For the construction of small and light buildings, such as bathhouses or cottages made of timber, rounded logs or frames, gazebos and cottages, you can use a simple columnar foundation made of wood. Its installation is quite labor-intensive, but the cost of arranging such a foundation is several times less than if you pour a concrete frame.

To install a column-type wooden foundation, you must use only those types of wood that are resistant to moisture. Teak, larch or pine are optimal, subject to high-quality pre-treatment. It is these types of wood that can serve as foundation pillars for decades. It is worth noting that to create columnar foundation supports, it is better to use exclusively the lower part of the tree trunk, which is called the butt and is characterized by increased wear-resistant characteristics.

Important: it is desirable that the diameter of the wooden support post be at least 200 mm. At the same time, it is worth deepening the columnar foundation made of wood to a depth of at least 50 cm (for the internal walls of the house), and to a depth of 75-115 cm (for load-bearing external walls of the building).

In order for wooden poles to last longer, it is necessary to treat them with an antiseptic before installation. This additional protection of wood allows you to increase the service life of columnar supports by 1.5-2 times.

Advantages and disadvantages of a wooden foundation

A wooden foundation made of free-standing supports has a number of advantages, which are:

• Simplicity of building a foundation for the house;
• Low cost of work;
• Excellent thermal insulation of a house on a wooden foundation, since wood perfectly retains natural heat and does not allow cold from the ground to penetrate into the building;
• Wood has the property of elastic deformation, which makes such support pillars as wear-resistant as possible under the influence of ground movement and house pressure on them.

The disadvantages of a wooden foundation include a low service life, estimated at several tens of years. This negative side of wood can especially manifest itself on waterlogged soils.

It is worth noting that different types of wood have their own service life, different from others:

• Thus, oak supports can last on average 15 years, and if they are treated with high-quality antiseptic, the service life can be increased to 27-32 years;
• Larch will last less in total - only 7-8 years. If the wood is treated before installation, it will be possible to increase the service life of these wood species to 11-15 years.

However, even such a minus does not prevent a wooden foundation from being in demand, especially among self-made summer residents.

Construction of a foundation on wooden supports

Work on the construction of a wooden foundation is carried out in several stages. So, first of all, it is necessary to calculate the parameters of wooden supports. All dimensions are calculated in accordance with the characteristics of the soil and the total mass of the future building. As a rule, the depth for wooden supports on external walls is made from 75 cm to 115 cm. For internal walls, the installation depth of the pillars can be slightly reduced to 50 cm.

Important: in this case, the above-ground part of each pillar must be in the same horizontal plane for all supports.

To calculate the length of a wooden support, you need to add the underground length of the support and its above-ground part. As a rule, the protruding part of the post is about 60 cm plus a small margin for the necessary cutting. The distance between future supports should be no more than 2 meters. But at the same time, each support pillar must be located under all the joints of the walls, in places of corners and protrusions.

Antiseptic wood treatment

This is the most important stage in the construction of a wooden columnar foundation. It is worth knowing that harvesting logs for poles is best done in the cold months between November and January. The wood must be sanded in advance and the upper and lower parts must be marked in accordance with the growth of the former tree.

As an antiseptic method, you can choose one of the following:

• Burning wood to a strong charcoal crust;
• Chemical treatment of wood.

Each method has its own implementation features, advantages and disadvantages.

Firing method

In this case, the tree must be properly burned on all sides to a length equal to its underground part and plus 20-25 cm of the above-ground part of the pillar. You can burn wood either with a blowtorch or over a fire. The wood burning method requires compliance with certain rules:

• So, the wood must be burned evenly and ensure that the thickness of the crust does not exceed 2 cm;
• Before firing, the perimeter of the wood should be treated with clay, a layer of 1 cm;
• After the firing technology, the pillars should be coated with bitumen mastic or resin.

Chemical wood treatment

This type of antiseptic wood treatment is much simpler than firing, but requires certain costs for the purchase of chemicals. The following suspensions can be used as antiseptics:

• Aqueous solutions. This is the simplest type of suspension. You can prepare it from improvised means, such as table salt and boric acid at the rate of 950:50 g, respectively, per 5 liters of just boiled water. The resulting solution is used to treat the wooden support along its entire length.

