often used.

In addition to the usual columnar foundation, there are several other types of foundations for a house. Among them, a monolithic pile base is distinguished.

Externally, it is a concrete base without seams. It is very durable, and this is its main advantage.

The second type is a prefabricated columnar base. It is built from stones, bricks and reinforced concrete blocks. The main advantage is that construction proceeds very quickly. But due to the not very reliable seams, this design is not particularly durable.

Columnar foundations differ not only in the principle of construction, but also in their depth. There is a shallow columnar foundation and a recessed one.

The first type involves deepening the supports from 40 to 70 cm. Typically, a shallow columnar foundation is made in an area with rocky or sandy soil.

At a recessed base, the supports go to a depth of 0.5 to 1 m, i.e. below the soil freezing zone. Often this type of foundation is made on clay soil, which has a lot of water.

There are other types of pile foundations, which will be discussed in more detail below.

The general construction technology is basically the same, as is the construction of a columnar foundation of any type.

One of the most popular types is the support-column foundation. Most often it is used for the construction of wooden houses from timber.

Its cost is quite low, so the support-column foundation is popular. Often, a support-column foundation is used to build a bathhouse or veranda.

The supports are installed at the corners of the building and under the walls into which windows and doors are built. The distance between the base pillars should be from 1.5 to 2 m.

If a bathhouse is being built, then a cushion of sand is formed, and then a support-column foundation is built directly on it.

The supports are dug into the ground, and then the next ones are attached to them to the desired height. The same method is used to construct wooden buildings from timber.

A columnar foundation is not suitable for a brick house. You can try to make such a foundation for a house from foam blocks, but you need to carefully calculate the columnar foundation so that the piles can withstand the load of the structure.

If the construction of a house is carried out from foam blocks, then everything needs to be calculated correctly so that the construction goes faster.

Sometimes a pile foundation is built from plastic pipes. It is usually made for external sewerage. Such a foundation is not suitable for a veranda or bathhouse.

Even though the supports are made of plastic pipes, they can last about 50 years.

In addition, they withstand frost well, and the base made of plastic pipes is quite strong, but at the same time light. The cost of plastic pipes can be different - gray ones are cheaper, orange ones are more expensive.

Features of a base made of pipes and with a grillage

A foundation with a grillage is often used for brick buildings. The advantages of this design are reliability and stability; such a base is less susceptible to any displacement.

In order for the base supports to hold better, a grillage is made between them (a sole that evenly transfers the load of the structure to the soil).

Quite often, a grillage is used for a shallow foundation.

There are low and high grillages. The first type is located above the soil level, and the second is done at some depth. However, both of these structures distribute the load of the structure well, so the house becomes stronger.

The most commonly used grillage is made of concrete or reinforced concrete. Wooden and metal grillages are used much less frequently and less often.

A foundation with a grillage is more suitable for foam blocks at home, since for this type of structure it is very important to correctly distribute the load. For a veranda this type will be too complex, although it depends on the type of structure.

Another popular type of foundation is a columnar foundation made of asbestos pipes. This type is one of the cheapest, like the columnar foundation.

The foundation using asbestos or steel pipes is erected using permanent formwork. This type of base is used for wooden houses made of timber. If you plan to have an attic in the house, then it is better to take asbestos pipes with a diameter of about 20 cm.

The technology for constructing such a base is not very complicated. To begin with, cylindrical holes are made in the ground, after which a frame of reinforcement and asbestos pipes are inserted into them.

Then you need to pour one-third of the concrete mass into the hole, during which a hydraulic cushion is obtained. At the same time, the concrete mixture is leveled (using vibrocompression) and its remains are poured.

On final stage buildings, it is necessary to treat the pipes with various solutions for waterproofing, since the pipe can retain moisture that gets on it for a very long time.

It is advisable to immediately place a load on such a foundation, otherwise the pipes may come out of the ground a little. This is not scary, but it’s still better to put the load on them right away so that you don’t have to level them later.

Such a base may be better suited for a foam block house. But first you need to make sure that the load will be optimal.

Otherwise, a house made of foam blocks may warp. But for wooden houses made of timber, such a foundation is more suitable, there are fewer risks. This base may also be suitable for a veranda.

Block foundation and strip base

The next type is a columnar foundation made of blocks. Making such a foundation with your own hands is not very difficult.

Most often, this type of foundation is used for wooden buildings - bathhouses, verandas or houses made of timber.

For a house made of foam blocks, this option may not be very suitable due to the fact that the supports are designed for small, lightweight buildings. But a columnar foundation made of blocks is much easier to build than a columnar foundation.

Most often, a columnar block foundation is made from reinforced concrete components. Such construction can be carried out very quickly, since the construction of the base is carried out according to the type of brickwork.

First, the area is properly prepared for construction, then a sand cushion is formed.

After this, waterproofing work is carried out so that the base does not deteriorate from water. Then the water supply is laid.

