The construction of a log bath, like any other object, begins with the arrangement of the foundation. Building technologies do not stand still, and there is no unambiguous answer to the question of which foundation is better for a log bath. In each case, only an individual solution is applicable. It will depend on the type of structure, its weight, soil features, terrain, material capabilities of the developer. In order to save money, many prefer a foundation on piles; for durability and increased strength, a reinforced strip foundation is required. The strength of the log house will directly depend on the correct choice of the type of foundation.
How to choose the type of foundation
How to build a bath from a bar so that it is stable, durable and reliable? There are several important factors influencing the choice of foundation design:
- Building weight;
- Features of the structure of the soil.
Important! If the type of foundation is chosen incorrectly and the technology of its installation is violated, there is a risk of misalignment of the bath structure, up to its destruction.
The most dangerous natural factor for the integrity of the building foundation is soil freezing. With uneven thawing on one side of the building, the soil can “float”. In this case, the brick foundation will not save even reinforcement. Monolithic bases made of concrete and metal are much stronger, but they can also crack. For more stability, anchor sites are created on such soil.
To determine the nature of the soil, they dig a hole up to one and a half meters deep and evaluate the composition of the soil. It is important to investigate the level of groundwater. For clay, gravel and sandy soil, a columnar or tape construction of the bath foundation is more suitable. For soft swamp and garden soil, a pile foundation is required. The most versatile option - fine sand or rocky rocks - any option is suitable for them.
The foundation of a log bath can be buried or shallow. In classical construction technology, it is believed that the depth of the base of the structure should be greater than the depth of soil freezing. But it should be borne in mind that the wooden structure has a relatively small weight and dimensions, therefore it is permissible to reduce the cost of arranging the foundation of the bath by reducing its depth. That is why a shallow base is increasingly being used.
Column type foundation
The columnar version is great for wood and frame structures. Such baths are light in weight and do not exert a significant load on the foundation. The columnar base is simple in design, but at the same time it is famous for its exceptional reliability. Each element of such a base is located in the nodes of the structure, which have an increased load. These are the joints of the walls, the corners of the structure, the runs. The distance between the elements of the base is no more than two meters. The pillars are made of stone, brick and concrete. Supports are installed on crushed stone pillows.
The arrangement of a columnar foundation for a log bath does not require impressive expenses. In addition, this simple work can be done by yourself, as it does not require professional skills.
Note! The columnar foundation is suitable for freezing soil. With its help, you can significantly increase the life of the bath structure.
Algorithm for building a columnar base:
- digging holes for each post;
- filling the pit with sand and gravel;
- installation of waterproofing;
- installation of formwork on each pillar;
- fixing reinforcing rods;
- pouring concrete;
- a bundle with a grillage around the perimeter;
- bitumen waterproofing.
The disadvantages of the columnar option include the impossibility of arranging the cellar, but do you need a basement in the bath? The columnar foundation is not placed on moving and heaving soil. Such a construction base requires additional floor insulation and work to drain rain and wastewater.
Belt type base
The tape base is considered a classic and economical option. The constructed foundation can have a prefabricated and monolithic structure.
A monolithic base is made using formwork, filler and reinforcing material. The prefabricated foundation is made up of reinforced concrete blocks. This design is easy to install, but allows moisture to pass through at the joints.
Shallow strip foundation has a depth of up to seventy centimeters. The base, located below the freezing level of the soil, usually has a depth of 120-160 centimeters.
Algorithm for arranging a strip foundation:
- site cleaning and leveling;
- marking the foundation with a cord;
- digging a trench;
- backfilling of a sand and gravel cushion twenty centimeters thick;
- foundation waterproofing device;
- formwork installation;
- installation of reinforcing material;
- layer-by-layer pouring of concrete;
- installation of vertical studs for fixing the base of the log house;
- waterproofing the foundation surface with bitumen and removing the formwork.
The metal-reinforced strip base is suitable for difficult, heaving soils.
Pile foundation
A screw pile foundation makes it possible to build a log bath on difficult ground. This technology was developed for military purposes and is now successfully used in residential construction.
The foundation on piles can be installed on any soil, including in areas with difficult terrain.
The pile is a pipe with a propeller-blade that is screwed into the soil. Piles are of several types:
- metal;
- concrete;
- wooden.
Such piles are relatively inexpensive and can be installed even on marshy ground.
The disadvantage of the pile version is its service life - up to half a century.
slab foundation
It is a monolithic slab under the entire building. The foundation made of slabs has excellent bearing characteristics, suitable for complex soil prone to subsidence. A slab is an excellent foundation option when groundwater is close to the soil surface.