Important: it is prohibited to use an aqueous solution if the groundwater level in the area is high. Under such conditions, the suspension will simply be washed off from the surface of the post, since it does not have the property of deep penetration into the structure of the tree. Here it is better to use white spirit or solvent.

• Clay paste. This type of product can also be mixed independently from sifted fatty clay and water. The resulting composition is coated with wooden pillars for the foundation.
• Finished chemicals in the form of solutions of ferrous sulfate, sodium fluoride, zinc chloride, sodium fluoride or ammonium.
• Oils - anthracene, coal, shale, creosote, etc.. But such products are the most toxic of all, so you should follow all the rules specified in the instructions.

Important: the most effective antiseptic is the one that has good penetrating ability, is non-toxic, is gentle on metal fasteners without causing them corrosion, and is also resistant to fungus.

Drilling holes for pillars

The next stage of work when constructing a wooden foundation is digging holes for supports. You can dig a hole simply with a shovel, or you can use a garden drill of the required diameter.

Important: the diameter of the hole for installing support pillars must be 1.5 times the cross-section of the wooden support.

After the holes are ready, it is necessary to make a strong sand cushion 15-20 cm thick. It must be slightly moistened and compacted well.

Before installation, it is worth making a special waterproofing bandage for each pillar. To do this, use roofing felt or roofing felt, with which they wrap the underground part of the support in several layers, gluing them with bitumen mastic. As a result, even when the soil moves in a horizontal plane, the layers of soil will simply slide over the supports without causing harm to them.

Installation of supports

Wooden poles are installed in the prepared pits with the intended part down. To ensure even installation, you can use a building level. All supports must be strictly vertical. It is important that all supports are installed strictly along the axis of the walls. To achieve this, you must first mount the supports in the corners of the house and then stretch the mooring cord between them. This can be fishing line, wire or nylon thread. It is along this that the horizontal of the installed pillars is leveled.

Important: for greater reliability, all supports can be installed on a special cross, which is attached to the bottom of the wooden support. This will significantly increase the wear resistance of the pillars.

After installing the pillars, it is necessary to backfill the supports. To do this, use fine crushed stone or river sand. Bulk materials are poured in layers of 15-20 cm and compacted well, maintaining the verticality of the installed piles.

Lastly, all mounted pillars must be aligned horizontally. For these purposes, a special fishing line is used, which must be stretched at the same height between all supports. It is along this that the excess tops of the logs are cut off. It is advisable to waterproof all open areas of the ends with bitumen mastic or pieces of roofing felt.

And finally, at the ends of each support it is necessary to make special spikes, onto which the wooden beams of the walls of the house will subsequently be attached.

Thus, it becomes clear that a columnar foundation made of wood is an option for a simple and unpretentious foundation for light temporary buildings.

The construction of any building or structure begins with the construction of a foundation -. It takes on the entire load from the structure and transfers it further to the ground.

The foundation is one of the main structural elements of the entire building, which means that the reliability of the structure directly depends on the strength of its foundation. The required type of foundation is selected based on an analysis of related factors, namely the purpose of the structure being built and the condition of the soil on the site.

Today, many different types of foundations are known, the most common being concrete and reinforced concrete. But this was not always the case; earlier, in past centuries, the basis of buildings was mainly a wooden foundation.

Today it is also quite relevant for the construction of light buildings: bathhouses, gazebos, seasonal country houses, summer kitchens, and various outbuildings.

Foundations for wooden houses have a number of undeniable advantages:

• - first, and one of the most significant, is the low cost of the material;
• - simplicity and ease of construction;
• — no need to use expensive mechanisms;
• — does not require specialized knowledge;

All these factors allow you to build a wooden foundation with your own hands.

• various solutions, for example, one of them: for 5 liters of boiling water - 1 kg of table salt and 50 g of boric acid. Stir well until the ingredients are completely dissolved and process the logs at least twice;
• clay paste. Clay in a dry state is sifted and diluted with water until a plastic mass is obtained, then the pillars should be coated, dried completely and used in construction;
• ready-made compositions available for sale - a solution of sodium fluoride, ferrous sulfate, zinc chloride, and others;

• antiseptics from oils - shale, anthracene, creosote, coal.

When choosing an antiseptic, you must take into account its effect on metal parts if you plan to use them. It is also necessary to remember about the presence of unpleasant odors and negative effects on people. And it can be used environmentally for residential buildings.

