How to mark the foundation for the fence. We select the optimal foundation for various designs of fences
The choice of the type of foundation for the fence depends on its purpose and the materials that it was decided to use in the device. The main criterion is the weight of structures installed above ground level. A massive fence will require the use of a powerful foundation. A light fence will lighten the underground part of the structure by choosing more compact solutions, it is easier to do it yourself.
Ready-made strip foundation for a corrugated fence
When building from bricks or small-sized wall blocks, the developer has practically no other choice than a strip foundation. However, the strip foundation can be used in other cases. When there is a need to completely separate the territory, leaving no gap between the ground and the fence, then it will also be the most reasonable solution.
An example of such a choice would be a strip foundation for a mesh or corrugated fence. Compared to pillars on separate bases, a strip foundation is a more expensive and labor-intensive option. But it guarantees reliability and the maximum level of isolation.
Fence strip foundation options
Although the construction of such a foundation will be expensive, in any case, there are options to reduce costs.
Scheme of the strip foundation for the fence
The foundation can be made in the form of a solid monolithic wall, the base of which is at the level of the soil freezing depth, and the upper cut goes to the design mark above the relief level. A somewhat more economical way is to construct monolithic columnar foundations interconnected by monolithic crossbars. The cost of such a foundation is lower.
The stability of the structure to frost heaving is ensured by the depth of the columnar foundations.
The crossbars perform the function of foundation beams or grillage, distribute the weight of the intermediate sections of the fence on the columnar foundations. They protect from frost heaving with a sand cushion and side sprinkling.
In some cases, precast concrete crossbars can be used, but this is rather an exotic option, used when there is an excess of suitable materials from the dismantling of other buildings.
The device of a sand cushion under the foundation
The construction of almost any foundation for the fence can be done with your own hands.
Materials for the strip foundation
The choice of possibilities is small. You can confidently use only monolithic concrete and rubble concrete. The same materials are used in the construction of any monolithic foundation for a different purpose. Monolithic concrete will be more expensive, although more technologically advanced. The rubble concrete will allow the use of improvised resources in the form of local stone or large pebbles, the cost of which will be significantly lower, as well as doing some of the work with your own hands.
You can use the brick fragments from dismantling the walls. It should be noted that not all mineral resources should be used for backfilling. Recommended materials include granite and basalt. Softer rocks, such as limestone or other chalk deposits, should not be used below ground level.
An example of a foundation for a natural stone fence
In this case, it must be taken into account that the rubble concrete base cannot be reinforced in a suitable way.
Therefore, with significant loads from the wall of the fence or soft soils with a high level of groundwater, it is better to refrain from such a decision.
Width and depth of the strip foundation
The strip foundation for the fence in the general case should be somewhat wider than the wall resting on it. For example, if it is 25 centimeters long, then you need to stop at a foundation width of 0.3 meters. Using piece blocks 20 centimeters wide, the foundation should be made 0.25 meters wide.
When a fence has different element thicknesses, such as posts and adjoining fencing elements, the width of the foundation will be determined in the same way, taking into account the different geometry. The mark of the bearing supports of the foundation or the entire tape at one laying depth cannot be less than the freezing level of the soil in your region.
Device diagram and dimensions of a monolithic strip foundation
You can find out the standard freezing depth in normative documentation, for example, in SNiP 2.02.01-83*.
The use of monolithic concrete
The most expensive and technological way to build a strip foundation will be the use monolithic concrete. At the same time, all technological methods and the sequence of work do not differ from those used in most other cases, creating the same structures. The brand of concrete is selected depending on the loads. The load on the base is determined by the choice of material for the fence wall and its height.
A massive fence with brick walls made of ceramic or silicate material will require the use of B25 concrete. If it is decided to use a lighter material or limit itself to a small height, then B20 grade concrete can be used, the cost of which is lower. In this case, it is necessary to comply with all requirements for laying concrete. Work should be carried out in the warm season, preventing the base and concrete mixture from freezing.
