The strip foundation has proven itself to be a reliable and durable foundation for any type of building. Due to its versatility and relatively low price, this type of foundation is widely used in the construction industry. Having in your arsenal basic knowledge in construction, a set of necessary tools, technical means and a great desire, you can easily turn into reality the idea of building a strip foundation with your own hands. You will learn how to pour a strip foundation with your own hands without experience and organize the work correctly from our step-by-step instructions.
Before you begin preparatory work, you should decide for yourself what type of strip foundation you prefer to see as the basis of your future building. There are two types of strip foundations:
- Shallow;
- Recessed.
The first type of strip foundation is suitable for those who want to save their time and money. The construction of a shallow foundation does not require deep trenches. It is an excellent solution for the construction of small buildings. Experts recommend giving preference to a shallow strip foundation when building structures such as:
- Wooden houses;
- One or two-story buildings made of foam concrete or aerated concrete blocks;
- Frame buildings using Canadian construction technology;
- Monolithic structures with permanent formwork;
- Small stone buildings.
The depth of this type of foundation does not exceed 50 cm.
A recessed strip foundation is suitable for buildings with heavy walls, concrete covering and an underground garage or basement. When choosing this type of foundation, it is necessary to correctly calculate its depth. To do this, it is enough to determine the level of soil freezing and subtract 30 cm from this value.
Preparatory work
At this stage, it is necessary to draw up a detailed plan for subsequent work, bring all construction materials to the site and place them near the work site. You should also carry out calculations of the required materials, as well as dimensions. In this case, specialized online calculators will come to your aid.
Marking
Probably the most important stage in the construction of any type of foundation is marking the land plot. Before starting it, it is necessary to clear the entire surface in the area of the future foundation from debris and cut off the top layer of soil to a depth of 15-20 cm, which will help to avoid biological processes of decomposition of organic matter. After arranging the construction site, you can proceed directly to marking. For this:
- A peg, which can be a piece of reinforcement, marks the location of the first corner;
- From it, using a vertical and plumb line, mark the position of the second and third corners;
- A string is also pulled from the second and third corners and the fourth corner is determined;
- Having measured the diagonals and made sure that the angles are set correctly, a rope is pulled between the pegs;
- Stepping back from the resulting marking inward at a distance equal to the thickness of the future foundation, mark the internal contour.
Having finished marking, we begin to dig a trench. To do this, we select the lowest point of our marking and from it we count the remaining depth, using the building level. For a small building, a depth of 40 cm will be sufficient, and only a shovel will be enough to dig a trench, although you can easily use the services of an excavator.
Educational video about markup:
Foundation cushion and waterproofing layer
So, the trench is dug, and the next step is to settle the sand bed with a mixture of gravel. This pillow is covered in layers, each of which is watered and compacted. According to standards, the thickness of the entire layer must be at least 15 cm. A waterproofing film is placed on the pillow as a protective layer. A rough concrete mortar can also serve as an alternative, but in this case you will have to wait a week until it hardens.
Installation of formwork
Dimensions of formwork for foundation
The formwork materials can be planed boards, slate, moisture-resistant plywood and oriented strand board (OSB). The formwork is installed vertically to a height of 30 cm, which will allow for the construction of a basement in the future. In order to subsequently install the sewer pipe and water supply, asbestos concrete pipes are laid in the formwork. If you want the formwork material to be able to be used after the foundation has been poured, place a plastic film between the formwork and the concrete. The formwork is dismantled 6 days after pouring the concrete.
Laying reinforcement
The reinforcement for laying in a trench with a cross-section of 1-1.2 cm is fastened with a special knitting wire so that cells with sides of 30 to 40 cm are formed. It is not advisable to use welding to fasten the reinforcement, since corrosion may subsequently form at the coupling points. The optimal distance of reinforcement from the edges of the formwork is 50 mm. This placement is the most effective in a monolith. Instead of steel reinforcement, fiberglass reinforcement can be used, but its characteristics must be equivalent.
Pouring concrete
The concrete solution is poured gradually and in layers of 15 cm from a height of no more than 1.5 meters. Each layer is compacted with a wooden tamper or deep vibrator, which increases the overall density.
You can buy concrete for the foundation or make it yourself. In the latter case, the proportion of cement, crushed stone and sand is 1:3:5. If work is carried out at temperatures below 00C, then a concrete heater is used, and potassium chloride or table salt is added to the solution.
Completion of work
The poured concrete is covered with a film and left for at least 2 weeks, during which it will gain strength. If work takes place in hot weather, the hardening concrete is sometimes watered with water so that the cement continues to gain strength and does not turn into dust. It is possible to erect the walls of a building on a do-it-yourself strip foundation only after the concrete has completely matured.
The basis of any structure is the foundation. The stronger and more correctly it is installed, the longer any building will last.
But to make a high-quality base, you need to spend a lot. The third part is the cost of the building - this is the average price of a good foundation.
Therefore, to save money, many people want to know how to make a foundation with their own hands.
First you need to choose the type of foundation, because there are several types: strip foundation, columnar, pile and slab options. We will explain below how they differ from each other.
Strip foundation
The most versatile and frequently used type of building foundation is a strip foundation. It cannot be used only in permafrost and for structures “on water”.
The essence of the foundation is a closed strip - the base, stretching along the perimeter of the building and in place of the load-bearing internal walls. The photo of the foundation clearly shows that the thickness of the strip should be the same in all areas.
