The foundation for the fence: varieties and features

Almost all owners of personal plots sooner or later face the problem of installing a fence. But no matter how light or heavy it is, in any case, in order for the structure to be reliable and properly serve for a long time, a foundation is needed.

The foundation is the main bearing part of the fence. The service life of the entire enclosing structure depends on how correctly its type is chosen and how well it is made. If the foundation is weak or not there at all, then the fence may be crooked, it may be driven during the heaving of the soil during the spring thawing of the soil, or it may fall altogether.

The foundation for the fence performs several important functions:

• ensures the stability of the entire structure of the fence;
• allows you to evenly distribute the load on the fence structure;
• in the presence of a foundation, the soil is retained on the site and is not washed out of it with water during rain or snow melting;

• serves as a barrier to penetration of melt water into the site;
• with a foundation, the fence looks much more aesthetically pleasing and more reliable.

Despite the above important functions that the foundation performs, during the construction of the fence, many owners of household plots, calculating their costs, still think about whether it is worth making a foundation for the fence. It all depends on what type of fence it is decided to install on the site.

If this is a light blown-through structure made of a chain-link mesh or a wooden picket fence, then it is quite possible to do with concreting only the supports themselves. But at the same time, it must be remembered that even for light fences this is not the most reliable foundation, and such a fence will last 5-7 years from the force.

The most common option for arranging a foundation for a fence is a strip foundation. It is most suitable for the construction of stone fences or fences with stone pillars, between which a fence made of profiled sheet, forging, wood and other materials is fixed. The concrete base of such a foundation allows the load to be evenly distributed. The strip foundation is suitable for installing metal supports in it with the subsequent fastening of fencing structures to them.

For a device of this type of foundation, a trench is first dug out to the calculated values ​​of depth and width, at the bottom of which a cushion of rubble and sand is arranged. Formwork up to 30 cm high is arranged above the trench. Pillars are installed inside the trench and fittings are laid. Next, the foundation is poured with concrete.

The most budgetary option for arranging a base for fence supports is a columnar foundation. This type of foundation is most suitable for heaving soils. The supports can be metal or asbestos poles, concrete masonry or screw piles.The distance between the supports is usually 1.5-2 m.

Depending on the type of soil and climatic conditions, a hole is dug under the supports to a depth of 1-1.5 m. A cushion of rubble and sand is placed on the bottom and compacted. Next, the pillars are installed, they are fixed vertically and the pit is poured with concrete.

This type of foundation is used for the construction of fences made of concrete slabs, forging, profiled sheets, especially in the presence of brick pillars. For the device of the columnar-strip foundation, they first dig out a trench about 0.5 m deep.

In it, in marked places, holes are drilled with a depth exceeding the depth of soil freezing. Next, formwork is installed in the trench, a mixture of sand and crushed stone is poured, reinforcement is installed. After that, the foundation is poured with concrete.

The type of fence is one of the main factors that determines how the foundation should be.

For fences made of profiled sheet, forged elements, mesh, wooden picket fence, two types of foundations are used. The first option is when the foundation is made for each support (columnar). For this, a hole is dug in the soil. A pillar is buried in it, and the space around it is filled with concrete.

The second option is a strip foundation, which is a trench dug in the ground, into which supports are installed with a certain step and poured with concrete. This foundation design is used when the pillars are located at a fairly small distance from each other.

Separately, it should be noted that if it is supposed to install a fence made of corrugated board with a height of up to 1.2 m, then pouring a columnar foundation can be completely dispensed with. If the height of the profiled sheet is over 1.2 m, the strip foundation will have to be poured. Since this material is distinguished by increased windage, in a strong wind, the columnar foundation may simply not withstand the load, and the supports may tilt or fall altogether.

If you plan to make a fence with brick pillars, then the base for it should be quite serious. Such fences are very sensitive to uneven shrinkage. In pillars made of brick, stone or blocks, a mortgage is usually installed, connected to the crossbars of the entire enclosing structure.

