This article will discuss how to make a columnar foundation with your own hands when building a bathhouse. In contrast, its construction requires significantly less building materials, which is a definite advantage in terms of saving money. So, look at the contents and go to the desired section of the article.
This type of foundation is a series of load-bearing pillars located at key points and places with significant loads from the weight of the structure (in our case, a bathhouse). As a rule, pillars are located under all load-bearing walls, in corners and places where they intersect with each other. If there are internal partitions or other heavy structural elements, exerting large loads on the foundation, then additional pillars are also installed under them.
The optimal distance between pillars is considered to be about 1.5-2.5 meters. To give stability and combine the pillars into a single rigid structure, they are connected to each other by grillages, which also serve as supports for the base of the building. When the distance increases beyond 2.5 meters, it is necessary to install more powerful connecting beams, called rand beams.
The main type of columnar foundation used in construction is monolithic reinforced concrete foundation. However, depending on the nature of the soil at the construction site, as well as the weight of the structure, foundations made of rubble concrete, stone, brick, wood, asbestos concrete or steel pipes filled with concrete, and other building materials can be used.
Before building a columnar foundation with your own hands, you need to consider the following points:
- The structure must have no basement and be light in weight;
- The cost of materials and labor for a columnar foundation is one and a half, and sometimes even two times less than for a strip foundation;
- Columnar foundations are least susceptible to heaving forces when the soil freezes;
- Columnar foundation is preferable when
- its settlement on the ground is much less than that of strip foundations;
- the height of the strip foundation is more than 1.5 meters (from the point of view of saving materials).
- It is not recommended to build a columnar foundation:
- with a height difference under the foundation of more than 2.0 m;
- on soft soils with significant movement in the horizontal direction, which can lead to tilting (overturning) of the pillars;
- on soils with low bearing capacity, such as peat and clay soils with a high water content;
- if the structure is heavy ( brick walls, as a rule, with a thickness of more than 500 mm, reinforced concrete slabs, panels, blocks...);
- if a plinth is required for the construction of walls, since its construction will require significant financial investments.
Design features of the foundation for a bathhouse
Considering that a bathhouse made of wooden beams, in terms of its design parameters and materials used, is a lightweight structure, X In soils, it is advisable to build a shallow or shallow foundation. This is explained by the fact that frost heaving forces will act on a buried foundation below the freezing depth of the soil, significantly exceeding the load on the foundation from the weight of a light structure. The result of this will be deformations in the entire structure: settlement, distortions, cracks, etc.
Depth of laying a non-buried foundation, as a rule, from 40 to 50 cm and should be within the range of values from one third to half of the calculated freezing depth.
Feature of a shallow foundation is that the depth of the pillars should be less than the freezing depth by 50-70%. For example, with a standard freezing depth of 1 meter, the depth of load-bearing columns should be in the range from 50 to 70 cm.
As is known, frost heaving forces are exerted on the foundation, directed towards its plantar and lateral surfaces. To reduce friction, the side surfaces are treated with bitumen mastic, synthetic lubricants or resins. . In a simple way can serve as insulation of the foundation from the ground using roofing felt, as well as its insulation in the area where the soil layers adjoin. In addition, foundations made of monolithic concrete without reinforcement, brick or rubble are made tapering upward, which allows the load from the weight of the bathhouse walls to be evenly distributed.
In case of significant impact from soil movements in the horizontal direction, grillages or rand beams are used, which make it possible to tie the columnar foundation into one whole, and thereby increase its load-bearing characteristics.
When constructing columnar foundations, one should be guided by the following minimum values for the cross-sectional dimensions of the pillars, mm:
- From stone - 500-600;
- Made of brick – 380;
- From rubble – 400;
- Monolithic concrete – ø400 or 400x400;
- Made of wood – 200.
When building a bathhouse with your own hands, you can adhere to the following order of preparatory work (for all materials):
- Examination .
- Marking the foundation (for details, see) taking into account the fact that pillars must be installed at all corners, intersections and joints of load-bearing walls. If the distance between two adjacent pillars is more than two meters, then an additional pillar is marked in the middle. It is important to know that the optimal distance between columnar supports should be in the range of 1.5-2.0 m.
- Digging a hole manually or using special equipment (drill) for each post. Their dimensions should be so large that it is convenient to install a reinforcement cage, formwork or sheet roofing felt in them. For example, if the diameter of the pillar is 400 mm, then the diameter (width) of the pit should be 100-150 mm larger. The depth of the hole depends on the condition of the soil and the seasonal freezing depth.
Monolithic concrete foundation
- The concrete column foundation has very high strength and long term operation (about 140-150 years). For a wooden bath we use a shallow foundation with a depth of 500-700 mm (excluding sand backfill).
- When constructing light and wooden buildings without basements, including bathhouses, there is no need to install special formwork. It is enough to use a widely used method in which roofing material or glassine is used as formwork. To do this, you need to roll up the roofing felt in the form of a pipe of the required diameter and appropriate length, and secure it with reinforced tape.
- Insert the prepared pipe into the hole, pour 10-15 cm of construction sand and pour water to compact it. Then pour another 10-15 centimeter layer of sand and water again. After compacting the sand backfill, a reinforcement frame is installed, the diameter (or diagonal) of which should be 5 cm less than that of a roofing felt pipe. It is important to align the prepared formwork strictly vertically - this will reduce the effect of the pillar overturning during operation of the building.
- Concrete is poured into the formwork prepared in this way, which is compacted with a special vibrator or a piece of steel reinforcement.
Brick foundation
This type of foundation is built from red clay brick. Depending on the physical condition and characteristics of the soil, climatic conditions and the quality of the brick, as well as the strength of the masonry, its service life can be 50-100 years.
- The most important condition for the construction of this type of columnar foundation is the quality and strength of the masonry, since the pillars can collapse prematurely and cause deformation or destruction of the bathhouse itself.
- The width of the hole for the pillars should ensure convenience when laying bricks, and its depth should be 0.5-1.2 m (excluding backfill and cement base).
- Sand, gravel or crushed stone with a layer thickness of 10-15 cm is poured into the bottom of the pit and a cement reinforced screed 15-20 cm thick is made on top of it. As reinforcement, you can take a steel mesh with 3-4 mm wire or reinforcing rods connected with wire in the form grates.
- After the brick laying is completed, the pillars are treated with bitumen to prevent direct contact with the ground.
- The cavities between the soil and the post are filled with crushed stone or gravel.
Wooden foundation
- Designed for the construction of lightweight wooden buildings. The main material for pillars (“chairs”) is the butt part of pine or oak with a diameter of at least 25-30 cm. The shelf life of such a foundation (subject to compliance with all technological requirements) for oak is up to 25-30 years, and for pine – 10- 15.
- The width (diameter) of the pit should be one and a half times the size of the wooden support. For example, if the diameter of the trunk is 30 centimeters, then the diameter of the dug hole will be 45 cm.
- Before installation in the pit, the lower butt part is burned with a blowtorch to a length exceeding the depth of the support by 30 cm, and then treated with tar, antiseptic and bitumen.
- When building a bathhouse, you can use one of two options for laying wooden supports: non-recessed or recessed. In a buried foundation, the depth of laying columnar supports is at least 1.2-1.4 meters.
- When constructing a non-buried foundation, the pillar rests on wooden base in the form of a cross 70 cm long. For greater stability, the support is connected to the cross with its lower spike.
- If a buried foundation is being built, the supports are installed on stone or concrete. The concrete base is made on a sand backfill 10-15 cm high. The wooden support is pressed 10-15 cm deep into the fresh concrete solution - this ensures its stable and rigid fixation in the ground.
- After installing the supports, they are first covered with gravel (crushed stone), and then with a 10-15 cm layer of soil.
What else do you need to know when building a columnar foundation with your own hands?
- To prevent moisture, snow, dust and cold air from entering the lower part of the bathhouse, the space between the pillars must be closed. The strength of a concrete structure can be reduced by up to 20% if the concrete is prepared either too liquid or too thick.
- For wooden foundation use boards treated with antiseptic and bitumen.
- For monolithic or brick supports, a concrete screed is made on a sand cushion 15-20 cm high above the top ground level. At the same time, it will serve as the basis for the construction of a basement. To prevent cracking of the screed, it is reinforced with metal rods in the form of a frame. Concrete is poured into pre-installed formwork. How to prepare concrete, see.
- M400 – best brand cement for building a foundation for a bathhouse. It is also important to take into account that shelf life affects the strength properties of cement. So, when stored for about 6 months, the strength decreases to 25%, and up to a year or more - by 30-50%.
