Even a person who does not have special knowledge in the construction business will say with confidence that a capital structure must be built on a solid foundation. A building such as a garage is no exception. The quality of use and the service life of the building depend on the foundation. And you will not doubt the strength of the foundation made by yourself.
The need for a foundation for a garage
The need for a foundation is undeniable, as it gives the building stability and maintains the integrity of the walls. In a building such as a garage, a concrete base isolates all objects in the room from moisture coming from the ground. In a garage without a foundation, the metal parts of the car are prone to rapid corrosion.
The basis for buildings can be:
- natural;
- artificial.
As a natural base, the soil under the foundation of the garage can be used, which, by its natural characteristics, is able to ensure the stability of the structure. The composition of the soil, which has these features, comes across infrequently, so it requires additional strength, that is, the laying of an artificial foundation.
A reliable foundation for a garage is necessary when the soil in the area is unstable or has other features that further affect the integrity of the structure of the building.
Before proceeding with the construction work on installing the foundation, it is necessary to study the properties and qualities of the soil. Since there are several types of it, not all of them are suitable for the construction of structures.
There are various methods to improve the quality of the soil, which help to make its properties suitable for foundation installation.
The main types of soil are:
- Rocky with a solid structure.
- Consisting of large fragments of rocks.
- Sandy.
- Clay formations.
- Peatlands.
If we talk about the reliability of the foundation, then the rocky type of soil is the best option for building a garage. It is presented in the form of hardened volcanic ejecta and rock mixtures, tightly pressed against each other. It lies in a continuous or fissured massif. This soil is ready for the construction of a garage on its surface, without installing a foundation.
Coarse clastic soil contains gravel, as well as fragments of crystalline formations. The peculiarity of this soil is that it consists of 50% fragments and grains exceeding 2 mm. Unlike the previous type of soil, it does not consist of a solid structure.
Since the size of the constituent coarse-clastic soils is different, it is customary to divide them into types:
- boulder (blocky);
- pebble (gravel).
The foundation for a garage in such soil should be deepened by 50 cm.
Sandy soil is one of the main ones. It contains about 50% of the material with a cross section of more than 2 mm. A distinctive feature of this soil is flowability and lack of plasticity. Under the influence of moisture and load, this soil tends to be heavily compacted.
One of the unfavorable soils for laying the foundation for a garage is clay soil. It reacts to different conditions: when it dries, it can shrink, at a high degree of humidity it can form landslides, and at low temperatures it can swell. This happens because the structure of the clay soil has a scaly shape with cavities. Due to this, moisture accumulates in the pores of the clay, which contributes to the viscosity of the entire soil. In this case, it is necessary to install a pile foundation, and the laying should be carried out below the freezing level.
The high content of plant residues in peatlands makes this soil unreliable for the construction of foundations. As a rule, this soil is highly moistened and differs in that it tends to shrink unevenly. This characteristic makes it practically unsuitable for building a strong foundation. If there is a need to build on this soil, then it is replaced with sandy. This case involves the installation of a foundation in the form of screw piles. Perhaps this foundation will be the only way out of this situation.
Preparation: what material to choose, the pros and cons
When building a garage, various materials are used. The most popular of them, with all the necessary characteristics, are:
- Cinder blocks.
- Foam blocks.
- Expanded clay blocks.
Cinder blocks are a very popular material for the construction of the foundation and walls of small buildings. In its manufacture, a cinder-concrete mixture is used, consisting of sand, ash, fine particles of gravel, expanded clay, slag. Due to its relative strength and easy masonry, this material is widely used for laying foundations for garages.
Cinder blocks are made hollow and solid. Empty blocks differ in the volume of hollow cells. Solid blocks must be used for the foundation of the garage.
Cinder blocks used as a foundation have their advantages:
- it is an inexpensive material;
- it is durable and reliable in use;
- due to its dimensions, the speed of laying the foundation increases;
- since concrete is needed only for gluing blocks together, the cost of this foundation is much less than that of a strip or slab base;
- It has a high level of fire resistance.
The foundation of cinder blocks has its drawbacks:
- this material is not intended for use in clayey, loose or heaving soil;
- under transverse loads, the cinder block has low strength characteristics;
- low level of moisture resistance.
The most common materials for laying the foundation include foam block. It is one of the types of cellular foam concrete. In the manufacture of the foam block, cement, sand and water are used, to which a foaming agent is added.
The advantages of this material are as follows:
- it does not use impurities harmful to humans;
- possesses heat-insulating and sound-proofing characteristics;
- has a low coefficient of shrinkage and water absorption;
- fire resistant, thanks to which it can withstand direct exposure to fire for 120 minutes;
- its properties and qualities do not change under the influence of variable freezing or thawing;
- has a low specific gravity (0.4–0.8 t/m³);
- has low hygroscopicity (the material is able to stay on the water surface for more than 20 days);
- foam blocks are easy to process, ditch, drill;
- The service life of this material is more than 100 years.
The disadvantages of foam blocks include the following:
- this material has relative brittleness and low bending strength;
- has a high moisture absorption, which requires careful finishing and waterproofing;
- suitable for the foundation of only small buildings.
The use of expanded clay concrete base allows you to design buildings higher than for the base of foam blocks.