Such a foundation is suitable for any building and allows you to build a high-quality basement or ground floor.
The supply of housing communications at the base can be positioned as conveniently as possible for their operation.
The main disadvantage of this type of foundation is the large amount of excavation work and building materials.
Columnar foundation
For small buildings, to save materials, it is recommended to use a columnar foundation. It allows you to provide a high-quality foundation for a lightweight building with less time and effort.
The foundation for a house consists of pillars at the points of maximum load of the building (corners, on long sections with calculated steps, under load-bearing walls).
You can build supports from brick, concrete, or even wood (only rot-resistant wood - larch, for example). The depth for the pillars is selected taking into account the material and type of soil.
After installing all the supports, you need to tie them into a single system for greater strength.
The disadvantages of the foundation include the impossibility of founding a basement. The base is not suitable for heavy buildings; unstable soil types also preclude its use.
Pile foundation
The foundation of a house on stilts is similar to a columnar foundation, but it is not. The main difference is the depth of the supports. Due to their small diameter compared to the pillars, holes for piles are not dug, but drilled. This allows you to install the supports to greater depths and dig them into more stable rocks.
Otherwise, the technology for placing and tying supports is identical to the columnar foundation.
The main disadvantage of this base is the use of special equipment. However, recently piles with a screw at the end have begun to appear, which allows them to be screwed into the rock like a self-tapping screw. This is what made the piles accessible to the layman.
Slab foundation
One of the most rarely used types of foundation. Reinforced slabs are usually used more often for roads and boulevards, but some people also use them as a foundation for a house.
To create it, a gravel-sand cushion is first poured, after which reinforcement is placed and the foundation is poured. This creates a “floating” foundation for the house.
The advantage of such a basis is independence from the type of soil and its freezing in winter.
But there are many more disadvantages: the impossibility of creating a basement, the difficulty of connecting communications, the high consumption of materials, and the possibility of construction only on level ground.
Now we will tell you in detail about the creation of a strip foundation, as the most common and universal in construction.
Foundation construction plan
To build a reliable and strong foundation will require a lot of calculations. Knowing the future dimensions of the structure, you need to calculate the depth of the foundation and its width.
And here we will make an important clarification. It is best for a specialist to independently calculate these parameters. The fact is that the correctly calculated depth and width of the foundation determines whether the foundation of the future building, and therefore your life, will support it or not.
There will be a lot of nuances when calculating, but only professionals know them. For small buildings, if you decide to do without calculations, the depth of the building will be small and the width will be a multiple of 100 mm.
Step-by-step instructions for building a foundation
- Mark the territory.
- Carry out excavation work (dig trenches).
- Create a bed of sand and gravel.
- Make formwork for the foundation.
- Lay the future foundation with a reinforcement belt.
- Provide ventilation (if necessary) using pipe sections.
- Pour concrete.
- Smooth the surface until it hardens.
- After a week, remove the formwork.
- After another 3 weeks, the concrete will completely harden and waterproofing can be done using roofing felt and hot bitumen.
- Lay a brick plinth on top of the concrete and waterproof it.
The foundation is ready!
DIY foundation photo
There are many technologies in construction that make it possible to form a reliable, stable and durable foundation of a residential building - its foundation part. Let's figure out what the advantages and features of the poured method are, and get acquainted with step-by-step instructions on how to make a strip (that is, poured) foundation yourself.
Pouring the foundation for a house with your own hands
Real construction conditions influence the choice of technology
The decision to choose a foundation construction method is made based on the characteristics of the soil. Poured (tape) technology is appropriate only if the construction of a house is carried out in non-subsidence soils. If there are peat bogs on your site, the ground is saturated with water and is clearly swampy - a flooded foundation is not for you.
Strip foundation
A high-quality poured foundation can be made even without being a professional, if you follow the sequence of actions recommended by experienced craftsmen. Filling is a relatively simple, profitable, financially accessible technology that has been proven for decades.
Calculation of a strip foundation for a house
Even in an area with complex terrain, it is easy to create a guide trench and it is not at all necessary to strive for zero error when determining the level of its bottom - when pouring, the liquid solution fills all the voids (in contrast to the requirements for level accuracy if the foundation is created from slabs or blocks). Strip foundations are ideal for low-weight structures: frame-type houses, timber or logs.
Video - Poured Foundation
Start of work: digging a pit or trench
Step one. Decide on the area that the future foundation should cover with its outer perimeter. Before the excavator begins excavating the soil, markings are made (wooden stakes, posts, etc.).
Marking for strip foundation
The thickness of the foundation (thickness of the tape, selection of reinforcing elements) depends on the weight load that is expected from the house being built. Experienced builders and technologists know how to correctly calculate the width and depth of a trench, taking into account the characteristics of the main building. It is recommended to consult with specialists in order to further avoid overloads that could lead to the destruction of the foundation.
Step two. It is important to decide in advance whether you will have a basement space or not. If you want to have a basement or storage area under the house, you will have to dig a wide pit in which the poured foundation will act as walls. However, most often strip foundation is practiced in small depths and basements with a low ceiling are of little interest to anyone, so it is not the foundation pit that is relevant, but the trench.
However, the choice of “pit or trench” is influenced by another factor - the size of the future structure. When the area of the future building is small (say, 5x8 m or 7x9 m), it is more convenient to use a solid pit with an internal approach to the foundation. Subsequently, the void is filled with selected soil or tightly filled with construction waste. On larger sites (from 10x12 m), it is advisable to dig a long trench and not touch the soil at all from the inner perimeter.