It should be remembered that this type of base is best secured with thick concrete mortar. Under no circumstances should it be diluted with water.

To make it stand even more firmly, you need to coat the seams that were formed during the construction process with a concrete solution.

It is especially good to make such a columnar foundation with your own hands for frame house. For a house made of timber, this type may also be suitable, but here you need to know all the possible disadvantages.

The next type is a column-and-strip foundation. This type is monolithic, most often it is used to build wooden houses.

To make a columnar strip foundation with your own hands, you use TISE technology (a special drilling rig for making wells).

To build a column-and-strip foundation, reinforcement is placed into the holes and then filled with concrete mortar.

The result is a pole that can withstand heavy loads (up to 15 tons). This type is called strip, because the construction technology is similar to the construction of a simple strip foundation.

Typically, wells are made 15 cm below the freezing area of ​​the ground. This type of construction may take longer than other types because drilling is a difficult process.

In addition, the ease of work also depends on the type of soil and what time of year the laying is carried out. In winter, such work is almost impossible to do.

Another disadvantage of this type is that the lower part of each hole will have to be further expanded in order for everything to be correct.

After the wells are ready, reinforcement is placed in them and concrete is poured. But not completely, but by one third, to insert a piece of roofing felt (tar paper jacket) for greater strength of the base. When the concrete solution dries a little, you can pour the rest.

The advantages of such a base are that the supports can withstand a load of more than 10 tons, and they also tolerate low temperatures.

After this, a grillage tape is made, it is reinforced and secured 15 cm above ground level.

In addition to these types of foundation, you can make a columnar brick foundation with your own hands. This type is not used often because it is expensive.

However, brick supports can last much longer than wooden ones. This type can be used for wooden buildings or buildings made of foam blocks. However, the structure should not have more than two floors.

A pile foundation with a shallow depth is also quite popular. Its use is most advisable on slightly heaving or non-heaving soil.

If the house is built on rocky ground, then it is better that it be made of timber. Verandas are also sometimes built using this type of foundation.

This option is not very suitable for a house made of foam blocks, but you can always consult with specialists to make the right choice.

The choice of foundation for a house or other building is influenced by many factors. For each specific case, a different foundation design can be used. In first place in terms of frequency of use is the strip structure; for unstable soils, a pile foundation is common. It is quite simple to build a columnar foundation with your own hands, which in some respects is not inferior to the listed foundation options. This design has its own variations and nuances in the bookmark. Each of these points will be discussed in the article.

Benefits of the solution

During the use of this type of foundation design, users and builders managed to compile a certain list of positive qualities that were identified. Among them are:

• possibility of independent design;
• relative simplicity of calculations;
• possibility of use on various types soils;
• Possibility of use in areas with level differences;
• the ability to avoid site planning;
• high construction speed;
• long service life;
• relatively low project cost.

Perhaps these nuances do not apply to all types of columnar foundation designs, but for a classic structure with a concrete grillage this is exactly the case. There are also disadvantages, of which there are significantly fewer. One of them is the impossibility of constructing heavy buildings whose walls are made of brick. The latter is capable of exerting significant pressure on the base, which often leads to destruction. This occurs due to shrinkage, although on an industrial scale this foundation design is used for brick buildings on soils with permafrost. Another unpleasant point is the inability to build a basement or garage directly under the house, since a foundation of this type does not provide for laying a monolithic structure to a great depth.

Pay attention! Columnar foundations are most often used for the construction of structures that use gas-filled blocks or are made using frame technology. Construction of buildings made of rounded logs is also allowed.

Types of designs

The design of a columnar foundation will largely depend on the specific building it will be used for. If we are talking about an ordinary gazebo, then its dimensions will be significantly smaller than those needed for a bathhouse or cottage. According to the material used, the types of columnar foundations can be divided into:

• monolithic with a concrete grillage;
• monolithic with a wooden grillage;
• brick;
• bud-filled;
• rubble concrete;
• wooden;
• monolithic from asbestos pipes;
• columnar-pile.

The first design option is the most durable. This is due to the fact that the pillars and grillage are a single structure that is capable of evenly distributing the load exerted on all pillars. This design is more expensive than others, but will last much longer. Such a columnar foundation allows the construction of houses of several floors using frame technology or from logs. The next version of a columnar foundation with a grillage is made using a similar technology. Its pillars are also flooded monolithic concrete with reinforcement, only they can be laid on them wooden beams, which are the basis for the walls of the structure.

Most often, when they talk about a columnar foundation, they mean the third design option, which is laid using bricks. Unlike previous options, a columnar brick foundation is quite simple to construct and requires relatively lower costs. With good soil quality, as well as the right approach to construction, a service life of several decades can be achieved. Many ancient buildings that have survived to this day were built precisely on this type of foundation. In some areas, it is possible to build a house with several floors on a foundation of this type.