The base with the use of this material is expressed in the following positive criteria:
- is an effective heat-insulating material;
- expanded clay concrete blocks have good resistance to biological influences;
- after building a garage with this foundation, the structure gives minimal shrinkage;
- when exposed to open fire, toxic substances are not released;
- the composition of the material is safe for humans;
- this material is assigned to the first class of radiation safety. Due to its properties, it accumulates harmful radiation and keeps them;
- its cost is lower than a brick of the same volume;
The disadvantages of expanded clay concrete base include:
- under dynamic impact, blocks can collapse or crack;
- the use of a waterproofing and heat-insulating layer is mandatory;
- material is difficult to handle. When exposed, uneven edges are formed.
The strip foundation has the form of a reinforced concrete structure located along the intended perimeter. This foundation can be made of various building materials: brick, concrete blocks, or be a monolithic concrete base.
The service life of the base depends on the material used when laying it:
- strip foundation made of brickwork will last from 40 to 60 years;
- block construction will remain strong for 50 to 80 years;
- a monolithic base will not require repair for 150 years.
The advantages of the tape base include the following:
- this foundation is easily built thanks to a simple creation technology;
- the base is suitable for different building materials;
- if you plan to organize a cellar in the garage, then the base will serve as walls;
- the tape base is not affected by sudden changes in temperature.
The disadvantages of this foundation include the following criteria:
- the organization of this foundation requires a large amount of material and auxiliary structures;
- when building a foundation, a lot of labor is required.
Calculation of the required amount depending on the area, type of garage and the height of the foundation itself. Examples
The durability of the foundation is directly related to the correct calculation. The uniform distribution of the weight of the structure on the ground depends on this. Failure to comply with these conditions will entail unpleasant consequences in the form of additional monetary costs for correcting deformations of the building or repairing your car. Given these points, before building the foundation, it is necessary:
- Make an accurate drawing of the future garage and its foundation.
- Examine the characteristics of the soil to determine the type of foundation.
- Based on the information received, select the necessary materials for the foundation.
To make an accurate calculation of the parameters for the foundation for a garage, it is necessary to know the characteristics of the soils occurring at the construction site. The depth of the foundation for this building is determined by the distance of the freezing point from the surface of the earth.
Below is a table with the values of soil loads:
For a more convenient calculation of the load on the soil, you can use the values in the table to apply a simple formula:
S=U/R, where S is the area of the base, U is the weight acting on it, R are the measured values of soil changes. All parameters U and R are determined by standardized tables.
When laying the foundation, regardless of the characteristics of the soil, it is necessary to adhere to the basic rule - the foundation must rest on solid soil located below the freezing point. The only exception is clay soil and peat bogs. In this case, it is advisable to use a pile foundation.
If the soil freezes from 10 to 30 cm, then the depth of the base can be made about 40 cm. It should be borne in mind that under the foundation a pillow of gravel and sand is needed, the thickness of which must be at least 40 cm.
For a building such as a garage, the following types of foundation are used:
- Pile.
- Tape.
- Slab.
The calculation of the required amount of concrete for this base is carried out by calculating according to the following formula: S=3.14 R², where S is the volume of the required amount of concrete in m³, R is the radius or perimeter of the pile column. The resulting figure must be multiplied by the length and total number of concrete pillars (piles).
If you use these computational techniques, you can easily calculate the consumption of concrete in cubic meters.
To find out how much mixture is required per pile, it is necessary to determine its diameter and length. As an example, the pile diameter will be 0.1 m and its length 2 m. These parameters must be applied to the formula 3.14 0.1² = 0.0314. The resulting figure must be multiplied by the length of the pile: 0.0314 2 \u003d 0.0628 m³ - this is how much is needed to make one concrete pile. Now it is easy to calculate how much concrete will be needed for all piles. To do this, it is necessary to multiply 0.0628 by the number of holes prepared for piles.
To calculate the right amount of concrete required for a strip base, you must have information about the height and width of the strip. Since it is rectangular in shape, its area is determined by multiplying these indicators. To determine the volume of the foundation, it will be necessary to multiply its cross-sectional area by the length of the strip base. The total value of the tape structure consists of the sum of all the volumes of the parts of the tape. The calculation of each part of the base is carried out according to the following formula: V=S·L, where S is the cross-sectional area of the tape in meters, L is the length of the tape base in meters. It is easiest to make calculations if the tape around the entire perimeter has the same cross section. If it is equal to 0.16 m², with a length of 24 m, then by substituting these numbers into the formula, you get the following: V \u003d 24 0.16 \u003d 3.84 m³. As a result, it became known how many cubes of concrete mix are needed for a strip foundation. This option is only suitable for calculations of a tape with the same cross section.
How to determine the amount of solution if the tape base has a different cross section? To do this, you need to multiply, and then add the results, and the resulting figure will indicate the amount of consumption of the concrete mixture. If the section of the base is 0.16 m² with a tape length of 14 m, 0.2 m² with a length of 6 m and 0.25 m² with a length of 8 m, then by applying these dimensions to the formula, you can see the following example: V = 14 0, 16+6 0.2+8 0.25=5.44 m³.
To calculate the required amount of concrete for a slab foundation, you should use the formula: V = S H, where S is the total area of the slab foundation, H is its required thickness. If it is necessary to create a slab foundation with a length of 12 m, a width of 8 m and a height of 0.15 m, then in the formula these values \u200b\u200bare as follows: V \u003d 12 8 0.15 \u003d 14.4 m³.
In the event that a basement is provided in the garage, it will not be difficult to calculate the required amount of concrete. For this, the formulas used in calculating the slab base are useful. If its estimated length is 6 m, width is 3 m, the thickness of the base and walls is 0.15 m, and the height of the walls is 2 m, you need to make a calculation for the base and each wall, and then add the results.