When using firing as a protective measure, you need to clean the log from the bark, sand it and treat it with a burner until the surface is lightly charred. There is no need to burn it strongly, as the wood may lose its load-bearing properties.

When choosing wood for a foundation, it is better to give preference to the most durable types, such as spruce, pine, oak, fir, beech and larch. For example, burnt oak does not rot in the foundation, and buildings erected using this wood can last for many decades.

Let's consider the variety of wooden bases used:

• pile There are two types of timber piles - stand piles and hanging piles. The first ones are used in the case when good, strong soil is not deep and the rack piles rest on it.
• The second type - hanging piles are used when strong layers of soil are not reachable deep, and the load is distributed due to the friction forces of the side surfaces. Typically, the pitch of piles is from 0.8 to 1.5 meters. The technology for making such a foundation involves driving piles to a certain depth and fastening them to each other to impart rigidity to the entire structure.
• 
  . As the name suggests, the components of this foundation are pillars or so-called chairs. These can be single pillars installed along the line of future walls with a certain pitch, or they can be composite structures in the form of mutually intersecting logs. Such pillars are installed in prepared pits in increments of 2 to 4 meters. Wooden column foundations for houses have been widely used in the past and are still in demand today.
• strip foundation. This foundation is made in various ways - in the form of installing short columns (0.9 to 1.3 meters long) next to each other in a strip, the so-called hemp-type foundation, or in the form of horizontally laid wooden elements, for example, sleepers. The depth of the tape is taken taking into account the capital structure of the structure; the deeper it is, the more solid the foundation is, and the longer the structure being built is expected to operate. It is carried out as follows - a trench is dug along the contour of the future structure, the depth of the trench is determined depending on the desired result. Next, wooden logs are installed or laid and then covered with sand.

Step-by-step instructions for building a log foundation

Let's consider the step-by-step implementation of work on the construction of a wooden foundation:

Choosing the type of future foundation

Depending on the purpose of the structure, it is recommended to select foundations according to the following principle - the more permanent the structure, the stronger and more solid the foundation. It is not advisable to use it for light seasonal structures such as gazebos and summer kitchens. And for a residential building it can also be used from oak, which is known for its high strength qualities.

Construction of a columnar wooden foundation

Preparing the construction site

Along the perimeter of the future building, dig a trench to the full depth of the foundation structure, lay drainage pipes and fill it with a sand-crushed stone mixture; such a system will not allow moisture to accumulate in close proximity to the wooden base and will thereby extend its service life.

Preparation of elements and construction of foundations

Ancient house in Japan on a columnar foundation

After completing the preliminary work, you can proceed directly to preparing the logs themselves using any of the methods described above and carry out construction and installation work on the construction of the foundation of the future structure. Backfilling of pits with installed structures must be done with clean sand, this will help prevent contact of wooden pillars with moisture, since sand does not hold water, allowing it to pass freely. After the construction of the underground part, strapping work is carried out, creating a spatially rigid structure capable of absorbing further loads.

The name depends on what material is used in its construction. Next, a larch foundation will be discussed in detail. It can be installed under bathhouses, houses made of timber and logs. The construction of a columnar wooden foundation is considered the simplest and cheapest method. Larch has high biological resistance. After antiseptic treatment, larch poles can stand in the ground for several decades. The lower part of the tree trunk, called the butt, is most often used. The log must have a diameter of at least 20 cm: for external walls 75-155 cm, for internal walls at least 50 cm.

Before installation, larch poles must be treated with an antiseptic.

This will protect them from rotting and increase their service life. The lower end of the log, the underground part of the pillar, and the part of the log located at a height of 25 cm above the ground are treated with an antiseptic.

Preparation of pillars and antiseptic treatment

In order for a wooden columnar foundation to last as long as possible, the logs need to be properly prepared and antiseptic. Pillar-chairs are usually prepared from November to January. Before antiseptic treatment of logs, it is necessary to sand and mark the bottom and top, in accordance with the direction of tree growth. There are several antiseptic methods: chemical methods and firing to a coal crust.