Pay attention! Other types of blocks can be used as the basis for a brick foundation. In this case, the strength and stability of the base will depend entirely on the quality and strength of the material used.

A rubble-filled columnar foundation is laid using brick or stone from old structures. This solution is suitable for stable soils and for areas where there are no level differences, since the stability of such a foundation is significantly lower than that of previous options. The base of the structure made of rubble concrete is also built using the materials mentioned above, but the connecting link in this case is cement mortar. The result is a monolithic, but not reinforced structure.

The wooden base of the structure is now practically not used, but it still remains relevant for areas where it is necessary to raise the structure to a considerable height in order to avoid flooding. This applies to warm parts of the world. A similar method was used in other areas, but proper implementation requires special treatment of the wood to prevent rotting and drying out. A wooden columnar foundation is an excellent solution for additional buildings near the house. This applies, for example, to terraces. In addition to antiseptic impregnations, wood is also coated with waterproofing material. As the latter, bitumen mastics are often used.

Another interesting design option is a foundation made of asbestos pipes. Most often, it is manufactured using a solution similar to a monolithic columnar solution. In this case, the pipes act as formwork, into which reinforcement rods are inserted and concrete solution is poured. Usually a pipe with a diameter of 20 cm is used. A column-pile foundation is made using screw or other types of piles. In the first case, no special equipment will be needed to build the foundation, except for a concrete mixer. Screw piles can be installed in place by a small crew of three people.

The advantage of this solution is the greater stability of the structure base. This is due to the fact that the pile is immersed to a considerable depth, which passes the freezing level and reaches dense layers of soil, where fixation is carried out. The design with screw piles can be used for a log house or a frame house. If we are talking about bored piles, which are intertwined with a metal frame with a concrete grillage, then such a foundation is used when constructing houses from blocks.

Varieties by depth

The difference between foundations is made not only by the materials that are used to lay them, but also by the depth to which the foundation is mounted. To put it simply, then, as with strip foundations, there are two types:

• shallow;
• buried.

In the first case, the immersion is usually 50 or 80 cm, which somewhat reduces the cost of equipment for the base itself. This support structure is used for buildings that are light in weight. A recessed structure involves the use of supports that go 150 or 200 cm into the ground. This depends on the level of freezing. This design is more preferable for areas where there is heaving soil or high instability of the upper layers. In addition to the depth of the base, the height at which the grillage is located also varies. In this regard, the following are distinguished:

• aboveground;
• ground;
• buried.

Above-ground foundation design options are excellent for cases where the upper layers of the soil have a high degree of heaving. If the grillage is laid directly on the ground, there is a possibility of distortion or damage. In the case of constructing an above-ground version of the structure, the pillars are made of greater height in order to raise the grillage to a certain height. The disadvantage of this solution is the need for additional floor insulation. This is due to the free ventilation of the space under the house. Usually the sides are closed and only small openings are left for ventilation.

The ground version of the structure is built on a prepared bed of sand and gravel. It is placed so that it is flush with the surface. On the one hand, this eliminates strong blowing, as is the case with the above-ground version of the structure, but on the other hand, for such a structure there is a need for a correct approach to waterproofing. The shallow version of a columnar foundation is very similar to a similar strip foundation, but additionally, supporting elements in the form of pillars or piles are prepared in the trench, which are sunk to a considerable depth. The second and third options are most often implemented using a concrete grillage.

Basic Concepts

Almost all types of columnar foundations have one principle according to which they are constructed. Certain nuances are important to consider in order to achieve success. Among them:

• pillar pillow;
• heel support;
• column design;
• arrangement of columns;
• grillage device.

If we are not talking about pile supports, then preliminary backfilling must be done under the posts. For these purposes, medium-grained sand is usually used. The thickness of the pillow itself depends on the amount of moisture in the soil, as well as the expected weight. It can reach 30 cm, and the minimum permissible value is within 10 cm. If additional drainage is required, then an additional layer of crushed stone is laid under the columns, which allows water to pass through faster than sand. The functional purpose of such a pillow is to uniformly distribute pressure, as well as reduce the level of humidity under the posts.

For monolithic columns, which are made by pouring, soles are made, which are a small concrete slab with a thickness of up to 50 cm. It is wider and longer than the supporting column in order to increase the interaction area. The next nuance of such a foundation is the need for reinforcement. If we talk about monolithic foundation, then no questions arise regarding reinforcement, but this also applies to other options. Only in this case is external reinforcement carried out, which eliminates the deformation of the columns. To prevent moisture from rising to the grillage and the building, it is necessary to approach the issue of waterproofing correctly.

It is important to correctly determine the number of columns in the foundation and distribute them throughout the territory. This will determine how the load will be distributed. The projection of the posts above ground level will depend on the placement of the grillage, as well as the topography of the site. In some cases, owners of houses on columnar foundations prefer to make a fence. This is an additional concrete structure that is placed between the columns to cover the underground space. Reinforcement is also required for it. The fence for the columnar foundation further strengthens the entire structure.