Such a foundation is used infrequently, mainly when other types of foundations are not suitable for one reason or another.
Calculation instructions
To determine the size of the base of the bath, it is important to take into account the weight of the future structure and the distinctive features of the soil.
For calculations, you will need to use three formulas:
- Depth H = h * kT * kL
h - soil freezing standard in the region;
kT - coefficient of soil heating during active heating of the steam room (0.7 - 1);
kL - coefficient value of the frequency of use. - Base size A = B (C * D)
A is the width of the base;
B - the mass of the structure, taking into account the roof, furnace and the number of visitors;
C is soil resistance.
D - base length; - Number of poles or piles X = B (C * Z)
X - number of piles;
B is the mass of the structure;
C - soil resistance;
Z is the sectional area of the pile.
Moisture protection
For a good log bath, it is important to properly waterproof the foundation. The safety of the structure depends on this procedure. It is important to additionally insulate the floor, because in the bath the bulk of the heat can go through the pouring floors.
For the foundation of the tape type, roofing material is most often used. It is laid on the base, gluing with hot bituminous grease.
For a bath, the blind area is important. If you neglect its installation, wastewater will wash away the soil and the bath will warp.
As the first crown, logs with a diameter larger than the wall material are used. The first crown is carefully fixed and insulated.
Insulation of the foundation of the bath
In order for the bath to fully work, it is important to properly insulate the foundation. This is especially important for baths that are used irregularly. It is known that the heat loss of the base is up to a quarter of the heat loss of the structure as a whole.
In warm weather, the foundation without thermal insulation is covered with condensate, and remains wet all summer. From this, the surface of the concrete is covered with fungus and mold. In winter, the foundation is subjected to a load of buoyant forces. In just a few years, such processes can lead to significant destruction of the support. That is why it is important to carefully insulate the foundation from the inside and out.
Proper insulation helps:
- reduce the cost of heating the bath;
- ensure a stable temperature in the steam room;
- increase the service life of waterproofing and protect the foundation from adverse effects.
Various materials are used for insulation:
- The soil is not the most reliable, but it is a free insulator. The foundation is covered with soil. With such insulation, a ventilation shaft is mandatory.
- Expanded clay - perfectly retains heat and has a relatively low cost. Can be used in combination with soil. Fragile material, so it must be protected from mechanical damage.
- Expanded polystyrene - suitable for any base, not afraid of moisture. Expanded polystyrene is produced in the form of plates and sheets.
- Polyfoam - suitable for insulation of a tape-type base. Styrofoam insulation is an economical and simple option.
Conclusion
The choice of the type of base for the bath, its size and material depends on the mass of the structure and the characteristics of the soil at the construction site. The bath is an easy-to-view structure, but it should be borne in mind that a log cabin has a significant total mass. The issue of building a foundation must be approached very carefully - any violation of technology is fraught with sad consequences, up to the destruction of the structure. A well-thought-out base structure, properly hydro and thermally insulated, is the key to a long service life of the entire structure.
For our ancestors, log cabins were the only available material for building houses, however, even after the appearance of other building materials, they did not lose their popularity. The reason for this fact lies in the desire of people to take a break from the bustle of the city and become closer to nature.
A tape shallow foundation is ideal for a log house, its depth should be approximately 500-700 mm.
What foundation to choose?
The foundation for a log house can be tape with a deep or shallow foundation and columnar. It is determined by the characteristics of the soil in a given region. under a log house with a deep foundation are effective if the building has heavy walls and ceilings or assumes the presence of underground premises. The depth of laying such a foundation is 20-30 cm below the level of soil freezing.
Tape shallow base - the best option for log houses.
Its laying depth is 50-70 cm. If we are talking about a small bath, then the depth of the base can be reduced to 40-50 cm. Having decided to choose such a foundation option, consider insulating the soil surface around it to reduce the freezing depth. The positive side of the tape base of the house is its low thermal conductivity.
The columnar foundation for a log house is the most economical. It is being built under light wooden or frame buildings, verandas. Pillars under the frame are laid at all intersections of the walls and in the corners with a distance of 1.5-2 m to the depth of soil freezing. for log cabins the most rational. The consumption of materials and labor costs for them are cheaper than for tape ones by 1.5-2 times, and with deep laying - by 3-5 times. Depending on the scale of construction being carried out, the basis of the columnar foundation can be reinforced concrete piles, wooden poles, metal asbestos pipes.