Firing helps protect the wood from contact with the ground and rotting. Firing is carried out using a blowtorch and open fire. They burn that part of the wooden chair that will be underground, plus a part 20-25 cm long that is above the surface of the ground. Before firing, the pillar is coated with clay with a layer 1 cm thick. The log must be burned very slowly and carefully, making sure that the thickness of the coal crust does not exceed 2 cm. The pillar is then treated with thick resin or bitumen.

The chemical method involves impregnating the pillars with special chemicals before installing them. If you don't have time to burn slowly or are wary of working with fire, treat the wood with an antiseptic solution. An effective antiseptic should not cause corrosion in metal fasteners or degrade the quality of wooden posts. It should not have an unpleasant odor or pose a danger to humans and animals.

Now on the antiseptic market you can find modern products that, in addition to protective functions, also have decorative properties. However, antiseptics also have their disadvantages. Aqueous solutions cannot be used if the posts are in direct contact with wet soil, as they are easily washed off from the wood. In wet soil, you need to use products based on organic solvents. Oily antiseptics are the most toxic, so they must be used strictly according to the instructions.

Wooden columnar foundation. Option I: 1 – log pillar; 2 – waterproofing; 3 – concrete support; 4 – sand cushion. Option II: 1 – log pillar; 2 – waterproofing; 3 – bracket; 4 – wooden support; 5 – sand cushion.

To build a larch foundation, you will need the following materials and tools:

• wooden poles;
• shovel;
• sand;
• waterproofing materials;
• wooden beams;
• saw.

Wooden poles must be installed in the corners of the future house or bathhouse, at the intersections of walls and along the perimeter of the foundation in increments of 1.5-2 m.

A columnar foundation made of wood is built in compliance with all the rules for constructing columnar foundations. Support pillars must be fixed in a strictly vertical position with a certain pitch and depth.

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Calculation of the length and number of pillars for a larch foundation

Wooden columnar foundation. Option A:
1 – log pillar; 2 – waterproofing; 3 – concrete support; 4 – sand cushion. Option B:
1 – log pillar; 2 – waterproofing; 3 – bracket; 4 – wooden cross; 5 – concrete support; 6 – sand cushion.

The depth of laying wooden pillars is determined depending on the structure of the soil and the weight of the future building.

The length of the wooden support consists of the length of the pillar located underground (75-155 cm), plus the length of the above-ground part of the log with a small margin taken into account when sawing the pillars to the general level.

The distance between the pillars is determined by calculations and usually does not exceed 2 m. The number of supports depends on the area of ​​the building and the weight of the building structures. The bearing capacity of the soil also needs to be taken into account.

For example, a log with a diameter of 250 mm rests on soil with an area of ​​500 mm. If the soil has a load-bearing capacity of 2 kg/cm², each pillar can carry 1 ton of the mass of the house. Moreover, with a known consumption of building materials used to construct the foundation, you can easily calculate the number of supports required to install a specific structure.

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Digging holes and creating a sand cushion

To install larch posts, you need to dig holes with a diameter of at least 35 cm, i.e. 1.5 times the diameter of the logs. If the diameter of the support is 30 cm, you need to dig a hole with a diameter of 45 cm. Holes can be dug in several ways. The manual method involves digging a hole with your own hands using a shovel. This method does not require costs, but is very labor-intensive. The mechanized method using special equipment will require additional costs, but will save your time and effort. A layer of sand 10-20 cm thick is poured into the bottom of the prepared pits, followed by compaction.

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Columnar foundation: main stages of construction

Before burying wooden supports in the ground, it is necessary to ensure waterproofing of that part of the pillar that will go underground. To do this, it is impregnated with an oily solution and wrapped with roofing felt or roofing felt, gluing the waterproofing layers with bitumen mastics. This will protect the surface of the post from contact with the soil and reduce the likelihood of rotting and freezing to the ground. The use of a waterproofing stocking minimizes the impact of frost heaving forces on the pole.

Wooden columnar foundation: a – bed; b – piles.

The wooden support is installed in a dug hole, aligned in a vertical position. Wooden posts are placed along the walls, and they must be installed exactly along the axes of the walls. To do this, lighthouse poles are installed in the corners of the future house and at the intersections of walls, into which nails are then driven and a cord (nylon thread, wire or fishing line) is pulled tightly. After this, they begin to install the intermediate supports, checking the vertical position along the plumb line, and the horizontal position along the mooring (cord).