Step three. The trench should be slightly wider than the future wooden formwork (form for pouring concrete). The gap is necessary as space for free access to the formwork and to ensure maneuverability of working tools. The most common trench width is about 25-35 cm.
Marking the foundation of a garden house
Approximately the same depth of the foundation along its lower part, provided that the terrain is relatively flat. In places where the relief is lower, it is advisable to keep this figure to a minimum, and where there is an increase in relief, the body of the foundation will be buried much more deeply into the ground. At the planning stage, it is necessary to take into account the curvature of the construction site and make a careful calculation of the difference between the highest and lowest levels of relief.
Attention! In case of uneven terrain, the bottom of the trench is made level, but in no case inclined, not “repeating” the relief slope! In other words, the concrete strip should have the same height everywhere, since the vertical load on the foundation from above from the side of the future house is uniform.
Creation of a flood channel - formwork, cushion, reinforcement
Step one. Shields are made from wooden boards, which are installed vertically and form a pouring channel. Use substandard wood, wood processing waste, etc. It doesn’t matter what the formwork looks like from the outside - the main thing is that the inside of the boards is as smooth as possible.
Formwork for strip foundation
The opposite walls of the formwork are pulled together in several places with temporary fasteners, secured vertically from the outside and additionally supported by inclined blocks - so that when pouring a heavy concrete mass, the formwork walls are not torn apart and the shape of the poured foundation remains unchanged.
The opposite walls of the formwork are pulled together in several places using temporary fasteners
Step two. Sand is laid out at the bottom of the trench in an even layer, the thickness of which depends on the individual characteristics of the building under construction - 4-5 or 8-10 cm. The task of the sand cushion is to provide natural shock absorption. After all, even on stable soils, movements in the ground that are invisible to the eye occur.
It is advisable to isolate the sand from the concrete mortar with some kind of linen material of a synthetic composition (so that the process of decomposition does not begin inside the concrete pouring. Insulation allows you to retain moisture and cement laitance in the concrete, thereby preventing the foundation from becoming more fragile.
Step three. Reinforcement is placed inside the filling channel. Reinforced mesh is the most common for these purposes; the cost of it is usually included in the estimate. An iron rod is also used. The optimal thickness of bar elements is 8-12 mm. In private construction, any long, flat metal objects (cuts of metal pipes, fragments of old iron beds) are often used.
Reinforcement is placed inside the pouring channel
Attention! Do not weld reinforcing elements under any circumstances. Just tie them together (use wire or special fasteners sold in stores). Welding takes away the plasticity and protection from ruptures from the foundation during those minor movements in the soil that are natural with changes in temperature, humidity, and shrinkage of the house.
Do not weld reinforcing elements under any circumstances.
Preparation of mortar, pouring concrete
Step one. When purchasing concrete, give preference to brands M-200, M-250 and M-300. Typically, the construction of private houses and buildings involves such volumes that a small concrete mixer is enough. In it, the concrete mixture acquires the necessary mobility (in other words, consistency). The poured mass is easily distributed inside the formwork and carefully fills the smallest air cavities.
Concrete M-300
The composition of the solution is best agreed upon with specialists who have experience in construction in your region and are well versed in the characteristics of dry concrete. There is an easy way to check the viscosity of concrete (its mobility) manually: scoop up a handful of the solution and squeeze it tightly in your fist, then unclench your hand. If all the water has left, the concrete solution is not entirely successful - it has low mobility, and when it hardens, there is a high probability of small cracks forming inside the foundation. If there is concrete milk (mush) left on your hand, the mixture is prepared perfectly! The foundation of such concrete will be dense, ductile, and durable.
Concrete mixer
Step two. It is undesirable to fill during rain and snow (sometimes construction is carried out in spring or autumn, when there is light precipitation - at this time it is better to cover the formwork and wait for the weather to clear). Pour concrete in such portions that in one cycle the entire area at the bottom of the formwork is filled. Ideally, you need to start work in the morning, so that by lunchtime or evening you can fill the entire box layer by layer.
Attention! Sometimes on large areas the foundation is poured in parts. Keep the same principle: layer by layer horizontally, but never “side by side” vertically. Remember that the weight load of the house on the foundation is always directed from top to bottom.
Step three. In hot weather (temperatures above +19...+22 °C), it is necessary to periodically pour water over the foundation. This will improve its strength when setting concrete. When the formwork box is completely filled with mortar, you should wait 25-30 days for the concrete to gain maximum strength.
However, the first construction work on the house without serious weight loads can begin within 10-15 days after pouring the foundation. At this stage, the concrete has gained about 75% strength, and there is no point in wasting time.
Pouring strip foundation
Step four. After the foundation concrete has completely hardened, the formwork can be removed, but the process of creating the foundation is not over. Be sure to make a concrete blind area around the outer perimeter of the house.
The meaning of the blind area:
- prevent contact of the foundation with rain and melt water;
- protect the foundation soil from moisture accumulation;
- move the winter freezing zone away from the house.
Monolithic reinforced blind area
Blind area of strip foundation
Don’t forget to also build drainage structures on the roof and along the walls of the house. After all, even the strongest foundation is not immune to decomposition processes that can occur over time if water and moist fumes are allowed to unimpededly affect concrete.
The construction of the foundation must be taken extremely seriously, because this is the basis of the future home, its strength will depend on it.