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Strip foundation for a wooden house
The construction of the foundation begins with the marking of the site. The area should have a slight slope to one side to ensure good drainage of storm water and to prevent flooding from melt water.
For marking, you can use fragments of reinforcement with a cross section of 10 mm and ordinary fishing line. Attach the fishing line to the reinforcement using a level, select a straight line under the foundation zero and mount a cast-off foundation - two pegs driven into the ground along the width of the future pit, connected by a perpendicular plank. The cast-off is attached at a distance of 1-1.5 m from the facade of the house. The width of the foundation is calculated based on the construction of the walls, not less than the width of the wall increased by 10 cm. Next, mark the internal boundaries of the foundation and internal partitions.
The depth of pouring the foundation for the house corresponds to 0.4 m. The sand cushion has a thickness of 10-15 cm. A simple mathematical calculation allows us to conclude that the depth of the pit at the bottom point will be 0.55 m, and at the top - 0.7 m. excavation is determined by multiplying the length of the pit by the arithmetic mean depth, taking into account the unevenness of the site, if any.
Under the log cabins, it involves the arrangement of a sand cushion, which allows you to reduce the load on the foundation during seasonal heaving of the soil. The top of the sand cushion must be tamped and leveled with a level. You can speed up the work on the formation of a sand cushion by pulling the fishing line at a level that corresponds to the thickness of the cushion. Then the sand is filled and compacted with a special roller. Wet sand compacts on its own, so when compacting, the sand must be watered.
Formwork for the foundation for log cabins is a structure that gives the concrete the necessary shape. It can be fixed and removable. Formwork panels are made from edged boards. The length of the shield from the side of the foundation is less than the thickness of the board. The shields on the inside are knocked down with nails, and then the nails are bent from the outside. After assembling the panels, they proceed to the installation of the formwork.
The end parts of the shields are connected using self-tapping screws so that the shields fit snugly and the mortar does not pass into the slots. After assembly, the shields on top and sides are reinforced with spacers. The greater their number, the more reliable the formwork under. To prevent the liquid component of concrete from being absorbed into the boards, roofing material or glassine is fixed to the inner walls of the finished formwork.
Reinforcing the strip foundation for log cabins allows you to get a qualitative change in the properties of concrete and increase the ability to maintain mechanical strength. The reinforcement performs the function of a kind of skeleton and makes the strip foundation as durable as possible.
The reinforcement grid is placed at a distance of 3-5 cm from the edges of the foundation, so that after pouring the concrete, it is completely inside the solution. For reinforcement, reinforcement with a cross section of at least 12 mm is used.
Experts recommend using reinforcement that is integral in length, the smaller the number of connections, the stronger the strip foundation will be. Tie jumpers to the lower rods with a knitting wire with a distance of 40 cm. Then tie vertical rods to the corners of the resulting cells. In addition, welding can be used to connect fittings.
The strip foundation is poured with concrete grade M-200, M-300, M-400, prepared from sand, cement and crushed stone in a ratio of 3: 1: 3. Concrete is poured into the formwork gradually in order to eliminate the possibility of voids. Each layer of mortar is carefully compacted with rammers. To give the foundation maximum strength, the upper part must be sprayed with water.
The foundation is the basis of the reliability and durability of the future building, so it is necessary to choose it as responsibly as possible. Log houses are lighter in weight than concrete and brick buildings, so they can use different types of foundations. The foundation for the log cabin of the house is selected depending on the layout and size of the building, the characteristics of the soil and many other parameters - the most accurate calculation and adherence to manufacturing technology are important.
Types of foundations for log cabins
What foundation is needed for a log house? To answer this question, geodetic studies are first carried out. The fact is that the foundation of the house is affected by the forces of frost heaving when the soil freezes.
In this case, the foundation will rise up in winter, and fall again in summer. The right choice of base will minimize these fluctuations and protect the building from skewing. The foundation for a log house can be of several types:
- Tape base. This is one of the most common options, as it can be used for most types of soil with shallow freezing.
For example, such a solution would be optimal for the Moscow region and other areas of the middle lane. A shallow strip foundation for a log house is a monolithic concrete strip, which is located around the entire perimeter of the future building. This is a support for all load-bearing walls, it also allows you to create a basement.
- Column base. On heaving soils, this is the best option, since it can be used to minimize the impact of soil movements. Such a foundation for a log house is concrete pillars, which are located in the corners of the building, at the intersection of walls and other points that are under increased load. This type of foundation is cheaper, as it requires less material and is built much faster.