Pay attention! In areas where flooding is possible, the height of the pillars can reach up to 2.5 meters above ground level. The calculation is based on the maximum level to which the water rose in the area.

Self-calculation

The key to successful completion of the construction of the structure is the calculation of the columnar foundation and preparation of the project. They begin even before the process of preparing and planning the site for the foundation. It is better if a professional in his field provides assistance in drawing up the project. Thanks to this, it will be possible to take into account all the nuances that relate to the soil and the expected load. The wishes of the customer himself are also taken into account. The main initial parameter for drawing up a design project is the area allocated for the building. The next important indicator is the mass of the structure. To correctly draw up all the documents, you will need a geodetic survey of the area and linking the future structure to a specific site.

During the design, the following points will also be taken into account:

• soil specifics;
• proximity of aquifers;
• soil freezing level;
• number of floors;
• materials for construction;
• possible additional loads.

The first and second factors will determine the required depth of columns or piles for the foundation structure, as well as their level above the ground. The third factor is necessary to determine below what depth the supporting elements of the foundation should be located. The number of floors affects the number of supporting elements, as well as the choice of material for construction. Additional loads that may be caused by wind, changes in soil or precipitation are taken into account. All these factors give a clear understanding of the number and parameters for the pillars of the future foundation.

With sufficient experience, you can try to perform the design work for the structure yourself. To do this, you will need to collect all the data relating to a specific area. They can be found on the official websites of various services or obtained directly from the services. When taking readings, knowledge of many formulas will be required. But even the use of online assistants may not help, since important factors that can only be assessed while staying at a specific site will be missed. If you turn to specialists who have already performed dozens of calculations for a specific region, you can be sure that they have a good knowledge of all the nuances of the soil in the area. In addition, professional services involve the issuance of specific documents that will be required when obtaining the necessary permits for construction.

Construction process

Each foundation design option has its own construction nuances, so it’s worth considering step-by-step instructions for several options. The first of these will be a monolithic columnar foundation.

Monolithic option

After drawing up the design design, it’s time for practical work. The first step is to prepare and mark out the area for a monolithic columnar foundation.

As you can see in the photo above, it is necessary to pre-mark the area where the structure will be located. To do this, the corners of the building are marked with pegs. A clearly visible rope or twine is stretched between the latter. Particular precision of angles is not required, since the marking of the structure is carried out for preliminary preparation of the area for construction.

The next step is to remove the top layer of soil along with the vegetation that is located on it. To make work easier, you can compact the area to make it easier to move around.

When the preliminary stage is completed, you can move on to more precise marking of the foundation structure. To do this, the corner pegs are placed exactly in their places, and the distance between them is checked. It is also necessary to determine whether the diagonals of the resulting figure of the future foundation structure are equal. If they do not match, then it is worth finding out which of the corners has the wrong angle and moving one or more columns.

In accordance with the developed project, markings are applied to the columns that will be installed later. For these purposes, additional stakes and ropes are used. The latter are stretched in places where the rows of columns will pass. The photo shows that the string, which is stretched in the middle, marks the edge of the pillars of the foundation structure. Simultaneously with this procedure, notes are made on where exactly the columns for the foundation will be located.

If you pay attention to the photo above, you can see that the master specifically marks the boundaries of the pit for the post. To do this, four pieces of reinforcement are driven in along its edges, which makes orientation easier during digging. You can start with it immediately after marking a specific element of the foundation structure. This can be done mechanically or manually. Everything will depend on the quality of the soil that exists in a particular area. A square heel with a side size of 40 cm is considered standard, but in certain cases it can be increased to 80 cm. It is this size plus the gap for the formwork that the foundation pit for the column should be.

The distance between individual pillars of the structure can vary from one to three meters. When the pit for the foundation column is ready, it is necessary to waterproof the lower part, where the heel of the supporting element will be poured. In the photo above you can see that for this purpose a polyethylene oilcloth is laid on the bottom. The density of the oilcloth should be 200 microns. It is located with a twist on the walls. Additional waterproofing and at the same time formwork for the structure is bikrost, roofing felt or similar material that does not have powder. Waterproofing can be fixed to the wall using nails or other fasteners. Subsequently, it will be pressed down by concrete. The height of such formwork should be equal to the height of the heel, which will be poured under the column.

The next step in constructing a columnar foundation structure is the preparation of reinforcing elements that will be poured with concrete. For these purposes, rods with ribs that have a diameter of 10 mm or more are used. It is necessary to calculate the elements in such a way that the heel is larger in size, and the vertical reinforcement corresponds to the post. The height of the reinforcement must be sufficient to combine the pillars with the monolithic foundation grillage, which will be poured later.

