Strip foundation for a frame house. Do-it-yourself columnar foundation for a frame house - secrets of technology Columnar foundation on monolithic reinforced concrete supports

Often replaces the purchase of an apartment. These types of housing are almost the same in cost, but in the case of building a frame cottage, the budget can be saved significantly. All work on the construction of the structure - from the base to the roof - can be done independently, knowing the technology. Building a foundation for a frame house with your own hands is not difficult even for a person who has not previously dealt with such matters. In this article we will look at the types, methods of construction and the advisability of using one or another type of foundation for each case.

What is a frame cottage?

The technology for building modern lightweight houses came to us from America. Another name for them is Canadian. In these countries, most suburban buildings are made using this technology, which is fully justified: the home is warm, reliable, lasts for many years, is cheap, and can be built quickly. In Russia, such objects appeared relatively recently (about 15 years ago), but are actively gaining popularity due to their qualities.

The technology for constructing frames is as follows:

Thus, the construction of the walls is very light. Which foundation is better for a frame house? Definitely not powerful, it is not necessary. This allows you to save not only construction time, but also money on materials and labor.

Is there a single solution?

There is no exact answer to the question of which foundation is best for a frame house. There are many types of lightweight structures, the use of which is optimal in a particular case. The basis can be:

  • pile;
  • tape;
  • columnar;
  • shallow;
  • slab.

Different materials are used for the foundation:

  • concrete;
  • reinforced concrete;
  • tree.

Thus, there may be several options for constructing a foundation for a house. The choice is influenced by:

  • house size;
  • number of storeys;
  • soil freezing depth;
  • availability of groundwater;
  • soil type: mobile, wet, viscous, hard;
  • presence/absence of a basement.

The best foundation for a frame house is one that takes into account all the nuances of construction and geological conditions. A properly selected base will last a long time and help save time and money.

Determining the characteristics of the base

The first step is to determine the type of soil at the proposed construction site. The best way to do this is to order geotechnical surveys. Experts will determine:

  • the exact type of soil and its characteristics;
  • availability of groundwater and its nature;
  • They will draw up a site plan taking into account elevation changes and terrain features.

True, such pleasure is expensive and takes a lot of time. Another option is to find a neighbor in the area who has already applied for such a service and has the results of an examination of his territory. As a rule, soil characteristics in one area have the same properties.

If there is no neighbor with a conclusion, you can try to determine the type of soil yourself. To do this, follow these steps:


  • Rocky soils consist of rocky and gravel bases. They are strong enough, able to withstand any weight, and do not retain water (provided they do not contain a large amount of clay).
  • Coarse sands and cartilaginous soils are also characterized by a low degree of heaving and a strong foundation.
  • Fine sandy soils are not the best option for construction. They retain water, which solidifies in the upper layers and acts on the foundation by pushing and compressing. This property is called heaving.

  • Loams and clay are the most unfavorable type of soil. Their mobility and buoyancy depends on the height of groundwater. But even in their absence, there is often enough moisture from precipitation. In areas with such soils, large puddles form because water drains into the ground very slowly.

The type and depth of the foundation for a lightweight frame house depends on the geological conditions of the area.

We take into account the depth of freezing

This aspect is relevant for soils subject to heaving. Rocks that do not retain water serve as a solid foundation in any season, unlike fine sandy and clay soils. If the latter are present, the depth of the foundation should be greater than the freezing value, then it will be able to firmly fix the building in one place and position. This is necessary to prevent uneven subsidence of the structure, which can lead to damage to the integrity of the house, its destruction or large investments in repairs.

It is also important to find out about the presence of groundwater. If they are present, you need to look for a way to deal with them or equip the structure in such a way that it is able to withstand a humid environment and conditions of severe heaving. The depth of soil freezing is not included in the calculations of a pile foundation.

Deciding on the design

Based on the work done to determine the type of soil and the depth of its freezing, you can decide which foundation design for a frame house is optimal in a given location.

  1. On clay soils and fine sandy soils, a pile foundation is installed. It fixes the structure in durable layers below the groundwater level.
  2. Shallow slab foundations work well on heavily heaving loams and silty rocks. They play the role of a “boat”, capable of staying afloat and holding the house in one plane over the entire area of ​​the structure.
  3. Rocky, coarse sandy, gristly soils themselves serve as a solid foundation, and therefore do not require a solid foundation - strip, shallow and columnar will be sufficient.

In the presence of groundwater, special types of waterproof concrete are chosen and additional waterproofing of the foundation walls is used. If the GWL is high, you should abandon the basement. In addition, it is advisable to install a drainage system throughout the site or directly near the house: a trench is dug along the perimeter, through which excess liquid drains in a given direction.

Pile-grillage foundation

This is a widespread type, universal in use. Since Russia is not rich in hard rocks, heaving soils of varying degrees of freezing predominate over most of the territory; pile foundations are used for the construction of buildings for various purposes and number of storeys. The pillars penetrate deep into the soil and are fixed with their lower ends in dense layers. Due to this, the structure resting on them is securely fixed relative to the ground surface.

To build a pile foundation for a frame house with your own hands, you first need to calculate the number of pillars for the structure. To do this you need:

  1. Look into the project, if there is one. If it is not there, see further.
  2. Draw the perimeter of the future house on paper to scale. Mark the installation locations of the piles with dots (in all corners, where walls meet, along the perimeter in increments of 1.5-2 meters). Since a frame house is light in weight, reinforcement of the structure will most likely not be required, so a simple arrangement will suffice.
  3. Count the number of marked points.