An example of a massive concrete foundation for a brick fence
The use of frost-resistant additives for concrete is possible, but they create certain risks. Additives will allow the mixture to be laid, but positive temperatures are still needed to gain strength.
Concrete must be carefully compacted. This is done either by the bayonet method, or with the help of a vibrator head. When bayoneting, a piece of reinforcement with a diameter of 12 millimeters or more is used. When laying the concrete mixture in hot weather, it is necessary to protect it from drying out. To do this, the site of the monolithic structure is covered with plastic wrap and periodically irrigated with water for several days.
The use of rubble concrete
Rubble concrete has practically no technological differences in the construction of structures from traditional monolithic. The only difference is the larger aggregate placed separately from the concrete mix. Therefore, this type of foundation is preferred by amateurs to build with their own hands.
The process of pouring rubble foundation
Stone filling is laid out in rows up to 30 centimeters high and over the entire width of the foundation. After that, a concrete mixture or sand-cement mortar is poured just above the backfill level.
It is very important to carefully fill all the voids between the stones with concrete. Sometimes the sequence of work is different. Backfill elements are sunk into a small layer of concrete or mortar, up to 15 centimeters high. The choice of techniques depends on the specific circumstances and the size of the material. For the sedimentation of the mixture and its distribution over the voids, only bayonet will have to be used, since large rubble elements will interfere with the work of the vibrator head. This reduces manufacturability and increases labor costs, but allows you to do the work yourself.
Care for freshly laid concrete is carried out in the same way as with a conventional monolith. Either frost protection or irrigation with water during the setting period is required.
Schematic diagram of a rubble foundation for a fence
Trench and soil foundation
The trench, or foundation pit, is carried out to a depth slightly exceeding the mark of the bottom of the concrete. This requirement is due to the fact that the concrete structure should not rest on natural soil, but on sandy bedding 150 millimeters thick, which is easily done by hand. It is made of sand of medium size and carefully compacted.
It should be noted that the base soil should not lose its initial properties. That is, its freezing, soaking and decompaction is unacceptable. If such transformations have occurred, the disturbed soil layer is replaced with a sand backfill of the required thickness with mandatory compaction. The width of the trench in the upper part is determined by the type of soil and its angle of repose. At the base, it will be 20–30 centimeters wider than the thickness of the foundation for the installation of a sand cushion and the installation of formwork.
foundation trenching
In some cases, formwork for rubble concrete foundation optional. Construction is carried out by filling the trench with backfill and.
This option is possible in dense, hard and dry clay soils. But in general, formwork is necessary. The trench after the foundation is covered with sand of medium size with layer-by-layer compaction. The use of clay soils for this is highly undesirable. When wet and subsequently frozen, they can cause significant deforming and pushing forces that adversely affect the structure.
Features of the grillage device
The foundation for relatively light structures can be made in the form of a grillage. In this case, the main supports on which columns or fence posts are installed are poured to the freezing depth.
Drawing for mounting the foundation grillage
Depending on the type of concreting used, they are made as a concrete or rubble-concrete strip foundation. The section, made in the form of a crossbar or foundation beam, is laid to a depth of 0.5–0.75 meters.
Its sole is cast on a sand cushion 25–30 centimeters thick of compacted medium-sized sand. The element is covered with sand from the sides to a width of 15–20 centimeters, this work can be done by hand.
This solution allows you to distribute the weight on the main foundation supports, while protecting the elements of the grillage from frost heaving of the soil. The height of all foundation elements is displayed under the design elevation defined for this section of the fence. The grillage should not be made of rubble concrete, since it cannot be reinforced. Concreting of foundation elements of the same height should be carried out simultaneously as a supporting part and grillage.
An example of mounting a foundation grillage for a fence
Reinforcement
The strip foundation for the fence works in rather difficult conditions. First of all, due to its length and due to the absence of transverse elements. Therefore, there is a high probability of cracks and deformations in the base, which can lead to the destruction of the building envelope. Although this requirement cannot be considered mandatory, but if there is an opportunity and desire, it is better to implement it.