To make it easier to bend the reinforcement, you can make a similar device to the one shown in the photo above. For this, two metal corners are used, which are screwed to the wall. Moreover, their length is equal to the length of the element that will bend. The distance between the two strips is equal to the diameter of the reinforcement that is used for the foundation. To make it easier to bend the rods, you can use a metal pipe as a lever.

To make it easier to assemble the sheathing, stands are made, as shown in the photo above. A support is screwed to the vertical plane, in which notches are made at a distance from the reinforcement bars that will be embedded in the column. Additionally, a stand is made that can be rearranged depending on the length of the reinforcement. She can be seen on the right.

After this, the horizontal structural elements are distributed at an equal distance. To do this, use a tape measure or other device. The next step is to lay two more vertical posts, as seen in the photo above. To fix the structural modules together, it is necessary to use a binding wire that securely clamps them in place. For knitting, you can make a small hook yourself, which will simplify the task.

Reinforcement under the heel is performed separately and is represented by a small square in which rods are laid perpendicularly, as shown in the photo above. They are tied at all intersection points to ensure reliable fixation.

Next, preparation of the supporting supports of the structure is carried out, which will raise the reinforcement under the heel and under the column a short distance from the ground. This is necessary so that the element is filled with concrete mortar and from below.

The reinforcement for the heel structure is installed on plastic legs, and the reinforcement for the posts is fixed on top. All elements are tied together with knitting wire. So that it turns out as shown in the photo below.

Once the reinforcing elements for the columnar foundation structure are ready, formwork is manufactured for each column. An OBS board with a thickness of more than 12 mm is perfect for this. If you take a material with a smaller thickness, it will bend under the pressure of the concrete solution. To properly reinforce a columnar foundation, concrete must cover the mesh by at least 5 cm on each side. This means that the length and width must be 10 cm greater than the reinforcing elements. The height can be 5 cm greater.

To fasten the walls of the formwork under the posts together, hangers for a plasterboard profile are suitable. In this case, the middle part of the structure is cut out and only perforated strips remain, which are bent into the corners, as shown in the photo below. They are screwed to the walls and combine them into the required structure.

When all the elements are ready, they are assembled into a common structure, which will ensure high-quality pouring of the foundation.

In order for the OSB structure under the foundation columns to have a sufficient water-repellent effect and not to swell under the influence of moisture from the solution, it must be covered with cold-prepared bitumen mastic. This is done both externally and internally.

The next step is to install the armored belt under the foundation structure in the prepared pits.

The frame must be placed exactly in the middle of the prepared pit so that the concrete solution can freely and evenly fill the space around the structure. In addition, the structure must be exactly vertical and level. To achieve this, you can resort to the trick shown in the photo below.

A regular bubble level is used to ensure the structure is vertical. After this, the reinforcing base is tied to an additionally laid beam so that there is no displacement during pouring. The beam is fixed with weights in the form of bricks or other devices.

In this way, all elements that are responsible for the stability of the columnar foundation structure are installed.

Next, concrete is mixed for the foundation structure. The columns will be filled in stages. The first step is to fix the heel of the column under the foundation. It is enough to knead for each heel. The mortar for the foundation structure can be laid with a shovel. Its level will be equal to the height of the prepared waterproofing. To evenly distribute the concrete in the heel under the foundation, you will need an electric vibrator. It is lowered into the solution to fill any voids and remove air that could weaken the foundation post structure.

All that remains is to wait for the time during which the heel under the foundation column gains strength. As soon as this happens, you can begin installing the formwork for the column, which was prepared from OSB sheets. The formwork is placed in such a way that the reinforcement is located in the middle.

If you pour concrete into the formwork without fixing it, this will lead to displacement of the formwork and disruption of the foundation structure. Therefore, it is necessary to perform backfilling, which will fix the formwork under the foundation column. When performing backfill for the foundation structure, soil may get into the column form. To prevent this from happening, the upper part of the formwork structure under the foundation is covered with a thick film, as shown in the photo above.

Additionally, it is fixed to the formwork using a construction stapler so that the oilcloth does not move during work.

For backfilling, you can use the soil that was removed when digging pits for the foundation columns. It is carefully poured between the pit wall and the formwork under the foundation column. After this, compaction can be done using a hand tamper, which can be easily made from a log and a small handle-shaped crossbar.

To protect everyone who will move around the construction site, it is necessary to cover the protruding rods with plastic bottles. The latter are easy to find and will do the job perfectly.

To make the backfill dense, you can additionally compact it with water, which will allow the soil to sink under its own weight.

The protective film is removed from the formwork under the foundation column. There are small pebbles and other debris left at the bottom of the structure that may interfere with good adhesion. To eliminate this, you can remove them using a regular or industrial vacuum cleaner, the tube of which will be tied to a pole, as shown in the photo above.