The next step will be to decide which piles to use: ready-made reinforced concrete or screw products from the factory or poured into ready-made wells on your own site.

  1. The finished pillars are buried using a special installation. They are hammered to the required level in the designated places, then the remaining ends are cut off to the level. For a lightweight building, it is enough to buy piles with a minimum cross-section.
  2. Screw metal supports are tightened with a special device.
  3. If a decision is made to construct piles independently, then first wells are drilled, the bases of which must be made wider for stability. The depth depends on the geological conditions of the area. You need to get to solid ground. Then a waterproofing material is installed into the cavity, for example, a hollow pipe or twisted roofing felt. After this, the frame is laid and concrete is poured. It is optimal to use a solution of the M300-M400 brand. It would be good if it contains special additives that give the stone water-resistant properties.

The piles are installed, now you need to arrange a grillage. In the future, the wall frame will rest on it.

The grillage can be prefabricated or monolithic. The difference lies in the installation method:

  1. The prefabricated one is mounted on reinforced concrete piles topped with a cap.
  2. Monolithic is installed at the construction site: formwork is installed, if necessary, a cushion of ASG is laid at the bottom of the grillage, waterproofed with roofing felt and a finished frame is installed, which is connected to the reinforcement of the pile pillars. After this, the concrete mixture is poured.

The foundation is ready. It is worth noting that this design does not imply the presence of a basement.

Columnar foundation

Optimal for flat terrain in relatively stable soils. Similar to pile, but less buried.

You can build a columnar foundation for a frame house with your own hands using the following technology:


A grillage is arranged on the finished pillars. This is done according to the same principle as in a pile foundation. It may not be there, then a wooden beam is laid on the tops of the racks, which will serve as a support for the frame.

The final stage is the installation of a wall that fills the space between the pillars. A trench 20-30 cm deep is dug between them, the base is filled with concrete, and after it hardens, a wall is laid out. If this is not done, then the lower ceiling will require additional insulation so that the floor in the house is not cold.

It’s not at all difficult to make a columnar foundation for a frame house with your own hands. It is important to remember that building a basement with such a design is a very problematic task, so this idea should be abandoned. On the other hand, the foundation is built quickly and is much cheaper than a pile or strip foundation.

Wooden foundation

A kind of hybrid of pile and column. A wooden foundation is suitable for building a small frame house, but due to its comparative fragility, it is rarely used for residential cottages. It is optimal for country houses: the impact of minimal loads on the base, low cost of installation and material, high speed of the device. In addition, the tree has natural elasticity, which allows it to regain its original shape after minor deformations from soil heaving.

The lightest designs have seasonal frame-panel houses. The foundation for them can be very simple. It is in such cases that they are used. Although in Venice high-rise buildings stand on such foundations for hundreds of years, therefore one can argue about durability in this case.

Certain types of wood are suitable for piles: beech, larch, oak, pine. Sections of wood with a diameter of at least 20 cm are suitable for blanks. The product can remain round or acquire a rectangular cross-section with a side of 20 cm. Piles are treated with special solutions that prolong the life of wood in unfavorable conditions. Before directly burying them, you should wrap the post with 1-2 layers of roofing material or other polymer material, then the soil will not stick to the product. This will allow the pile to slide relative to the base in a vertical direction when the soil is heaving, and will also preserve it for a longer period.

How to mount a wooden foundation for a frame house with your own hands:

  1. Markings are made according to the already known scheme: corners - intersections - perimeter in increments of 1.5-2 meters.
  2. Transfer the location of the pillars to the site.
  3. Holes are dug in the ground with a diameter 1.5 times larger than the pile. The depth must exceed the soil freezing level and reach dense layers. If they are not available, the pole should be placed 0.5 m below the level.
  4. Make a pillow of stones or a wooden cross.
  5. Pour 15-20 cm of concrete mixture and immerse the pillars in it. When the solution sets, it will fix the pile.
  6. The soil is backfilled and compacted.

Lightweight strip foundation

Widely used among developers due to its low cost and high installation speed. A lightweight strip foundation for a frame house is used on solid foundations, where there is no need for large depths and massive support.

The main difference between this design and the usual one is the reduced depth of the sole and the dimensions of the tape itself. This is acceptable for lightweight structures, in particular for residential frame houses.

Installation technology:


A lightweight foundation for a frame house is convenient because it does not require special preparation and installation of additional structures for the construction of walls.

Plate

Soils are not always conducive to standard construction solutions. There are many areas in Russia with clayey and highly heaving soils. But this is not a reason for them to be empty. Even for such cases, there are solutions.

If you happen to purchase a plot of land with floating soil, it is advisable for construction to arrange a slab monolithic foundation for a frame house. It is quite possible to do this with your own hands. The technology is similar to creating a lightweight tape:


The monolithic slab is located at ground level, and also involves the construction of a basement (it serves as the floor). A more massive and recessed one is not needed for a small house; this type is used for large buildings.

Insulation and waterproofing

The foundations of a wooden frame house require special finishing. Waterproofing is desirable for all structures below grade for any material. This way the elements are better preserved. This is especially true when the groundwater level is high.