The best reinforcement option would be to install two belts of reinforcement with a diameter of 12 millimeters or more, with a step in the transverse direction of 100–150 millimeters. Longitudinal reinforcement should be tied up after 30–40 centimeters with transverse rods. Reinforcement of the grillage is necessary both in the middle part, for the perception of bending loads, and at the junction with columnar foundations.
Reinforcement should be calculated taking into account the load on the grillage. But minimum requirement it can be considered the use of three reinforcing bars with a diameter of 12 millimeters in the middle and lower section and three rods of the same diameter about a meter long - in the upper, at the junction of the grillage to the buried part of the foundation.
When doing reinforcement with your own hands, do not forget the requirements for providing a protective layer of concrete. Its thickness from the outer edge of any concrete element to the outer surface of the reinforcement should not be less than five centimeters. The formwork of the element determines its outer edge, the clearance control is carried out before the start of concreting. In the process of pouring the foundation, if necessary, the installation of embedded elements is carried out.
Waterproofing
Does not require a device coating waterproofing as opposed to building foundations. Although if it is done, it will not be worse, the concrete will be less exposed to groundwater. But vertical waterproofing between the concrete base and brick or block wall elements must be done.
For it, you can use one or two layers of waterproofing, roofing felt or similar material. The choice is determined by the difference in prices for them. Installation of waterproofing is carried out on a layer of bituminous mastic.
Fence Formwork
When building a fence around the site with your own hands or with the help of hired specialists, you need to understand how the necessary work is performed correctly. Consider the question of how to make a formwork for a fence.
Finished formwork for pouring the foundation
Why is she needed
Even relatively light and sheet materials need a foundation. The appearance of the fence, its verticality and correct geometry depend on how securely it is fixed in the ground. A rickety fence worth several tens of thousands of rubles will spoil the mood of the owner every day, who decides to save a couple of thousand on the foundation.
The fence is affected by wind loads, which are transmitted to the foundations by means of pillars. But soil movements as a result of precipitation and frost heaving have a greater influence. Even slight rolls cause visible displacement of the posts and can lead to cracks in the brick elements of the fence. Therefore, the fence is placed on a solid foundation.
Usually it is made of monolithic concrete. This is not a very difficult, albeit time-consuming work that many seek to do with their own hands to save money.
It looks like concrete poured into the formwork
For a concrete monolith, a formwork is required, which forms its future geometry.
Do-it-yourself fence is a profitable solution. In this case, there is no need to pay strangers: with the proper level of preparation, the work can be done independently. One of the most important parts of the structure is the foundation. It is from him that strength and reliability will depend.
There are currently no special normative documents for private construction. When designing and erecting, you can rely on the "Foundations and Foundations". The following sets of rules may also be useful:
- "Foundations of buildings and structures";
- "Loads and impacts";
- "Construction climatology and geophysics" (now canceled, but suitable for quickly determining the depth of soil freezing).
When designing a strip foundation for a fence with your own hands, it is necessary to take into account several factors at once that affect the size of the structure, the depth of the sole and the reinforcement of the strip foundation for the fence.
It is worth remembering that in private construction it is difficult to strictly adhere to regulatory documents. This can lead to waste of materials and forces.
Before you make a strip foundation for a fence, you need to consider the type of fence. There are three main options:
- lungs;
- medium;
- heavy.
Light fences are made of racks and non-massive materials (mesh, reinforcement rods, corrugated board, wooden shields, pickets). Such structures are highly resistant to uneven deformations. Fences with non-continuous filling (mesh, rods, pickets) are also resistant to tipping over under the influence of wind loads.
Medium fences are a combined structure consisting of massive pillars (brick, stone, concrete) and lighter filling (profiled sheet, reinforcement rods, picket fence). This option requires a more reliable foundation, as it is sensitive to displacements.
The third type of fences is heavy. They are completely made of rubble, concrete or brick. Such fences are damaged when the base is deformed, and also exert great pressure on the ground. The most difficult thing is to prepare the tape for just such a design.