- Factors that reduce the strength and operational durability of a columnar foundation:
- uneven depths of pillars;
- low-quality starting materials and their preparation in violation of the technological process;
- uneven load on columnar supports from the weight of the structure;
- the depth of the supports is incorrectly selected;
- erroneous assessment of the condition of the soil at the construction site;
- Construction of supports onheavingsoils were produced longer than one construction season. This circumstance affects the uneven deformation of the pillars. For example, if some supports were left for the winter without load from the walls, while others were built in the warm months of the year. This can, at best, greatly complicate the further arrangement of a columnar foundation for a bathhouse (grillages, plinth...) with your own hands.
For reference
Grillage(German) Rostwerk, from Rost – lattice and Werk structure) – the upper part of a pile or column foundation that distributes the load onto the foundation. The grillage is made in the form of beams or slabs that unite the heads of pillars (piles) and serve as a supporting structure for the elements of the structure being erected.
A grillage is also a single or double deck made of logs or beams laid on a crushed stone, sand or gravel bed, and serves as a foundation for light buildings.Pickup– a wall between the pillars that serves to insulate the underground space of the structure. It is an additional load-bearing structure, more evenly distributing pressure on the ground from the entire building.
Randbalka- a reinforced monolithic reinforced concrete beam, manufactured at the construction site and used to connect the foundation pillars to each other through the release of steel reinforcement. Sometimes a metal profile is used: a channel or an I-beam.
Wikipedia
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More articles on the topic “do-it-yourself bathhouse”.
If you build a columnar foundation for a bathhouse with your own hands, provided that the soil characteristics are satisfactory, this will ensure minimal construction costs. This is a reliable choice for areas with soil that is not prone to subsidence and swelling. This type of foundation consists of pillars buried in the soil made of different materials.
The columnar foundation is used for bathhouses made of logs and timber, and panel buildings. The frame structure of the bathhouse can also be installed on such a foundation. This is an ideal and economical option for lightweight wall structures and small buildings. The cost of material resources and labor costs for a columnar foundation is 1.5-2 times lower than the cost level for constructing a strip foundation.
A tangible result when constructing a columnar foundation for a bathhouse with your own hands will be real savings in money.
Columnar foundation structures
Let's take a closer look at how to make a columnar foundation for a bathhouse with your own hands and which foundation design to give preference to.
The foundation consists of a number of pillars located along the axes of all load-bearing walls, at the corners and intersections of the walls. The pillars are placed under internal partitions and other massive structural elements, such as a sauna stove. The best distance between pillars is 1.5-2 m.
Construction of a load-bearing building structure from various materials
Initially, the question arises of choosing a suitable and accessible material. The columnar foundation is made of:
- From wooden pillars - logs with a diameter of 200 or maybe timber using insulating materials and treatment with antiseptics. Least durable. Practical if the structure is being built for a period of up to 10 years;
- Made of brick, the size of the columns in plan is 380x380, stone 500x600;
- Made of concrete blocks 400x400;
- From steel pipes or asbestos-cement pipes filled with concrete;
- Made of monolithic concrete 400x400.
A bathhouse on a columnar foundation is being built on a prepared site; below are step-by-step instructions for its construction.
Preparation of work
First, the site is cleared of debris and graded. The top plant layer, at least 30 cm thick, is cut off. If necessary, the site is drained to drain the water. On clay soil gravel and sand preparation of the required thickness with leveling is arranged. If there is a large difference in height between the sides of the site, it is necessary to level the surface to avoid distortions of the walls.
The plan of the bathhouse is transferred to the land using a tape measure, level, stakes and twine, marking the axes of the building.
Excavation
The laying depth of non-buried columns, as a rule, is from 40 to 50 cm; it should be less than the soil freezing depth by one third of the value.
It is typical for a recessed columnar foundation that the supports are laid to a depth less than the freezing depth by 50-70%. So, if the soil has a freezing depth of 1.2 m, then the laying depth should be from 60 to 80 cm.
Holes for supports are dug manually or using a drill. Their depth is greater than the calculated backfill depth by the thickness of the sand bedding. The cross-sectional size of the pits is made larger by 10-15 cm for ease of installation of the reinforcement frame and formwork.
The bottom of each pit is filled with sand, moistened with water and then compacted.
Installation of a non-buried supporting structure
Basic principles of construction
Regardless of the chosen material, the columnar foundation is installed almost according to the same scheme - a hole of the required depth is prepared, filled with 15-20 cm of sand, which is compacted after pouring with water, then a support is placed. Let's look in detail at how to install poles made of various materials.
Wooden foundation
The construction of a lightweight building, such as a bathhouse, allows the use of wooden poles. For the “chair” posts, the lower part of the log is used - the butt with a diameter of 25-30 cm. It is better to use pine or oak. The size of the pit should be 1.5 times the diameter of the support. Preparation for installation consists of burning the lower part of the support with a blowtorch, treating it with an antiseptic solution and coating it with bitumen in accordance with building codes. These measures will extend the life of the tree. As a rule, pine supports last up to 10-15 years, and oak supports up to 25-30 years.
When building a bathhouse, one of two methods of constructing pillars is used - non-buried, in which a wooden pillar, the height of which is 70 cm, rests on a wooden base and is buried with a pillar height of 1.2-1.4 m. In the latter case, it is better if the support is installed on concrete preparation in a hole for reliable fixation, followed by backfilling with crushed stone and soil.
Brick foundation
The installation of brick pillars dictates the condition of durable and high-quality masonry in order to avoid destruction of the pillars and deformation of the walls of the bathhouse itself. The cross-sectional area of the pillar consists of 4 bricks. The pillars are laid to a depth of 0.5 to 0.7 meters
The service life of a brick pillar foundation can be 50-100 years, depending on factors such as climatic conditions, soil characteristics, brick quality and masonry strength.
It is important to use only solid red fired brick, which has the least properties to absorb moisture and good strength. Sand-lime brick is completely unsuitable for this purpose.
A sand and gravel cushion up to 20 cm thick is placed along the bottom of the pit, poured with liquid cement mortar and laid with a steel mesh made of wire with a diameter of 3-4 mm or reinforcing bars.
After completion of the masonry, waterproofing is installed on the surface of each pillar, for which roofing felt and bitumen are used, preventing contact of the masonry with the ground.
The sinuses are filled with soil or crushed stone and compacted.
Foundation made of concrete blocks
Scheme of a recessed and shallow foundation on a sand cushion
An obvious advantage of this type of foundation is the speed of its installation. Ready-made concrete blocks are used. These are solid blocks, or with small voids, which have dimensions of 20x20x40 cm. The quantity is calculated based on the design of the future construction.
The foundation of blocks is installed in the same way as brick pillars. Each row consists of at least two blocks. The next row is laid perpendicular to the previous one on masonry cement mortar and so on until the required height is reached. As a rule, 20-30 cm from the surface of the area is sufficient. Then work is carried out to waterproof all surfaces of the structure using roofing felt and bitumen mastic. The seams need to be treated especially carefully. It is necessary to finish by backfilling the sinuses with previously removed soil.
Pipe foundation
Load-bearing building structure on asbestos-cement pipes with a diameter of 200 mm
A convenient type of columnar foundation is considered to be metal or asbestos-cement pipes with a diameter of 200 mm. Their advantage is that they can be easily cut to the required length using a regular grinder with discs for cement or metal. The pipe should protrude approximately 40 cm from the ground surface.
Pipe surfaces must be waterproofed. It is done either by coating with bitumen or by covering with roofing felt on bitumen mastic in order to avoid corrosion and the negative effects of external factors.
Each pipe is lowered into a drilled hole with a diameter of 250 mm and a depth of approximately 1 m. Crushed stone is poured into the bosoms to a level of 40 cm from the bottom of the hole. It is advisable to insert reinforcing bars with a diameter of 12-14 mm into the pipe for strength.
After the preparatory work, you need to fill the pipe cavity with grade 400 concrete and compact it. Then fill the space between the pipe and the walls of the pit with small crushed stone or excavated soil.
An important note is that you need to cover the concrete columns with film and let them sit for 7-10 days to gain strength.
Monolithic concrete foundation
This type of foundation is very common and most reliable. The foundation, made according to the technology, has a service life of about 150 years.
It is enough to pour a shallow foundation under a wooden bathhouse.
Initially, you need to set up the formwork, which is prepared from edged boards. Then arrange a sand cushion and pour it with water and tamp it down. Next, you need to install the reinforcement cage, fill it with M400 concrete and compact it with a vibrator or a piece of steel reinforcement. The formwork can be removed after 2 weeks, depending on weather conditions, when the concrete gains strength.
After the concrete has gained strength and waterproofing work has been carried out, the cavity of the pits is filled with soil. You can begin installing the walls of the bathhouse, installing beams, roofing, and installing the floor.
What is the best way to make a floor on this type of foundation?
In order to protect the floor in the bathhouse from cold air and snow, a special wall is usually made of brick or concrete between the pillars with technological openings for communications and ventilation. This wall is called a fence. It serves to enclose the underground space; later it can be carried out additional insulation pick-ups with polystyrene foam. The question of how to close it is solved when covering the facade of the entire bathhouse.