Thermal insulation of the foundation and basement walls will ensure minimal costs for insulating the floor of the first floor. In those houses where there is no basement, the space between the ceiling and the ground can be filled with expanded clay and sand. These materials prevent heat from being drawn out from the lower room. To prevent them from getting wet, you can line them with a roofing felt sheet on both sides.

The walls of the strip foundation and grillage are laid on the outside

columnar foundation for a frame house calculation - columnar foundation for a frame house calculation

In connection with the planned construction of a frame house in the village (to replace an old log hut), I thought about the choice and calculation of the foundation. After quite a long search on the Internet, it was decided to go with a columnar foundation. The only thing left to do is to calculate the loads and refine the foundation design based on these loads.

Columnar foundation- this is a foundation of several pillars buried in the ground in a certain order and connected into a single frame by means of wooden, metal strapping or a reinforced concrete grillage.

Columnar foundations are used mainly for the construction of wooden or frame houses with a height of no more than 2 floors, bathhouses, and outbuildings, the specific gravity of which does not exceed 1000 kg/m³. It is not practical to build heavier houses on such foundations due to the relatively low strength of the pillars and the insufficiently large total area of ​​the base.

Although a columnar foundation is the cheapest, if it is designed correctly it will also be a reliable support.

Advantages of a columnar foundation:

  1. saving money and labor costs by reducing the volume of excavation and concrete work;
  2. high speed of construction of the zero cycle.

The main disadvantage of a columnar foundation:

  1. unpredictable behavior of individual foundation pillars with a frivolous attitude of the developer to the study of soil properties on the site (especially for foundations without a monolithic grillage).

Differences between a columnar foundation and a strip foundation:

  1. suitable for lightweight buildings (wooden buildings without a basement, columns, etc.);
  2. is a series of supports located at the most loaded points.

Types of columnar foundation:

  1. by design features:
    • monolithic, which has great strength, because made of reinforced concrete.
    • prefabricated, which consists of individual elements, and therefore has weak points at the seams (joints).
  2. according to the depth of the base:
    • buried - placed below the freezing level, required on clay soils.
    • shallow - made at a depth of up to 700 mm, suitable for sandy or rocky soils.

Calculation of the columnar foundation of a frame house

Initial parameters for calculating a columnar foundation:

  1. soil type and elevation difference at the site of future construction;
  2. depth of groundwater;
  3. soil freezing level;
  4. house design (location of load-bearing and internal walls).

The most important contraindication for choosing a columnar foundation is the high groundwater level. It should not be allowed to come closer than 50 cm to the bottom of the pillars. In addition, the pillars must be laid deeper than a layer of fertile unstable organic soil.

First, it is necessary to examine the soil at the site of future construction. This is discussed in detail in the article at the link http://moi-domostroi.ru. Remember: having decided to build a columnar foundation, it is imperative to do test drilling 0.5-0.6 meters below the expected depth of the pillars to identify water-saturated soft soils (quicksands).

After examining the soil, it is necessary to determine the load that the house and its foundation will exert on the load-bearing soil, in other words, calculating the weight of the house. The approximate weight of the future building is estimated (there is no point in calculating the exact weight, but when calculating, try to take into account the loads due to household utensils), after which the type of columnar foundation is selected. If in doubt, it is better to take a more durable option.

Approximate specific gravity values ​​for individual structural elements

Notes:

1) When the roof slope angle is greater than 60º, the snow load is assumed to be zero.

2) When calculating the foundation, the approximate weight of the foundation itself is added to the weight of the house. Its approximate volume is calculated and multiplied by the specific gravity of reinforced concrete equal to 2500 kg/m³.

Source: http://moi-domostroi.ru/stolbchatyi-fundament/

After determining the weight of the house, we calculate the minimum required total area (S) of the bases of all foundation pillars:

S = 1.3×P/Ro,

where 1.3 is the safety factor;

P - total weight of the house including the foundation, kg;

Ro - design resistance of load-bearing soil, kg/cm².

Rо value

The Ro value, also called the bearing capacity of the soil, can be taken approximately from the table below:

Note:

The calculated resistance values ​​are given for soils located at a depth of about 1.5 meters. At the surface, the bearing capacity is almost one and a half times lower.

Having calculated the value of the total area of ​​the bases of all pillars, we can now determine their required number depending on the diameter or cross-sectional dimensions.

Calculation of a columnar shallow foundation on supporting soles for my frame house

So, the frame house with an attic that I designed has dimensions of 8 by 8 m, the ceiling height of the 1st floor is 2.5 m, the roof area is 108 m2, the walls are 200 mm thick with foam or mineral wool insulation (the final decision has not yet been made).

To calculate the load, I will take the following parameters for the mass of 1 m2 of structures:

  1. basement floor 75 kg;
  2. attic 75 kg;
  3. walls 70 kg;
  4. roofing 30 kg;
  5. payload of premises (furniture and people) 210 kg;
  6. foundation 2500 kg/m 3 ;

When calculating the mass of the walls, I summed up the area of ​​all walls, including internal partitions, obtaining the following result: the area of ​​the walls of the first floor is 121.5 m2, the area of ​​the internal walls of the attic is 41.5 m2. Thus, the mass of all the walls of the house is equal to (121.5 + 41.5) * 70 = 11,410 kg.