Another important factor that determines the reliability and durability of the fence structure is the depth of the foundation.

For light fences, the most optimal depth is 50-60 cm. With such a depth of laying the foundation, the required structural reliability is ensured, as well as an economical consumption of building materials. But if a light fence will be installed on stone pillars and there will be above-ground masonry between them, then the foundation may be slightly raised.

With heavier structures, the situation is more complicated. When building a foundation for them, one cannot ignore, in addition to weight, also the structure of the soil, and the depth of its freezing in this area.

The lower level of the foundation should be located 40 cm below the freezing depth. To clarify this mark, you can use building reference books.

If a massive fence structure is being erected on soft soils, in which groundwater flows quite high, it is better to play it safe and lay the foundation deeper in order to prevent deformation of the structure due to strong subsidence of the soil. A higher foundation location is possible on solid soils. The foundation on shale soils can well be built at a depth of no more than 25 cm.

Making a foundation for a fence with your own hands is not difficult. You just need to make all the necessary calculations in advance and strictly adhere to the step-by-step instructions when performing the work.

To calculate the depth to which it is necessary to lay the foundation under medium gravity and heavy fences, it is necessary to take into account the following factors: the design features of the fence, the depth of soil freezing, the slope of the terrain, the structure of the soil and the height of the groundwater.

In order for the calculation to be correct, it is necessary to calculate the area of ​​the foundation. So, if we have a foundation 50 meters long and an assumed width of 30 cm, then we can easily determine its area (15 m2), which will later become the basis for calculating the depth of the foundation.

In addition, it is necessary to determine the reliable foundation area, which is determined by dividing the pressure of the above-ground part by the foundation base, corrected for the reliability factor, the soil resistance and the working condition factor.

On heaving clay soils, it is best to perform a combined type of foundation. Before pouring the columnar-strip foundation under the fence, you must first dig a trench corresponding to the calculation of the depth and width. In the places where the pillars are installed, drill holes for the installation of the pillars.

Further, along the entire perimeter of the future base of the fence, wooden formwork is performed. At the bottom of each pit, under the pillars, roofing material folded in two layers is laid. Next, the pillars are installed and the foundation tape is reinforced with a mesh of reinforcement.

Now you can start pouring concrete. Fill it correctly - with horizontal layers. If it is not possible to fill the entire tape at one time, then it should not be allowed that in one place the formwork was filled to the top, and in another it would not be at all. The concrete will dry for 3-5 days.

Shallow tape foundation is even easier to make. It is laid above the level of soil freezing. Therefore, such a foundation is susceptible to seasonal ground movements. Such a base is more suitable for the device in areas where the soil has a uniform structure throughout the entire area of ​​the fence.

For the construction of such a foundation, a shallow trench (0.5-0.7 m) is dug, at the bottom of which sand (0.15 m) is laid and tamped. A layer of crushed stone (0.15 m) is poured on top. Crushed stone with sand is a kind of drainage base, thanks to which water will be drained from the foundation. Further, holes are drilled into the trench for pillars with a depth of 0.3-0.4 m.

Next, the pillars are connected with reinforcement by welding. Install the formwork. After that, they start pouring concrete, adhering to the general rules described above. After the concrete is poured, be sure to once again make sure that the pillars are level.

There is another alternative option for the foundation device - from old car tires. But it is rather controversial and does not meet widespread use in the construction of foundations for fence structures.

In order for the foundation under the fence to serve for a long time, it is necessary not only to fill it correctly, but also to protect it from atmospheric precipitation. And for this, it is necessary to perform a blind area or ebb, which is a sill passing along the entire perimeter of the foundation with a slope to the side opposite to the foundation base.

Ebb tide can be done both simultaneously with pouring the foundation, and after. To do this, a trench is dug out along the entire fence line to a width of about 0.5 m and a depth of 0.15 m, which is covered with gravel and compacted. When the ebb is performed simultaneously with the foundation, reinforcement bars are released from it towards the blind area. If the ebb is done after the installation of the base of the fence, then holes are made in it and reinforcement rods are inserted into them.