The problem of organizing drainage in a bathhouse must be solved at the stage of constructing the foundation. This is relevant if it is planned to install a pourable floor. The installation of a pouring floor has the utmost simple design, in which a ladder is installed for draining water.
Do-it-yourself columnar foundation for a bathhouse
Do-it-yourself columnar foundation for a bathhouse: how to make a building support structure for a bathhouse, the main points of the device.
How to make a columnar foundation for a bathhouse - types of construction options
A separate well-equipped modern bathhouse is the dream of all summer residents and owners of country houses or cottages. To build such a bathhouse, it would be useful to use the services of professional, experienced builders. However, if you want to try your hand and save a little, you can start building a bathhouse yourself.
As with any building, the strength and solidity of a structure depends on its foundation. Since the construction of baths from logs or beams is quite common, the construction does not require a very solid complex foundation. In this case, a columnar foundation for a bathhouse is optimal. It consists of support columns sunk into the ground made of wood, concrete, pipes, stone, brick or cinder blocks.
Preparatory stage
At the preparatory stage, the area is cleared of debris, after which the area for the future bathhouse is marked. The top layer of soil along with grass, about 30 cm, is removed.
After this, you can drive pegs around the perimeter of the building and pull a thread to mark the axes of the bathhouse on the pillars. It is worth noting that if the terrain of the area has significant unevenness, it is better to use the help of experienced craftsmen to calculate the height of the columns. Proper foundation design will allow you to erect an ideal building without distortions or unevenness.
Ground work
Whatever material for support pillars Whatever you choose, the method of installing them will be similar, with the exception of the foundation with a grillage.
The installation depth of the support pillars depends on:
- soil type;
- soil freezing depth;
- depth of groundwater location.
You can determine the groundwater level, as well as the type of soil, by digging a hole 1-1.2 m deep. If the soil is not heaving, that is, it does not freeze deeply, and also if groundwater is not found, then this foundation depth is considered optimal.
But if the soil contains clay (heaving soil), then you should measure the freezing depth and dig a hole under the foundation 40 cm deeper than this level. Note that the more clay, the deeper the ground freezes.
If these conditions are neglected, the columnar foundation for the bathhouse poured with your own hands will collapse very quickly.
Support pillars should be located at the corners of the building, along the entire perimeter, at the intersections of walls, under partitions, at a distance of 1.5-2 m, depending on the weight of the structure.
Recesses for posts can be made either with a shovel or with a special drill, which makes holes with perfectly smooth walls.
Depending on the material, the thickness of the recesses for the support pillars may vary, but in any case it should be 7-10 cm wider.
The optimal thickness of the columns made from various materials is as follows:
- 50×50 – for brick and stone columns;
- 60×60 – columns made of rubble stone;
- Ø200 mm – asbestos cement pipes;
- 30-35 cm 2 – reinforced concrete supports;
- 25-30 cm 2 – for intermediate posts.
Under each post, at the bottom of the hole, you need to lay a sand cushion, that is, a covered layer of sand, filled with water and carefully compacted. Next, we’ll tell you how to make a columnar foundation for a bathhouse.
Columnar foundation made of pipes
Pipes made of metal or asbestos cement with a diameter of 20 cm are considered the best option for the construction of a columnar foundation. They are easy to cut into pieces of the required length. Such a column should protrude 40 cm above the surface.
To protect pipes from destruction due to moisture, they should be treated with special waterproofing mastics or wrapped with rolled materials, for example, roofing felt with bitumen.
The finished supports are lowered into the recesses as evenly as possible.
In the spaces between the posts and the edges of the hole, fill in the soil that was previously removed from the hole, or sand and gravel that needs to be compacted. The thickness of this layer is 40-50 cm. Next, several reinforcement rods with a cross-section of 12-14 mm are inserted inside each column, 7 cm from each other. Their length should exceed the height of the pillars by 20%.
Now you should fill the columns with concrete solution. It is optimal to use M400 cement, sand, small or medium crushed stone. To prepare concrete with your own hands, you should use a ratio of 1: 1.5: 3. Add 400 g of water per kilogram of cement. Concrete must be poured in several approaches.
After pouring the concrete, the columns are covered with film and left to dry and gain strength for 7-10 days. After this period, you can begin work on the construction of the bathhouse.
This technique is quite popular because it can significantly save time and money, and can also be done independently.
Brick columnar foundation
Preliminary preparation for the construction of this type of foundation is similar to the previous type. However, it is better to dig holes for posts by hand and make them a little wider to make it easier to work with.
A layer of sand 15-20 cm thick should be placed at the bottom of the recess and, after watering it with water, compact it thoroughly. A concrete base will subsequently be poured onto this sand cushion. For strength, reinforcing rods with a cross-section of 12-14 mm, cut to fit the size of the hole, are placed in the hole perpendicular to each other. The reinforcement at the intersection points is fastened together with wire with a diameter of 2-3 mm. Next, pour a 20 cm layer of concrete using M400 cement.
After a few days, when the concrete has hardened, brickwork can begin. The brick must be solid, for example, brand M-100, which is resistant to low temperatures and quite durable.
As you lay the brick, you should check its level to ensure that the finished support is level. Additional strength of the structure is given by the reinforcing mesh placed every 3-4 rows of bricks. The finished pillar is walled to a height of 15-20 cm from the ground surface, covered with roofing felt with hot bitumen or mastic for waterproofing. After a week, you can fill the hole around the post, thoroughly compacting the soil.
Although brick supports at first glance are quite strong, they can still be exposed to weather conditions at the seams and collapse over time.
Columnar foundation made of building blocks
To build this type of foundation, you will need industrial concrete blocks. Often, blocks with small voids or solid ones are used, the dimensions of which are 20 × 20 × 40 cm.
The advantages of this material are its strength and resistance to high loads. Basically, the principle of constructing a columnar foundation from blocks is similar to a brick one.
The differences in the technology of building a foundation from blocks to bricks are as follows:
- a thicker reinforced concrete base is required, about 50-70 cm, since the weight of the blocks is much greater than that of brick;
- as a cushion under the base, you can use not sand, but coarse or medium-fraction gravel, which will have a beneficial effect on the speed of moisture removal;
- starting to lay the first row of blocks, a small layer of fresh concrete mortar should be poured under it, serving as a cushion;
- in each subsequent row there should be at least two blocks, and in adjacent rows they are laid perpendicular to each other on a cement mortar.
The last laid row of concrete blocks should rise 20-30 cm above the ground level. The entire column is covered with a layer of waterproofing to prevent the influence of moisture and temperature changes on the blocks themselves and the seams between them. During installation, we must not forget about monitoring the level, which must coincide with the center lines of the markings for the bathhouse structure. The remaining gap around the laid posts must be filled with soil selected from the holes and compacted thoroughly.
If the foundation is laid on an area with uneven terrain, the depth of the block columns will be different, otherwise the finished structure may warp and the foundation will collapse.
Columnar foundation made of cement-sand mortar
A columnar foundation with reinforcement, made of concrete, is considered the most reliable and durable of all possible options.
Preliminary preparation and work with the soil are carried out according to the general scheme. To reinforce the columns, it is necessary to assemble a frame from reinforcement. To do this, vertically installed rods with a diameter of 12-14 mm are connected with thin wire to pieces of smooth reinforcement, 6-8 mm in diameter, closed in circles or squares.
To pour a concrete column of a certain diameter, formwork is used. To assemble it, you can use an edged board, chipboard or any other suitable material. A significant disadvantage of such a foundation is its labor intensity and financial cost.
The bottom of the hole under the post is covered with a 10-20 cm layer of sand, which is carefully compacted. A roofing material or polyethylene film is laid on top of the sand cushion, which will become a barrier to retain moisture in the poured concrete.
Concrete solution grade 400 is prepared from cement grade M400, coarse sand, and fine or medium crushed stone. Mix the ingredients in a ratio of 1:1.5:3, adding water at the rate of 400 g per kilogram of cement.
The solution must be poured in stages, tamping the concrete every 30-35 cm of filling to expel the air.
When the pouring is completed, the columns need to be covered with film so that the solution gains strength and does not begin to crack. After a few days you can remove the formwork.
Concrete support pillars must be protected with a layer of waterproofing, and the free space in the pit must be covered with earth and compacted.
If you want to save time and money when pouring a columnar concrete foundation, you can avoid standard rigid formwork. An alternative in this case would be soft formwork made of roofing felt with fiberglass mesh. In this case, the recess under the post is made using a drill whose diameter exactly matches the size of the future support.
