With the onset of winter, concreting is much more difficult, and most importantly, such work requires careful preparation and full compliance with all construction regulations. When pouring a foundation into frozen soil in winter, you should be prepared for the fact that in the spring the ground will thaw and sag, and the foundation will crack, which will entail.
But sometimes life makes its own adjustments. The estimated time for work is disrupted, and the foundation, which was planned to be poured in the summer, needs to be built when the thermometer drops below zero.
You can take a chance and try to create a reliable foundation for yours in adverse weather conditions! The experience of site users suggests that during such construction the main thing is to arm yourself with knowledge and not leave anything to chance!
Pouring the foundation in winter
Forum user with nickname AlecScrab The builders proposed pouring the strip foundation in winter, in December, so that it would set by spring, and in March they would begin to raise the walls. They promised to significantly reduce the prices for their work, because... Now is not the season, and they have few orders.
Needless to say, the offer is tempting, but the forum member is haunted by the question: at sub-zero temperatures, and whether this will further affect the strength of the strip foundation.
Profanus:
– Concrete gains strength in 28 days, but this is at “plus” temperatures, and at negative temperatures concrete may not gain strength at all.
The forum member’s verdict is this: pouring the foundation in winter is beneficial only for builders, because... they want to make money. And for himself, he would never pour the foundation in winter, even with serious benefits.
If the air temperature during the day drops to +5°C, and at night the thermometer drops below 0°C, then such construction conditions are considered winter.
During winter construction, the foundation must be poured using antifreeze additives and a special technology for warming the concrete. And this leads to a significant increase in the cost of construction estimates. The rise in price may completely offset the benefit from the seasonal reduction in prices for construction work.
According to 44alex, If you pour concrete in winter in compliance with all the technology, it will work out cheaper if only the workers work completely free of charge.
The cons of winter monolith
According to a forum member with the nickname Greenpeak, construction monolithic foundation It’s not worth doing in winter because:
- additional costs for concrete are required;
- special requirements for laying and curing concrete are required;
- electrical heating of the concrete (or other heating) is required under constant temperature control;
- short winter days lead to additional costs for lighting the site and insulating the shed for workers who are not eager to work in the cold;
- you might run into large number low-quality materials.
Emelya:
– At first I also wanted to pour the foundation in winter, but, looking at the ordeals of my neighbors who poured their slab last year in December at -5 C, I changed my mind. Now they have pieces of concrete peeling off the edge of the slab and falling off. The top layer was apparently caught by frost, but it crumbles underfoot.
Hydration reaction
To understand what the technology of winter foundation pouring is and how much the complexity of such work increases, it is necessary to consider the processes that occur in concrete when it is poured at subzero temperatures.
During the hardening process, hydration reactions occur in concrete, during which cement minerals, interacting with water, form new compounds. Dewatering of concrete in early dates can slow down or stop the hardening process and lead to a lack of strength, as well as cause shrinkage and cracking.
At sub-zero temperatures, water freezes without having time to react with cement. Therefore, the hydration reaction does not occur, which means the concrete does not harden. The strength of the foundation and its durability are also significantly reduced. Water frozen in concrete expands in volume, the coefficient of adhesion of concrete to reinforcement decreases, which leads to further destruction of the foundation. Therefore, building a foundation in winter requires careful adherence to complex pouring technology.
Therefore, most developers are distrustful of winter concreting. However, if you approach the matter wisely and arm yourself with the necessary knowledge, you can pour a high-quality foundation even at subzero temperatures. And sometimes this is the only way out.
How to make a shelter for heating a foundation
Forum member's foundation Svetoch – shallow tape for a house 10x10. He only managed to dig a trench and began tying the reinforcement. I wanted to pour the concrete in the middle of the week (with anti-frost additives, since at night it has long been a minus). And then it turned out that weather forecasters were promising rain and snow. The forum member was worried whether it was possible to leave the dug trench with formwork, a partially filled foundation and reinforcement for the winter.
Costeapechnik:
– If you leave everything as it is, the reinforcement will rust and the base of the tape will burst! The foundation must be poured completely, and rain and snow are not a hindrance, the main thing is to take care of the concrete after pouring.
Forum user with nickname Georgespb understands how to make a shelter for pouring a foundation and what type of shelter for heating a structure is the most reliable.
motorist:
– The shelter is made like this: a large tent is erected over the perimeter of the foundation, a heat gun is installed in it, and the temperature inside rises to positive.
Required gun power depending on outside temperature
They also heat concrete using electricity - welding transformer connected to the fittings.
For this, there are special transformers for heating concrete products: current is supplied through electrodes placed approximately 40-50 cm apart in the foundation.