Floor area (ground and first floor): 8 * 8 = 64 m2. Weight of floors 64*2*75 = 9,600 kg.

Payload of premises: 64 * 210 = 13,440 kg.

Weight of the attic floor (attic with insulation): 108 * 200 = 21,600 kg.

Snow load mass (under worst conditions): 108 * 190 = 20,520 kg.

The total weight of the house is approximately 77 tons.

Foundation weight (22 supports): 4 m 3 * 2500 = 10,000 kg.

In total, the weight of the house with the foundation is about 87 tons.

Since according to the project I plan to install 22 pillars, I now need to determine the required area of ​​their base (soil: 50 cm fertile layer, then sandy loam, groundwater located below 2 m).

The minimum required total area (S) of the bases of all foundation pillars:

S = 1.3×P/Ro,

S = 1.3 * 87,000 (kg) / 3.5 = 32,314 cm 2

Now we find the required area of ​​one support: 32,314 / 22 = 1,468 cm 2, which corresponds to a square with sides of 38 cm.

If we take the support size as 0.6 m x 0.6 m (base area 3600 cm 2 or 0.36 m 2), then the total base area of ​​all supports will be equal to 7.92 m 2, and the load on the ground will be no more than 1.3 * 87,000/79,200 = 1.42 kg/cm 2 , which provides the necessary load-bearing capacity of the foundation (after all, under the soles of the supports at my foundation there will be bulk soil with compaction, i.e. R 0 should be no more than 1.5 kg/cm 2).

Construction of a columnar foundation

Tools that will be needed when constructing a columnar foundation:

  1. Shovel.
  2. Formwork.
  3. Roulette.
  4. Ruberoid.
  5. Geotextile with a density of 200 g/m2.
  6. Reinforcing frame.

Marking a columnar foundation

Due to the fact that I am going to build a columnar shallow foundation (and the design of this type of foundation assumes that its depth will not exceed 80 cm), the technology will be as follows:

  1. The fertile layer of soil is removed at the construction site;
  2. According to the project, holes measuring 0.6 x 0.6 m and 55-60 cm deep are dug in the mineral soil in the places where the supports are located;
  3. the pits are covered with geotextile 200 g/m2 and filled with crushed stone 5-20 in a layer of 25-30 cm, which is compacted, then the geotextile must be wrapped and a layer of roofing felt placed on top;
  4. tie a reinforcing frame for the soles from 12mm reinforcement, lay it on the bottom of the holes (the reinforcement bars should not come into contact with the ground), ensure that the ends are brought upward (up to 15 cm) for connection with the reinforcement of the pillars;
  5. fill the bases of the pillars (in my case, the formwork will be the walls of the pits).

For the formwork of the pillars themselves, I will use old boards and plywood left over after dismantling the old building), although some suggest using a free-flow asbestos cement pipe with a diameter of 300 mm. Reinforcement of pillars - 12 mm reinforcement.

Do-it-yourself construction of frame houses is a fairly high-quality and, most often, inexpensive way to build a separate apartment building and your own house. The construction of any frame house begins with the sequential pouring of the foundation or the installation of special supports that form a columnar foundation. The question is often asked about how to make a columnar foundation with your own hands. Why columnar construction is increasingly being chosen in individual and multi-apartment construction - let’s try to figure it out.

Characteristics of a columnar foundation

A columnar foundation for a frame house is made of successive load-bearing pillars, which are placed under the walls of the frame house. The supports of a columnar foundation are usually placed along the entire perimeter of the walls according to the construction project, and will be mounted on them.

Columnar foundation made of polystyrene foam blocks.

A foundation using columnar supports is necessary where the greatest load is expected on the elements of a frame house, at the junction of wall slabs, in the corners of a frame house and where spans will reach a height of 2.5 m.

On a note

The distance between the supporting pillars and their size will directly depend on the complexity of the structure and the weight of the frame house. The weight of the materials used during construction affects this type of foundation.

Parameters of a columnar foundation

  • If you decide to make a columnar foundation with your own hands for a frame house, then the optimal distance between the two supports will be from 0.5 to 1.5 m.
  • Columnar supports of a frame house are installed in dimensions of 250x400x200-400 mm for rectangular shapes and 150-300 mm for round supports.
  • The distance above the ground should be no more than 500 mm.
  • The columnar foundation of a house with your own hands can easily lie at different depths - depending on the soil on which the frame house is being installed, the number of floors and the complexity of the frame structure being built.

A columnar foundation for a frame house can be placed in a single horizontal area, which will ensure the most optimal installation of the crowns of the lower frame of the house and create a solid structure.

DIY columnar foundation

Why is it most profitable during construction work to build a columnar foundation for a frame house with your own hands?

  • Firstly, unlike strip or grillage type foundations, it dries much faster and gives a lower percentage of shrinkage.
  • Secondly, it is not inferior in cost, and even outperforms other types of foundations. In addition, if you make a columnar foundation with your own hands, you can avoid significant costs for heavy equipment or expensive construction crews and payments for their activities.
  • Third, foundation supports can not be erected simultaneously, but in order of priority.

Do-it-yourself columnar foundation made of pipes.

You can build a columnar foundation made of pipes with your own hands, regardless of the time of year. It is also possible to partially replace or repair the support when the house is ready, as well as to strengthen one or more supports additionally.