- The slab foundation is used much less frequently due to the high cost, but such a foundation can rightly be called the most durable. It is a monolithic concrete slab that can support the weight of a very large building. However, such a base is "floating", that is, it will move when the ground moves.
- On weak soils, the only possible solution is a pile foundation. This is a base of concrete pillars that are driven or screwed into the ground, this technology has been used for many centuries, but it is not so common in low-rise construction.
The foundation of a log house is selected according to several criteria, and price often plays a decisive role. Tape and column bases are the cheapest, so they remain the most common. Let us consider in more detail the construction of a shallow strip base as the most practical and popular option.
Technology for the construction of a strip base for a log house
It is not so difficult to build a foundation for a house from a log house with your own hands. The advantage of the tape version is that no excavation is required, and excavation can be done in a few days.
A shallow foundation for a log house is laid to a depth of 50-70 cm, for a bath you can do 40-50 cm. This design can be used for both one-story and two-story wooden buildings.
Work on its construction begins with cleaning the site from debris, vegetation and marking it with ropes and pegs. They outline the location of the walls, it is important to make sure that the angles between them are strictly 90 degrees.
After that, internal marking is performed, which is carried out taking into account the thickness of the walls. As a result, it will be possible to see the contours of the future home.
The soil is removed: the width of the base is about 40 cm, the depth is up to 70 cm. A pillow of sand, 12-15 cm thick, is poured into the trench and carefully compacted, sometimes gravel is added to the sand.
The sandy layer is additionally well spilled with water and compacted again to give it maximum density. After that, you can proceed to pouring the base, which is carried out in several stages:
- Formwork is installed from shaped boards, the frame should rise about 30 cm above the ground. This will provide both a solid foundation and a basement for the future building. The formwork must be strictly vertical.
If it is supposed to be reused, a polyethylene film can be laid between it and the concrete.
A log house with a foundation will be very reliable. With a properly built foundation, such a building can serve for decades, and the walls will not turn out to be skewed.
The base gains maximum strength in about a month, after which you can proceed to the construction of walls. The foundation is recommended to be additionally insulated.
The foundations of log houses can be built in different ways, but in any case, one cannot save on the quality of materials. It is recommended to purchase cement only from well-known enterprises; it is more profitable and easier to use a concrete mixer in work. This will achieve a high-quality homogeneous solution, which will ensure the strength of the base.
The foundation for a log house should provide a reliable and durable support for a wooden house and at the same time become a barrier to the penetration of the negative influences of the soil base. For a wooden house, it is important that the size of the foundation for a log house does not go beyond the perimeter of the building (this is economically unprofitable). Overhang of logs outside the foundation for a log house can create unforeseen centers of stress in the walls, which will lead to the destruction of the load-bearing structures of the house, so the optimal size of the base of the log house is important. It remains to decide which foundation is better for a log house.
log house
The log cabin is the walls of the house, made of solid logs. In the corners of a wooden house, logs are connected into so-called crowns. In the lower part of the log, a part of the tree is cut out with the width of the transverse diameter of the log. Wooden elements in the corners of the house form castle systems that do not need additional reinforcement. This confirms the popular expression - to build a house without a single nail.
Such houses are most often built in areas where timber is available to the consumer at a low price. Such places include Central, Eastern Siberia and the Far East. Although it is worth noting that the popularity of building private houses from solid wooden elements has increased widely in all regions of our country.
A small specific weight, excellent thermal insulation qualities, durability and environmental friendliness of wood are an indisputable advantage over other building materials.
Types of foundations for a log house
The foundations for log houses can be completely different. This largely depends on the composition of the soil base, the depth of soil freezing, the level of groundwater and the weight of the building. Therefore, the foundation for a log house can be of the following form:
- tape;
- columnar;
- pile;
- pile-screw;
- slab;
- combined.
Before finally choosing the design of the base of the house, it is good to listen to the advice of the owners of neighboring houses. If the log house has stood for more than 10 years without any special incidents, it is worth taking a closer look at what and how its foundation is made of.
Tape
The strip foundation for a log house is the most common supporting structure. The base for a wooden house with dense soil and a low level of soil freezing is often made shallow.
The diagram shows the width of the monolithic tape 300 mm. This indicator is directly tied to the average diameter of the logs from which the walls of the house will be erected. If sanded logs with a diameter of 420 mm are harvested, then the width of the monolith must be at least 450 mm. The device of a shallow foundation for a log house with their own hands is quite accessible to people with minimal experience in construction work.
The depth of the foundation for a wooden house should be greater than the thickness of the soil freezing. If the soil freezes by 100 mm, then the foundation is deepened by 200 mm.