After preliminary filling with sand and laying a layer of waterproofing, roofing felt rolled into a ring is lowered into the hole. After this, a frame of reinforcement is installed inside, and further pouring of concrete is carried out similarly to the method with rigid formwork. In this case, after the concrete has gained strength, a ready-made support is obtained, covered with a waterproofing layer, so that further construction work can immediately begin.
Foundation with grillage
The construction of a foundation with a grillage is important if you are planning to build a basement floor, or if the entire structure of the bathhouse is supposed to be very heavy, made of brick, for example. A grillage is a reinforced strip structure that serves to tie together all the foundation columns into a single whole. This structure serves to evenly distribute the load over the entire area of the foundation.
To fill the grillage, you should build formwork from edged boards 20-40 mm thick, plywood, OSB or other similar material. Inside, the structure will be reinforced with a metal rod with a cross-section of 10-12 mm. To prepare the solution, you will need concrete grade of at least 150. It is optimal to use concrete grade 200, which consists of M400 cement, coarse sand and small or medium-sized gravel. The proportion for mixing concrete yourself is 1:2.5:4.5. Water is added at the rate of 400 g per 1 kg of cement.
When calculating the consumption of lumber for formwork, it is taken into account that the width of the grillage exceeds the size of the poured columns by 10 cm, and its height should be at least 30 cm.
When calculating the material consumption for formwork, take into account:
- The height of the grillage itself, to which you need to add another 20 cm so that the formwork rises slightly above the concrete.
- The thickness of the lumber itself must be added to the size of the future grillage.
- The entire total length of the grillage.
If you multiply all the parameters found, you can get the amount of required material, measured in m3.
Having purchased the required amount of material, you should assemble the formwork box. Holes should be cut in the bottom of the box corresponding to the dimensions of the installed support pillars, which should freely rise slightly above the bottom of the box.
Next you need to assemble the reinforcement frame. For it, reinforcement bars and transverse square clamps are used, which can be made from smooth thin reinforcement or from 6-8 mm wire. Clamps need to be installed every 30-35 cm along the entire length of the formwork. The reinforcement is connected to the clamps using knitting wire. The width of the frame should be such that there is 5-7 cm left to the walls of the formwork, and its length should be equal to the length of the entire future grillage.
In cases where the distance between adjacent pillars is too large, the formwork can be additionally supported by wooden supports installed clearly horizontally.
The reinforcing frame installed in the formwork must be fastened with pieces of reinforcement protruding from the support pillars.
If you have a concrete mixer truck equipped with a full capacity required concrete, then the formwork can be filled with mortar in one day. At the same time, do not forget to remove air from the concrete with a construction vibrator, a piece of reinforcement, or a regular shovel.
But if you have to mix the solution yourself, the process of filling the grillage may take several days. In this case, one part of the grillage is poured at a time, dividing it vertically into segments. When pouring each next section, the edges of the already hardened concrete are thoroughly moistened with water to achieve better adhesion of the concrete.
Once the entire formwork has been filled with concrete, it is covered with plastic film and left for several days to harden. After the concrete has completely dried, you can remove the formwork, obtaining a finished grillage.
Note that a columnar foundation for a bathhouse in any of the design options is stronger and more reliable than, say, a strip foundation. In addition, it requires less time and material costs and can be done independently.
A columnar foundation for a bathhouse: how to make a bathhouse on pillars with your own hands, photos and videos
A columnar foundation for a bathhouse: how to make a bathhouse on pillars with your own hands, photos and videos
Columnar foundation for a bathhouse - do-it-yourself manufacturing technology
Foundation – important element any bath that provides it with durability, wear resistance and reliable operation.
Choosing the most suitable type foundation base carried out at the planning stage of the future structure.
Standard columnar foundation - the best option for the construction of lightweight baths - panel, frame, wood and foam blocks.
Building such a foundation with your own hands is quite simple; our step-by-step instructions will allow you to follow the step-by-step execution of the work.
Key Features
The columnar foundation, made for modern lightweight frame-type baths weighing up to 1000 kg/cubic m, is characterized by simplicity, accessibility and low cost of arrangement.
The support-column foundation has significant advantages that distinguish it favorably from other types of foundations:
- The design and calculation of a columnar foundation can be done on your own, without the use of additional equipment or the involvement of third parties;
- A foundation of this type can be installed on any soil with a low level of heaving and deep groundwater;
- Laying the foundation is possible in areas with significant differences at different points;
- The construction of a columnar foundation is carried out in a short time. Minimum period – 14 days;
- Provided high strength and the durability of the finished structure (the minimum service life of such a foundation is 50 years);
- Low cost of consumables and construction work.
Among the significant disadvantages are the following factors:
- The base is not suitable for the construction of heavy structures made of brick, concrete, cinder block;
- This type of foundation is not recommended for bathhouses equipped with basements;
- To protect against increased moisture, additional installation of a waterproofing layer is required.
Types of columnar foundations
A columnar foundation for a bathhouse or residential building structurally consists of special supports (pillars) installed in the ground at a level of up to 155 cm with a protrusion of 0.25 to 0.55 m in the ground part.
Installation of supports is carried out at the corner points of the building, as well as at the junction of walls and partitions. If there is a slope at the construction site, it is recommended to install additional supporting elements up to 3.6 meters long.
The main elements can be located at a distance of 150 to 300 cm from each other.
A distinctive characteristic of such a base is the arrangement of a grillage - a special system consisting of rand beams and strapping supports. It is designed for uniform and safe distribution of mechanical load on the finished base.
For frame and wooden baths, beams or logs made of wood are used as strapping elements; for concrete and brick structures, channels and beams made of metal are used.
Before you build a columnar foundation with your own hands, you should determine the type of landscape and the technology for constructing the structure. This affects the choice of building materials for the foundation and its depth.
To build foundations of this type, the following materials are used:
- Pipes made of asbestos cement, metal and plastic;
- Blocks;
- Frost-resistant brick;
- Stone;
- Iron and rubble concrete;
- Tree.
When choosing a certain type of material, it is important to correctly calculate the load-bearing capacity coefficient, on the basis of which the appropriate support section is determined.
For structures made of concrete and blocks, a support with a cross-section of 45 cm is sufficient, for concrete and rubble stone - up to 65 cm. When using pipes with a diameter of up to 35 cm, it is additionally recommended to strengthen the hollow structure using a frame made of thin reinforcement and a concrete mixture.
This parameter is determined by the design and technical features of the future foundation, as well as the geological parameters of the soil.
According to the depth of laying, a columnar foundation for a bathhouse can be:
- Recessed - the filling level is below the permissible level of possible soil freezing;
- Shallow - depth ranges from 45 to 75 cm from the top soil level;
- Non-buried - located in the upper part of the soil. At the installation points of the supports, the top layer of earth is removed and filled with non-metallic material.
According to the construction technology, foundations can be monolithic or prefabricated.
The most popular options for monolithic foundations are:
- Columnar strip foundation. It is intended for the construction of frame-type structures and wooden buildings - residential buildings, gazebos and bathhouses. It is characterized by simplicity of arrangement and reliability of operation. The basis of the foundation is special holes in the ground, where reinforcement is installed and the concrete mixture is poured. The finished column can withstand ultimate loads up to 16 tons;
- Reinforced concrete columnar foundation. It has increased strength, wear resistance and good load-bearing capacity. It is erected from asbestos-cement and metal pipes installed on a protective cushion of sand and gravel. To increase strength, a reinforcing belt is made.
A monolithic columnar foundation is a fairly practical and economical option that is suitable for the construction of country houses and baths.
We offer you a complete technical manual that will help you make a columnar foundation with your own hands in a short time.
Preparatory and design work
At the preparation stage, the future columnar foundation for a bathhouse and a house requires correct calculation load-bearing capacity of the structure along the cross-section of the support pillars.
For monolithic design The minimum permissible cross-section is 25 cm. To increase the stability of the structure, it is recommended to expand the base of the pillars with special ledges: for a height of up to 60 cm, the width should be 120 cm. The permissible pitch for installing pillars is up to 2 meters.
Next, the site is prepared for construction - garbage removal, cutting off the top layer of soil to a depth of 22 cm along the perimeter of the future bathhouse. In this case, it is recommended to make indents from the perimeter of the base up to 200 cm.
The second stage is carrying out horizontal adjustments to the level of the site with the elimination of existing flaws - holes, mounds, hills, crevices. For this, a mixture based on gravel and sand is used.
Marking for support pillars and their installation
The third stage is preparing the marking of the area for the installed support pillars. This is done as follows:
- Arrangement of cast-offs - installation of support pillars in the corners at a distance of up to 200 cm from each other. The same scheme is used to move the remaining supports in accordance with the approved development plan;
- Tensioning ropes along the external axes for each load-bearing wall, as well as along the internal axes for partitions;
- Checking the accuracy of diagonals for all internal and external walls.
Installation of pillars requires the preparation of holes, which can be dug manually or using specialized equipment. The depth of the holes is 20 cm, width is up to 50 cm.