Materials for columnar foundation

Before starting construction, it is necessary to familiarize yourself with the technical characteristics of the future frame house, as well as study the soils that are present at the construction site. The materials chosen for construction work will differ from this. Materials for a columnar foundation will vary in shape, cross-sectional size of the pillars, as well as the depth of the supports in the ground.

Let's look at the main types of material that are selected for making a pillar foundation:

  1. Reinforced concrete - the pillars of such a foundation are poured into pre-fabricated wooden formwork of rectangular cross-section. Additional strength of the foundation is provided by steel bonded reinforcement installed in concrete pillars. Which can be ordered on the website ukazs.rf
  2. Rubble and rubble concrete are stones of natural origin that have both an irregular shape and two conditionally parallel sides. Load-bearing resistance can be ensured by proper selection of materials and connections between stones, correct design of pillar connections and strict adherence to instructions for laying supports of this type. If the base of the foundation is made of rubble or rubble concrete, laying reinforced wire with a cross-section of 6 mm or more or reinforcing mesh will give it additional durability. The cushion of fine sand under the support does not exceed a thickness of 300 mm. If the soil under the construction site is heterogeneous, then the base of the reinforced concrete foundation pillars is expanded due to protrusions.
  3. Under a columnar foundation, ready-made wall blocks of regular rectangular shape are selected from blocks with your own hands. In the basic version, the blocks have a size of approximately 200x200x400 mm. Wall blocks are installed both underground and in the above-ground part of the foundation, cushion blocks are installed at the base of a columnar support in a trapezoidal shape.

Quite often, additional strength of a structure can be imparted not only by a combination of materials, but also by a combination of different types of techniques in constructing the foundation.


Columnar foundation with grillage.

On a note

One of the most common types of work, when you build a columnar strip foundation with your own hands, it combines the installation of pillars in the underground part and pouring concrete along the entire perimeter in the above-ground part. Or carrying out work with precision, but vice versa - a strip foundation underground, a columnar foundation - above ground.

Types of columnar foundation

There are various classifications of foundation types made from columnar supports. Foundations are distinguished by the shape of the pillars: round columnar, a base with square supports, and pillars with a rectangular cross-section. According to the method of constructing the foundation, they are distinguished - with digging a trench, installing reliable formwork, pouring a concrete mixture, and a foundation using prefabricated technology made of bricks or blocks.

Let's learn more about the nuances of how to install a columnar foundation with your own hands; a video fragment is presented below.

Columnar foundations are classified by the depth of the pillars underground. The deeply buried type is installed on clayey or heaving soil areas, with the column located below the level at which the soil freezes in winter, about 1.5 meters.

Installation of a columnar foundation for a frame house with a slight depth is advisable at a depth of no more than 0.5 meters - it is installed on a sand bed. It can also be mounted on a gravel bed when there are sandy and heaving soils. Another type of columnar foundation, when the supports are not buried. This type of foundation is ideal with low weight, and is most often used on sandy soils.

Columnar foundation: step-by-step instructions

So, we have looked at the advantages of this construction technology, now we will look at how to make a columnar foundation with your own hands, step-by-step instructions will help you understand all the intricacies of the work. How to install a columnar foundation with your own hands, photo.

Step-by-step pouring of a columnar foundation made of pipes.

  1. It is necessary to begin preparing a summer cottage for the construction of a frame house, and to do this, we first level out all the large mounds in the excavated soil layer. The obligatory shallow recess must be made a couple of meters larger in area than the selected foundation design.
  2. The project for the future foundation of the house is transferred to the land plot with the help of pegs and fishing line. The future location of the supports is outlined, holes of the appropriate size are dug.
  3. The sand and gravel base is filled in and thoroughly compacted.
  4. If necessary, wooden formwork is installed to fill the future solution.
  5. Materials are laid out on the prepared surface - rubble, bricks, blocks.
  6. Installation of reinforcement and pouring concrete mixture. Metal reinforcing mesh consists of long rods, there can be three or four of them. The rods are fastened with wire reinforcement in different areas at intervals of 250 mm.
  7. Concrete must be poured gradually - in layers of 300 mm. with a mandatory puncture with an iron rod to seal and eliminate air bubbles.
  8. A columnar foundation made of blocks must be waterproofed with your own hands after removing the formwork. It is recommended to use sheets of reinforced roofing felt, liquid glass or a molten resin composition can be used.
  9. The role of the final fastening element is played by the lower frame of the frame house on a columnar foundation. It is recommended to do it from high-quality timber at a distance of at least 500 mm from the ground.

Nowadays frame houses are created in almost all climate zones. Due to the light weight of the structure, a foundation with low load-bearing capacity is used during its construction. A simple option is a columnar foundation.

Advantages and possible disadvantages of a columnar foundation

A columnar foundation is a simplified version of a pile foundation. The structure is a network of supports installed along the perimeter of the walls and in places of greatest load. The maximum step between supports is 2.5 m. All pillars are connected to each other by a grillage (horizontal strapping). Columnar foundations for frame buildings are used in 2 types: monolithic concrete (made by pouring into supports) and prefabricated (constructed from ready-made blocks or stones). Despite the fact that the structure is constructed without completely pouring concrete over the entire perimeter, such foundations have a number of advantages that make the structure reliable and durable.