The norms for the depth of the concrete base of the log house are directly related to the number of storeys of the structure (the weight of the structure).
The device of the strip foundation is as follows:
- On the construction site, markings are made, fixing it with pegs and a cord.
- They carry out earthworks - they dig trenches around the perimeter of the house and under the internal load-bearing walls.
- Install the formwork of wooden panels.
- The shields are reinforced with struts with wedges. Between parallel rows of shields, spacers are made of timber.
- Shields from the inside are covered with sheets of waterproofing (roofing material, plastic film or other material).
- Sand is poured into the bottom of the trench, which is rammed to make a pillow 200 mm thick.
- A reinforced frame is laid in the formwork. The frame is made of 4 longitudinal rods of a periodic profile with a diameter of 8 mm to 12 mm.
- Longitudinal reinforcement is fastened with short rods, connected with wire into a single structure. In some cases, electric welding is used.
- The formwork is poured with concrete mortar.
- After the concrete has hardened, the formwork is dismantled. The foundation for the log cabin is ready for further work.
Concrete work is best done in the summer. It must be expected that concrete gains its initial bearing capacity in 28-30 days after pouring.
The photo shows that, in a monolithic tape, vents are made in increments of 1.5-2 m, which provide natural ventilation of the underground, which prevents the accumulation of moisture inside the basement space.
Columnar
The device of columnar supports for a wooden house is done in order to save consumable foundation material. Columnar supports are erected from natural stone, brick, concrete monolithic pillars. One of the best options is the base of the log house from asbestos-cement pipes. Such supports are also called bored piles.
The foundation for a log house from asbestos pipes is erected as follows:
- The building plan is transferred to the construction site, marking the location of the supports.
- Wells are drilled at marked points. If excavation is carried out to a depth of 2.5 m, then this is done with a hand drill. Deeper excavation is carried out by mechanized method.
- The bottom of the wells is covered with sand and gravel in layers of 200 mm. The bulk pillow is rammed to a dense state.
- Asbestos pipes are lowered into the well.
- Knitted or welded reinforcement frames are placed in the pipes.
- Pipes are filled with liquid concrete mortar (usually concrete M 300 is used).
- The vertical outlets of the reinforcement are connected to the grillage. If the framing of the grillage consists of a metal profile (as a rule, the channel is used with the shelves down), then the reinforcement is welded to the grillage.
- A wooden beam or board is laid on the grillage. Then they build walls from logs.
Usually, point supports are installed in increments of 3 m. So, with a load-bearing wall length of more than 12 m, the number of supports should be at least 6 pcs.
pile
On weak soils, a wooden house is erected on a pile foundation. Reinforced concrete piles are installed with a pile driver. The length of the piles is calculated in such a way that the end of the pile enters the dense layers of soil to a depth of at least 300 mm.
Piles can be reinforced concrete and metal. The supports, passing through weak layers of soil, strongly compact the soil around them. Namely, thanks to this property of pile foundations, it becomes possible to build houses from logs with a height of 2 - 3 floors.
The top of the piles is tied with reinforced concrete beams or a monolithic tape. The ground part of the piles must be covered with waterproofing. Waterproofing is usually arranged from roofing material on bituminous mastic.
The space under the log house is covered with profiled flooring, brickwork or other material. Be sure to arrange ventilation holes in the lining of the basement.
Technology of installation of reinforced concrete piles
Piles are installed using specialized installations (hammers). The clogging process is divided into two stages:
- preparing the pile for installation;
- clogging of the support.
Preparing the pile for installation
If we take into account that a standard reinforced concrete pile 12 m long weighs about 4 tons, then its delivery to the installation site is carried out on a wheeled or caterpillar platform. A hole is drilled in the marked place - a lettered well. The end of the pile is dragged to the hole. With a special lift, the support is lifted and set in a strictly vertical position.
pile driving
The supports are driven in with a hammer equipped with a diesel or hydraulic power unit.
Failure may occur during pile driving. This comes from a strong sharp compaction of the soil. The support is allowed to "rest". Driving continues until the design depth is fully reached.
Pile-screw
Screw piles today are becoming increasingly popular with developers. Screw piles are mounted both manually and mechanized. Screw supports have a number of advantages over other types of bases for wooden log houses:
- installation of piles does not depend on the season because there are no wet processes;
- the pile field is created in a short time;
- piles up to 2.5 m long and up to 108 mm in diameter do not require the use of mechanized installations and are installed manually.
Basically, for the installation of a pile-screw base for a log house, supports are used that can be manually installed. Installation of screw supports is carried out as follows:
- At the indicated points, shallow holes are made with a hand drill (no more than 300 mm deep).