From this it follows: 3 6 0.15 \u003d 2.7 m³ - concrete mixture is necessary for the base.
Now you need to calculate the required volume of concrete for each wall. To do this, its length should be multiplied by the height and thickness: 6 2 0.15 \u003d 1.8 m³. Since there are two similar walls in the basement, the value must be multiplied by two: 1.8 2 \u003d 3.6 m³.
In the same way, we calculate the other two walls: 3 2 0.15 \u003d 0.9 2 \u003d 1.8 m³. The volume of concrete for each individual wall and base is found. Now you need to calculate the total volume. To do this, add up all the results: 2.7 + 3.6 + 1.8 \u003d 8.1 m³ - this amount of concrete is needed to install the base and basement walls.
Tools for the job
To lay the foundation, you will need the following tools:
- Concrete mixer.
- Shovel, screw and bayonet shovel.
- Cord and wooden pegs.
- Electric jigsaw or hand saw.
- Screwdriver.
- Electric drill.
- Tanks for water and solution.
- Pliers.
- Yardstick.
- Building level.
- Big square.
- Nails and screws.
- Thick polyethylene.
Step-by-step instructions for the correct arrangement of different types of foundation
As mentioned earlier, different types of foundations can be applied to the garage structure, such as:
The location of each type of base must be marked with a measuring tape, pegs with cast-offs and a cord. Wooden planks nailed to pegs act as cast-offs. The height of the pegs must be at least 50 cm from the ground. The cord is attached to a driven nail in a cast-off. Two parallel cords, the distance between which should be 40 cm, define the area of \u200b\u200bthe future trench. Then, depending on the type of foundation, holes, a pit or a trench are dug.
Tape
- In accordance with the markings, dig a trench 40 cm deep and 40 cm wide.
- Pour sand at the bottom of the trench, which must be compacted until a layer 20 cm thick is obtained. The sand is better compressed if it is made wet.
- On top of the sand cushion, you can fill up a layer of gravel 10 cm thick.
- After that, make a metal frame from reinforcing bars. To do this, use a cross section of 8 to 15 mm. Metal rods must be fixed with wire. The distance between the bars should be at least 20 cm. This design will give strength to the tape base.
- Then you need to make formwork from boards or plywood. Its height should rise above the ground by at least 30 cm. To strengthen the structure, use wooden clamps or stops.
- After installing the metal frame and formwork panels, you can proceed to pouring the concrete mixture. For a relatively small building, such as a garage, M200 grade concrete is suitable. Using a concrete mixer, make a ready-made solution that needs to be poured into the prepared formwork. The height of the concrete should be between 30 and 40 cm from the ground surface. It should be remembered that the tape base must be done completely at one time.
- After pouring concrete into the formwork, it must be covered with thick polyethylene or roofing material. This must be done, as direct sunlight adversely affects concrete. From this, it can become covered with cracks due to uneven solidification. Once the foundation is poured, it takes time for it to harden. Depending on the ambient temperature, the terms for strengthening the tape base have limits from 3 to 6 weeks. After the specified period, the strip foundation is ready for the construction of garage walls on it.
Belt pile
Do-it-yourself slab construction
How to fill columnar
Video: do-it-yourself foundation
When the type of foundation is chosen correctly, taking into account the characteristics of the soil, you can be sure of the reliability of the foundation for the garage.
If you need to build an inexpensive, but durable and convenient garage, take a look at the frame buildings. The mass of the car is much greater than that of any furniture, so you need a reliable foundation that you can build with your own hands.
The columnar foundation is easy to manufacture, but not the best for frame garages
Pillar foundation. This type of foundation is the easiest to use. It can be made without seeking the help of professional builders. A columnar foundation is often chosen if you plan to make a wooden floor in the garage. It is arranged in different ways, and during the construction they use all kinds of materials - concrete blocks, reinforced concrete products, bricks, or even combine different materials. But this is not the best solution for a frame garage. When choosing a columnar foundation, you will have to make a powerful flooring from timber and thick boards that will be able to withstand a decent mass of the car. In addition, it will be necessary to resolve the issue of a convenient check-in device - a special entrance ramp. True, for a lightweight structure, especially if there is a problem with the minimum construction time, this is a valid option.
Strip foundation is the best option for frame garages
Strip foundation. Perfectly supports the weight of the frame structure. It is more difficult to make it, since it will be necessary not only to manufacture the formwork, but also to reinforce the structure in compliance with all the requirements of the technology. It will take more time to build, as you will need to wait until the poured concrete seizes and matures.
But the strip foundation has the possibility of building a well-equipped and convenient viewing hole. You can make both wooden and concrete floors. If you decide to make wooden flooring, then you will have to provide additional supports for laying the log, it is convenient to make them in the form of concrete or brick columns. Or you can simply dig in wooden posts treated with mastic at the necessary points.
If you are planning a frame garage, then there will be no trouble with a slab foundation
Slab foundation. It is mistakenly considered the most difficult base for a frame garage, since before pouring concrete it is necessary to lay several layers of gravel, sand, crushed stone and compact them well. Such a foundation is much more expensive than other foundations for a garage, and more effort will be required. But this way you will make a very reliable floor that will last a long time. Even if after some time you decide to build capital walls instead of a frame structure, then your foundation will already be ready.
By design, this is a monolithic, flat reinforced concrete support. Buildings on slab foundations stand stable, even if the soil is weak or mobile. It is also called a floating foundation, due to the fact that no matter how the soil moves, the walls will not skew.