Before pouring the next portion of concrete under the foundation, it is necessary to wet the heel under the foundation, as well as the formwork. This is done for better interaction between the components of the foundation structure. After this, you can fill the column into the prepared formwork. The solution must be compacted with a vibrator to eliminate the presence of air in the structure. To ensure that the foundation column does not lose too much moisture during the process of gaining strength, it is necessary to put an oilcloth on the foundation reinforcement, which prevents soil from getting inside the column.

After pouring the foundation columns, you can begin digging a trench between the foundation columns. In this case, a trench will be needed to construct a grillage for the foundation. Its depth is calculated in such a way as to accommodate a cushion of gravel and sand. The second in this case will be 30 cm, and the first will be sufficient at 15 cm. In this case, it is also necessary to decide at what level the foundation grillage will be located. If it is a little deep, then you need to go deeper to this level.

The first to be laid is a sand cushion under the foundation structure, which is well compacted. Next, the second cushion is backfilled under the foundation in the form of fine crushed stone. It also needs to be compacted well to ensure uniform distribution of the load from the foundation to the ground. For this, a gasoline or electric vibrator is used. It is best to work by placing it perpendicular to the trench under the foundation, so as not to collect rubble along the edges.

When the backfill for the foundation structure is ready, you can proceed to the construction of formwork for the columnar foundation. Wooden beams will be needed. The length of such a beam for foundation formwork should be such that it can be 45 cm immersed in the ground and protrude to the full height of the foundation grillage. To make it easier to hammer the timber into the ground, it must be sharpened from below with an axe, as shown in the photo.

After this, the element is leveled and driven in with a sledgehammer to the required depth. It is necessary to periodically check the level of the structure, as it may go astray. In addition, this will be the key to the correct installation of formwork under the foundation.

A board is nailed to the installed supports under the formwork. It is necessary to arrange the individual elements for the foundation formwork in such a way that there are no gaps between them.

The foundation formwork board will deform from exposure to moisture, so it must be protected. The easiest way to do this is to use plastic film. It is fixed to the boards using a construction stapler.

To strengthen the formwork structure, jibs are installed that rest against another rack. The elements are mounted through one rack. The free racks are connected to each other using knitting wire, as can be seen in the photo below.

Additionally, transverse elements are nailed on top of the structure, which tighten the walls of the foundation formwork together. It is first necessary to lay reinforcement inside, since this will be problematic later.

Pay attention! To reinforce the foundation, reinforcement with a diameter of 14 mm is used. In this case, the clamps can be made from rods with a diameter of 8 or 10 mm.

The reinforcement that remains protruding from the foundation columns must be bent to intertwine it with the reinforcement for the grillage. It is tied to the rods, which are laid in the formwork using a knitting wire.

When everything is ready, you can pour the foundation with concrete. This is easier to do with a concrete pump, which can be directed along the entire perimeter of the foundation. After pouring, the foundation grillage is processed with a vibrator and leveled with a trowel.

When the foundation has gained a sufficient measure of strength, the formwork can be dismantled and the foundation can be cleared of soil residues. You can clearly see the process of installing the structure of this foundation in the video below.

With brick pillars

This design option is constructed somewhat simpler than the previous one, but it is worth understanding that a columnar foundation made of blocks cannot be used for serious buildings. It is perfect for sheds or gazebos where the weight will be minimal. Marking for this type of foundation structure is carried out in a similar way as for the previous option.

The pits for the foundation columns are constructed with a small margin so that the support pad is slightly larger than the area required to support the blocks. Crushed stone is placed on the bottom of the prepared pit. Its layer can reach 20 cm. It is important to compact the material well. It not only ensures proper distribution of the load, but is also responsible for drainage, which will eliminate the impact of liquid on the laid blocks.

After laying the crushed stone, sand is poured. Its layer will be ten or more centimeters. It is important to compact it well and level it in a horizontal plane.

After this, you can proceed to laying the blocks. They are leveled and secured with cement mortar. The second row is laid out perpendicular to the first to ensure ligation of the seams for greater structural strength. Foundation waterproofing in the form of roofing felt is laid on top of the blocks. It is necessary to prevent moisture from entering the grillage, which can rot from it. It is most often used as a grillage for such foundation structures. wooden beam with a cross section of 15 cm. It is laid along the entire perimeter of the foundation.

At the intersections of the structure, weaving is done using a tenon joint. The photo shows that two beams can also be connected using the half method. In this case, in each of the elements for the foundation grillage, a cut is made to half the thickness and width of the log. After this, the two foundation elements are fixed to each other using a pin or a self-tapping screw with a hex head.

Pile option

The next option for foundation design, which can also be classified as columnar, is a pile foundation with a grillage. For independent construction of the structure, screw piles are suitable, which are easiest to install without additional equipment. Such a foundation is sufficiently reliable and allows it to be anchored in strong layers of soil. This is done quite simply, since piles for such a foundation can be selected in a wide variety of lengths. The only question will be the convenience of screwing them in. In some cases, additional platforms will be required when work begins. But most often such a foundation is installed without them.