- The pile is inserted into the hole with a screw.
- The installation of the support is carried out by a team of 3 people. Two workers rotate the pile around its axis with the help of levers (metal pipes) inserted into the holes in the head of the support shaft.
- A third worker controls the vertical position of the pile.
- Installed piles are cut with an abrasive wheel to one level.
- Metal platforms are welded to the upper ends of the trunks.
- They make a binding of piles from a channel.
- A beam is laid on the grillage.
- On the finished foundation, walls are erected from logs.
slab
The base in the form of a reinforced concrete slab under a wooden house is made on very weak soils. Such a foundation requires the use of large volumes of concrete and reinforcement:
- The site is covered with rubble. Then arrange a sand cushion.
- A frame made of metal reinforcement is laid on the compacted sand.
- A protective border is arranged around the perimeter of the site so that liquid concrete cannot flow out of the base.
- The entire site is filled with concrete.
- After 28 days, the base is ready for the construction of the log house.
Combined
Building a log house on a slope creates a lot of inconvenience. The way out of this situation can be a combined type foundation device. The reinforced concrete slab is supported on a pile foundation or on a strip-stepped foundation on the sides along the slope.
More video process:
Wooden houses made of logs will stand long and strong if the right foundation design is chosen. In particularly difficult cases, it is better not to engage in the construction of a foundation for a log house with your own hands. Professionals will always come to the rescue: they will draw up design estimates and carry out high-quality construction of the foundation for a wooden house.
Filimonov Evgeny
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How to build a foundation for a log house. Foundation types. Stages of work. Step by step work.
In order for a wooden house to be reliable and durable, the foundation for a log house must be made in accordance with all standards. If you perform it yourself, you need to know all the nuances of its arrangement.
Foundation types. Stages of work. Norms in the construction of the foundation. How to fill the foundation under the log house. How to properly mark the site, the device of the pit and formwork. How to perform concrete reinforcement, preparation and pouring of the foundation.
The process of building a log house is preceded by laying the foundation, which should become a solid foundation that protects the building from adverse environmental factors. About what kind of foundation for a log house to choose and how to build it, we will consider further.
The main and most important part of any building is the foundation. Therefore, before building a log house, it is important to choose the right type of foundation that will contribute to the long-term operation of the building. The main characteristics when choosing the type of foundation are the type of soil and the load of the building itself.
We suggest that you familiarize yourself with the main types of foundations that will help in the further construction of a strong and reliable log house.
Tape type foundation- represents the base of the building buried in the ground. There are two types of strip foundation:
- deeply buried;
- surface.
The use of the first option is associated with the construction of a log house with a heavy structure or in the presence of an underground room. The depth of laying such a foundation is from twenty to thirty centimeters from the lowest freezing point of the soil. This foundation is very laborious and expensive, it is used in the construction of multi-storey buildings made of concrete, brick or stone.
A strip foundation of a surface type is used in the process of building a log cabin of a bath. In this case, its height is from fifty to seventy centimeters.
Column type foundation- the most low-budget and easiest to implement. It is used in the construction process of non-weighted wooden or frame buildings. When equipping such a foundation, pillars are installed in the ground, which help to withstand the load and contribute to its uniform distribution. The installation of pillars is carried out along the perimeter and in the center of the building, always in the corner areas, at the intersections of the walls or the largest load. This type of foundation is not suitable for all types of soil, therefore, before its construction, it is necessary to take the soil on which the log house will be built to a specialized laboratory, where its properties will be determined. Installation of pillars is carried out at a depth of 150 to 200 cm.
If you plan to build a log house on this type of foundation, it is recommended to use a profiled or glued beam. With the help of this material, the building will become more attractive and colorful. If the massiveness of the log house is high enough, and the building is powerful, then it is appropriate to use rounded logs adapted to withstand heavy loads.
If we compare the consumption of materials for the construction of the foundation of these two types, then 2-5 times less building materials will be required for arranging a tape foundation than for a column foundation. In most cases, the use of a columnar foundation is appropriate for the construction of a block-beam or frame-type log house. When building a bath, there is no need to equip the base, so in this case, a columnar foundation is a good option.
There are several types of columnar foundations in relation to the material of manufacture:
- reinforced concrete piles;
- steel pipes;
- asbestos pipes;
- screw;
- plastic pipes.
The most common and commonly used type of columnar foundation is screw. Its cost, ease of installation and duration of operation makes it popular. The installation of such a foundation involves the deepening of screw piles by screwing. The main components of a screw pile are the shaft and the blade.