The main problems in construction
When designing a fence, it is important to consider the effect of two phenomena:
- windage under the influence of wind loads (overturning);
- uneven deformation of the base.
The latter include:
- shrinkage of the soil (its compaction after the manufacture of foundations, sections of the fence can be lowered);
- frost heaving of the base (fence sections can rise).
To avoid trouble, it is necessary to take measures to combat frost heaving and carefully compact the base under the foundation.
Advice! You can understand whether the soils on the site are prone to heaving by looking at the neighbors' fences. If they were "led" to different sides, most likely it was this property of the soil that was to blame. It is worth looking only at the fences that have stood for several winters.
Classification is carried out according to three main features. According to the manufacturing method:
- Made. Great for mass construction, increases the speed of construction work.
- Monolithic. Most often used in private construction. Eliminates the need to hire expensive lifting equipment.
By depth:
- not buried with low bearing capacity;
- shallowly buried;
- deep laying.
By section type:
- rectangular;
- t-shaped section with broadening at the bottom.
light fences
In this case, it makes no sense to build a deeply buried foundation for a tape fence. This is not cost effective.
Under a fence made of corrugated board with your own hands, a shallowly recessed tape of rectangular section (laying depth - 0.7-1 m) is suitable. During its construction, it is important not to forget about the main problems: heaving and windage.
The width of the foundation is recommended to be at least 350 mm. At the same time, reinforcing meshes made of rods with a diameter of 3-4 mm and a cell size of 50x50 mm should be laid in the upper part at the places of rigid connection of the tape and fence posts. The protective layer of concrete for galvanized meshes is 30 mm, for "black" - 60-70 mm. Such a mesh will prevent damage to the fence under the action of the wind (relevant for structures made of corrugated board and wooden shields).
Fence posts are usually supported below the sole of the tape and concreted. This allows the fence to more effectively resist overturning and ground movements.
Lightweight fencing.
When laying the sole of the foundation above the freezing depth, it is necessary to prevent heaving. The step-by-step instruction in this case is as follows:
- Backfilling of a sand cushion with a thickness of 30 to 50 cm. Replacement heaving soil on non-porous at the level of the sole allows you to avoid pushing the structure out of the ground. The sand becomes a damping layer. It should be large or medium fraction. The material is laid with layer-by-layer compaction.
- Backfilling the sinuses with sand avoids the effect of heaving on the side surface of the foundation. Backfill requirements are the same as in the previous case.
- Laying a drainage pipe at the level of the sole (20-30 cm below). It is important to observe the correct slope of the pipeline. The maximum distance from the drain to the side surface of the tape is 1 m.
- Device storm sewer for organized removal of excess moisture from the site.
- Insulation and waterproofing of the structure with extruded polystyrene foam.
Important! The supporting structure for the fence differs from that for the house in that there is no point in making an insulated blind area.
A fence made of corrugated board on a strip foundation can be built without fear of frost heaving, if non-rocky soils lie on the site: medium and coarse sand, coarse-grained rocks without dusty inclusions.
Medium fences
Fences of this type do not respond well to uneven ground movements. To prevent destruction, it will be necessary to pay great attention to the fight against heaving. On firm, non-rocky soils, a shallow tape can be used.
In other cases, it is reasonable to combine the tape shallow foundation with concrete pillars or bored piles. Additional supports are placed under massive pillars. The depth is set so that it is greater than the depth of freezing of the soil. The methods of dealing with heaving and windage are used the same as in the case of light fences.
Another option: columnar or pile foundation with tape grillage. At the same time, a gap of about 10-15 cm is left between the concrete tape and the ground, which will prevent damage to the tape when the soil buckles. The gap is made in two ways:
- A layer of low-strength foam is laid between the ground and the tape, which plays the role of a damping layer.
- Before pouring the structure, a layer of sand 10-15 cm thick is laid on the ground, after the concrete has hardened, the sand is removed. At the same time, the gap is closed with sheets of asbestos (slate), which will prevent soil shedding.