Columnar foundation for a frame house

Advantages of a columnar foundation:

  • Costs less than tape analogues;
  • Can be made by yourself;
  • Quickly erected;
  • Its construction does not require heavy equipment;
  • Easy to repair;
  • The poles can be installed at any time of the year, including winter.

The disadvantages of the design include a large amount of manual work (if there is no drilling equipment) and the need for additional insulation of the floors, since the frame structure practically hangs in the air.

Preparation for production

At the preparatory stage, it is necessary to find out the dimensions of the future structure, the load on the foundation of higher structures and the bearing capacity of the soil. Before building a frame house, you can do a soil test yourself. To do this, you need to drill several holes in the area. The depth of the well is below 50 cm of the base of the foundation. In this way, the type of soil and the absence of aquifers are determined.

Soil characteristics:

  • Rocky - soils with a high content of stone or gravel, have a strong foundation, hold the load well, and do not collect water.
  • Coarse sands are a strong base with low heaving.
  • Fine sand - not suitable for construction, as they are characterized by high heaving. They collect water in the upper layers and act as a buoyant force on the foundation.

Calculations of depth and number of pillars

Columnar foundations can be recessed (for water-saturated and clay soils) and shallowly recessed (for rocky and sandy soils with low groundwater levels). The height of the buried foundation depends on the average depth of soil freezing in your area. The base of such a foundation should be located 30–50 cm below this level. Before starting work, you should calculate the load of the house; for this, the weight of the walls, ceilings, roof and the weight of the foundation are summed up.

If the slope is more than 60 degrees, the snow load is 0.

To determine the weight of a reinforced concrete columnar foundation, you need to multiply its volume by the specific weight of reinforced concrete (2500 kg/m³). To calculate the weight of one column, the following formula is used: V=3.14*G²*h. V is the volume of the column, G is the radius of the column, h is the height of the column. All values ​​are indicated in meters. The resulting value must be multiplied by the number of pillars, and we will get the total volume of the foundation.

Bearing capacity of different soils (in kg/cm²):

If the load on the soil exceeds the bearing capacity of the soil on the site, you need to increase the number of columns.

Material selection and quantity calculation

Different materials are used to construct a columnar foundation:

  • Wood is a very short-lived material; even when treated with protective compounds, it will last no more than 20 years.
  • Stone pillars - usually constructed from rubble or granite stones. They are distinguished by durability and reliability. The disadvantage is its massiveness and labor-intensive construction.
  • Monolithic concrete pillars.

The number from the table must be multiplied by the length of the pole (in meters) and the number of supports.

The reinforcement for the columnar base is corrugated, class A, with a diameter of 10–12 mm. Metal rods are needed the same length as the supports. For a post with a diameter of 10–14 mm you will need 4 bars of reinforcement. They are placed at a distance of 10 cm from each other and tied every half meter with smooth and thinner reinforcement with a diameter of 6 mm. Thus, for a two-meter pole you will need 8 m of thick and 1.2 m of thin reinforcement. We multiply the resulting figures by the number of supports and obtain the footage of the reinforcement required for the columnar base.

Required Tools

Before starting construction, you need to prepare the following tools:

  • Concrete mixer;
  • Shovel;
  • Roulette;
  • Level;
  • Nails and screws;
  • Hammer;
  • Cord;
  • Pegs;
  • Hand drill;
  • Master OK;
  • Pipes or boards for formwork.

Step-by-step instructions for creating a foundation with your own hands

Site marking

Before starting work, markings are made - pegs are driven into the corners of the future building and a cord is pulled. At this stage, it is imperative to check the diagonals. They should be the same. Next, debris and vegetation are removed from the entire area and the installation locations for the pillars are marked.

Digging holes and waterproofing

Drilling holes for a columnar foundation

For foundations made of monolithic concrete or asbestos pipes, it is convenient to use a motor drill. The pits can be either straight or widened at the bottom. A wider sole will increase the load-bearing capacity of the base and increase its resistance to heaving. Now you need to waterproof the foundation. To do this, a pipe made of roofing felt or polyethylene should be lowered into each hole. The upper edges of the waterproofing must be pressed to the soil with stones or sprinkled with earth.

Creation of formwork and installation of reinforcement

Opalwood from pipes for a columnar foundation

Formwork of asbestos or metal pipes (fixed) or boards (removable) is installed in finished wells. Then reinforcement with a diameter of 10–14 mm (at least 4 pieces) is inserted into each pit. Horizontal jumpers are made from thinner rods of 6 mm.

Installation of reinforcement in boreholes for poles

All pillars must be installed in such a way that the grillage is strictly horizontal. To do this, select a starting point and then use a level to mark the height of each support.

Concrete pouring and grillage

Installation of formwork for grillage

For the construction of columnar foundations, M200 concrete can be used. Filling is done in layers of 20–30 cm, each section is carefully compacted. Concrete is poured without interruptions to prevent the formation of transverse seams. After the pillars have dried, a grillage is installed. To make it, horizontal formwork is installed on top of the pillars along the entire perimeter of the foundation. Then the reinforcement frame is laid and concrete is poured. Standard grillage dimensions are 2.5–2.5 m (width and height).

Video: pouring a columnar foundation with concrete

A columnar foundation is one of the simplest and most economical solutions for frame buildings, which is quite feasible to implement on your own. Use our advice and good luck with your work!