Among the main advantages of this type are:
- fast foundation installation process;
- the possibility of installation on the soil of a marshy type or on soil with a high level of groundwater;
- no need to level the foundation;
- it is not required to wait a certain time after the installation of piles;
- performance of work at any time of the year;
- high level of maintainability.
The most optimal type of foundation in terms of price and quality is a surface strip foundation. Its construction will not require as much money as for a deep-buried strip foundation, but its quality will not be as low as when arranging a columnar foundation. When equipping a log house, a depth of 45 to 75 cm will be quite enough. Even if small movements occur, they are acceptable for a building from a log house.
The foundation for the log cabin of the bath allows you to reduce the depth of laying to forty centimeters. When using a foundation of this type, it is imperative to insulate the soil surface to reduce the risk of freezing. The main advantage of arranging a shallow foundation, in comparison with a columnar foundation, is the absence of the need for arranging thermal insulation of the floor.
But, nevertheless, the main factors determining the type of foundation used in the construction of a log house are:
- soil type;
- ground water level;
In order to accurately determine the type of foundation required, it is better to entrust this issue to specialists, they will determine the height of the foundation into the ground with an accuracy of up to a centimeter.
Foundation for a log house: marking
The most important process in the construction of the foundation is the marking. If the markup is done incorrectly, then it will be impossible to remake the foundation, and this will affect the quality of the log house.
Expert opinion
Filimonov Evgeny
Ask an expertThe main requirement for the site on which the foundation will be located is its absolute evenness and a slight slope to one side.
The slope is necessary so that the water, in rainy spring weather, flows down, and does not settle and does not destroy the foundation.
To carry out marking under the foundation, you should use ordinary reinforcement bars and a fishing line or rope. It is better to give preference to fishing line, as it does not stretch, does not sag and is resistant to temperature, gravity or moisture.
First of all, start by fixing the fishing line to the reinforcing bars, and then, using the level, select a straight line, which will become the starting point for forming the foundation. Install a cast-off foundation, which consists of two pegs driven into the ground, forming the width of the pit. The place of fastening of the cast-off from the front section of the house is 150-200 cm.
In accordance with regulatory documents, the minimum distance between the house and neighboring buildings is 300 cm. The interval between the facade of the house and another building is at least 500 cm.
When the necessary boundaries are observed, proceed to the creation of markup. First of all, remove the layer of vegetation and completely level the site. After that, based on the preliminary design of a log house or a bath, apply the contour parts of the foundation. The design of the walls affects the width of the foundation. The minimum width of the foundation is the width of the wall 10 cm.
Make markings around the perimeter and hammer in the reinforcing bars in the corners. Check the evenness of the markup. To check the angles, use laser levels or a tape measure. All corners of the building must be straight. When the corners are set, pull the fishing line over the reinforcing bars.
Now proceed to marking the inner boundaries of the foundation. This process is much easier, as the corners are already aligned, and all that remains is to measure the desired width distance, set the pegs and pull the fishing line. Next, you should check the evenness of the entire structure and proceed to the next stage - the equipment of the pit.
Earthworks for the manufacture of the foundation for the log house
There are two options for arranging the foundation:
- trench;
- pit.
The first option is several times cheaper and less expensive in relation to the amount of work. The construction of the pit involves being in the log house of the basement. If there is no basement in the log house, a trench is the best option.
Based on the slight slopes of the site for the construction of the log house, you should use the water level, which will help calculate the lowest and highest slopes. The depth of the pit being constructed depends on the highest point of the site. It is on the basis of it that the depth of both the pit and the trench should be determined.
The average depth of pouring a trench under a log house is forty centimeters, while the size of the sand cushion, which is from ten to fifteen centimeters, is not taken into account. The total depth of the foundation for a log house is 55-65 cm.
Using the water level, when constructing a pit or trench, it is necessary to level their bottom in accordance with the level of the horizon.
To determine the cubic capacity of the earthworks performed during the construction of the foundation, multiply the length of the pit by the average depth.
To reduce the load on the foundation during the spring swelling of the soil, it is necessary to first lay a pillow of sand. At the same time, sand is poured, which is gradually compacted and leveled. To make the process of building a sand cushion fast, you should stretch the fishing line so that its height matches the height of the sand cushion. This is followed by the process of backfilling the pit or trench and tamping with the help of special equipment.
After the trench is dug and the pillow is rammed, the process of installing the wooden formwork follows. The main function of the formwork is to give the necessary shape to the concrete surface.