A corrugated fence on a strip foundation in the presence of concrete pillars requires more attention than a lightweight structure.
heavy fences
Most of the financial and labor costs will be required for the construction of a massive structure made of brick, stone or concrete. The design has the following disadvantages:
- large mass and high ground pressure;
- sensitivity to deformations;
- windage, the need to take into account wind loads.
In this case, it is necessary to rest the fence on a reliable foundation:
- With good soil strength, a shallowly buried T-section tape can be used. The option is suitable for non-porous bases. Clay soils will require additional measures to combat heaving.
- In other cases, a recessed tape is used with support 20-30 cm below the freezing depth.
Every 30 meters in the tape it is necessary to provide a vertical expansion joint. A waterproofing layer must be provided between the foundation concrete and the fence material (brick, rubble). To do this, you can use rolled materials. The side surface for protection against moisture is coated with bitumen in two layers.
Foundation width selection
The width of the tape is selected by calculation. To do this, use the same technique as when calculating the parameters of the foundation for the house. But it is important to remember about wind loads. The building has a higher rigidity, so it resists tipping over well.
In private construction, you can use approximate values. In most cases, having built a structure with a width of 30-35 cm, you don’t have to worry about reliability and durability.
So we decided to put up a fence. The basis of this structure will be the foundation, and the quality of the entire structure will depend on its strength.
The base is necessary so that the fence does not undergo deformation on the ground.
If you have the necessary skills, you can make the foundation for the fence with your own hands.
A solid foundation is necessary so that the fence is not subjected to soil deformation
Types of fences
Before proceeding with the device of the base, it is necessary to decide on fence type:
- easy;
- middle;
- heavy.
After determining the type of foundation, you can begin to start work.
For light type fences
For a light type of fencing - corrugated board, picket fence, chain-link mesh - on solid ground, a less expensive method of column filling is quite suitable.
Along the perimeter of the future fence, pits are dug with a depth of 80 to 120 cm at a distance of 1 to 5 meters, pillars are installed in them, bursting with stones and poured with concrete. When using corrugated board the distance between the posts is recommended no more than 2 meters, taking into account the windage of the material under wind loads.
This video shows how to build a foundation for a fence:
If the soil is loose, sandy or silty, a tape-pillar type of foundation for a do-it-yourself fence is suitable. This type of plinth is best suited for do-it-yourself construction.
Pouring order
We divide all the work into five stages in order to do it without mistakes fence foundation:
- It is necessary to make markings along the perimeter of the foundation: for this, pegs are driven in and the rope is pulled, be sure to fix it at the corners. At the turning points, it is necessary to hammer in a peg, also mark a place for the gate and the gate.
- They dig a trench 35-40 cm wide and up to 50 cm deep, in places where the pillars will be installed, they make recesses up to 90 cm. The recommended distance between the pillars is 2 meters, and the height of the pillar, taking into account the underground part, is at least 2.5 meters. We install the pillars, fix them strictly vertically with stones, broken bricks and gravel, check the level - this is important. The bottom of the trench is covered with a 5 cm pillow of gravel.
Follow the rules for pouring the foundation under the fence in order to end up with a solid structure
- They begin to install a reinforcing belt from corrugated reinforcement 10-15 mm, it is not recommended to use welding at the joints, it is better to use wire, longitudinal reinforcement should be corrugated, with a diameter of at least 12 mm, and transverse and vertical reinforcement can be smooth and smaller diameter. The reinforcing belt is first made and then lowered into the trench, be sure to tie the posts - this will strengthen the structure.
- They put up formwork. To assemble it, you can use improvised materials - old boards, plywood, slate, and so on. This will reduce the cost of construction, the main task of the formwork is to provide the foundation with a flat surface. Expose and wedged the formwork 25-30 cm above the surface, check the possibility of leakage of the filling mixture. Conduct a thorough check of the formwork before starting concrete work. The formwork is a temporary element and should be easily dismantled upon completion of work.