It is quite possible and affordable to build a columnar foundation for a frame house with your own hands. This foundation option is considered an inexpensive and traditional type of foundation for low-rise construction. It cannot be said that this structure is easy to build from scrap materials. Before deciding on the type of supporting supporting structure of the house - the foundation, you need to take into account the category of soil under the foundation, calculate the load from the walls and roof, and perform proper markings. The construction of the load-bearing foundation of a building is, first of all, a competent calculation, the correct selection of materials and the consistent implementation of the construction process.

Features of columnar foundations

A frame-type house belongs to the class of lightweight construction buildings with characteristic point loads on the foundation. Typically, such houses do not provide for the construction of a basement, and therefore choosing a columnar foundation as a load-bearing foundation will be appropriate and economical.


For example, when building a wooden house, separate pillars are installed under load-bearing wooden beams or beams, which will take the load from their weight. If the construction of a frame house is carried out in an area where the main building material is wood, then it is possible to install a columnar foundation made of wood. Cuttings with a diameter of 15 to 30 cm from the butt part of pine or oak logs are suitable for a foundation in the form of “chairs” installed in a vertical position in an open pit.

A characteristic feature of a columnar foundation is that the point load from the weight of the house structure is transferred to individual foundation pillars, and not to a concrete strip, as with a strip foundation structure.

Method of constructing columnar foundations

In construction, columnar foundations are arranged in the following ways:

  • Monolithic. The design is a type of concrete pillar reinforced with a spatial metal frame, consisting of four working rods made of reinforcement with a diameter of 10 to 18 mm and a distribution rod made of smooth-drawn metal wire with a diameter of 5 or 8 mm. A monolithic columnar foundation has the advantages of reinforced concrete structures with high technical indicators for strength and reliability.
  • Made. The building materials for a prefabricated columnar foundation are brick, lightweight concrete stones (cinder block or bentonite), rubble stone, and reinforced concrete blocks. Such a foundation is erected quickly and does not require numerous costs for formwork and reinforcement as for a monolithic foundation. The disadvantages include the presence of numerous seams connecting materials, which leads to weakening of the structure.

Types of columnar foundations

The main factors when calculating the lower level of a columnar foundation are the determination of the soil class, the level of freezing and the presence of groundwater at the construction site.

Depending on these indicators, foundation structures can be divided into the following types:

  1. Recessed with the base of the lower mark greater than the depth of soil freezing by 500 -1000 mm. Recommended for the construction of foundations on clay soils with large amounts of groundwater that can erode the foundation.
  2. Foundation with a shallow penetration into the ground of 400 -700 mm. Naturally, there should be no groundwater in such an area.

Regardless of the type of construction and construction material, it is recommended to install a columnar foundation on sand preparation.

There is such a pattern: the deeper the base of the foundation, the smaller the thickness of the sand cushion. With a shallow foundation, the thickness of the sand is up to 500 mm, and with a deep foundation - 200-250 mm.

Video instructions for installing a columnar foundation:

How to make a columnar foundation correctly

In order to properly arrange a columnar foundation for a frame house, it is recommended to calculate its parameters and draw up an as-built diagram of the location of free-standing pillars. The foundation elements are placed in the corners and under the load-bearing structures of the frame house in such a way that the permissible distance between the pillars does not exceed 2 or 2.5 m. It is advisable to contact a specialist architect for calculations to correctly collect the current loads on the foundation and link the specific conditions of the site under development.

Preparatory work

On the planned site for the installation of a columnar foundation of a frame house, the fertile soil layer is removed and holes are marked for placing free-standing pillars. The pegs are hammered in, and a rope or cord is pulled along a single horizontal level.

The intersection of the cord will indicate the location of the centers of the foundation pillars. The holes are dug to the calculated depth with some reserve for the installation of a drainage and sand cushion, as well as for the installation of the formwork system. The soil removed from the trench is removed from the construction site so that after the first rain the building site does not turn into a clay mess.

It is important to carefully measure the diagonals between the pegs - the top marks of future posts should be in a single plane with a minimum distortion of 1 cm. It is best to use a long strip with a level or a construction laser level for these purposes.

Instructions for installing a monolithic columnar foundation

The construction of a columnar monolithic foundation is carried out in several stages:

  1. After marking the location of the foundations, excavation work is carried out to dig a trench for each individual pillar.
  2. The bottom of the trench is carefully protected, sand is added to a thickness of up to 100 mm.
  3. The sand cushion must be spilled with water and carefully compacted. After the sand has dried, they begin to install the formwork.
  4. According to the design size of the foundation column, removable or permanent formwork is installed from available materials: boards, plywood, polystyrene foam, metal panels.
  5. The formwork is securely strengthened so that when concrete is poured, the formwork structure does not fall apart or creep. Professional builders advise additionally sealing the formwork walls with PVC film to prevent the concrete mixture from leaking through the cracks.
  6. If there is a need for reinforcement, then a spatial reinforcement frame or long anchor bolts are inserted into the formwork for subsequent fixation of the foundation frame.
  7. As the concrete mixture hardens, the color of the concrete changes from dark gray to light color. This color change indicates that the concrete has reached 70% of its design strength and it is time to remove the formwork.

After removing the formwork, the foundation structure should be coated with resin or bitumen to prevent capillary moisture from entering. It is recommended to backfill the foundation pillars with clay with careful layer-by-layer compaction.