There are two types of formwork:
- removable;
- fixed.
The construction of the formwork is the most time-consuming and important process in the arrangement of the foundation.
For the manufacture of formwork panels, an edged board is used, which, although more expensive than ordinary boards, differs from them in a number of advantages, including:
- smooth and even surface;
- cheaper costs for finishing the basement part, since its quality when formwork from edged boards is much higher than when installing formwork from ordinary boards;
- the presence of specific measurements of the edged board allows you to control the height of the formwork of the future foundation;
- the possibility of repeated use of such formwork.
The shield installed along the length of the foundation should be slightly shorter, by the thickness of the board installed along the width. The inner part of the formwork is upholstered with nails that connect all its parts. After assembling the panels, you should proceed to the installation of the formwork on the trench.
The assembly of the end parts of the formwork is carried out using self-tapping screws. This process allows the shields to fit snugly together and reduces the risk of mortar seeping through the gaps. The sides and top of the formwork need to be reinforced with spacers. The reliability of the formwork being constructed depends on the number of spacers. Concrete mortar heavily loads the structure, so the formwork must be strong. In order to avoid the solution getting on the boards and its absorption, as well as in order to make the foundation walls perfectly even, a glassine or roofing felt coating should be installed on the inner walls of the formwork. Make sure that the height of the formwork is greater than the height of the foundation itself.
To determine the cost of the formwork, which is based on an edged board, you need to divide the length of the entire perimeter by 600 cm, the length of one of the boards, and the height of the formwork is divided by 15 cm - the height of the board. Thus, we get the right number of boards that will help build the formwork for the foundation. The amount of glassine depends on the required formwork height. This material is in a rolled state, the width of one roll is a maximum of forty centimeters. To fix the glassine, you will need a construction stapler with staples. When the formwork is ready, you need to proceed to the next process, which includes reinforcing and strengthening the walls of the foundation.
In order to increase the mechanical strength of the concrete foundation, as well as to increase its mechanical strength, a reinforcement process is necessary. Reinforcement is a kind of skeleton that holds the entire load and increases the durability of the foundation. The distance between the edges of the foundation and the reinforcement grid is 30-50 mm. To reinforce concrete, you will need reinforcement with a cross section of 1.2 cm. Reinforcement is laid on brick, previously laid in two rows.
To increase the strength of the foundation, one-piece reinforcement should be used, and a large number of joints should be avoided. With the help of a knitting wire with an interval of 40 cm, you need to tie the jumpers. Vertical bars are installed on the corner parts of the reinforced structure. To make the connections as strong as possible - use a welding machine.
Then, also install the top and bottom row of the structure with jumpers of forty centimeters. To determine the cost of reinforcement, it is necessary to determine the number of jumpers required for reinforcement.
When the reinforcement is completed, proceed to install the ventilation of the basement section of the foundation. This will require a pipe made of asbestos cement or plastic, the diameter of which is 10 cm. To prevent concrete from getting into the pipe during the pouring process, you must first close it with sand or rags.
Expert opinion
Filimonov Evgeny
Professional builder. 20 years of experience
Ask an expertTip: The installation of the pipe should be done with a slope that leads to the street so that the water or condensate that has accumulated in it can easily drain to the ground.
When pouring the foundation, a mandatory component is the presence of a concrete mixer or automixer, which will provide a uniform structure to the concrete. And the vibrator will help to make the foundation structure homogeneous, get rid of excess air in the solution and increase the adhesion between concrete and reinforcement.
The process of preparing the solution includes the use of cement grades two hundred, three hundred or four hundred. The choice of a particular brand depends on the individual characteristics of the object and the season in which the work is carried out. To prepare the solution, you will need cement, sand, aggregate in the form of crushed stone and water, in a ratio of 3x3x1, and water is calculated in accordance with the required viscosity of the solution.
Concrete is poured gradually in order to avoid the formation of air accumulation. Each of the layers requires the use of a vibrator that compacts it. For a good fit of concrete to the formwork, it is necessary to carry out periodic tapping, which will help distribute the load from the solution evenly.
In order to avoid stratification of the mixture, it is necessary to fill one of the layers very quickly. To avoid cracking and to make the foundation as strong as possible, pour it with water after pouring, during the entire drying period.
In rainy and gloomy weather, as well as in winter, it is recommended to cover the foundation with polyethylene to avoid washing off the top layer. After a minimum of three weeks, the formwork is removed and the construction of the log house begins. This type of foundation is suitable both for the construction of an ordinary log house, and as a foundation for a log cabin of a bath.