- Pouring concrete. Concrete in stages with horizontal layers and different type solution. A rougher one with gravel or crushed stone is poured into the ground, and soft sand and cement are poured above the ground. With phased pouring, it will be possible to avoid voids in concrete. The formwork is removed after 5 days. In dry weather, the foundation must be watered to prevent cracks. Subsequent work can be started after complete drying, when the base gains strength.
Foundation for the middle type
The average type of fencing implies a mixed structure: powerful pillars made of brick, cinder block, stone or betonite and light material between them - such as a wooden picket fence, corrugated board or a rebar lattice.
Such a fence requires a more reliable base. For these types of fences, as well as for light ones, a strip foundation for a fence is suitable.
A feature of medium structures is the installation of additional supports at the installation sites of the pillars.
To do this, where there will be pillars, they dig holes, given that the depth of the foundation for the fence should be greater than the freezing layer, and 50 × 50 cm wide, we knit a reinforcement frame, insert it into the hole and concrete.
For heavy structures
Heavy fences are structures made of brick, stone or concrete and have a large mass, therefore, if the foundation is not properly constructed, they are often subject to deformation; these fences require a more powerful monolithic tape base.
When constructing this foundation, it is necessary to dig the entire trench with a depth of 30-40 cm more than the freezing depth, in order to achieve maximum reliability, it is necessary to make a more powerful reinforced belt from reinforcement of at least 12 mm, it is thanks to the reinforcement that the load will be distributed evenly throughout the structure.
It must be remembered that the width of the fill must be greater than that of the wall of the structure, by 15-20 cm. Thus, a monolithic strip foundation of special strength will be obtained.
An important step is the pouring of concrete, therefore, before proceeding to this process, you should make sure that everything is ready and check for necessary tool. The foundation is poured with ordinary concrete. For the manufacture of the solution independently, the necessary proportions are 2: 2: 1 (crushed stone: sand: cement).
Such a concrete base for the fence will last for many years without defects and damage.
Any personal plot sooner or later requires fencing. Therefore, this problem is relevant for their owners. In order for the installed fence to serve as a solid structure and stand for a long time, it is required to lay out the foundation.
Features and functions of the foundation
The main bearing part of the fence is called the foundation. The life of the entire fence will depend on the type and quality of its implementation. With a weak foundation device, or its absence, the fence may squint. Also, swelling of the earth can lead to such a problem, which will entail the destruction of the building envelope.
The foundation for the fence performs the main functions:
- affects the stability of the fence;
- makes it possible to equally share the load on the entire structure;
- provides soil retention for suburban area during showers and during the period of snow melting.
Foundation types
The most famous option is considered to be a strip foundation for a fence. This is a necessary element in the manufacture of stone fencing. The base in this case makes it possible to make a uniform load. The strip foundation is applicable for making pillars in it.
Initially, you need to dig a trench according to the calculated data. On its bottom fall asleep rubble with sand. A formwork with a height of up to 30 cm is built above the pit, and support pillars and metal reinforcement are laid inside. At the end, the foundation is to be poured.
A cheaper option for building foundations - columnar foundation. This type is often used for sandy or clay soils.
Asbestos or metal poles serve as reliable protection. The support can also be brickwork made on the basis of concrete. The gap between the two supports is approximately 1.5-2 m.
Depending on what kind of soil and weather conditions, they dig a trench under the supports to a depth of 1-1.5 m. A sand-gravel cushion is poured into the very bottom of the pit, after which it is compacted. Then they put the pillars in a vertical position, and the trench is poured with concrete.
Often people use a combined foundation that combines the above two types of concrete. Its application is carried out in the construction of concrete-tiled fences, profiled sheet structures.
The price of a foundation for a fence with brick pillars consists of the prices of the stocks used. Based on whose production it is, the cost of one bag will come out. On average, it varies from 200 to 250 rubles.
Manufacturing
Preparing the foundation for the fence yourself is quite simple. It is only necessary to first calculate everything and adhere to all points of the instructions when carrying out actions.