Types of foundations.
There are several types of foundations, but the most popular of them is the strip foundation. The reason for such unusual popularity is extremely simple: inexpensive materials, ease of reinforcement, and also the fact that anyone can do it themselves once all the nuances of how to pour the foundation for a house have been studied.
Ribbon structures are used mainly in those houses that plan to have a basement. In other words, it is ideal in our case. But such construction is a very responsible procedure for which you should properly prepare.
Introductory video - types, types and secrets of pouring a foundation for a house
Preparation.
Stage one.
We mark the area where the foundation will be built. For this we need fishing line and several pieces of reinforcement. Such markings should be made either in full accordance with the dimensions of the future house, or ten centimeters wider (to make digging convenient).
It is worth remembering that not only the back side is marked, but also the inside (the best distance is about forty centimeters, so you will be as comfortable as possible when digging).
Stage two.
When the markings are ready, you should not rush to start digging a trench. First, it is better to check the diagonals, because they must coincide with each other.
Let's start building the foundation for the house
Stage one.
Digging a pit. In principle, everything is very clear here, so we will not expand on this topic.
Stage two.
The main load will fall on the lower area of the foundation, so we must soften it. This could be, for example, ordinary sand, with which we fill the bottom of the pit, and then compact it thoroughly, periodically pouring water on the sand.
The pouring of the foundation must fully comply with all the requirements, so we build a special formwork (for this, ordinary cut planks are suitable for us). Such a simple move will soon significantly reduce the cost of leveling the foundation walls.
Moreover, you will be able to control the height of the formwork. When the board has fulfilled its function, do not rush to throw it away - it will serve you well as a rafter.
Stage three.
We nail the formwork together with nails or tighten it with screws, it doesn’t matter. The only thing to remember is that when using nails, the caps must be on the outside. In this case, the walls of our foundation will be quite smooth, and dismantling after the mortar has hardened will be significantly simplified.
Stage four.
Don't forget about sewer holes. You need to take care of them in advance, because if you make holes after the base has hardened, the solidity of the structure will be grossly violated.
We also said that for greater strength it is necessary to use metal reinforcement, which should consist of two rows. In order for it to be securely fastened, you need to use a knitting wire - it will perfectly fasten the jumpers together.
But if you do not have such wire, you can use welding (although we do not recommend this technique, since it can later lead to rusting).
In addition, the foundation will be more reliable if the reinforcement is installed crosswise and lengthwise. When the formwork is finished, we check the structure for strength (otherwise it may shift after pouring).
Stage five.
To build our foundation, it is best to use lightweight concrete, and the reinforcement should be made of fiberglass. After this, perhaps, the stage of preparatory work ends. Next is the actual filling.
And here you may have a completely adequate question: how to pour the foundation for a house correctly? First of all, it is necessary to correctly calculate the proportions of the solution that will be used.
What should we know about pouring a foundation ourselves?
Before starting the pouring process, make sure that the solution is thick enough (if not, dilute it with water). It is advisable to first acquire a deep vibrator - this will contribute to the uniform distribution of concrete throughout the entire volume of the foundation. In addition, this removes air bubbles, which could subsequently cause structural failure.
You should also determine in advance the level at which the concrete will be poured. When it is poured, the surface is leveled and all irregularities are removed using a regular trowel.
If you carry out work in cold weather, it is necessary to use special additives that accelerate the hardening process. It is advisable to fill the entire area within one day, no need to delay.
What is needed to properly harden the foundation for a house?
The approximate hardening time for concrete is two weeks. And all this time you need to carefully care for it: moisten the surface if it dries out too quickly, cover it with polyethylene in case of rain.
After seven days, we cover the entire surface of the structure with bricks - this will displace the resulting voids.
As for the formwork, it can be removed after three days. And finally, when all the time is gone and the solution is completely dry, you can proceed to the next stage - constructing the base, but this article, alas, is not about that.
In the end, I would like to add a few words about the restoration of the foundation: it needs to be done in several stages, because creating a foundation under a finished structure is much more difficult than from scratch. But in general, we have looked at how to lay the foundation for a house.
Video lesson on pouring a foundation alone
In private housing construction, several types of foundations are used, each of which has its own design features.
- Tape– the structure is a monolithic reinforced concrete frame that exactly follows the contours of all load-bearing walls of the future building. Advantages- simple design, done by hand. Suitable for the construction of buildings with a large area. Relatively affordable price. Flaws– constant monitoring of the lines is necessary even at the stage of excavation. The larger the building area, the greater the possible error.
- Columnar– the main bearing load is carried out on reinforced concrete supports buried in the ground. They are made independently by pouring concrete into prepared recesses with reinforcement pre-installed there. The number of supports and the pitch between them is calculated based on the weight of the building. Installation at the junction of walls is required. Advantages– very cheap and does not require the use of heavy construction equipment. For soils with deep underground water, this is an ideal solution for the construction of small one-story buildings. Flaws– when installing on clayey and heaving soils, as well as those with a freezing depth of more than half a meter, the pouring depth will be at least two meters.
- Slab– it is also called floating. It is used in the construction of buildings on soft soils with high groundwater levels, unstable and heaving. Structurally, it is a reinforced concrete slab with a thickness of 40 cm or more, depending on the weight of the building and the type of soil. Such a base simultaneously acts as a floor for the basement or ground floor. It is made by pouring concrete into a pit corresponding to the area of the building with pre-installed reinforcement. Advantages– can withstand buildings of different heights; when pouring, it does not require formwork or manual mixing to ensure uniform distribution of the composition among the trays. Flaws– high consumption of concrete, correspondingly high cost, therefore inappropriate for the construction of large buildings.