There are 2 types of slab foundations - smooth and with special stiffeners. They give additional stability, increase the strength of the foundation, resist deformation, keep the base and the building in a horizontal position. The top of such a plate plays the role of a floor - for this reason it is made smooth. It is difficult to build such a foundation for a frame garage, and much more money will be required for it.
The pile foundation is good for weak soil, but will not pull a heavy structure
Pile foundation. If you have weak soil (for example, with a large slope or solid sand), then take a closer look at the foundation on piles (preferably on screw piles). Such a foundation is a metal pipe with helical blades. This design improves grip on the ground.
The average bearing capacity of a pile foundation is 4-5 tons, which is quite enough for a frame garage. But if you need to build a heavier structure, this type of foundation will no longer suit you. Be sure to cover all the metal with anti-corrosion compounds, this will significantly increase the life of the entire foundation.
Brick foundation - outgoing nature
Brick foundation. The most outdated and economically disadvantageous design. It is often said that the foundation for a frame garage made of bricks is very reliable, but these are just rumors. If there is an extra brick available, then it will be more practical and economical to lay down a columnar foundation from it. But in this case, a lot of high-grade cement will be required for the necessary strength of the posts - otherwise the brick will not last long. Currently, developers almost do not use a brick base, considering this option of the foundation to be economically impractical.
A block foundation can withstand any weight, but it takes a whole construction team to build it
Block foundation. If you need a heavy garage of a large area, then it is best to use a block foundation. Its device is expensive and requires the involvement of heavy equipment. But it stands out among other options for high reliability, long service life and a truly extraordinary load-bearing capacity. The disadvantages include the high cost of material and work, the complexity of mounting the structure (it is impossible to fold it on your own) and the need to prepare the site (leveling the area, creating a pit, etc.).
Which option is better to choose
In most cases, a strip foundation is used for a frame garage.. It is easy to manufacture, economical, strong enough to withstand the load of frame walls and a car. In addition, it can be applied to many types of soils.
The depth of the strip foundation for a light building will not exceed 0.5 meters. Before pouring concrete, a reinforcing cage is mounted.
Interesting! Two-story and sometimes three-story buildings are erected on reliable soils on strip foundations.
The main advantages of the strip foundation:
- Can be built by yourself.
- Minimal shrinkage, no wall deformation.
- With high-quality filling, it can withstand a large mass.
- Increased strength.
It is convenient to use such a foundation if the floor in the frame garage is cement, pouring the screed simply over crushed stone poured onto the ground.
Disadvantages of strip foundation:
- The costs are higher than with the construction of a columnar foundation.
- You can fill it only in the warm season. During heavy rains or in winter, it is impossible to make a strip foundation.
- Requires hiring equipment - an excavator for preparing a trench and a concrete mixer.
- It takes a long time to wait until the concrete gains full strength.
- Additional work is needed - the manufacture of formwork, the creation of a waterproofing layer.
Foundation design calculation
The calculation of the foundation can be done without the help of specialists
The construction of the foundation for the construction of a frame garage should begin with the preparation of the construction site. It consists of designing the building, cleaning the territory and marking the dimensions of the foundation.
Garage design can be done without involving specialists. Estimate the required dimensions of the garage and what should fit in it.
It is advisable to provide a small margin of free space, as you will need somewhere to store spare parts, tools, and other things.
From the parking lot to the wall, you must retreat at least 1.5 meters.
The strip foundation is calculated in two ways: taking into account the bearing capacity of the soil and the deformation of the soil. The first one is much easier.
The foundation is calculated last. It serves to transfer the load from the mass of the garage to the ground. And the mass will be known after you decide what materials to build the garage from. Therefore, before planning the foundation structure, you will need:
- Create a general building plan;
- Decide whether there will be a viewing hole and what size;
- Determine the material for laying the base and its height;
- Decide what kind of insulation will be used, as well as methods of exterior and interior decoration.
For all materials it is necessary to determine their specific gravity. To do this, it is better to prepare a table, after which the calculations begin.
Conventionally, the calculation is divided into several stages:
- Calculation of the future load on the foundation;
- Determining the characteristics of the tape;
- Necessary adjustment.
Effect of building weight on foundation
By the time the influence of the weight of the building on the foundation is calculated, the general plan should already be ready.
The weight of all materials to be used is summed up:
- Wall (the total area is used);
- Floor and materials used for its device;
- Floors and ceilings;
- Roofing materials;
- Foundation (approximately so far);
- fasteners.
By this time, a general plan with the dimensions of the building should already be prepared. It is easy to calculate the load from the materials used - you need to determine the area where they will be located and multiply by the specific gravity.
Calculate the width of the sole
Let's move on to calculating the width
- Foundation depth + plinth size = total height;
- Tape width.
The length of the foundation is already known - this is the total length of the walls that will stand on the foundation. The depth of the sole is determined by the type of soil on the site. There are special tables for this purpose. After that, it is necessary to calculate the width of the foundation - this indicator is affected by the weight of the materials and the gap between the walls.
Foundation impact
Next, you need to calculate how the garage will affect the foundation with its mass. The total weight of the building is divided by its area. It is not difficult to determine the area of \u200b\u200bthe foundation - we multiply its width by its length. After that, the total weight of the garage must be divided by the base area in cm 2. We find the specific load per 1 cm 2 of the strip foundation.
If the soil on the site has a bearing capacity higher than the mass of the garage, the sole area is calculated correctly. If not, then you need to make adjustments.