If it is necessary to carry out the construction of fence structures on a site with a large slope, then the foundation for it should not be inclined. In such cases, a stepped base is built, each section of which is strictly horizontal. In the lowest place, the foundation is made level with the soil. The transition from level to level is done by steps. The length of the ledges should be at least 2 times greater than their height. The height must be at least 0.6 m.

To improve the appearance of a concrete foundation, you can make decorative plaster on it by spraying it with a special textured plaster or colored solution milk using an ordinary broom.

The base under the fence can also be painted with special concrete paints. You can also find colorful coatings for curbs or curbstones in hardware stores. For painting concrete substrates, acrylic, latex, epoxy, polyurethane, alkyd compounds can be used.

Acrylic paint is made on a water basis with the addition of acrylic dyes. Due to the presence of copolymers in their composition, it creates a polymer layer on concrete surfaces that protects the foundation from the effects of environmental factors. This paint is easy to apply, dries quickly and is economical.

Latex paint is composed of water, pigments and polymers. Sometimes silicone or acrylic resins may be present in it. This paint can be applied to the concrete base immediately after it has hardened.

The most durable foundation paints are considered to be epoxies. They can protect the concrete base for almost a quarter of a century. The paint consists of two components - epoxy resin and a special hardener, which are mixed immediately before application. The composition is applied in two layers. Epoxy coatings are vapor-permeable, which is very important for concrete substrates, resistant to the sun, acids and alkalis.

Polyurethane paint also consists of two components that must be combined immediately before applying the paint composition. The paint is applied in two layers. The advantage of polyurethane paints is that they improve the properties of concrete, are frost-resistant, form a protective coating, and close microscopic cracks and pores in concrete.

Alkyd paints are made on the basis of alkyd resin. They have a rich palette, dry quickly, are resistant to sunlight, frost-resistant, have an economical consumption.

But before choosing this or that remedy, you need to pay attention to whether it is suitable for a given climate.The paint should be applied only on a dry and free of contamination concrete base.

There are two ways to waterproof a foundation base:

• At the bottom of the trench, on top of the laid rubble, a layer of polyethylene or roofing material is laid, which will protect the concrete from moisture, which will increase the service life of the base of the fence.
• The second method is to use special waterproofing materials that are added directly to the concrete. Penetron is one such additive. When using such a composition, the entire volume of the foundation becomes resistant to moisture penetration. Moreover, concrete retains this property throughout its entire service life.

Experienced builders are advised to adhere to certain rules when constructing a foundation for a fence:

• It is possible to start erecting a foundation for a fence only when the type of soil, the depth of its freezing, the type of fence structure, its dimensions and, accordingly, the range of possible risks will be determined. If a question remains unclear, it is better to seek professional advice so that you do not face difficulties later;
• If during the calculation it turns out that the load on the concrete base is quite significant, then it is better to make a full-fledged strip foundation instead of a grillage, which is located practically on the surface of the soil between deeply laid piles;

• When preparing the concrete mix, do not use broken brick, expanded clay or wood. All these materials are capable of absorbing water and after a certain time they will simply rot, and the strength of the foundation structure will significantly decrease;
• The mortar for pouring the base under the fence is prepared from sand and cement in a ratio of 3 to 1. First, you should combine the cement and sand, and only then add water, continuing the mixing process. The solution should have a fairly thick consistency and not contain lumps;

• Since the foundation is poured immediately around the entire perimeter (that is, a rather large volume of solution will be needed immediately), it is better to prepare the concrete mixture in a concrete mixer or order a delivery of the ready-made solution;
• To increase the strength characteristics of the base, granite chips or crushed stone can be added to the solution under the fence;
• When pouring the foundation in cold weather, special concrete additives should be used to prevent the mortar from freezing.

For information on how to fill the foundation under the fence with your own hands, see this video.