The issue of marking for a foundation design based on screw piles at the initial stage is relative. This is due to the fact that during work you should push off from the first pile. Its installation for the foundation is determined by the plan, which indicates exactly how the house should be located on the site. It is necessary to choose any corner of the foundation from which it will be convenient to start work. This pile will be the starting point from which it will be easy to make the rest of the measurements for the foundation.

It will be easier to install the pile if you prepare a small pit for it. Typically, a depth of 30 cm is sufficient for these purposes. The diameter of the pit is made slightly larger than the diameter of the foundation pile. You can dig it out with a garden drill, if its diameter allows this, or with a regular shovel.

It will be easier to install such a foundation if you do not just screw in the pile using a lever that is inserted into the hole, but with a special device. You can rent a pile sleeve, as shown in the photo above. Thanks to the arcs that are located on the sides of the coupling, it is easier to transfer force from the lever, which is in any position. In this case, the immersion of the pile under the foundation proceeds smoothly. Rotating a pile under the foundation through a hole that is located on top is not always convenient, since there may be restrictions on the area of ​​movement around the pile.

As a lever that will be used to immerse the pile into the ground, one pipe will not be enough, since the direction of the force that will be applied with its help can change the position of the foundation pile, which is very inconvenient. To build the structure you will need at least two levers. The length of each is from three meters. In some cases, longer levers will be required to properly install the structure if the pile must lie quite deep.

To make installation of the structure easier, at least three people will be required. Two of them act on levers. The third person’s task at the initial stage is to keep the pile in a vertical position. As long as the main part of the pile is on the surface, there is no point in using a bubble level for the structure. This is due to the fact that the pile still has a significant amplitude of movement.

Pay attention! The wall thickness of the lever must be at least 3 mm in order to provide the required force for screwing in the pile.

Screwing occurs clockwise. This can be determined by the direction of the screw at the end of the pile structure. As you can see in the photo, the main load during screwing of the structure for the one who holds it in a vertical position falls not on the hands, but on the shoulder. Hands act as assistants, since it is almost impossible to grasp a pile of such diameter well. The emphasis is supported by half-bent legs with legs widely spaced.

As soon as most the structure of the pile will be in the ground, it is necessary to increase the force, since screwing in will be more difficult. To do this, the levers are extended to their maximum distance so that only a small part engages the coupling arcs.

As soon as it becomes clear that the pile has taken a good position and is firmly held by the soil, you can proceed to the precise vertical positioning of the structure. To do this, you will need a level that can be fixed to the body of the pile with a magnet. The photo shows that the level is located on the pile for a reason. It is placed perpendicular to the two support arms. This is the only way to correctly track the position of the pile. To make monitoring easier, you can use another level, which is installed directly under the lever.

When the level is in place, you need to position the structure in a slightly different way. If in the previous version the pile was held by the shoulders, now it must be leveled with the weight of the body, directing it in the opposite direction from the one in which the pile is tilting. Support is also provided on legs widely spaced and bent at the knees.

The deeper the pile goes, the more effort will have to be made to guide and rotate it. You may have to enlist the help of a few more people, as can be seen in the photo.

When the installation of the first element of the foundation structure is completed, it is necessary to determine the point at which the second corner pile will be located, which is in line with the first. It is best to take measurements at the centers of the circles. This means that the end of the tape measure is installed on the central part of the pipe. The distance to the center of the second pile for the foundation is measured. It will be equal to the total length or width of the house, from which the width of one wall is subtracted. Once the distance is determined, it is necessary to position the foundation piles on the same line. The easiest way for these purposes is to find a common landmark, for example, a fence, and place the foundation structure at the same distance from it.

The second pile is screwed in in the same way as the first. But now it is necessary to monitor not only the vertical level of the foundation pile, but also the distance at which it is located from the first pile. If in the process there is a need to adjust the position of the structure, then you should not act by simply tilting it in the intended direction. The photo shows that the pile must be tilted in the opposite direction to the one in which it is necessary to align the pile. After this, two turns of the pile are made under the foundation, and it is leveled to a vertical position. If this fails to achieve the desired effect, then the operation must be repeated.

When two piles are already in place, you can proceed to the installation of the third. The point of its installation is calculated somewhat more complicated than in the first and second cases. To install the third pile of a columnar foundation structure, you must be guided by the Pythagorean theorem. The width of the building is known, the length is also known, now you need to calculate the diagonal or hypotenuse of the right triangle. To do this, the thickness of the wall is subtracted from the width and length, since the measurement is taken at the centers, and each figure is squared. The sum of the resulting numbers will be the size of the diagonal. The photo shows that one of the ways to mark the third point of the foundation structure is to use two tape measures. At the intersection of the required values, the location of the third pile is located.

