What is the best foundation for a log house. Technology for the construction of a strip foundation for a log house. Videos log house foundation

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:

1. On the construction site, markings are made, fixing it with pegs and a cord.
2. They carry out earthworks - they dig trenches around the perimeter of the house and under the internal load-bearing walls.
3. Install the formwork of wooden panels.
4. The shields are reinforced with struts with wedges. Between parallel rows of shields, spacers are made of timber.
5. Shields from the inside are covered with sheets of waterproofing (roofing material, plastic film or other material).
6. Sand is poured into the bottom of the trench, which is rammed to make a pillow 200 mm thick.
7. 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.
8. Longitudinal reinforcement is fastened with short rods, connected with wire into a single structure. In some cases, electric welding is used.
9. The formwork is poured with concrete mortar.
10. 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:

1. The building plan is transferred to the construction site, marking the location of the supports.
2. 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.
3. 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.
4. Asbestos pipes are lowered into the well.
5. Knitted or welded reinforcement frames are placed in the pipes.
6. Pipes are filled with liquid concrete mortar (usually concrete M 300 is used).
7. 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.
8. 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:

1. At the indicated points, shallow holes are made with a hand drill (no more than 300 mm deep).
2. The pile is inserted with a screw into the hole.
3. 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.
4. A third worker controls the vertical position of the pile.
5. Installed piles are cut with an abrasive wheel to one level.
6. Metal platforms are welded to the upper ends of the trunks.
7. They make a binding of piles from a channel.
8. A beam is laid on the grillage.
9. 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:

1. The site is covered with rubble. Then arrange a sand cushion.
2. A frame made of metal reinforcement is laid on the compacted sand.
3. A protective border is arranged around the perimeter of the site so that liquid concrete cannot flow out of the base.
4. The entire site is filled with concrete.
5. 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.

Houses made of logs are in steady demand due to the successful combination of aesthetic appearance, thermal insulation properties, environmental friendliness, ease of installation and affordable price. A log house is durable if you follow the construction technology and use protective compounds for wood.

In addition, it is important to choose and equip the foundation correctly, otherwise the uneven deformation of the underground base will lead to distortions of the log house. This is fraught not only with jamming of doors and windows, but also with the appearance of gaps between the crowns, the occurrence of cracks in the logs, and the gradual destruction of the structure.

In order to choose the right type of foundation, it is necessary to take into account the characteristics of the soil at the construction site, the level of groundwater, the dimensions of the house (total area, number of storeys), as well as the properties of the foundation structures themselves. There are the following types of foundations:

• slab;
• columnar;
• pile (including pile-screw);
• tape (monolithic, prefabricated).

When determining which foundation is best for a log house, it is important to understand the principles of installation and the performance properties of each type of foundation.

Slab construction

Among all types of foundations, this option is one of the most expensive, since the foundation is a monolithic slab of reinforced concrete. In addition to the high cost and material consumption, the slab foundation makes it impossible to equip the cellar under the house.

However, the arrangement of a monolithic reinforced concrete slab is a practical solution when building a house on a site with swampy or moving soil. The slab foundation is called "floating" because it moves during seasonal ground movements, it prevents the wall structures from deforming due to uneven loads.

Any type of soil is suitable for using a slab base, but in most cases it is impractical due to increased financial costs, given that a log house is characterized by relatively low weight and does not need a reinforced base.

The technology of mounting a slab-type structure includes the following stages of work:

• leveling the site and preparing a pit with a depth of 20-30 cm;
• laying and tamping of sand and gravel cushion;
• installation of a waterproofing layer that protects the sole of the foundation from moisture;
• fixing the formwork along the perimeter;
• installation of the reinforcing cage (two levels of reinforcement, rod thickness 12-16 mm, distance from the ends of the reinforcement to the formwork - 5 cm, fastening with knitting wire, since welding reduces the strength of the metal at the joints);
• pouring a concrete mixture with a uniform distribution of material over the surface;
• removal of air bubbles from monolithic concrete.

It takes 1.5 months for the slab foundation to gain strength; during solidification, the concrete should be covered from precipitation and the hot sun. The thickness of the slab is selected depending on the characteristics of the structure; for a log house, a base up to 30 cm thick is sufficient.