Necessary materials and tools
To make a foundation, you need the following materials and tools:
- Roulette 10 meters long;
- Level;
- Fishing line, nylon thread or cord;
- Shovel;
- Several rolls of roofing material (depending on the length of the foundation);
- Fittings, and wire for knitting;
- Crushed stone, cement, coarse sand;
- Liquid waterproofing;
- Small concrete mixer.
Preparatory work
The area where you will build a garage needs to be flat, without debris.. It is desirable to remove the fertile soil layer. After preparing the site, marking begins. Referring to the plan, the edges of the foundation are beaten along the cord. When the stakes are clogged, and a rope is stretched along them, they check the geometry of the future foundation (they measure the diagonals - they should be the same). Check the corners - they should all be exactly 90 degrees, with the wrong corners you will end up with uneven garage walls.
- If in winter the soil on the site does not freeze deep, then you can lay the foundation to a depth of 40 cm and prepare the same amount for a sand cushion;
- For loamy soils and clay, it is necessary to deepen the foundation by 1.5 m so that it does not collapse due to the dynamic qualities of such soil;
- On the sands, a trench is dug to a depth of 80 cm - there are no heaving processes on such soil.
Foundation instructions
Work seething
The foundation trench is covered with fine gravel or coarse sand to reduce heaving processes and prevent water from accumulating under the sole.
After that, the recesses for the installation of piles are prepared with a drill. They must be placed at the corners and along the perimeter of all walls at intervals of 2 meters.
Important! It is necessary to install wells to a depth exceeding the level of soil freezing by 0.5 meters.
The diameter of the holes must freely pass the installed piles.
Coarse-grained sand is poured into the holes with a layer of 18-20 cm - it will serve as a pillow. It must be well watered and compacted. After that, metal or asbestos-cement pipes are lowered, concrete mortar is poured into them by 30 cm. Then the pipe is slightly lifted so that the concrete flows out - creating a kind of sole, it will ensure reliable adhesion of piles and dense soil.
Until the concrete has hardened, it is necessary to align the piles vertically with the help of a level. When the concrete sets, bars of reinforcement are lowered into the pipes, tied together in the form of a lattice. The reinforcement cage should protrude from the pipe and reach the top of the foundation.
After that, a wooden formwork from boards is created at the soil level. It is assembled with nails and self-tapping screws, reinforced with bars in the corners. All protruding parts of the formwork must be outside the structure. The walls must be strengthened by installing struts and fixing the ties. A reinforcing cage is installed inside the formwork. Bars with a thickness of 8-16 mm (taking into account the load) are connected in the form of a grid at the intersection points, the reinforcement is connected with wire. It is necessary to connect the reinforcement of the piles and the reinforcement cage of the foundation.
The prepared foundation and piles are poured with concrete mortar. During pouring, it is necessary to pierce the solution with a rebar to help the air escape. After that, the upper part of the foundation is smoothed and protected from precipitation by covering it with plastic wrap.
While the foundation dries, you need to control its moisture content. Drying must not be allowed. In the heat, the foundation gaining strength should be periodically watered.
When the concrete is completely set, you can begin waterproofing the foundation. To do this, use bituminous and polymeric roll materials - for example, roofing material or self-adhesive film. Before work, cover the surface of the concrete with an antiseptic and a primer. When the surface is completely dry, it is waterproofed.
After that, it is necessary to insulate the foundation, most often polystyrene is used for this purpose. Plates are attached to the surface with a special adhesive. When it seizes, the plates are additionally fixed with dowels.
Important working points
If you do not take into account a number of nuances, the service life of the foundations can be significantly reduced.
When creating the foundation, it is necessary to take into account several subtleties of the process that will help prevent many problems:
- It is permissible to make a pillow not from sand, but from fine gravel;
- The outer part of the formwork must be covered with bitumen, and roofing material must be glued on it;
- The foundation tape should be 30-40 cm wide and not more than 70 cm high - depending on the planned load on the foundation;
- It is desirable to connect the bars of the reinforcing cage not by welding, but to fasten them together using a knitting wire;
- If in some places your formwork has risen from the ground, then you need to add sand there, which can be removed 10 days after pouring the foundation.
Improperly performed work will significantly reduce the life of the foundation and can even lead to cracks in the walls.
It does not matter what size frame garage you will build. Perhaps this is a small room, or maybe a solid building for 2-3 cars. But the foundation for it must have the necessary margin of safety. This directly affects not only the life of the entire structure, but also your safety.
Building a garage is troublesome, but also partly enjoyable. At least everyone who is passionate about construction work can enjoy the process itself. The construction of the garage begins, of course, with a drawing. And the basis for it, like any other building, is the foundation. An incorrectly laid foundation can destroy all the work, so you need to know all the subtleties of its arrangement. In the article we will talk about how to fill the foundation for a garage with our own hands, consider various options: tape, floating, rubble concrete.
First stage
- The first stage of work is a drawing of the future structure. It is necessary not only to calculate the amount of materials for the garage. Before you make the foundation for the garage, you must also decide on the location of the structure and know where to dig a trench and how big it will be. Therefore, all drawings and plans are prepared in advance.
- At the initial stage, a place for construction is selected. It is advisable to conduct a soil analysis before construction work. This is necessary in order to know the characteristics of the soil. Depending on the type of soil, additional structures will have to be installed (for example, a drainage system). Also, the soil significantly affects the depth of the foundation.
- If you don’t want to conduct a soil study, then on average you need to set the depth of the trench for the foundation at around 1 meter, and its width should be at least 40 cm.