For greater stability and increasing the load-bearing area of ​​the support, the lower part of the larch chair must be installed on a wooden cross with struts (for non-buried foundations) or a concrete slab (for buried foundations). To make a cross, take 2 wooden blocks up to 70 cm long, fastened together crosswise. The support chair is usually secured to the cross using metal brackets. For greater stability, a spike is cut out in the lower part of the log, and a nest is made in the upper beam of the cross. This simple design allows you to increase the supporting area of ​​wooden chairs, making the columnar foundation resistant to the forces of frost heaving.

To increase the reliability of buried wooden foundations, a cushion is made of monolithic concrete. A layer of concrete 20 cm thick is poured onto the bottom of the sand cushion and, without allowing it to harden, the pillar is immersed to a depth of 10-11 cm. After the concrete has hardened, the wooden chair is rigidly fixed.

Wooden foundation– this is a suitable solution if you or other small buildings are made of lightweight building materials. Most often, columnar structures are created, as this allows you to more economically spend not only money, but also time, and also do without the involvement of professionals.

Wood selection

The best material for wooden foundation- This is oak wood, as well as coniferous species: pine, larch. The main advantage of such wood is its resistance to the development of rot and destruction by microorganisms. Pine and larch are not afraid of waterlogging. On the contrary, under the influence of moisture, the wood seems to turn to stone, becoming even more durable.

Today, wooden poles are buried in the ground only after being treated with special protective substances - antiseptics. This allows you to increase the service life of the foundation by one and a half to two times. Mandatory processing is subject to such parts of a wooden columnar support as the lower edge, the entire underground part, as well as the protruding end of the log to a height of 25 cm from the ground level.

Usually, to build a foundation, wood is taken from the bottom of the trunk - the butt. The diameter of the log section is from 200 mm. The pillars are buried in the ground by 75-150 cm (external walls and key components inside the building) and by 50 cm (secondary internal partitions).

Advantages and disadvantages of a wooden foundation

Considering wooden foundation, first of all, the following advantages should be noted:

• ease of design and installation;
• budget savings;
• reduction of heat loss through the floor;
• no deformation due to excess pressure due to the high elasticity of the wood.

At the same time, a wooden foundation also has a significant drawback - a limited service life, which is also reduced due to the increased soil moisture on the site. Thus, oak pillars will last 15 years without treatment and up to 30 years if they are impregnated with antiseptics or fired. For pine and larch the terms are 7 and 15 years, respectively.

Preliminary preparation of foundation logs

Antiseptic treatment is the next mandatory stage in the preparation of foundation supports. After this, the wood will be reliably protected from the destructive activity of microorganisms, rot and mold. You can choose natural or chemical processing.

The natural way is to burn logs until a coal crust forms. As a result, the inner layers of wood will be freed from contact with soil masses, and therefore from infection with rot. Before firing, clay is applied to the pillar in a layer of 10 mm, and then subjected to heat treatment with a blowtorch or in the fire of a fire. The entire underground part of the support should be burned, as well as the area protruding above the ground to a height of 20-25 cm.

Be careful: the firing depth should not exceed 20 mm. After this, the wood is treated with resin or bitumen.

The chemical method is antiseptic treatment with special water- and oil-based (preferably) based preparations, as well as antiseptic wraps with roofing felt or roofing felt.

How to calculate the number and length of wooden foundation supports?

Wooden poles must be installed in the corners of the building, at the intersection of internal walls and their adjoining external walls. The number of intermediate supports is determined in accordance with the rule: they should be located in increments of 1.5-2 meters.

Creating wells for deepening wooden posts into the ground

The diameter of the well should be approximately one and a half times larger than the diameter of the wooden supports. You can dig holes either manually with a shovel or using special equipment. The depth of the wells is determined in accordance with your planned depth of pillars plus a margin of 10-20 cm for arranging a sand base. Foundation formwork made of wood is not needed, and this is another argument in its favor.

Waterproofing of pillars

Before installation in the pits, each wooden support is wrapped in roofing felt or roofing felt coated with bitumen mastic. Such a waterproofing “stocking” will reliably protect the underground part of the pillar from waterlogging and rotting, and will also prevent the foundation from being pushed out and lifted due to swelling of the soil.