Note:

• The construction of a brick oven in a house with a monolithic foundation is problematic - due to uneven heating of the slab, reinforced concrete will begin to collapse. It is required either to use a reliable heat insulator, or to provide a “window” in a monolithic slab at the design stage for arranging an independent base for the furnace.
• An extension to the house on a monolithic slab should be erected on the same basis - when choosing a different type, there is a high risk of deformation of the extension (and at the same time - the main frame) due to uneven movements of the base.

columnar construction

The columnar foundation is one of the most economical. When choosing such a base, consider the following factors:

• suitable only for stable soils, not prone to frost heaving, with a low level of groundwater;
• the difference in height of the surface of the construction site should be no more than 2 m;
• suitable for the construction of one-story buildings of a small area due to the limited bearing capacity.

The arrangement of the base consists in the preparation of pits for each column with a gravel-sand compacted cushion and a waterproofing layer of roofing material. The depth of the pit should be below the freezing level of the soil.

The columns are located at each corner of the log house, at the intersection of partitions and walls, under jambs, with a step of 1.5-2 m under long walls. The surfaces of the posts should form a horizontal plane.

The columns are made:

• from brick or stone laid on mortar;
• from asbestos pipes (fittings are installed inside and concrete is poured);
• from monolithic reinforced concrete;
• from precast concrete blocks.

If the supports are installed in soil that is not prone to movement, a compact log building will last a long time.

Pile, pile-screw foundation

According to the principle of operation, the pile foundation is similar to the column foundation, only special elements designed for high loads are used as supports. The method of driving piles into the ground depends on the type of element. The advantages include the possibility of construction on a site with a large elevation difference, no need to carry out volumetric earthworks.

The advantages of pile foundations include the ability to install on difficult soils. For heavy capital buildings, reinforced concrete piles are used, but the foundation for a log house does not require serious financial costs for the piles themselves and the equipment for their installation, it is enough to use screw piles.

Screw piles are steel pipes with special blades at the lower end for the convenience of immersing the element into the ground. Due to the special coating, the metal is protected from corrosion. In order for the building to stand for a long time, piles with a wall thickness of at least 4 mm are selected and the metal is additionally processed at the border of the soil and the atmosphere - this is the most vulnerable area.

The diameter of the piles is selected depending on the size of the base and the number of storeys of the building, as well as taking into account the characteristics of the soil, otherwise there is a risk of pipe deformation when the screw element is immersed. A deformed pile incorrectly perceives and transmits loads, which reduces the strength of the foundation.

Screw piles are used on soils of any type (including loose ones), with the exception of swampy and rocky ones. The foundation process includes:

• for installation of piles according to the project;
• digging holes for piles;
• screwing piles using manual devices or a special mechanism;
• control of the verticality of the elements, cutting off the protruding parts in such a way that a horizontal plane is formed;
• welding mounting plates or erecting a monolithic reinforced concrete grillage.

Screw piles are a good option for building on slopes, on soft soils, in conditions of close water occurrence.

Tape base monolithic

This type of foundation is in demand during construction on gravel, sandy-rocky and sandy soil. The depth of laying the foundation is determined taking into account the tendency of the soil to frost heaving - for heaving it is about 1.5 meters, for non-heaving - 60-80 cm.

The width of the tape must exceed the width of the wall and be at least 30-40 cm. A width of 12 cm or more will make it possible to lay the logs of a wooden floor without cutting into the lower crowns.

The monolithic reinforced concrete tape has a closed contour, the support is provided under the external walls and partitions.

The arrangement of a tape monolithic base provides for:

• site preparation (removal of fertile soil layer, leveling);
• marking and digging a trench, laying a sand and gravel cushion;
• formwork fastening;
• installation of a reinforcing cage made of embossed rods with a cross section of 10-12 mm, fastened with a knitting wire;
• uniform pouring of the concrete mixture and removal of air bubbles.

A freshly poured foundation is protected from drying out in the heat and getting wet in the rain. Strengthening takes about a month.

The advantages of a tape monolithic foundation include: uniform distribution of loads from building structures to the soil, resistance to deformation, cost-effectiveness in comparison with the slab version, the possibility of arranging a cellar.