But this method of warming up requires special attention!
sem2005:
– An experienced craftsman is needed to install the electric heating correctly and ensure that the required temperature is maintained.
This method of heating concrete increases the likelihood of injury to workers. electric shock. That is why, in order to avoid accidents, it is necessary to use a transformer with a voltage of 36 volts. Overheating of concrete is also fraught with severe cracks, and underheating can lead to freezing.
Antifreeze additives
For concrete with antifreeze additives, the strength at the time of its cooling to the temperature for which the additives are designed must be at least 30% of the design for grades up to 200, 25% for concrete grade 300 and 20% for concrete grade 400.
For concrete without the use of antifreeze additives monolithic structures and the monolithic part of prefabricated monolithic structures, the strength at the time of freezing should be:
- not less than 50% of the design value for concrete grade 150,
- 40% – for concrete grades 200–300, 30% – for concrete grades 400–500,
- 70% – regardless of the brand of concrete for structures exposed to freezing and thawing.
If antifreeze additives are used, this ensures the process of cement hydration and concrete hardening, but at subzero temperatures these processes proceed slowly, and in this case the concrete gains critical strength after about a month of hardening in the cold.
Concrete that has reached critical strength by the time of freezing acquires the required design strength only after thawing and maintaining at a positive temperature for at least 28 days! This means that it is necessary to maintain a positive temperature of the covered foundation not only during concreting, but also after.
To summarize, we can say that pouring the foundation in winter time and at negative temperatures leads to an increase in the cost of the estimate and requires careful monitoring at all stages of work. In return, developers get the opportunity to speed up the implementation of construction work and prepare the foundation for the house ahead of time before the start of the spring construction season.
FORUMHOUSE tells you what temperature to maintain at. You can also read about.
Here you can find the most complete and detailed information about. How to pour what its decent quality depends on - a heated discussion of a “cold” issue.
This video talks about the nuances of reinforcing shallow
It is better to carry out any construction in dry, warm weather. But private house, if it is built with your own hands, it is built in your free time. One warm season is usually not enough for this. In order not to drag out the process for many years, some of its stages are carried out in the winter.
The grillage (or foundation) can be made of blocks or slabs. In this case (as well as during construction), the peculiarity is that the individual elements are fixed with cement-sand mortar. Basically the same rules apply to it as to concrete.
Pouring the foundation in winter at minus 5
Measures necessary to install a quality foundation in winter:
- use of modifiers;
- heating the solution;
- thermal insulation of the finished foundation.
The problematic component of concrete is water. Even if it is liquid during pouring, complete dehydration is impossible. Those. the solution does not set due to the evaporation of water, but freezes. This problem is solved by adding special modifiers to the mixture that slow down hardening, which allows the concrete to gain strength.
The modifying substance is selected in accordance with frost resistance indicators. The required amount is indicated in the instructions, there is a scale on the package: the norm depends on the temperature. The minimum permissible air temperature is -25 degrees.
Please note
When preparing a solution with a modifier, the amount of water is reduced by 10-15%. At high air humidity (60% or more), additives cannot be used.
You should also study the instructions for interaction of the ingredient with the metal.
To dilute the mixture in winter, heated water is used. The poured foundation needs to be warmed up, especially the first couple of days. For heating, you can use a heat gun (power is selected depending on the size of the foundation). Another option is a heating cable or reinforcing bars with a 380-volt electric current.
Concrete gains strength within a month. After this, you need to make vertical and insulate the finished base. If there is a lot of time left before the arrival of spring, the foundation is preserved: covered with a waterproofing film and thermal insulation material:
- expanded polystyrene (foam);
- sand;
- expanded clay;
- sawdust;
- priming.
All insulation materials are hygroscopic to one degree or another; they must be covered with thick polyethylene on top.
The easiest option is to cover the base with snow. In this case, the film must be laid under the snow, otherwise during the thaw the concrete will absorb water.
Contents of the article
The foundation can be built in winter. Yes, it’s expensive, yes, it’s difficult, but it’s possible. Therefore, do not listen to the skeptics, just read this article and build a “winter” foundation. After all, modern construction technologies make it possible to implement any customer’s whim.
That is, despite the assurances of “experts,” everything can be done, and at any time: be it in winter or in summer.
Three reasons to build a foundation for the winter
If you take a closer look at the problem, the process of winter construction turns from a dangerous fad into a rather risky, but profitable solution.
After all winter arrangement foundations for residential buildings and industrial buildings promises us the following benefits:
- Firstly, in winter you don’t have to worry about the strength of the walls of the trench or pit. That is, the risk of soil collapse at this time of year is minimal. The reasons for this effect are quite clear - frozen soil “works” like formwork or a supporting frame.