Installation of wooden foundation supports

First, the main pillars located in the outer corners of the building are placed in the pits. Nails are driven into each support, onto which a non-stretch cord is pulled, ensuring that it is in a horizontal plane. It will become a guide for placing the upper edges of all other supports at the same level. It is very important to observe the strictly vertical installation of pillars in the pits.

To make the foundation more reliable and stable, the logs are installed on:

• stone “heel” (a layer of concrete mortar or a suitable size stone). The thickness of the concrete layer is about 200 mm. The pillar is immersed in 100 mm of not yet hardened concrete;

• wooden cross (if the foundation is not buried). The length of each of the two elements of the crosspiece should be approximately 70 cm. For fastening strength, a spike is cut out at the lower end of the support log, and a socket is cut out in the center of the crosspiece.

The space in the well between its walls and the log is filled with coarse bulk materials: coarse sand, crushed stone, gravel, brick fragments, etc. Every 200-250 mm of backfill is carefully compacted.

The final stage

Focusing on the stretched cord, align the upper ends of all foundation logs. Next, the sections are treated with antiseptic treatment and waterproofed with roofing felt.

To create a grillage, take suitable-sized logs or beams from the lower rim of the walls and make nests in the places where they adjoin the pillars. Spikes are made on the pillars, approximately equal in height to the height of the beam/log of the grillage.

As a result, you will receive a strong and deformation-resistant foundation for outbuildings that are small in size and weight or, for example, a cozy wooden bathhouse.

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The name of a specific foundation depends primarily on which building materials will be used in its construction, as well as on the type of foundation, for example: strip prefabricated and continuous strip, pile and column foundations.

You should know the basic nuances that must be taken into account in order to correctly build a columnar foundation made of wood.

As a rule, it is installed under structures such as a bathhouse and other light yard structures, the frame of which is made of logs or timber.

The main advantages and disadvantages of columnar foundations

Construction is the simplest and cheapest way. To lay such a foundation, it is best to use oak or coniferous wood (pine, larch), since these tree species have the greatest biological resistance. After antiseptic treatment, logs made from this wood will stand in the ground for several decades without destruction.

The columnar foundation has the following positive characteristics:

• a very simple technological process for performing construction work;
• fairly low cost;
• any buildings that are built on a wooden foundation will not lose heat, since wood is an excellent natural heat insulator;
• poles made of wood have the property of elastic deformation, this makes it possible for them not to deform or collapse from excess pressure, unlike poles made of other building materials.

By building a wooden columnar foundation, you will save money, but you need to know that the loss will be in the duration of its service, since the main disadvantage of such a foundation is considered to be a relatively short service life. This is especially typical for those owners of country cottages whose area tends to frequently change soil moisture.

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Preparation of the necessary material and its antiseptic

Pile driving schemes: A – ordinary; B – spiral; B – sectional.

First of all, you need to know that the construction of a columnar foundation includes the following steps:

• procurement of necessary materials;
• processing of wooden posts (antiseptic or firing);
• clearing and marking the site;
• digging holes;
• construction of a sand cushion;
• installation of a waterproofing layer;
• installation of pillars (to increase the supporting load-bearing area, the chair can be mounted on a concrete slab or crosspiece);
• reverse compaction;
• alignment of racks (horizontal plane);
• performing waterproofing and antiseptic treatment of the ends.

When preparing material for laying a wooden columnar foundation, experts recommend using the lower part of the tree trunk. In this case, its diameter must be at least 200 mm.

According to experts, chair posts are prepared in the autumn-winter period of the year (November-January). Before carrying out protective treatment, they need to be sanded of bark (cleaned) and the bottom and top must be marked based on how the tree grew.

Before you begin installing the pillars, they must be antiseptic, so the columnar foundation will serve you 2 times longer.

Methods for preserving wood:

• firing until a coal crust appears;
• chemical antiseptic treatment of wood.

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Wood processing methods

Firing until a coal crust appears allows you to protect the wood from direct contact with the ground and the formation of the rotting process. Firing can be done using a blowtorch, gas torch or fire. Burning of a wooden post is carried out throughout its entire part, which will be located underground, and that which will be located above its surface.

Before starting the firing process, a small layer of clay (10 mm thick) must be applied to the pillar. It is necessary to burn a wooden post very slowly and carefully; you should constantly ensure that the depth of charring (charcoal crust) is no more than 20 mm. The end result will be treating the pillar with thick, slightly heated resin.