To determine the depth of laying the foundation, it is necessary to take into account the main points:
- design characteristics;
- the depth to which the soil freezes;
- terrain slope;
- the quality of the land layer and the height of the sandy waters.
For the correctness of all calculations, you need to calculate the area of \u200b\u200bthe base from the foundation. For example, if the length of the supporting structure is 50 m and the width is 30 cm, then it is not difficult to calculate the area (15 m2) here. Subsequently, this parameter will be useful for calculating the depth at which the foundation is laid.
At the same time, it is necessary to reveal what its reliable area is. We divide the pressure index of the above-ground part by the value of the bearing base, corrected for the reliability index, by the soil resistance and the coefficient of working conditions.
The final result must be compared with the expected area. The final must be higher than the calculated, otherwise it is subject to adjustment.
fill
How to fill the foundation under the fence correctly? The heaving soil layer requires pouring a combined foundation. Before starting work, it is required to dig a trench, the size of which must correspond to the calculated depth and width. Holes must be drilled in the place where the support poles will be installed.
Then, a wooden formwork is made around the prepared base. At the bottom of each dug hole under the post, you need to lay a roofing material, laid in half. After that, the installation of supports and the reinforcement of the foundation with the help of a reinforcing mesh is done.
Next, the foundation bay begins under the fence in the horizontal direction. When pouring the concrete mixture, it is impossible to allow the formwork to be hidden from one end to the very top, and from the other it is completely absent. Drying time for concrete takes about 3 days.
In hot weather, the foundation should be moistened with water. The formwork is removed from the tape after 2 weeks.
Filling a tape shallowly buried foundation is easier. It is laid above a layer of frozen soil. For this reason, the correct foundation for the fence is resistant to interseasonal ground movements.
The foundation device is performed as follows:
- Make a trench to a depth of 0.5 m.
- Cover the lower part of the trench with sand (0.15 m) and press it down.
- Sprinkle the top with crushed stone (0.15 m).
- Drill holes for digging in pillars, pour sand on the bottom, insert supports and align them.
- Connect the posts to each other with reinforcement using a welding tool.
Install the formwork and pour the concrete mixture. At the end of the pouring work, you need to make sure that the pillars are installed evenly.
For other types of fences
It will be necessary to fill in a columnar foundation for a fence made of corrugated board when the height of the fence is up to 1.2 m. If the parameters of the profiled sheet are exceeded, a strip foundation will be needed.
Since the columnar type of material has a high windage, it is subject to increased load during a hurricane. As a result, the destruction of the support and everything else can occur.
To make a fence holding on brick pillars, you will need to build a sufficiently strong foundation for it. Such fences are prone to damage with uneven shrinkage. In the pillars, a mortgage device is recommended. It is connected with the transverse parts of the entire fence for a strong fixation.
Photo of the foundation for the fence
A strip foundation for a fence is the best option for some types of fencing.
The depth of such a foundation can vary depending on the type of fences being built.
We will consider the technology for arranging such a foundation further.
Medium-heavy and heavy fences, represented by profiled sheet, reinforcing bars, massive fence, rubble, concrete and brick, require the arrangement of a reliable foundation, due to the increased sensitivity of the structure to displacement and significant pressure on the ground.
Simple support poles that do not have a solid base are able to move under the influence external factors, and as a result, the fence becomes potentially dangerous.
If there is a need to erect monolithic and sufficiently weighty fencing structures, then it is necessary to consider not standard pillars as supports, but the arrangement of a strip foundation.
Types of tape type foundation
Foundations belt type for the construction of fences are represented by several types.
According to the depth of laying, such structures are:
- shallow foundations with low bearing capacity;
- deep foundations that go into the ground a maximum of a meter;
- shallow foundations, extending into the ground by a maximum of 0.4 m.
The latter option is used mainly in the construction of wooden fences, as well as fences based on a metal picket fence and profiled flooring.
Buried foundation foundations of the tape type are appropriate for the construction of stone or brick fences. In this case, the trench is dug below the freezing level of the soil. The width of the trench is determined by the weight of the material used in the manufacture of the fence.