These types are the main ones and individual solutions can be applied for each project based on the characteristics of the building. For example, to strengthen the structure, a strip foundation made of monolithic concrete or prefabricated blocks is installed on top of a columnar foundation.
Preparatory stage
Marking begins with the study of topographic photographs and accompanying documentation. This stage is also called zero, since the construction itself has not begun, but work is already underway. Here measurements are taken, the purpose of which is to create a contour for the base, as well as the demolition of green spaces and preparation of the construction site.
The evenness of the main supporting structures and compliance with the project will depend on the correctness of the measurements. When constructing small outbuildings, such as a garage, the use of analog measuring instruments is allowed. In residential construction it is necessary to work with laser rangefinders.
The width of the futurethey are taken to be several centimeters larger than the thickness of the enclosing structures resting on it. An allowance for the thickness of the formwork for strip structures must be taken into account.
When pouring underground supports and calculating their number, it is taken into account that they must be installed in places where walls join.
To mark the perimeter, wooden pegs are installed in the outer and inner corners, connected by pieces of twine. After marking is completed, a control measurement is taken.
Excavation
This is the most labor-intensive part of construction, but nevertheless requires high precision. They can be performed:
- With the use of special equipment.
- Using manual labor.
The depth of the excavation must correspond to the design documents. The first option is more expensive, but it reduces time costs and makes work easier. Suitable for the construction of large and medium-sized buildings. For small outbuildings, the use of machines is unprofitable, since the foundation here is usually of a shallow type.
When pouring supports to a depth of more than a meter and choosing a columnar base, mechanized drilling is used. Soil removal for a slab foundation is carried out using a machine method, since the volume of work and time costs fully justify the use of an excavator.
In the case of a strip base, an excavator can also be used, but manual cleaning of the bottom and walls with a trench is required if formwork is not used. It is not recommended to keep the finished foundation pit for a long time without filling, as the edges will begin to crumble.
Formwork and reinforcement
To prevent the concrete structure from cracking due to multidirectional loads, it is reinforced. The process itself involves creating a frame of steel rods, which is subsequently poured with concrete and remains inside the body of the foundation. The connection of the rods can be welded or mechanical. Two types of round rod reinforcement are used:
- Ribbed – has increased rigidity.
- Smooth.
Formwork is the shape of the future base into which liquid concrete is poured. It is made of wooden, less often metal, shields.
A wooden structure can be made of plywood or boards.
Drainage and ballast
Regardless of the chosen type of base, it is necessary to arrange ballast, which is an intermediate layer between concrete and soil. This allows you to evenly distribute the load and reduce the impact of moisture on the structure.
For a slab or strip base, geotextiles are laid at the bottom of the pit, on top of which a mixture of sand and crushed stone is poured. The fabric will not allow sand to turn into clay over time.
The height of this layer is from forty to sixty centimeters, but not more than half the height of the entire foundation. Geotextile is placed under the columnar one depending on the depth of the excavation.
For better compaction, the sand is moistened with water and then the ballast surface is compacted manually or using a vibrating plate. After compaction is completed, the surface under the strip and slab foundation is covered with waterproofing and the installation of formwork and reinforcement begins.
Formwork
The height of the formwork is assumed to be equal to the height of the base or higher. Preference is given to panels made from edged boards, since plywood, due to long contact with wet concrete, quickly fails and cannot be reused.
The panels are installed along the perimeter of the foundation pouring, marked according to the plan. The boards should be adjusted to each other as much as possible, and to prevent leakage, polyethylene should be placed completely on the bottom of the mold. Its edges should extend beyond the upper border of the formwork.
The panels are connected to each other using fasteners, and are additionally reinforced with wooden supports, since the weight of liquid concrete is quite large.
Reinforcement
- For a columnar foundation - reinforcement is installed during the formation of the support body. The frame must first be made, for which three ribbed rods are placed longitudinally at an equal distance from each other so that they form a triangle in the profile. The connection between them is made with a wire of a smaller cross-section by welding in several places. The resulting structure is immersed in concrete when the mold is half filled. If you do not plan to weld any elements to the outward fittings in the future, then the height of the frame should be ten centimeters below the upper level of the support. This will prevent metal corrosion.
- For slab and strip foundations, the reinforcing frame is installed before pouring into the formwork. The longitudinal rods are fastened to the reinforcement coming out of the underground supports, if any, and additionally, transverse wire clamps are made. In other cases, the frame is simply laid on the prepared base.
Pouring concrete
The amount of concrete is calculated based on the size of the future foundation. It is recommended to use cement grades that are resistant to moisture. For simple-shaped foundations, the preparation and pouring of the mortar is done manually.
In the case of mechanized feeding from a concrete mixer, it is necessary to constantly help with available tools for uniform distribution inside the formwork. Liquid concrete has a fairly high viscosity and if the mass accumulating at the pouring point is not driven away, this will lead to static overstress, breakage of the formwork or overflowing over its top.
At the end of the pouring, the height level of the solution must be monitored, and the ends of the polyethylene used to protect it from leakage through the formwork should be bent in order to protect the structure from rapid drying.