The chemical method of treating wood involves impregnating it with readily available special chemicals. If you do not want to waste time on burning logs, then to antisepticize the wood, simply treat it with a special solution. For this purpose, you can purchase and use aqueous solutions such as: zinc chloride, ferrous sulfate, ammonium silicofluoride or sodium, sodium fluoride, etc.

There are also oily antiseptics, such as anthracene, coal, shale, and creosote oils. These substances are more effective; they are able to perform their protective functions even if the pillars are flooded with water.

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Calculation of the number and length of racks

A columnar foundation must be built according to generally accepted rules, according to which support pillars are mounted in the ground in a strictly vertical position with a certain depth and distance.

The depth of the supports must be determined based on the geological structure of the earth on your site and the total weight of the planned structure. Often it is 500 mm for internal walls and 750-1550 mm for external walls.

The length of the foundation support must be added from the length of the wooden pillar located underground (750-1550 mm), adding the length of the pillar located above the ground (no more than 600 mm). It should be taken into account that to the obtained result you need to add some margin, which will be needed to align the stands under the cord in a horizontal plane.

A columnar foundation is built with a set distance between the support posts, which is calculated by a certain calculation; the resulting value should not be more than 2 meters. It is also necessary to take into account that support posts must be located in all corners of the future building and in places where the walls are planned to intersect. The number of racks primarily depends on the total area of ​​the building and the weight of the entire structure. The bearing capacity of the soil in a particular area is taken into account, and not the bearing capacity of the foundation.

So, for example, if you plan to use a post with a diameter of 250 mm, it will rest on 500 mm of soil area. Under conditions where the soil has a load-bearing capacity of 2 kg/cm², each of the installed pillars will be able to carry approximately 1000 kg of the weight of the building structures. Based on this, if you know the consumption of building materials for the construction of a structure, you can calculate the required number of foundation posts without any effort.

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Preparing the recesses

To install wooden poles, you need to dig holes with a diameter of at least 350 mm, this is 1.5 times larger than the diameter of the pole itself. For example, if the diameter of a wooden post is 300 mm, the hole must be at least 450 mm in diameter.

You can make indentations in two ways:

• manual - use a shovel to dig holes with your own hands. Of course, this method does not require spending money, but it takes a lot of time and effort;
• mechanized method - using special equipment. This option for constructing pits will significantly save time and effort, but such a columnar foundation will cost much more.

After the holes have been dug, sand is placed on their bottom with a layer thickness of approximately 200 mm and compaction is required. Before installing wooden supports in the ground, it is necessary to waterproof the underground part of the pillar using one of the methods described above.

According to some experts, poles should be placed in holes with their tops down (i.e., in the opposite direction compared to the natural growth of wood). This will prevent moisture from moving through the vessels of the tree.

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Installation of wooden racks

Installation of logs must be carried out using a building level in order to install them strictly vertically. Wooden racks are mounted in dug holes along the future walls of the building; they must be located exactly along their axis. For this purpose, first of all, lighthouse posts are mounted at all corners and planned intersections of walls, after which nails are driven into them and the mooring (nylon thread, wire, fishing line) is pulled tight. Then you can begin installing all the intermediate pillars. It is necessary to check their position in two planes, vertical - along the plumb line, horizontal - along the berth.

To increase the stability and supporting area of ​​the pillars, its lower part can be installed on the following elements:

• wooden cross with struts ();
• concrete slab (recessed columnar foundation).

A wooden cross is made of two bars with a length of at least 700 mm, which are connected crosswise to each other. Often the support chair is connected to the wooden cross using several metal brackets. To increase the stability of the connection, a tenon is cut out at the lower end of the rack, and a socket for it is cut out in the upper strip of the cross. This very simple design of the crosspiece will not only increase the load-bearing supporting area of ​​the chair, but will also prevent the force of frost heaving from lifting wooden pillars from the pits.

Constructed using a concrete slab. This is an ordinary concrete pad, which is made from monolithic concrete. To build a concrete slab, you need to pour concrete with a layer thickness of about 200 mm at the bottom of a tightly compacted sand cushion and immediately, before it hardens, immerse the pillar into it to a depth of about 100-110 mm. This way, the columnar foundation will significantly increase its stability, because after the concrete hardens, the support posts will be rigidly fixed.