Depending on the manufacturing method, the strip foundation for the fence can be:
- prefabricated type;
- monolithic type;
- rectangular type;
- with a T-shaped extension at the bottom.
There can be several options for arranging a strip foundation for a fence:
- the use of reinforced concrete structures based on a cement-gravel-sand mixture, which is used to fill the reinforcing structure in the formwork; such a base is optimal for arrangement on sandy soils;
- the use of a rubble concrete structure based on a mixture represented by sand, cement and gravel;
- the use of a brick or rubble foundation structure with high strength and durability.
Strip-column foundation
In order to reduce the cost of building a foundation strip foundation for a fence, a structure is often erected based on rubble stone mixed with a standard cement-sand mortar.
The depth of the trench being dug, as well as its dimensions, are calculated taking into account the indicators of heaving of the soil, the features of all those used in the construction of the fence building materials and location of groundwater.
The device of the strip foundation for the fence - technology
The process of building a foundation for a fence includes the following main technological steps:
- digging a trench, the width and depth of which depends on climatic conditions, indicators of soil stability and the mass of the fence structure;
- laying and tamping at the bottom of the excavated trench of a gravel-sand cushion;
- welding and laying reinforcement;
- arrangement of formwork;
- pouring concrete strip.
Strip foundation for a fence - a diagram with dimensions
The concreting process is carried out by continuous filling of the trench concrete mix or laying the mixture intermittently. The first option is used on shallow trenches, and the second is used to create a voluminous foundation base.
At the final stage, after the pour has solidified, the formwork is removed and the soil is backfilled.
Foundation calculation
The correct calculation of the area of the strip foundation base allows you to determine the optimal proportions at which the level of maximum stability of the structure under construction is achieved:
[K(n) x F] / [K(c) x R], where
- (К(n)) – reliability factor;
- (K(c)) - coefficient of the conditions of the work performed;
- (R) - calculated indicators of soil resistance.
If necessary, you can use special calculator programs.
Mounting the base with your own hands
The arrangement of the strip foundation can be carried out without formwork or using formwork.
- The first concreting option is most often used to create a base with a depth of up to 80 cm, without a protruding concrete base or with a brick base.
- For the second installation method, it will be necessary to make a standard formwork, the height of which depends on the size of the basement part of the structure being erected.
Formwork for pouring concrete under a strip foundation
An important step in the installation of the base is to protect it from heaving of the soil. For this purpose, a drainage pipe is laid at the level of the sole with the correct slope, and the arrangement of storm sewers allows for the organized removal of excess moisture from the site.
Strengthening the foundation through reinforcement
For full-fledged reinforcement, reinforcement with a V8-10 mm diameter is used. For creating reinforcing cage it is required to connect all metal rods into a single structure using a reliable and strong wire. The width of the frame to be erected should be ½ of its height.
The most problematic areas of the frame are the corners, so they are in without fail must be reinforced with bent metal rods.
Pouring the solution into the formwork
Along the entire perimeter of the excavated trench, a formwork of wooden boards with a height of B15-20 cm is arranged. Such a simple design will prevent the soil from collapsing directly into the trench filled with concrete mortar.
A mortar of M200 concrete is being prepared for pouring, consisting of one part of cement, three parts of sand and five parts of crushed stone.
Concreting the foundation for the fence
The amount of water is usually 0.6-0.7 parts. Add water to the mixed mixture gradually. The solution ready for pouring must necessarily have a uniform consistency and good viscosity.
Protection of the foundation from moisture
The formwork can be removed after about ten days, when the concrete pour reaches a strength level of B70% of the standard values.
Then waterproofing is performed, which will prevent moisture from entering the walls of the fence being erected.
For this purpose, waterproofing materials are most often used, represented by bituminous mastics or roofing material.
Final works
At the final stage, all foundation sinuses are backfilled with medium-grained sand, followed by careful tamping. It is important to remember that the normative strength is gained by concrete, as a rule, within a month. Only after that you can proceed with the installation of the above-ground part of the fence.
Related video