Strip base prefabricated

A strip foundation for a log house using ready-made reinforced concrete blocks allows you to reduce construction time, since there is no need to mount the formwork, reinforcement cage and wait for the concrete to gain strength. Reinforced concrete blocks are laid on a prepared sand and gravel cushion.

A solution is used to fasten the elements together. The foundation walls of the blocks are built according to the principle of building brick walls - the elements are stacked apart.

The dimensions of the blocks are selected in accordance with the size of the building. For small buildings, it is enough to choose compact blocks weighing up to 30 kg - no construction equipment is required for their laying.

Reinforced concrete blocks with special additives or fillers make it possible to equip a foundation with increased resistance to aggressive traces (for acidic soils) with increased frost resistance.

Conclusion

The foundation for a log house is selected according to the ratio of functionality and cost. Wherein:

• the columnar base is not strong enough and reliable for capital construction;
• a recessed strip base and a monolithic slab are material-intensive options, they are redundant for wooden construction.

The best options are:

• tape base of shallow depth;
• a screw base with or without a grillage (the lower crown of the frame can be laid on mounting platforms on piles, the resulting structure has sufficient rigidity if the recommended step between the supports is observed).

The selected foundation should be mounted, observing the technology of work - the reliability and durability of the foundation depends on this.

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 on 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 mortar. 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 weight of log crowns is lower than the weight of brickwork. This allows you to arrange less powerful foundations for log cabins.

However, in addition to the mass of structures, geological and topographic conditions are taken into account. You can increase the operational life of the foundation of the house by carrying out a set of works on hydro and thermal insulation.

Features of foundations for log houses

Material costs for the foundation are estimated at more than 30% of the construction budget. The question of reducing the cost of this amount is relevant. However, it is necessary to take into account the volume of loads that the foundation experiences. The weight of the building is determined from the project, but the final decision on the type of foundation is made only after soil investigations, determination of the groundwater level (GWL) and
topographic survey. Possible options: slab, tape, pile-grillage, columnar.

slab

A monolithic reinforced concrete slab under the house is called floating: with ground heaving, elevation changes. At the same time, the walls also move, but the processes occur without distortions, which serves as protection against deformation gaps. Due to the high cost, slab foundations are rare in the construction of log cabins. A weighty argument for such a choice is weak loose soils.

Tape

Strip foundations are well mastered by builders. They guarantee durability and predictability. It is believed that a tape laid deeper than the freezing point is more reliable. But the side surface of the underground wall in this case is large, and the ground shifts acting on it can cause destruction. The perspective is seen in the ribbons of shallow depth with a high plinth. This solves a number of problems:

• the cost of work is reduced;
• loads associated with tangential heaving forces are minimized;
• it becomes possible to pour the foundation at a high GWL.

Strip foundation. Choice and ground rules

Pile-grillage

It is relatively inexpensive, which justifies the bookmark for individual houses. Pile driving involves the use of special equipment and related costs. This circumstance hinders the popularity of the method in private construction. Using modern technologies, it is possible to install piles manually: screw piles are deepened by rotation, bored piles are poured directly on the spot. The function of the grillage during the construction of log cabins is performed by the lower crown of the strapping. The pile foundation is acceptable for loose rocks. The downside is the susceptibility to lateral shifts, which makes operation unpredictable.

Columnar

Installing pillars under the house is an economical option for solving the issue of a foundation for a log house. The technology uses brick, concrete, timber. Bookmarking under a residential building is advisable only on dense soils.

Optimal foundation: costs for further operation

When choosing a foundation for a log house, they are guided by a number of criteria:

• compliance with bearing capacity;
• life time;
• material costs;
• complexity of installation;
• operating costs.

The foundation corresponding to the normative indicators does not require special maintenance during the operational period. It is only necessary to control the condition of the blind area, to clear the area of ​​snow and overgrowth in a timely manner, and to limit earthworks in the vicinity of the house. If, however, during the laying of the foundation, calculation errors were made, a set of works on waterproofing and insulation was not completed, then negative consequences are possible in the form of concrete cracking, the appearance of mold and fungus on the floor and walls. Given this, it can be summarized that the cost of a quality foundation pays off in the operational period.