Arrangement of sand cushion and reinforced frame
The fourth stage is arranging the pillow. To lay the pillow, a non-metallic and practical material is used, which acts as a support for the future foundation. The pillow manufacturing technology is as follows:
- A layer of dense fine sand – 15 cm;
- The layer of crushed stone of the middle fraction is 18 cm.
Each layer of the pillow is carefully compacted and moistened with water. When constructing a monolithic structure, it is additionally recommended to fix the cushion with a cement-based solution.
The reinforced frame provides additional rigidity, wear resistance and reliability of the finished structure. It is based on hollow pipes made of asbestos cement and metal, which are immersed in earth holes.
A reinforced frame is inserted into the cavity of the pipes and then filled with concrete mixture. When pouring concrete, vibration is required.
The vibration process serves to eliminate air voids and increase the strength of the supports. Reinforcement is performed in the longitudinal direction using A3 reinforcement with a diameter of up to 14 mm. Installation of horizontal jumpers is carried out in increments of 18 cm. For this, metal wire with a diameter of 7 mm is used.
To increase the strength of the finished structure, the base of the pillars is equipped with a monolithic or metal grillage. In such a case, the reinforcing bars should rise above the foundation at a minimum distance of 15 cm.
Waterproofing protection and backfill
To protect the foundation (ground and underground parts) from the effects of precipitation and groundwater, installing a waterproofing layer will help. For this, modern moisture-resistant mastics, rolled roofing felt and thin membranes are used.
After completing the waterproofing work, the cavities between the walls of the earth holes and support beams are filled. For this, regular soil or a mixture based on gravel and sand is used.
Backfilling is carried out in stages, with each previous layer being carefully compacted. The depth of one layer does not exceed 30 cm.
Removing the base
The fence is the base of the bathhouse, which performs aesthetic and protective functions - improves appearance facade and protects the structure from the penetration of cold and dirt.
The optimal pick-up height is 40 cm.
To ensure natural ventilation, air holes are provided in the intake - vents. In addition, all necessary communications are laid there.
For the construction of the fence, it is allowed to use any building materials - bricks, natural stone, cinder block. The finished structure can be faced with tiles, porcelain stoneware, decorative plaster, a ventilated facade, siding or ordinary roofing felt.
Before starting work on arranging the fence, it is recommended to make a cement screed 20 cm thick, which will provide the walls with reliable support.
The columnar foundation is reliable, durable and wear-resistant. Even a beginner can organize the work on its construction.
This foundation technology is successfully used in the construction of bathhouses, residential buildings, technical and utility buildings.
Do-it-yourself columnar foundation for a bathhouse: step-by-step instructions
A columnar foundation is a simple and reliable foundation for houses and baths. Main types, advantages and disadvantages of the design. Step-by-step construction instructions.
What is good about a columnar foundation for a bathhouse? Price and simplicity
The foundation is the basis of any structure, be it a bathhouse or any other building. The durability of the structure always depends on the quality of the foundation. This applies to any building, including a bathhouse. Therefore, when starting construction, it is necessary to study what types of foundations for baths exist and what buildings they are suitable for.
There are different types of foundations - strip, columnar and piles. A strip foundation resembles ribbons that take on the load of the entire building. A columnar foundation is the pillars on which the building rests. This foundation does not require careful soil preparation, is quite simple to manufacture and does not require special professional training.
Columnar foundation for a bathhouse or pile foundation: let's decide
A columnar foundation for a bathhouse is often the most cost-effective solution: rows of pillars placed at the intersection of nodes. The pillars are placed where there are load-bearing walls of the building, at the corners and where they intersect. If there are partitions or other massive structures inside the building that can put additional load on the foundation, then additional pillars should also be installed under them.
If you have to choose between a pile or columnar foundation, then due to the ease of execution, you should choose a columnar one. But this statement is only true if when the soil is strong enough, that is, it is not swamp or alumina, which has a lot of water.
Also, such a foundation should be used when when the mass of the building is small, otherwise the building will “float”. A columnar foundation is also called a pile foundation, but there is some difference. The fact is that pile foundations are used for large, massive, multi-story buildings erected on deep soft soils (sandy or subsidence), using the latest modern technologies and involving heavy equipment, which is completely impractical for an ordinary home bath.
Pile foundation - the same pillars, only more massive. Moreover, the piles are buried to great depths - up to or more than 5 meters. The pillars rest their base on the sole, and the side surfaces of the piles also work in addition. The cross section of the pile is smaller than the cross section of the pillar. In addition, the areas of application are also different - pile foundations are used on soils with poor characteristics. We recommend reading more about pile foundations in another article.
Columnar foundation for a bathhouse: what types of columns are there?
So what materials can be used for a columnar foundation?
In order for the columnar foundation under the bathhouse to be strong, preliminary work is carried out. To do this, you need to carefully calculate everything and make drawings. This stage is best done by professionals; the rest you can do yourself. When everything is ready, they begin to mark the area. This is done in stages.
- Leveling. At the same time, small differences in heights are unimportant.
- A peg is driven in. At a distance equal to the length of the wall, install another one and connect them with a cord.
- Thus, following the drawing, four pegs are driven in, connecting them with a cord. This is how the outer perimeter is formed.
- The same is done marking the internal perimeter, where the thickness of the walls is also taken into account. If there are several rooms planned in the building, then this is also taken into account when marking.
- Digging holes. The holes are dug to a certain depth. In this case, their location should be taken into account: corners, places where the walls are connected, and also where the heaviest load will be. The pitch of the pits is no more than 1.5 m.
- The holes should be the same in depth and be 50%-70% of the freezing depth of the soil. This applies to shallow foundations.
Shallow monolithic concrete
Such a foundation has enormous strength and a long service life (up to 150 years). If the bathhouse is wooden, then use a shallow structure, with a pit depth of 500 to 700 mm, not taking into account the sand backfill.
To build a lightweight building, you do not need to equip formwork. Simple roofing felt formwork will suffice. Roofing felt or roofing felt is rolled into a pipe of the required diameter and length, then fixed with reinforced tape.
Next, place this product in a hole, cover it with sand 10-15 cm thick and fill it with water to make the sand more dense. Sand again, and water again. After the sand backfill is compacted, you need to install a belt of reinforcement with a smaller diameter than the roofing felt tube, 5 cm.
Then a concrete solution is poured into this form, compacting it with a piece of log or a vibrator, or bayoneting it with a piece of reinforcement.
In this video, not everything is done as described above, but the essence is shown well.
If you have decided on a columnar foundation made of blocks, then you should pay attention to the fact that not all concrete blocks are suitable for this purpose. You should not take blocks made of expanded clay, sawdust and shell rock. You should also avoid blocks that have voids. It is best to use cinder blocks or ready-mixed concrete. Under no circumstances should gas or foam blocks be used.
This is what happens to foam block from humidity
Concrete blocks for point foundation
To arrange the foundation you need:
Conduct waterproofing concrete structures,
Livnevka. In order for the pillars to hold the structure well, it is necessary to make pillows in the holes. The pillow is 20 cm of sand poured onto non-woven material, and abundantly moistened and compacted. Or a similar layer of gravel, also well compacted.
Then blocks are placed at the bottom of the pit and secured with liquid cement mortar.
From bricks
For this foundation, burnt red clay bricks are used. Wherein the depth of the pits ranges from 50 cm to 1.2 m, and the width is such that it is easy to do masonry. The main condition for this foundation design is the strength and quality of the masonry, because poor quality work can cause the destruction of the building or its deformation.
So, in order to equip such a foundation, sand, crushed stone or gravel are poured onto the bottom of the finished pits. This layer should be 15-20 cm. Mounted on top concrete screed using reinforcement. Typically the reinforcement is wire mesh with a diameter of 3-4 mm.
After the brickwork is completed, the pillars should be covered with bitumen mastic so that the brick does not come into contact with the ground. The voids between the pillars and the ground are filled with crushed stone.
Stone is a natural and very durable material. It is ideal for constructing a columnar foundation. However, two stones differ from stone to stone. Soft, layered stones should not be used in construction. Irregularly shaped rock is best suited for construction. It is best to select flat stones. Usually stones are irregular in shape. When using them, such stones should be processed with a sledgehammer and a chisel, giving them more or less the desired shape and size.
1. Natural stone.
3. Concrete solution
5. Reinforced wire mesh
The stone can be placed either in a dug hole or in formwork. Formwork should be used only when the soil is loose. The technology for creating a pillar is as follows:
Place a sand cushion at the bottom of the hole;
Pre-soak the stone in water and then dry it, selecting the stones with the most correct shape. This is necessary to create the first rows;
Fill all the voids between the stones with crushed stone and fill with cement mortar;
When laying, it is necessary to make dressings, as when using bricks, otherwise the entire structure will crumble.