There are many types of foundations for a garage. Theoretically, the builder can install almost any of them, with the exception of those that may interfere with entry into the premises. When making a foundation for a garage with your own hands, it is better to choose a variety of it that does not require heavy equipment and a large amount of labor.
The most common option is a monolithic strip foundation. It is quite easy to perform, except for the abundance of earthworks. You can also make a concrete foundation, which is a kind of tape.
Strip foundation
- First you need to determine the size of the foundation. They depend on the size of the future garage and its severity, as well as on the characteristics of the soil. On average, the depth of the trench under the foundation should be from 70 to 100 cm, and its width is about 40 - 50 cm. The width can be increased. The length is determined by the dimensions of the structure.
- After the markup has been made, earthworks must begin. The depth of the foundation for the garage, like other characteristics, must be measured.
- When the trench is ready, you need to pour sand and gravel to the bottom. The composition is rammed to increase the density.
- Now it's time to install the formwork. There are two ways to get foundation formwork: you can buy it or make it yourself. The second option is less preferable if the builder does not have the skills of a similar job. In the process, it is very difficult to withstand all dimensions, and the formwork must be impeccably executed. Each of its elements must be made extremely accurately in size, so it is better to purchase a ready-made kit or order its manufacture. Formwork installation is standard. The main thing is to properly fix it in the process of work so that there are no distortions and deviations.
- After installing the formwork, it is necessary to start pouring the foundation. Before pouring, you should decide whether to reinforce the structure. If yes, then it is necessary to install reinforcing bars or even reinforcing mesh.
Concrete is not poured immediately, but in stages. At each stage, it is necessary to pour concrete so that its layer is about 20 - 30 cm. When this layer dries, you can do the next one.
Video
The process of creating a strip foundation in video format:
Butoconcrete
The concrete foundation of the garage is one of the most economical structures (especially when you consider that there are no expenses for the work of a construction team). For its construction, cement and rubble stone will be required.
- First, they mark the foundation and dig a trench, as in the arrangement of a strip foundation.
- Then they prepare rubble stone and cement grade 400, as well as sand and crushed stone.
- Sand and gravel are poured to the bottom and rammed.
- A solution of sand and cement is being prepared. For each bucket of cement, two buckets of sand should be placed. Water for such a composition will require about a bucket.
- The first row of rubble stone is laid on the bottom. From above, the stone is poured with a cement-sand mixture. Then you need to lay the stone again and pour the solution. So you should continue to work until the last layer of cement is equal to the edge of the trench.
Floating
A floating foundation is a type of tape structure. It is perfect if the garage will be built on not very reliable ground. Such a foundation will be able to withstand fluctuations in the soil and the vagaries of the weather, as well as fairly high loads.
What is a floating foundation? It resembles a reinforced concrete slab, which is deepened at the same time. For construction, cement, reinforcement or reinforcing mesh and roofing material will be required. In addition, you need to stock up on tools.
There are three types of floating (slab) foundation:
- ordinary;
- lattice monolithic or prefabricated;
- monolithic reinforced at the edges.
The most economical option is the first one. The second option, especially collapsible, is expensive. Medium in terms of strength and cost - a monolithic slab foundation with stiffeners.
For not too large garages, a simple floating foundation is also suitable. It will be indispensable on heaving soils.
- First, a pit of the required depth is dug. Usually it is determined by the nature of the soil.
- At the very bottom of the pit it is necessary to put sand. The sand cushion is compacted.
- After that, a reinforcing mesh is installed on the sand layer. It will serve to strengthen the structure.
- At this stage, you can pour the foundation with concrete. In some cases, the owners first install concrete blocks on the grid, and only then fill the structure with a mixture to strengthen it.
- After the cement has dried, it is necessary to make a floor in the garage. To do this, carry out the usual screed with sand and cement.
In any case, after the foundation is made, it is necessary to carry out hydro and vapor barrier of the floor. You can also install drainage systems.
If you decide to build a garage from foam blocks, then when building a foundation for it, you should take into account the technical characteristics of the blocks. The foam block itself is a lightweight material. Therefore, it is not necessary to build a foundation that is too powerful and heavy. In such circumstances, the type of soil at the construction site plays an important role.
On how to build a foam block garage, you can get more information in this article " Foam Block Garage".
If the groundwater level is below 2 m, then it is enough to build a strip foundation with a depth of up to 0.5 m. If the soil at the construction site is heaving, then it will be necessary to make the foundation monolithic, as an option from a concrete slab. Why such a contrast if the foam block itself is a light material? The fact is that this material does not tolerate bending loads well. As a result, it cracks and collapses. And if the soil starts to move, then a concrete slab is installed on the foundation to prevent this. As a result, the walls and foundation will be one. Walls made of foam blocks will never break.
But there is one limitation here. If it is planned to build a viewing hole in the garage, then a concrete slab is not suitable. In this case, it will be necessary to build a combined pile-tape or buried tape foundation.
Video
The following video material is about the device of the floating foundation:
Photo
The photographs show various options for arranging the foundation for a garage:
Even under a light prefabricated foundation, a foundation device is necessary. The base protects the building from moisture coming from the ground and ensures the stability and reliability of the structure.
The garage is a lightweight construction, so the most common base option is a strip foundation. Depending on the design of the garage and the type of soil, the foundation tape can be made of the following materials:
- concrete mix with reinforcement - the simplest and most affordable solution;
- cinder blocks - a reliable and durable foundation, quick and easy installation. Cons - the large weight of the blocks and poor thermal insulation, insulation is necessary, and these are extra costs;
- FBS blocks - can be installed on any type of soil. This tape will be strong and durable. The only negative is that for laying the blocks you need to use special equipment.