Saving on the foundation: why is the column foundation bad for a log house

When considering options for foundations, developers most often focus on cost. At the same time, attention should also be paid to the indicator of durability. The most expensive is the monolithic foundation, but at the same time its service life is estimated at 150 years, which exceeds the performance of the log house itself. Choosing a tape, you can count on 75 years of service. About 50 years are spent by experts on pile foundations, while the use of screw piles provides for the possibility of replacing them without destroying the building.

The durability of columnar supports varies depending on the material, on average it does not exceed 2-3 decades. This indicator is lower than the service life of log walls, which indicates the inappropriateness of such a solution.

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Waterproofing, insulation and maximum durability: what to consider when designing

The foundation is in contact with sedimentary and groundwater, as a result of which it is subject to negative impacts. When developing the project, the level of groundwater is taken into account. If their horizon is located above the lowest point of the foundation, then they construct drainage and drainage. Otherwise, shifts and destruction of the structure are possible.
Waterproofing and insulation of the foundation are carried out with liquid, dry and roll materials, which are selected depending on its type and are regulated by SNiP 3.04.01.87
The waterproofing of the slab foundation is made with rolled materials. They are spread over the dried concrete screed on the adhesive. Next, a layer of insulation (polystyrene, expanded polystyrene, etc.) is laid, which is covered with a film on top. Then another screed under the floor is performed.
Waterproofing strip foundation includes horizontal and vertical processing. Horizontal waterproofing is aimed at preventing the penetration of moisture in a capillary way, with vertical waterproofing, the basement walls are processed. An effective option for protecting the underground part of the foundation is the use of fixed formwork. For vertical processing apply:

• bituminous mastics;
• roll materials;
• liquid impregnations;
• dry putty mixtures.

The log house was actively used by our ancestors. Centuries have passed, and today there are many building materials available that are superior to the log house in many parameters. However, small huts and even roomy structures made of logs do not disappear anywhere. People strive for unity with nature and relaxation from the bustle of the city. This is all, of course, good, but if it is wrong to choose and make a foundation for a log house, there will be no sense. A solid foundation for a log cabin is one of the most significant elements of a house. Experts recommend choosing a strip foundation for building a house from logs.

The scheme of insulation of the strip foundation.

Belt structures

The strip foundation is a single system, which, as a rule, has the same width and height along the entire perimeter.

The difference in height can only be in the case when the building is being built on a land plot with a slope. perfect for massive structures located on soils with low bearing capacity.

To build a tape base for a log house, you will need the following tools and materials:

Scheme for the construction of a log house on a turnkey basis.

• roulette;
• building level;
• durable cord;
• pegs (pieces of reinforcement);
• formwork boards;
• fittings from 12 mm;
• nails;
• ruberoid;
• knitting wire;
• pipe for ventilation;
• sand;
• concrete.

The sole of the tape bases is arranged at a depth that is 20 cm below the freezing index of the earth. When the soil masses are dry or sandy, the strip foundation can be made higher than the freezing value, but not less than 50-70 cm from the ground level.

Scheme of reinforcement of the strip foundation.

If the bottom of the foundation under the log house is covered with sand, this will significantly save materials. The strip foundation is universal, it can be made on almost any type of soil. Sand should be covered in layers of 15-20 cm, in previously made recesses. For normal tamping, you need to fill in water.

Either gravel or gravel is placed on the sand. The layer thickness is 10 cm. The next step is to pour the solution, which includes sand and cement. Then pour the next layer. The part of the foundation, which is located above the ground, must be made according to the formwork system of a given height. The concrete mixture is poured there. When the foundation itself is ready, they proceed to the arrangement of waterproofing. A blind area with a minimum width of 1 m protects from precipitation and water. Now let's take a closer look at each step.

Pit for construction

Scheme of waterproofing strip foundation.

At the beginning of any construction, no matter what foundation is chosen, it is necessary to arrange a trench or foundation pit under it. If the house does not have a basement, you can simply dig a trench under the strip foundation. Construction without basements will be much more expensive, as the amount of land work and material consumption is reduced.

Most often, land plots have slight slopes in both directions, along the length and width, therefore, when arranging a foundation pit for a foundation under a log house, one cannot do without a water level. From the outside of the pre-marked perimeter, you need to determine the lowest point and, starting from it, choose the depth of the pit. It is important to remember that the depth of the pit must be the same at any point.

sand cushion

Scheme of a shallow foundation.