When assembling a pillar, you need to select stones in such a way that there is as little empty space between the stones as possible.
All voids are filled with smaller stones. This allows you to make a drainage layer in the pillars.
This foundation is based on wood.
For this foundation design, various types of wood are used - oak, pine, larch. These trees are biologically stable, since after they are treated with an antiseptic they will last for several decades. To make pillars, use the lower part of the trunk - the butt, with a fairly large diameter. Such pillars are buried to a depth of up to 70 cm for internal walls, and up to 1.5 m for external walls.
Easy to install
Wood has the property of elastic deformation, which helps it not collapse under excess pressure. Flaws:
Fragility. Oak treated with an antiseptic lasts up to 30 years, and pine or larch - up to 15 years. The pillars are mounted in all corners, where the walls intersect, and along the perimeter of the building with a step of 1.2 - 2 m from each other.
The holes are dug so that their diameter is 1.5 times larger than the column. At the same time, a 20 cm sand base is poured onto the bottom of the pit and compacted well. Next, the pillars are installed, having previously wrapped them in a waterproofing bandage consisting of roofing material glued with bitumen mastics.
The pillars are mounted strictly vertically and along the axis of the wall. At the same time, they are tied to lighthouses, where nails are driven in and cords are pulled - moorings. Then the remaining pillars are installed, determining the vertical by the plumb line, and the horizontal by the cord - the mooring. The posts in the pits are mounted on wooden crosses or concrete pads. Then along the cord - the mooring - their surface is cut down to level the horizontal. After this, waterproofing is done at the ends of the pillars. This procedure is carried out after backfill and compaction of pillars.
Bathhouse on a columnar foundation
Typically, baths are fairly light buildings, assembled from timber or frame-panel. It is for such buildings that columnar foundations are erected. If the soil is light, heaving or sandy, then there is no need to dig the pillars too deeply. A depth of 50-70 cm is sufficient. If the soil is heavy, clayey, then the pillars are dug into the ground below the freezing point of the soil. This is done so that the building does not warp in the spring.
Another disadvantage of a columnar foundation is its tendency to move horizontally. Solid brick or concrete building this foundation structure will not hold up.
Bathhouse on a columnar foundation with grillage
To make the structure more stable, the building on a columnar structure is reinforced with a grillage. The grillage is the upper part that distributes the load of the load-bearing structures of the building. Typically, a reinforced concrete frame is used, which is installed on poles dug into the ground. The grillage connects the heads of the pillars and serves as a support for the building. The name comes from the wooden lattice on which the wooden floor used to be laid.
Making a grillage
A grillage is made using various materials: metal, timber, boards, concrete. There are two types of grillage: monolithic and prefabricated.
A prefabricated grillage can also include a wooden grillage, which is mounted on poles for the construction of baths. The timber itself is impregnated with an antiseptic that prevents decomposition, and is laid on pillars or piles by means of a waterproofing gasket. The beam is attached to a post or pile with bolts or brackets.
The floor in the bathhouse is on a columnar foundation
Typically, the floor in such a room is made without a rough screed; edged or tongue-and-groove lumber is used. But this a budget option, unsuitable for the cold season. This floor is also called leaking. The design is quite simple: boards are placed on the joists, with gaps left between them so that water flows into a recess under the floor and goes away along the ditch.
Not leaking gender more complex design, which is a layer cake. Such a floor consists of a rough and finished floor, between which layers of hydro- and thermal insulation are laid. The finished floor boards are fitted closely to each other so that liquid cannot leak through the cracks. The boards are laid at a slight angle. This is done so that the water itself flows to the drain hole.
You can also fill in concrete floor in a bathhouse on a columnar foundation, there are practically no differences from a screw one.
A bathhouse on a columnar foundation is a cheap, reliable option for a country house or personal plot. Does not require large financial costs and physical effort, in comparison with other types of foundations.
Columnar foundation for a bathhouse: shallow, made of blocks, concrete, brick, floor on a columnar foundation
If you want to make a cheaper foundation for a bathhouse, then take a closer look at the columns. It’s not difficult to make a columnar foundation for a bathhouse, consider the types, what to make it from, how to make it, how to place the floor
It is difficult to imagine a country house or cottage without a separate room for taking water procedures - a bathhouse. When planning its construction, you should carefully consider all the design features of the structure, paying special attention to the construction of the foundation. As a base for a building for a bathhouse made of wood, panels, cellular types of lightweight concrete and other materials, various types of foundations are used.
The most common option is a columnar foundation, which has the necessary safety margin, is erected at a minimum level of costs, and is simple. Let us dwell in detail on the design and technological nuances, thanks to which a bathhouse on a columnar foundation has a long service life.
A column foundation for a bathhouse is one of the economical options for arranging the foundation for this type of outbuildings
Bathhouse on a columnar foundation - design features and technological nuances
A column-type base is a group of separately located vertical supports that support the weight of the structure installed on them and are mounted in areas with increased loads:
- corner areas of joining the main walls of the future building;
- points of mutual intersection of external walls and internal partitions.
Depending on the manufacturing method, the base for the bath is formed in the following options:
- monolithic. A solid base made of concrete reinforced with steel rods is characterized by the absence of joints and increased strength;
- team The composite structure is quickly assembled and consists of stones or bricks connected with cement mortar.
The degree of immersion of columns into the ground is determined by the level of freezing. Supports are carried out:
- buried below the depth of soil freezing by 0.5–1 m;
- shallow, immersed in the soil by 0.4–0.7 m.
Posts for this type of foundation can be constructed from a variety of materials
If a bathhouse is being built on a columnar foundation, pay special attention to the following points:
- the interval between vertically located elements is from one and a half to two and a half meters;
- the distance between columns decreases with increasing force on the elements of the supporting structure;
- changing the size of the pillars depending on the strength of the building material used for the supporting columns;
- the base rises above the zero mark at a distance of 0.2–0.5 meters, is leveled, waterproofed with roofing felt;
- compacted gravel-sand bedding 20 cm thick is a reliable basis for supports installed below the soil freezing level;
- filling the space between the columns with sand or crushed stone and then connecting the supports with concrete, stone or brick walls prevents the entry of moisture and reliably retains the heat of the room.
The construction of a foundation for a bathhouse is preceded by the following activities:
- Settlement stage. It is the basis for further work. Includes determination of soil type, groundwater depth and freezing level.
- Preparatory work. They provide for leveling the site for the construction of a structure, removing all vegetation and removing the fertile layer of soil.
- Site marking. The preliminary developed plan is transferred to the construction site using a cord, pegs, level and tape measure.
- Soil extraction. It is carried out according to preliminary calculations for the installation depth of supporting structures with the freezing depth exceeding 50 cm.
It is necessary to build a columnar foundation on a pre-prepared area
The formation of pits can be carried out as follows:
- manually using a shovel or a special drill with a cone-shaped working body;
- mechanized using mobile equipment to drill holes in the soil.
It is important to ensure the verticality of the walls, as well as compliance with the dimensions of the holes for supports made of various types material:
- columns made of rubble stone - 0.6x0.6 m;
- brick and stone supports - 0.5x0.5 m;
- tubular racks made of asbestos cement – diameter 0.2 m;
- supporting elements made of reinforced concrete – 0.3–0.4 m;
- wooden posts – 0.2–0.3 m.
After filling each pit with a sand cushion, moistening it with water and compacting it, you can begin to build a columnar foundation. Let us further dwell on the types of foundations and the principles of their formation.
The most popular are brick and concrete foundations, the service life of which is calculated in decades
Options for columnar bases for baths
The foundation for a bathhouse can be made on one of the following types of foundations:
- block, consisting of concrete or industrially produced reinforced concrete elements reinforced with reinforcement;
- concrete, poured into formwork and reinforced directly during the manufacturing process;
- brick or stone, the material of which is concreted with a binder cement mortar;
- tubular, consisting of metal or asbestos-cement pipes separately immersed in the ground;
- wooden, based on wood support elements treated with an antiseptic, capable of supporting the mass of light buildings;
- grillage, connecting the columns into a circuit that takes up significant loads from the mass of the structure.
The choice of material is determined by its load-bearing capacity, the design features of the base for the bathhouse, the weight of the structure, and soil conditions. If the soil contains coarse sand fraction, soil, clay inclusions, then a columnar foundation is the optimal solution.
Block base for a bath
The use of ready-made concrete or reinforced concrete blocks allows you to form a solid foundation in a limited time by installing elements in pre-made pits buried 50–70 cm into the soil.
It is necessary to select the material from which the foundation will be built at the design stage
Quite often, developers use solid blocks with dimensions of 0.2x0.2x0.4 m or products of similar sizes with internal cavities. Having increased strength, the block material is able to withstand significant forces.