Important. FBS foundation construction time is minimal, which significantly reduces construction time. This justifies the cost of renting special equipment. After all, the concrete foundation must harden for at least 21 days.
- gas silicate blocks - attract with low price and ease of installation, the material is frost-resistant. But gas silicate materials have many disadvantages, the main ones are low strength and a high percentage of vapor permeability;
- foam blocks are an inexpensive material that can be used for lightweight prefabricated metal structures. It should be borne in mind that the foam block shrinks a lot and often does not withstand high loads. Not the best option for a foundation.
Formwork for strip foundation
The strip foundation can be shallowly recessed and recessed. It depends on the type of soil on the site, the depth of soil freezing and on the material of the walls of the building.
On complex problematic wet soils with high heaving, it is better to choose a more expensive, but reliable type of foundation:
- pile foundation - these are racks of screw or bored metal piles tied with a reinforcing cage and fixed with a metal grillage. Installation time is minimal, high bearing capacity and relatively low cost;
- slab floating foundation - an expensive, but quickly installed design. Recommended for areas where there is a high groundwater table and moist, weak clay soils.
There is an erroneous opinion that it is easier to make an inexpensive columnar brick foundation for a garage. But such a base has a very low bearing capacity. The depth of the pillars must be done at least a meter or more, depending on the freezing point of the soil.
If the soil is clayey, then additional insulation will be needed. As a result, the ghostly savings in costs and work will cost a large investment of labor and money.
If you decide to do the construction of the foundation with your own hands, then the easiest option is a strip foundation. Next, we will consider the features of the device of this type of foundation for a garage.
Preliminary calculation of the strip foundation
What parameters determine the calculation of the foundation for the garage:
- soil strength;
- what material the walls of the garage are made of - the bearing load on the foundation depends on this parameter;
- what is the depth of soil freezing;
- the height of groundwater on the site;
- construction and number of storeys of the garage.
Determine the type of soil on the site
The foundation must stand on solid stable ground, the depth to which we will lay the foundation tape depends on the type of soil. For stable coarse-grained, crushed stone or gravel soils and for sandy soil, you can safely choose a shallowly buried foundation - up to 80 centimeters deep.
Clay, peat soils and loam - why you need to increase the depth of the foundation to one and a half meters:
- even at a slight sub-zero temperature, moisture, which is retained by clay soil, freezes and the soil swells, pushing out a rigid concrete base. When the soil thaws, the foundation tape lowers. As a result, the foundation is constantly exposed to deformation and quickly collapses.
Important. The depth of the foundation on clay soils should be below the freezing point.
- clay is unstable and quickly eroded at high groundwater levels. This also causes distortion and rapid destruction of the foundation.
On clay and peat soils and sandy loam, it is advisable to mount pile and slab types of foundations. If this is not possible, then the strip base should be buried below the freezing point of the soil by at least 20 centimeters.
On rocky and sandy soils, a shallowly buried foundation is quite enough - up to 80 centimeters deep.
Ground and seasonal water
The calculation of the foundation for the garage should take into account not only the height of the groundwater, which gradually erodes the base, causing deformation and cracks, but also seasonal natural precipitation.
If the site is located in a lowland, then melt and rainwater can seriously affect the foundation. Therefore, it is necessary to carefully examine the site and determine the passage of melt and rainwater flows. If necessary, arrange a drainage system that will turn the water around the foundation.
It is possible to check the occurrence of the ground layer of water only by drilling pits.
Important. A mandatory rule is that the depth of the foundation for the garage must be at least fifty centimeters above the groundwater layer.
garage wall material
The calculation of the foundation for the garage must necessarily take into account the material of the walls of the building. The width of the foundation tape and the depth of its occurrence depend on this:
- brick and concrete walls carry a high load on the foundation, so the width of the tape should be 10-12 centimeters greater than the width of the brick or block, taking into account the width of the formwork;
- lightweight metal prefabricated structures can be installed on a conventional shallow foundation.
When carrying out work, it is imperative to provide for the presence of a plinth, when installing the formwork, which must be at least 20 centimeters above the soil level. This condition is especially important for walls made of brick and wood. The basement protects the walls of the building from the destructive action of water from the soil.
Shallow or buried foundation
It is difficult to build an expensive buried foundation for a garage with your own hands, and such a building is not always profitable and necessary. If a serious capital building with a basement is planned, then it is worth spending money on building a deep foundation.
For a simple garage box with a small viewing hole, an ordinary shallow foundation is enough.
The device of a conventional shallow foundation for a garage
If you plan to equip a small inspection hole in the garage with your own hands, then the depth of the foundation tape should be at least one meter. This will provide a high bearing capacity of the base and prevent deformation of the base during earthworks.
Let us dwell on the important points of construction work, which will prevent the negative effect of heaving soil and moisture on the foundation tape and the wall of the building:
- it is imperative to insulate the foundation from the outside along the formwork with sheets of extruded foam or expanded polystyrene along the entire height of the tape, including the base. We choose the thickness of the penoplex, focusing on the climate of the region;
- a blind area device (50 cm wide), with foam insulation, will prevent freezing of the soil and deformation of the brick and concrete walls of the garage;
- storm sewer will ensure the drainage of water from the foundation;
- additional drainage at the level of the sole is necessary in case of high occurrence of groundwater at the site;
- it is necessary to provide high-quality waterproofing of the concrete tape using foam plastic or ordinary sheets of roofing material. You can also use bituminous waterproofing.