How to care for the foundation
Complete drying time is up to four weeks depending on the season and air humidity. All this time the structure remains in the formwork.
In the dry season with very dry air, the surface of the foundation is periodically sprayed with water.
The fittings exposed to the surface should be protected from corrosion by covering them with polyethylene. After the established period, you can remove the formwork and begin construction of enclosing structures.
When assembling the formwork, it is best to fix the panels facing each other with studs and nuts. You should first drill holes in the wood where the pin will go. After the solution has hardened, the fasteners can be easily removed and reused.
Almost every person in life has a desire to have their own home. Some hire a whole team of builders for this, others decide to do everything themselves. And, of course, how strong and reliable our structure will be depends on the correctness of construction technologies. Pouring the foundation is the main and priority stage of construction.
How to properly pour a foundation - the first stage
- It is better to carry out all work in summer in dry weather.
- We clear the area, mark the boundaries of the upcoming foundation.
- We take into account the total area and mass of the building, the topography of the site. It is better to consult with a specialist or someone who has already dealt with this stage.
- We mark the perimeter of the building. We install wooden wedges, pegs or any other limiters along the internal and external boundaries of the walls and stretch between them even parallel lines of rope, twine or fishing line (the distance between them should be about 40 cm).
How to properly pour a foundation - dig a trench
- To do this, you need to find out the depth of freezing of the ground. The average value is from 80 cm to 1 m, in some regions it is more (we consult with specialists from construction organizations). We add 30 cm to this number and get the depth of our trench.
- We strengthen the walls and install the formwork. We install it behind the markings; to do this, we place vertical panels made of the selected material at a height of 30 cm above ground level. This is done to secure and hold the shape when pouring concrete. Wooden formwork is most often used due to its low cost and simple installation procedure, as well as practicality and the possibility of further use of the boards.
- We pour a sand cushion (average thickness 20-40 cm) onto the bottom of the trench. Water it with water and tamp it down.
How to properly pour a foundation - we reinforce the trench
Concrete, as you know, has a very large mass due to its constituent components: crushed stone, sand, water and cement. In order for our trench to retain its shape when pouring concrete, it must be strengthened. In addition, the foundation needs reinforcement in order to further support the weight of the entire structure.
- We use wire ties or a frame made of metal rods.
- We lay the structure, retreating 5-7 cm on each side of the trench.
- Individual elements are additionally fastened to each other with wire or welded to avoid disintegration of the structure.
- You should get a non-movable rigid metal frame made of rods.
How to properly pour a foundation - pouring concrete
- We make the solution or order the finished mixture through intermediaries, which will be delivered in a concrete mixer.
- Pour the prepared mixture evenly, layer by layer. We make sure that no cracks or shifts form.
- It is advisable to compact each layer using a vibrating plate to avoid unevenness and the formation of bubbles.
- We are waiting for the concrete to harden (the process may take up to a month). Then we remove the formwork.
- To prevent the foundation from drying out on hot days, water it with a small amount of water; in damp weather, cover it with waterproof film.
The support of a structure is one of the key points during construction. The strength and integrity of the structure under construction depends on how correctly the calculations are made, the formwork is installed, the reinforcement is installed and the concrete is poured. There are special tables for carrying out calculations yourself, but for the first time it is better to consult with specialists from construction organizations. You can figure out the rest of the steps yourself.
How to pour a foundation for a house with your own hands?
The stability and long service life of a private house or country house are associated with the construction of its reliable foundation. This is a serious and one of the main stages of construction, requiring a responsible approach and requiring preliminary preparation. Forming a concrete base is associated with significant costs. Pouring the foundation for a house yourself allows you to reduce costs.
For the construction of private buildings, various types of foundations are used, the features of which must be studied in order to choose the optimal foundation for the house. With your own hands you can fill in a reliable base that will protect the building from cracks and deformations. You should carefully prepare for construction activities, especially if you have to carry out the work yourself, without the use of hired workers. You should carefully understand the sequence of work in order to correctly pour the foundation under the house with your own hands.
A reliable and strong house must have a good foundation
Let us dwell in detail on the nuances of the technology, consider the common types of foundations used as foundations for the construction of buildings. Let's figure out how to prepare a solid foundation for a house with your own hands.
Where to start laying the foundation for a house
If the question of how to pour a foundation for a house is being discussed, it means that a large set of issues have been resolved regarding registering the site, issuing a cadastral passport, and obtaining a building permit. The internal structure of the premises and the location of the building on the site have already been determined, and the homeowner can now begin building a reliable foundation for a country house. Considering that the level of costs for constructing the foundation reaches 30% of the estimated cost of work and the cost of an error is quite high, it is necessary to analyze the following factors:
- soil type at the construction site;
- degree of soil freezing;
- level location of aquifers;
- the mass of the building being constructed;
- design features of the building (presence of a basement);
- the nature of the terrain;
- the ability of the base to absorb loads and compensate for soil reaction;
- the amount of upcoming expenses.
It is a reliable foundation for both a house made of foam blocks and timber
Carrying out construction on problematic soils that are prone to swelling under the influence of temperature changes can cause cracking of the foundation and damage to the integrity of the walls. Deepening the foundation does not guarantee the stability of the structure during frost heaving of the soil. Having fully assessed the nature of the soil, analyzed the structural features, and the specifics of the relief, you can correctly decide on the type of foundation and the degree of its penetration into the soil.