When building a columnar foundation for a frame house with your own hands, you should remember that work should only be done in the warm season before the first frost. If this mandatory requirement is violated, then the foundation structure will be laid on a frozen soil base and, consequently, the foundation will simply collapse when the soil thaws.

Instructions for installing a prefabricated columnar foundation

A frame house can be installed on a prefabricated columnar foundation. The technology of its construction is much simpler than the construction of a monolithic foundation. If iron ore brick is used as a material, then there are several subtleties when laying it:

  • The construction of such foundations is possible on dry soils without horizontal movements.
  • The bottom row of bricks is laid on a sand cushion or concrete preparation.
  • The standard width of brick pillars is 250 x 250 mm or 380 x 380 mm. It is advisable to reinforce each 5th row with smooth-drawn metal wire with a diameter of 5 or 8 mm, or with reinforcement bars made of corrugated steel reinforcement with a diameter of up to 10 mm.

When laying brickwork, you should use a building level to ensure that the walls are strictly vertical. The seams between the masonry do not need to be sealed, since the brick surfaces of the pillars will definitely need to be plastered.

Columnar foundation made of small concrete blocks

Much faster you can build a columnar foundation from concrete blocks measuring 200 mm x 200 mm and 400 mm high. The technology for laying blocks is similar to the technology for bricklaying. A feature of the construction of block pillars is the need to perform coating bitumen waterproofing of the side surfaces and cushioning waterproofing from roofing material in 2 layers of the lower concrete block. Concrete blocks are mounted on a cement-sand mortar, the seams between them are filled with mortar.

For the construction of a frame house, a columnar prefabricated foundation made of concrete blocks will be the ideal solution.

Video example of a columnar foundation:

Strengthening a columnar foundation with a grillage

You can strengthen a columnar foundation using a grillage. The grillage is the upper part of the foundation, which evenly distributes the current load of the load-bearing elements of the frame house. Usually made in the form of a reinforced concrete, metal or wooden frame. The grillage and free-standing pillars connect and create a single closed foundation system, increasing the strength and reliability of foundations.


Type of strip-column foundation

At the same time, the risk of individual pillars overturning or vertical deviation during horizontal soil movement is significantly reduced. On mixed soils, when one pillar rests on sandy soil and the other on clayey soil, the entire building may become distorted and cracks may appear on the walls of the building, so installing a grillage on such soils will be a prerequisite for ensuring the reliability of the foundation of the house.

A grillage can be used to level out errors when erecting individual pillars with unequal upper levels.

Materials for manufacturing

It is advisable to use a grillage for monolithic and prefabricated foundation structures. If a frame-type house is made of wooden structures, then in this case the lower crown of the wooden one will serve as a grillage.

In construction, there are two types of grillage: upper and lower. The upper grillage is located above the ground level, and the low grillage is located directly above the ground. To create a grillage, as a rule, reinforced concrete or concrete monolithic foundation beams are used. Wood or metal are used much less frequently.

A monolithic concrete grillage is a suspended structure resting on the top of a columnar foundation. In construction, two options for creating such a structure are used: formwork with a bottom at the top level of the pillars and formwork along the height of the pillars to the level of the ground surface.

The empty space between the lower base of the grillage and the ground is filled with dry sand. In both cases, the interior of the formwork system is covered dry with a layer of waterproofing roll material. The formwork is installed 5 cm above the expected concrete level. For a frame house, the height of a high grillage is 25 cm or 30 cm, a low grillage is 50 cm with a width of 25 to 40 cm in accordance with the cross-section of the pillars.


The spatial reinforcement frame will carry the load in the body of the monolithic concrete grillage. The manufacture of the reinforcement frame is carried out in the following sequence:

  1. Four steel reinforcement bars of periodic (corrugated) profile with a diameter from 10 mm to 18 mm are prepared, equal in length to the monolithic grillage beam.
  2. To create a spatial structure, clamps are prepared in the form of separate rods equal in width and height to the grillage. Smooth steel wire with a diameter of 5 mm or 8 mm is used as clamps.
  3. Using binding wire, the reinforcing bars are tied into a single frame, in which four bars of larger diameter will serve as working reinforcement, and the clamps will be mounting or distribution reinforcement. Mounting fittings are installed in the frame in increments of 200mm to 400mm.
  4. When installing the frame, it is important not to forget about the need to create a protective layer between the reinforcement frame and the formwork walls of at least 30 mm. For this purpose, homemade metal products or special plastic stands are used.

In the formwork, embedded parts are installed from scrap materials (cuts of plastic or metal pipes) to organize ventilation and to secure the lower frame of the grillage.

Filling the grillage with concrete

After installing the reinforcement frame, they begin directly filling the formwork with concrete mixture. Concrete is poured evenly, preventing the formation of voids and cavities in the body of the monolithic grillage. When concreting, it is advisable to use a construction vibrator or, in its absence, a long piece of reinforcing bar or a shovel. The concrete mixture is carefully leveled along a pre-marked horizontal level.

You can make a columnar foundation with your own hands not only using the methods indicated in the article. Home craftsmen and craftsmen can use a variety of metal or asbestos pipes for columnar foundations of small frame houses. You can choose a combined method of combining different materials when constructing individual pillars.