If you do not save on waterproofing and drainage work, then the stability, strength and durability of the foundation is guaranteed.
How much does a simple strip foundation cost
How much will it cost to install a conventional strip foundation if earthwork and concrete work is done independently? The average price, which takes into account waterproofing and insulation, is up to five thousand rubles.
Useful video with a detailed description of what is happening:
What not to save on:
- purchase ready-made poured concrete with additives. The overpayment is small, and the strength and reliability of the mixture is guaranteed;
- do not save on waterproofing and insulation, extruded foam is an inexpensive material.
When choosing the type of foundation, calculate all costs. In some cases, a simple concrete tape with insulation and waterproofing will cost more than a quick installation of reliable screw piles.
Car owners who bought moving ground area, you will either have to put up with the additional costs, or choose columnar or screw foundation. The thing is that the mobile soil is not suitable for the foundation. You will have to remove the soil to reach a solid horizon. Since it can be located deep, a columnar or pile foundation for a garage will be an excellent option.
pile considered the best in terms of value for money. The structures are affordable, large-scale excavations will not have to be done when arranging such a foundation. But, most importantly, with piles you will quickly build a reliable foundation for a garage.
Most of the base will be underground. Its depth reaches 20 meters. The devices compensate for ground movement, protect the foundation and the building itself from seasonal fluctuations.
See photo below for what it looks like pile foundation:
Pile foundation for a garage: types
In specialized companies, you will buy piles of various designs.
According to the geometric shape, the following classification applies:
- pyramidal supports;
- round;
- rectangular products.
Density classification:
- structures can be integral;
- supports are hollow.
piles may have a different mechanism of protection against ground vibrations. Such a mechanism is located within the structure itself. That is why the principle of operation of the supports is also different. There is a gradation here:
- retaining elements;
- hanging piles.
Retaining drive in deep, they reach a solid level. The structure rests on a solid layer, there is practically no shrinkage. Hanging is used when it is difficult to reach a solid layer. Such elements are sunk into the ground, piles are like "hang" in him.
Loads are damped due to friction forces.
According to the installation method, piles are of the following types:
- drilled;
- with driving elements;
- on screw piles.
But it's best to use screw, because the first option involves the use of special equipment, which for the construction of a garage will be an additional expense.
It is possible to build a hybrid foundation for a garage - tape pile. The technology is based on the “sole” device. This design consists of piles going underground, fixed above the surface in a strip base. The tape itself for a more reliable fixation is slightly buried in the ground.
This method will fix the structure, there will be no strong shrinkage. The garage will stand securely even on water-saturated ground. The laying of such a foundation will be the best option for a site with difficult geological conditions.
Materials for piles and poles and installation
Piles and poles can be made from different materials:
- from metal;
- tree;
- reinforced concrete;
- concrete.
In addition, for self-construction, you can make a foundation for a garage from power transmission line supports, from waste reinforced concrete pillars. They are often made of rubble concrete, reinforcing it with reinforcement.
Watch video about pile foundation for the garage:
The pile and column foundation for the garage is distinguished by the following positive characteristics:
- High build speed. If you buy ready-made supports, the speed of construction will increase significantly. They will be enough to make a base for a garage.
- Minimum ground work. You do not have to hire people, fit special equipment, or dig trenches yourself. In addition, you will not need to think about the export of land. Using poles or piles, you will reduce the amount of land work, save time and money.
- Construction conducted in any season And in any weather. Piles are great for areas with harsh climatic conditions. The foundation is ideal for building a garage if you plan to build it in permafrost conditions.
- To build a garage no need to involve special equipment.
REFERENCE. Pile-grillage foundation made of monolithic reinforced concrete. This method will require a lot of time and effort, but it is 50% cheaper when compared with using ready-made parts from the factory.
self-deliver piles it is possible in this way: make a frame of reinforcement, and when the piles gain strength, then make a grillage. But this method also has one negative point. The fact is that there will be a gap between the ground and the garage. Monolithic grillage is not lowered below 0.3 m from the ground surface. This is due to the fact that the level of ground elevation can reach 15 cm during the off-season.
Pile screw foundation
Screw piles must be embedded in the soil. If their length does not exceed 1 meter, they can be installed using a key. In addition, you can take a barbell for this purpose.
Such screws are suitable for any soil, but there are certain rules for their installation. Specify the level of soil freezing, lower the supports below this level. For example, you decide to build a garage from timber on screw piles. The dimensions of the building will be 4x6x3.5 m, for this, buy a bar with a section of 150x150 mm. If the soil freezes by 1 meter, then the supports must be lowered by 1.2 m.
The sum of the loads is 19.5 tons, the sum includes the weight of the structure with the car, wind and snow loads. In addition, dynamic loading is included here.
The pitch for the supports is from 1.5 to 2.5 meters. Based on this, you will need to build a garage from 9 to 12 piles.
Dig a trench first. You will need to remove 10 cm of soil, and then mark the site. Dig trenches, lay drainage from sand and gravel. Cut holes, they should run in the center of the future concrete base.
The column should not occupy more than a third of the tape; make 2 m between the supports.
Fill supports: roll the roofing material into a pipe, fasten it with a fishing line. Install the pipe in the ground, it should rise to a third of the height of the base. Make waterproofing, this will increase the life of the foundation.
Observe safety precautions when pouring supports. At the top, make a second layer of waterproofing, this will protect the concrete from drying out.