There are two types of columnar foundations - a foundation made of blocks and drilled piles. Ordinary brick is often used as a basis for blocks, but its use is only permissible as a last resort if the building has minimal weight and the soil is sufficiently stable. Standard, according to GOST 6133-84, when arranging columnar base is the use of special foundation blocks 20x20x40 cm. As for drilled piles, they are usually made of concrete poured into asbestos-cement pipes, which are dug into the ground below the freezing depth of the soil.
As you know, before starting the construction of any building on a site, you need to carry out all the necessary calculations. And first of all, this applies to the calculation of the foundation, since the integrity of the entire structure will depend on its reliability. The main thing to consider here is the type of soil and the weight of the structure. Determining the type of soil is carried out using a series of tests and ideally requires calling specialists to carry out geological exploration work.
The weight of the building will determine the number of columns required, which will ensure that the building remains in a stable position. The choice of a simple columnar foundation for a bathhouse from columns assembled on the basis of foundation blocks is allowed only if the total weight of the structure is small (light wall material and the absence of a second floor).
Let's consider the process of making such a foundation using the example of a foundation for a small one-story bathhouse made of timber. This technology is suitable if the groundwater level in the area does not rise above 2 meters in the spring. The surface of the soil should not have any noticeable slope, and its composition should include either medium sand or clay of medium density or harder.
How to make your own foundation?
The first step is to mark the future foundation using a tape measure, wooden pegs and strong thread. The number of columns is taken so that the load on one support does not exceed 4 tons.
After taking all the measurements, installing the pegs and tensioning the threads, you can start digging holes. The depth is chosen based on the height of the fertile layer, but not less than 25 cm. It is necessary to completely remove the top layer of soil and get to the denser layer of soil underlying it.
The pillars are made from blocks 20x20x40 cm (more precisely 39x19x18.8 cm) with a masonry width of two blocks. Thus, the area of one column will be 40x40 cm, and the dimensions of the hole for it should be such that there is an indentation of 20 cm on each side. As a result, we get the final dimensions of 80x80 cm.
Next, each hole is filled with a layer of sand and gravel mixture (SGM) or sand 15 cm high. The resulting surface is spilled with water and compacted well. When all the holes are prepared, you can proceed to making the posts. One support consists of four concrete blocks 200x200x400 mm.
Each block is attached from the sides to the adjacent one with cement-sand mortar, in a ratio of 1 part sand to 2 parts cement. It is advisable to take quarry sand, but if only river sand is available, then it should first be asked through a sieve with a mesh of 2x2 mm. In the layer between the upper and lower tier, a masonry mesh with a rod thickness of 4 mm and a cell of 100x100 mm is additionally placed in the mortar.
The height of the top layer is adjusted using a level to the adjacent supports. It is important not to skimp on cement and carefully level the plane of each column. After everything is ready, the solution should be watered daily for at least two weeks, completely covering it with plastic wrap after each procedure.
The free space in the hole around the support is filled with sand or ASG to the level of the surrounding soil. Thus, all the columns end up in a small depth of 10 cm.
As you can see in the photo, the bathhouse, which is installed on this foundation, has small dimensions and is built of timber. A box made of logs or beams guarantees a more even distribution of the load on each support than a frame structure that has a less rigid structure.
It is also important to pay attention to the perimeter of the building. It is protected by an insulated waterproofed concrete blind area. If there are any doubts about the resistance of the soil to deformation under the influence of frost heaving forces (freezing of water in the soil, leading to its swelling), it is imperative to make a blind area with a heat-insulating layer. It will not only reduce the depth of soil freezing, but also protect the soil under the supports from being washed away by water flowing from the roof in the form of precipitation.
As an additional measure to minimize the negative consequences of soil erosion during periods of prolonged rain, a drainage pipe buried to a shallow depth is placed around the blind area. Organization drainage system- a separate big topic, but for regions subject to active soil erosion in the spring or during rainy periods, it is simply necessary to provide for its protection from the negative influence of water.
Almost all happy owners of private houses, cottages or country houses Would like to have a separate bathhouse on your property. To build it, you can use the services of professional builders or build a bathhouse yourself.
The basis for the strength and durability of every building is undoubtedly the foundation. Often, for the construction of baths they use wood material- logs or beams, thanks to which the construction is quite light. That is why it is advisable to build a bathhouse on a columnar foundation, which consists of support pillars buried in the soil different material. Such supports can be mounted from wood, brick, stone, pipes, foundation blocks, reinforced concrete.
Columnar foundation - diagram 
Before starting work, it is necessary to clean and level the site for future construction. To do this, we remove the top layer of soil (about 30 centimeters) under the planned building along with all the vegetation.
Then it is necessary to level out all the holes and irregularities as much as possible, and when clay soil backfill with sand and gravel.
Next, we transfer the plan of the bathhouse directly to the land using a tape measure, building level, ordinary wooden or metal pegs and construction thread to mark the axes. If the site is located in an area that has a significant difference in height between the sides, then to determine the height of the foundation pillars, it is advisable to use the help of a professional and level the surface. This is a guarantee that the future bath will not have distortions.
Excavation
Regardless of the choice of material for installing columnar supports, all foundations of this type are mounted according to a similar principle (except for the option with a grillage). This also applies to excavation work, before starting which you need to determine the type of soil, proximity to the surface of groundwater and the depth of its freezing.
These factors directly affect the installation depth of the support pillars. To determine the type of soil and groundwater level, you need to dig a hole at least 1-1.2 meters deep (optimally). If there is no groundwater at this depth, and the soil is not heaving - freezing, then this depth is quite sufficient for a columnar foundation of a bathhouse.
Otherwise, you need to dig to a dense, incompressible layer of soil, focusing on the following indicator: freezing depth + 40 centimeters. It must be remembered that heaving soils include those that contain clay. And the more it is contained, the more prone the earth is to freezing. If these conditions are not met, then under the influence of water or subzero temperature The foundation can not only crack or deform, but also completely collapse.
Columnar foundation supports must be located at the corners of the building, at the intersection of walls, along the entire perimeter and under the partitions every 1.5-2.0 meters, depending on the total weight of the structure. Holes for supports can be dug with a shovel, or you can use a special hand-held cone-shaped drill of the required diameter, thanks to which it is possible to obtain the most even holes.
Based on what material will be used for the construction of the columnar foundation, the required diameter of the holes is determined, which should be 7-10 centimeters larger than the following parameters:
- for pillars made of brick and stone, the optimal size is 50x50 centimeters;
- for pillars made of rubble stone - 60x60 centimeters;
- for asbestos-cement pipes Ø200 mm;
- for reinforced concrete supports 30-35 centimeters is enough;
- for intermediate ones it is 25-30 centimeters.
We pour about 20 centimeters of sand into the bottom of each prepared hole, add a little water and tamp it thoroughly, thus obtaining the desired sand cushion. At this point, the preparatory and excavation work is completed. You can begin directly constructing a columnar foundation from the selected material.
Columnar foundation made of pipes
The best option for a columnar foundation of a bathhouse is metal or asbestos-cement pipes Ø200 millimeters, which can be easily cut with a grinder into pieces of the required length. It should be taken into account that a pole made of a pipe should protrude above the surface by approximately 0.4 meters.
| Name of product | Weight of 1 pipe, kg | Internal external diameter, mm | Price 1 p/m, rub. |
|---|---|---|---|
| BNT 100*3.95m | 24 | 100/118 | 102,97 |
| BNT 150*3.95m | 36 | 141/161 | 165,79 |
| BNT 200*5m | 85 | 200/222 | 319,99 |
| BNT 250*5m | 125 | 238/266 | 392,76 |
| BNT 300*5m | 162 | 292/320 | 617,46 |
| BNT 400*5m | 279 | 365/407 | 958,66 |
| BNT 500*5m | 430 | 456/508 | 1732,51 |
Pipes must be protected from moisture and other negative factors. To do this, you need to make waterproofing - wrap the surface of the pipe with roofing material with bitumen, lining waterproofing materials, or treat it with special mastics.
The prepared pipes are carefully and evenly lowered into each hole.
The gap between the pipe wall and the soil is filled with previously dug earth or sand and gravel (layer thickness 40-50 centimeters), which it is advisable to compact thoroughly.
Reinforcing rods Ø12-14 millimeters should be inserted into the middle of the installed pipes at a distance of 7 centimeters from each other, which act as a reinforcing frame. Since the reinforcement must protrude above the finished pillars, its length should be 20% greater than the size of the pipe.
Having carried out these preparatory work, you can begin pouring the foundation pillars. The best option is concrete grade M400. It can be ordered from specialized enterprises or made yourself using a concrete mixer. At self-production It is enough to use cement grade M400, coarse sand, gravel of small and medium fractions, which must be mixed in a ratio of 1: 1.5: 3. The required amount of water is 0.4 part of the amount of cement taken.