Geological surveys will help to correctly determine the bearing capacity of various soil layers. Only after analyzing all the points and performing the necessary calculations by specialists should the structural design of the foundation for the house be determined.
Types of foundations
To correctly select the foundation required for the construction of a building, you should understand what types exist and what their differences are. Based on the degree of immersion in the ground, three types of foundations are distinguished:
- non-buried, characterized by the location of the sole at the same level or above the ground surface;
- shallow, with the base located above the frost line;
- recessed, in which the lower level coincides with or is below the freezing point.
Under heavy concrete buildings, a recessed foundation is made, which is fixed 20-30 cm below the freezing mark of the earth layer
During the construction of buildings, various types of foundations are used:
- monolithic. It is a solid concrete slab reinforced with steel rods. Has proven itself as a reliable base on quicksand or sandy soils;
- pile Used for the construction of buildings on soft soils prone to frost heaving. The construction of the base of the building on stilts is carried out using special equipment;
- tape The most common and reliable option, ensuring the stability of buildings on various types of soil. A concrete strip buried in the soil, reinforced with a spatial reinforcement frame, guarantees the stability of various types of buildings on any type of soil.
In most cases, when constructing private buildings, preference is given to a strip foundation, which guarantees the stability of the objects being built at reasonable construction costs. Various materials are used to construct the strip base:
- stone placed in a trench and filled with mortar;
- ready-made foundation slabs or blocks, the use of which speeds up the construction of the foundation;
- brick that needs waterproofing and is used to a limited extent;
- reinforced concrete for maximum strength.
Let us dwell on the reinforced concrete strip base in more detail.
This type of base is one of the simplest and most common
How to pour a foundation with your own hands for a house
According to a certain algorithm, the foundation for the house is poured with your own hands. It provides for the following stages of work:
- Preparation of the construction site with the removal of vegetation, debris, as well as marking the contours of the future foundation.
- Excavation activities, during which soil is excavated and foundation is added.
- Construction of panel formwork ensuring the tightness and rigidity of the wooden structure.
- Installation of the reinforcement cage inside the formwork with the connection of individual rods with knitting wire.
- Filling the formwork with concrete and then compacting the concrete mass to release air bubbles.
To finally understand how to build a foundation for a house with your own hands, we will consider in detail each of the stages of work.
Marking
Features and types of foundations. How to make a foundation for a house without mistakes? The main stages of laying the foundation and expert advice....
From Masterweb
22.04.2017 18:27Sooner or later, any builder is faced with the need to organize work to prepare the foundation for building a house. If there is a lack of practical experience, time should be devoted to studying the features of the processes of constructing formwork, tying reinforcement, pouring and protecting concrete foundations.
Purpose of foundation types
Let's be honest: not all plots have conditions that are ideal for building a house. At first glance, everything looks quite rosy: good ecology and appearance, minimal noise, closeness to natural nature. But sometimes the results of geological surveys indicate significant engineering complexity in constructing the foundation for a house. Fortunately, at the moment quite a lot of types of foundations have been invented, even for very difficult geomorphological conditions.
There is no special point in talking about strip foundations. They are designed for stable, dry, high-density soils and are designed according to the simplest scheme. However, strip concrete foundations can have varying degrees of depth depending on climatic conditions. You can also distinguish several typical sections of the tape: beam, T-bar, trapezoidal, etc.
Pile and pile-grillage foundations are used on soils that do not have sufficient supporting capacity even with normal depth. In this option, several design options are possible, the complexity of which depends on the number of floors and architectural features of the building. In general, such a foundation is a type of shallow strip foundation, but the strip does not perform a supporting function. It disperses the load onto the piles, which rest on a deeper and denser layer of soil.
The third type of foundation for a house is slab structures. They are used when high-quality thermal insulation is necessary or when constructing buildings on special categories of soil: highly plastic, heaving, water-saturated and sandy. An ordinary slab is unremarkable, but in order to save materials, it may have a cross grid of stiffening ribs, or contain utility lines or channels for them.
Excavation
Almost all types of foundations require excavation. Firstly, trench walls are convenient to use as formwork for the underground part. Secondly, the deeper the support plane is located, the less horizontal cross-sectional area is required for sufficient stability. The depth of excavation is determined by the results of geotechnical surveys.
You can prepare trenches for the foundation either manually or using an excavator. In the latter case, the width of the bucket should be only 75–80% of the width of the belt at the top. Finally, the walls and bottom are always cleaned by hand. After this, the bottom of the trench is prepared with an incompressible and non-heaving bedding: first sand, then fine gravel. The minimum thickness is a total of 20–25 cm, but the bedding can be thicker depending on the size of the foundation and hydrogeological conditions.
Preparation can also be done with concrete grade M100 or M150. This helps to more accurately maintain the lower protective layer of the reinforcement, as well as to more technologically close the horizontal and vertical waterproofing in the presence of a basement. After preparing the bottom, the walls of the trench are covered with plastic film; this is done to reduce the yield of laitance from the mixture.
Construction of formwork for the above-ground part
One of the main difficulties when constructing a foundation is the construction of high-quality and rigid formwork. If you are irresponsible at this stage, it is impossible to maintain the geometry of the foundation, which can lead to serious problems during the construction of load-bearing walls and finishing. Also, quite often, due to insufficient strength, the formwork ruptures, which ultimately results in damage to a large volume of expensive material.