A sand cushion is used in order to reduce the load on the concrete base during seasonal swelling of the soil. The upper part of the sand cushion, as well as the bottom of the pit, must be compacted and leveled.

You can speed up the work on the installation of a sand cushion if you pull the fishing line at a level that corresponds to the thickness of the cushion. After that, it remains only to fill the sand along the fishing line and carefully compact it with a special roller. Wet sand compacts on its own, so it must be watered during compaction.

The amount of sand required for a pad is calculated by multiplying the width of the trench by its length times the thickness of the pad.

Formwork for mounting

Scheme of examples of strip foundations.

Formwork is a structure that gives the concrete the desired shape. It can be fixed and removable. Formwork is one of the most time-consuming and significant processes of foundation work. Shields for this design, as a rule, are made of edged boards, which have many advantages. It costs more than a regular board, but it is smoother, and the smoother the board, the cheaper it will end up being to finish the outside of the plinth. The board has specific dimensions, which makes it possible to precisely control the height of the formwork of the future pouring. Therefore, it is better to choose a cutting board that can be used again.

The length of the shields on the side of the concrete base is usually less than the thickness of the board. From the inside, the shields are knocked down with nails, after which they are bent from the outside. After the panels are cut, proceed directly to the process of mounting the formwork.

The end parts of the shields are assembled using self-tapping screws so that the boards fit snugly against each other and the mortar does not pass through the cracks. After the shields are assembled, they are reinforced with spacers from above and on the sides. The more spacers there are, the more reliable the formwork will be, since its wooden walls may not withstand the pressure, because when pouring the mortar, they are under a lot of pressure. In order to prevent the liquid component of the solution from being absorbed into the boards, roofing felt or glassine can be fixed to the outer walls of the finished structure. At all points of the foundation, under the log house, the formwork must be made above the level of pouring concrete.

Reinforcement and ventilation

Scheme of the construction of a strip foundation.

With the help of reinforcement, it is possible to achieve a qualitative change in the characteristics of concrete and make it more durable and resistant to the influence of various kinds of loads. The fittings perform the functions of a kind of skeleton and make the tape base durable.

The reinforcing mesh should be installed at a distance of 30-50 mm from the edges of the strip foundation under the frame, so that after pouring the base, it is completely inside the mortar. To make high-quality reinforcement, you need to use reinforcement with a cross section of at least 12 mm. The reinforcement is laid on a brick in two rows.

It is best that the reinforcement is solid in length, because the fewer joints, the higher the strength of the foundation. Jumpers are tied to the lower bars of the reinforcement. This is done using a knitting wire, with a distance of 40 cm, after which vertical rods are tied to the corners of the resulting cells.

Whatever structure is erected, it is necessary to arrange ventilation of the basement. It is performed using pieces of plastic or asbestos-cement pipe with a diameter of 100 mm. When pouring, in order to avoid the solution from entering these holes, they must be covered with rags or covered with sand. And one more nuance: the installation must be done at a slight slope towards the street, so that the water that may form due to condensate has the opportunity to drain.

Pouring concrete

If such an opportunity is available, it is better to order an automixer with ready-made cement mortar purchased at the factory for the site for pouring the concrete base. In other cases, the solution is prepared on its own using concrete M-200, M-300 or M-400. The choice of brand of concrete depends on the characteristics of the object and weather conditions. A standard solution can be made independently from cement, crushed stone and sand in a ratio of 1: 3: 3. Also, water must be added to the mortar until the required consistency is obtained so that the mortar is not too liquid.

Concrete is gradually poured into the formwork, eliminating the possibility of voids, in which the constituent elements of the reinforcing structure will play their role. Each layer must be carefully compacted with rammers. In order for the mortar to lie well along the formwork, it must be tapped periodically. Filling the foundation to the full depth should be carried out as quickly as possible. To give the base under the frame maximum strength, its upper part must be periodically sprayed with water.

After the completion of pouring concrete, the process of building the foundation does not end. If the weather is cloudy and rainy, the flooded base is covered with plastic wrap. In hot weather, on the contrary, it needs to be watered and covered from the sun. The solution will completely harden only after three weeks, and only then it will be possible to remove the formwork, fix the first crown and proceed to cutting the log house.

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