The process of pouring the concrete mixture itself occurs in several stages (see table).
| Work order | Illustration |
|---|---|
| concrete is poured inside the installed pipe to a third of its height |
|
| the pipe rises, which allows the concrete to form a kind of cushion, and then is pressed into this base |
|
| Subsequently, we continue to pour concrete into and around the pipe step by step, compacting it every 0.3 meters with a deep concrete vibrator, and in its absence, a reinforcing rod can be used. This is necessary to get rid of air bubbles and improve the quality of concrete. |
|
We cover the piles made in this way with film and let them stand for 7-10 days. During this time, the concrete gains the necessary strength and the construction of the bathhouse can continue.
This method of constructing columnar foundations is one of the most popular due to its high reliability, relative cheapness, and speed of installation with minimal skills.
Prices for asbestos-cement non-pressure pipes
asbestos-cement non-pressure pipes
Preparatory and excavation work before arranging a columnar brick foundation is similar to working with pipes. But for the convenience of the master, holes for future pillars will not have to be drilled, but dug manually or using machinery, which is much faster, but also more expensive. At the same time, do not forget to slightly increase the volume for ease of operation.
We fill the bottom of the prepared pit with a fifteen- to twenty-centimeter layer of sand, which we compact, forming a sand cushion. On top of it it is necessary to pour a concrete base, reinforced with a mesh of reinforcement. To make the mesh, we take reinforcing bars with a cross-section of 12-14 millimeters, cut to the parameters of the pit. We lay them perpendicularly, forming square cells, the intersections of which are fastened with thin knitting wire with a diameter of 2-3 millimeters. For ease of knitting, you can use a special hook, which is worth purchasing at a hardware store. Thickness concrete base(M400) together with the reinforcing mesh should not be more than 20 centimeters.
Columnar brick foundation - diagram
After giving the concrete a few days to gain strength, you can proceed directly to the brickwork. It is necessary to take into account that hollow bricks are completely unsuitable for this. It would be optimal to use solid ceramic bricks (for example, M-100), which have the necessary strength and resistance to low temperatures.
When making brickwork, it is advisable to check each row with a level. This will allow you to get an even column. For greater strength of the pillars, you can lay a mesh of reinforcement after 3-4 rows of bricks. We bury the brick support of the foundation 15-20 centimeters above ground level and protect it waterproofing material– mastic or roofing felt with hot bitumen. After 5-7 days, we fill the finished brick pillar with earth, which we compact thoroughly.
Despite the popularity of this columnar foundation, it has its drawbacks. The seams between the bricks make such a support quite fragile and under the influence of unfavorable factors it can be destroyed.
Brick prices
For its production, industrial concrete foundation blocks are used. Most often we use a solid block or with minor voids measuring 20x20x40 centimeters.
It's durable construction material, withstanding significant loads. A columnar foundation made of blocks is mounted similarly to brick supports, taking into account some differences:
- due to the greater weight of the blocks, the thickness of the monolithic reinforced concrete base on top of the sand cushion varies from 50 to 70 centimeters;
- It is permissible to make it from coarse and medium fraction crushed stone instead of sand bedding. This helps remove any moisture present;
- before installing the first row of blocks, it is necessary to make a cushion of mortar, on which the building material should be installed;
- the row being installed must consist of at least two blocks. Each subsequent one is installed perpendicular to the previous one and fastened to it with ordinary cement mortar for masonry.
The last row of blocks is mounted 20-30 centimeters above the ground and covered with waterproofing material to protect the seams and the blocks themselves from moisture and low temperature conditions, which together can lead to the destruction of a columnar foundation of this type. When laying blocks on the surface, you need to carefully control their location relative to the marked axes of the future bathhouse building. We fill the gap around the mounted block supports back with previously dug soil, which we also tamp.
Block foundation - photo
Laying blocks on a sloping area requires special attention. Under no circumstances should block supports be laid at the same depth. This can lead to subsequent distortion of the bathhouse and destruction of the columnar foundation.
Concrete columnar foundation
A reinforced monolithic columnar concrete foundation is considered the strongest and most reliable.
To manufacture it, we carry out preparatory and excavation work in accordance with general technology. From reinforcement Ø12-14 millimeters we make round and square frames (we use 3 or 4 rods, respectively) of the required length, taking into account the protrusion above the post by 15-20 centimeters. To do this, we connect the rods with thin wire to round or square rings bent from smooth reinforcement Ø6-8 millimeters.
It is possible to fill a foundation pillar of the required size only with the help of formwork, which should be made from edged boards, wood chips and other suitable materials. However, this method is quite time-consuming, labor-intensive and financially expensive.
At the bottom of the prepared pit, pour a layer of 10-20 centimeters and compact it with a sand cushion, on top of which we lay roofing material or polyethylene, which is necessary to retain moisture in the poured concrete.
We immerse the assembled formwork into the hole and install a reinforced frame there.
Columnar foundation - formwork and reinforcement diagram
We pour concrete grade 400 into the formwork, which is prepared from cement grade M 400, coarse sand, fine and medium gravel, mixed in a ratio of 1:1.5:3 with water in the amount of 0.4 parts of the cement used.
Every 30-35 centimeters of pouring we tamp the concrete, removing air.
We cover the finished support with film and let it sit for several days, after which we remove the formwork from the hardened concrete.
We cover the finished supports with waterproofing materials and fill the sinuses with previously dug earth.
To reduce costs and time when arranging a columnar foundation for a concrete bathhouse, instead of rigid formwork, you can use permanent soft formwork, which is a roofing material with a fiberglass mesh. In this case, holes for the support must be made using a drill of the appropriate size. Having cut the roofing material to the required length, twist it and install it in the prepared hole. At the same time, a sand cushion and a bottom insulating layer are also necessary. Next, we install the reinforced frame and pour concrete as with removable formwork. Using this material, we obtain a finished pile, immediately covered with waterproofing material. And immediately after the concrete gains strength, the next stage of work can be carried out.
Photo – pouring process 
Prices for roofing material
roofing felt
Video - Pouring a columnar foundation
When constructing a heavier bathhouse building (for example, made of brick) or if you want to equip a basement, you can mount a columnar foundation with a grillage. This is a monolithic reinforced concrete strip structure that connects the top points of all foundation elements buried in the ground.
To fill the grillage, you will need formwork material: edged board with a thickness of 20 to 40 millimeters, plywood, OSB or other similar building material. As well as reinforcement with a cross-section of 10-12 millimeters and concrete of at least grade 150. Most often, grade 200 concrete is used to fill the grillage, and if you make it yourself, you need to mix M400 cement, coarse sand and medium or fine crushed stone in a ratio of 1:2, 5:4,5.
Let's calculate the amount of lumber for formwork. It must be taken into account that the height of the grillage should be at least 0.3 meters, and its width should be 10 centimeters greater than the width of the manufactured columnar supports.
- We determine the immediate height of the grillage and add another 0.2 meters to it since the height of the formwork must be greater than the level of concrete poured into it.
- We fix the thickness of the formwork material in meters.
- We measure the total length of the future grillage.
- We multiply all the obtained parameters together and get the required amount of material for formwork in cubic meters.
From the prepared lumber we knock down the formwork box. In its lower part, holes should be cut for the previously made pillars, which should rise slightly above the lower part of the formwork.
Video - Installation of formwork
From reinforcement rods it is necessary to make frames with transverse square clamps, which can be bent from thinner smooth reinforcement or from wire Ø6-8 mm. They will give the necessary strength and reliability to the structure. Every 30-35 centimeters we connect clamps and reinforcement rods with knitting wire in an amount equal to the entire perimeter of the grillage. We calculate the size of the frame in such a way that there is 5-7 centimeters from it to the walls of the formwork.
If the finished foundation pillars are located at a considerable distance from each other, then for reliability you can strengthen the formwork with wooden supports, which must be installed strictly horizontally.
Before pouring concrete into the formwork box, we will install a reinforcing frame, fixing its lower part to the reinforcement protruding from the columns.
Video - Columnar foundation. Formwork, reinforcement, pouring
If pouring is done from a concrete mixer truck, then pour the entire concrete mixture at once, removing air with a construction vibrator, a reinforcement rod, or simply using a shovel.
If you have to mix the concrete yourself and the pouring takes several days, then:
- at one time we fill in part of the grillage, divided vertically, not forgetting to remove the air;
- Before pouring the next part, the edge of the finished block with already hardened concrete is generously moistened with water.
Fill the formwork completely with concrete mixture, cover it with film and let it stand for several days. Then we carefully remove the wooden box and our hanging grillage is ready.
It is worth noting that regardless of the material used to construct the columnar foundation, this version of the foundation for a future bathhouse is more reliable than the traditional strip one, and at the same time is much cheaper (almost half).
Video - Pile-grillage foundation
Video - Nuances of constructing a pile-grillage foundation