There are three types of formwork: panel formwork, sheet formwork and permanent foam formwork. The difference between the first two varieties is small: in one case, the enclosing surfaces are formed with shields from boards 25 mm or thicker - on average, 1 mm is added for every 5 cm of foundation height. In the sheet version, decks are formed with plywood, OSB or chipboard, reinforced on the outside with stiffening ribs. Mostly waterproof materials with a thickness of 14 to 20 mm are used. The need to use sheets is dictated by high requirements for the smoothness of the foundation surface, which is important both during finishing and when installing hydro- and thermal insulation. Additional advantages include ease of use, high speed of assembly and dismantling, the possibility of repeated use (adjustable formwork) and subsequent use, and there are often economic benefits.
When assembling plank decks, the boards are knocked down and reinforced with vertical timber inserts. The thickness of the latter is 2 times greater than the board; the width should be sufficient to overlap the abutting ends of about 80–100 mm on each side. If the boards are more than a meter high and have a significant length, they are additionally reinforced with horizontal stiffeners of the same cross-section as the vertical inserts.
The most vulnerable places of the formwork are the corners and the lower zone. In these places, there is both a high static pressure of concrete and water hammer from the discharge of the mixture. For this reason, the bottom of the formwork must be tightened and strengthened through the existing stiffeners. This is done using pins (you can put them in MP pipe sleeves for reuse) or wire clamps, sometimes they are tied with reinforcement with penetration from the outside. An important point is that the metal embeds remain in the concrete and should not touch the working and distribution reinforcement. Between the metal rods, a protective layer of about 15–20 mm must be maintained. When tightening the connections of the lower zone, temporary spacers of the required length must be inserted inside the formwork.
In order for the formwork to maintain its spatial position, it is propped up from the ground with boards at an angle of 45–60% to the horizon. The board, placed edgewise, rests against a stake or directly into the ground, is tapped, and then screwed to one of the vertical crossbars. Sometimes additional planks are tied to the braces to provide support for the lower zone; it is also recommended to connect the soil stops with one or two lines of planks. A well-tightened bottom of the formwork does not need support, but for safety reasons it can be compacted with embankments of soil.
Calculation and tying of reinforcement
Independently calculating reinforcement is allowed only for small concrete structures with low responsibility. Correctly designing a reinforcement frame is not an easy task and requires special knowledge. At the same time, the matter is not limited to the calculations themselves; it is also necessary to correctly lay and tie the reinforcement elements together so that they retain their position after pouring the concrete.
One of the general principles for the distribution of reinforcement is as follows: the frame follows the shape of the concrete structure with a small, uniform indentation inward, due to which external protective layers of concrete of 35–50 mm are formed. The farther the reinforcement is spaced from the center of the foundation section, the better it does its job.
It is believed that the total steel content in the foundation cannot be lower than 0.1% of the cross-section of the reinforced concrete products. Laying of reinforcement must be carried out taking into account the requirement to ensure minimum protective layers of concrete, which are provided for by the project. Plastic reinforcement clamps will be a good help in this matter: flat plugs for support on the bottom of the formwork and “stars” that distance the frame from the side walls.
Concrete pouring, shrinkage
In general, the foundation structure has the following order: preparation of trenches, installation of formwork, lubrication of internal planes, assembly and placement of the frame. Pouring concrete is the final step in building the foundation, but even here a great deal of attention and caution is required.
The mixture can be supplied to the formwork in two ways. The first - directly from a concrete mixer or mixer truck, the second - with overload via a concrete pump. When pouring the mixture into a mold purely by gravity, the physical impact on the formwork is minimal: the reinforcement absorbs the fall due to its elasticity, and small portions do not have enough weight to spoil the geometry.
The situation is completely different with supply through a pump. The liquid moves in jerks and is forcefully thrown out of the sleeve in fairly large portions. At the same time, the already poured mass transfers the impact to the formwork to the fullest extent, which can lead to both divergence of joints and swelling if the sheet materials are insufficiently strengthened.
In order to avoid such phenomena, the foundation must be poured along the perimeter: first up to half or a third of the height, and then repeat the route once or twice. The optimal pouring height is 0.5 meters in one pass, however, if the total height of the tape is more than 1.5 meters, it is recommended to wait some time before setting begins. In monolithic concreting, a pause of up to 20 hours between layers is allowed; with a longer period of time, the formation of cold joints is possible.
Each poured layer of concrete must be compacted. This can be done either by hand pinning or with a submersible vibrator. In the latter case, you should try not to overdo it with shrinkage in one place and immerse the tip no deeper than 2/3 of the height. If additional compaction is necessary, it is better to carry out it according to the same principle as filling: along the perimeter with breaks for gravitational settling.
Protection and insulation
There is often a rush to remove the formwork, which causes open edges to appear on the concrete structure and accelerates the evaporation of water. Concrete must retain moisture in the surface layers for at least 7 days and in the core for up to 28 days. Therefore, if the formwork breaks down on days 3–5 in clear, hot weather, the concrete will have to be wetted several times a day. Early failure of formwork may be dictated by the need to reuse lumber in construction: in this case, they are not lubricated, but torn off before the concrete surface has completely set.
Waterproofing by injection and penetrating compounds is carried out until hydration is complete, approximately 10–12 days after pouring. To apply roll or coating insulation, concrete is given time to gain design strength during the full curing period. As mentioned above, the formwork may not be removed at all, performing insulating and waterproofing functions. In this case, the decks are sheathed from the inside with special materials: polystyrene foam, glass insulation, and others. published econet.ru
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