Pay attention! If you don’t have two long tape measures, then you can use twine on which the required size is marked.

After determining the location of the third pile under the columnar foundation, preliminary installation of the pile is carried out in the pit prepared for it. Once it is securely in place, it is necessary to re-measure to ensure that the foundation pile is in place. If there are certain errors, then it is necessary to level the foundation pile in the manner described above.

When the installation of the pile in place is completed, it is necessary to further secure it. To do this, the pit that was dug earlier is filled with soil. It is important to compact the latter well so that the upper part of the foundation pile does not become loose.

The fourth pile under the foundation is also mounted using the diagonal and wall dimensions. In this case, all the indicators are known, so you can use tape measures or twine and screw the pile into place under the foundation. Periodically, when screwing the pile into place, it is necessary to check whether the distances at which it should be in relation to other piles are maintained.

The support of the entire structure is ready, now it will be easier to install the remaining piles under the foundation. For these purposes, a string is stretched between all risers. It must be located as close to the ground as possible. It will be easier to operate if two strings are pulled between the foundation piles, which will mark the corridor in which the piles should be located. Each wall is divided into two halves. The resulting size is marked on a stretched string and a pit is dug under it for the pile of the future foundation. This must be done on all four sides of the house.

During screwing, it is necessary to ensure that the marked point is at the center of the pile pipe. All foundation piles are immersed to the required level.

Foundation piles will also be required for interior walls. To mark them, you can use the intersection points between the lines of existing piles. To do this, ropes are stretched between the piles, which are clearly visible. At the intersection points, where necessary, a pit is prepared and the pile is screwed in. At the same time, it should be positioned in such a way as not to strain the rope or deflect it. It is important to monitor the level of the foundation pile throughout the entire screwing process.

The pile should be located at the intersection of the stretched ropes as shown in the photo above. The ropes are tangential, so the center of the foundation pile does not coincide with the center of the pile that will be screwed in.

Once all the piles are in place, it is necessary to trim them horizontally. This will allow you to correctly position the foundation even on an inclined area. For this purpose, you can use two tools. One of them is a laser level. It's easier to use. It is enough to position the beam at the required height and project it onto the body of the piles. After that, markings are applied to the foundation piles and trimming is done with a grinder.

Another option is to use a water level. Before use, it must be well aligned to avoid any bends. Next, the container containing water for the hydraulic level is installed on one of the piles. One of the craftsmen lowers part of the tube into a container, and the second creates a vacuum so that water under its own pressure begins to fill the tube.

Next, the functionality of the hydraulic level is checked. Its two ends are connected together and a certain time is waited. After this, the liquid in the two pipes should reach the same common level. If this happens, then you can proceed to the process of measuring the height for the foundation piles. If not, then you should carefully examine it and identify kinks or places where airing has occurred.

Pay attention! The longer the hydraulic level, the more time it takes for the liquid inside it to calm down.

On one of the corner piles of the foundation, a point is drawn where all foundation piles should be located. One part of the hydraulic level is applied to it, and the second is brought to the next corner pile. Once the water level has calmed down, you can make a mark on the pile to guide the cutting. This way the mark is transferred to all corner piles of the foundation.

To mark a line over the entire area of ​​the foundation pile, it is necessary to make a pattern from a plastic pipe, which will be cut on one side for ease of installation on the pipe. Using a marker, draw a circle.

To transfer the marking line to the remaining piles, which are located in the middle of the foundation structure, it is necessary to pull a strong fishing line along the marks on the outer piles. It will be the indicator of the required line. After this, marking is carried out with a marker at the selected point. Using the prepared pattern, a line is drawn over the entire area of ​​the piles.

Once the marking of the piles for the foundation is completed, you can proceed to cutting all the elements along the drawn lines.

The next step is to fill the installed screw piles for the foundation. This is not done with concrete, but with an ordinary cement-sand mortar in a ratio of three to one. The solution must be liquid enough to fill the pile cavity. The purpose of this procedure is not to impart additional rigidity to the foundation, but to prevent the exposure of the internal walls of the pile to oxygen, which could lead to corrosion and destruction of the foundation. Filling is not done to the very top. It is necessary to leave a gap of 10 cm. It is filled with a dry mixture, which can be purchased ready-made.

The next step is to install the head on the pile. It must be located on a horizontal surface. The purpose of the head is to hold the grillage on which the walls will be fixed. The head is welded to the pile so that the fixation is as reliable as possible.

Welding seams are cleaned and coated with paint, which will protect them from corrosion. A video of the complete process of constructing this type of foundation is below.

Resume

As you can see, a columnar foundation is a fairly common design. It is an indispensable option when it is planned to build a small lightweight building. The last one can be a rounded log or frame. When laying the foundation, it is important to take into account all the features of the soil, as well as other parameters that were discussed in the article.