As a result, on some types of soil a trench or pit can only be dug in winter. For example, on loose soils or swampy areas in the summer, excavation work is not carried out at all - unstable soil simply crumbles or floats away, but in winter there are no such problems.
So, as you can see for yourself, winter construction still has its advantages. But what about the disadvantages: increased cost and decreased speed of work? You'll probably have to try them on. After all, perfect technologies simply do not exist.
Technologies for constructing winter foundations
The process of constructing a winter foundation is based on only three technologies:
- Casting in heated formwork
- Pouring formwork with frost-resistant mixture
- Refusal of concrete in favor of pile construction
All three technologies are quite interesting and simply force us to consider each of them in detail. This is what we will do further in the text. So:
Construction of a heated foundation
This process is based on an artificial increase in temperature in a trench, pit or directly in the pouring body. Moreover, such an operation involves the construction of an insulating tent over the construction site, separating the heated zone from the frozen environment.
It is advisable to use heated foundation construction at temperatures below -5 degrees Celsius. Because at a higher temperature, concrete transforms into cement stone without additional effort.
Technically, pouring a foundation in winter, in this case, does not differ from the classic casting of a monolithic strip frame (or columnar support) produced in the summer. That is, at the very beginning, excavation work is carried out, then the formwork and frame are installed, and lastly, concrete is delivered to the site.
However, there is one nuance in this process: before pouring the foundation in winter, a heating element is built into its body, in the role of which the reinforcement frame of the base can be used. Moreover, during the process of knitting the frame or installing the heating element, it is necessary to arrange at least two outlets extending beyond the formwork. These taps are used as terminals connected to the power line.
In addition, upon completion of the pouring, a temporary canopy is built over the construction site, inside which a heat gun is mounted. This heating device will regulate the temperature during the initial hardening of the solution.
After two or three days, the canopy can be dismantled and the gun can be turned off. At the same time, on top construction site Be sure to add a layer of moisture-resistant heat insulator. It will maintain the temperature of the heated foundation body.
To the advantages This technology can be attributed to the ability to use this method in any weather, even in the most severe frosts. Flaw heated foundation lies in the energy intensity of the process, which increases construction costs.
Frost-resistant concrete: features of arranging “winter” foundations
When deciding whether it is possible to pour a foundation in winter, you should not discount the technology of frost-resistant mixtures prepared on the basis of classic concrete flavored with additives. Such mixtures can be used with or without heating. After all, frost-resistant concrete turns into cement stone even at a temperature of -20 degrees Celsius.
Moreover, for the construction (filling) of a strip or columnar foundation, in this case, concrete with low moisture content is used. After all, additives that accelerate the maturation of cement stone must use up literally all the water contained in the concrete for this “operation.” And without water, the foundation is not afraid of any frost.
The process itself is practically no different from classical construction: the same excavation work, the same formwork, the same pouring. Therefore, even amateurs can cope with this technology.
A feature of this process is the need to protect the fill from contact with the atmosphere and environment, from which concrete can “pick up” excess moisture. That is, a frost-resistant solution needs absolute waterproofing.
Dignity This option is the simplicity of the pouring process, disadvantage – the need for precise control of concrete moisture, on which the success of the work depends.
Construction of a pile foundation in winter
In the previous paragraphs, we have already answered the question: “Are foundations made in winter?”, and even gave examples of technologies for constructing “winter” foundations. 
But the mentioned technologies are characterized by high cost and labor-intensive process. Meanwhile, there is a less expensive way to build a “winter” foundation.
We are talking about pile technology, or more precisely, about the arrangement of a foundation based on screw-type steel piles. In this case, the construction of the foundation does not require either expensive (especially in winter) concrete pouring, heating of the foundation body, or labor-intensive excavation work.
Vertical piles are simply screwed into the ground without any heating or digging pits. Of course, the simplicity of the process of installing piles affects the speed of construction in the most favorable way. In addition, such a serious operation as waterproofing the foundation is canceled - it is very difficult to organize this work in winter, therefore, construction will go even faster.
Well, after screwing the last pile into the ground (to the level of -500 millimeters from the soil freezing level), a horizontal grillage made of the same steel beams is mounted on top of the vertical frame for welding.
In the end, how dignity , you get reliable foundation literally in one week. Moreover, a steel foundation has almost no physical shortcomings , and the relatively high cost of this method of arranging the foundation can be justified by the speed of work and the possibility of using such technology in the most extreme conditions.
Is it possible to pour a foundation in winter?
In the age of new technologies and high speeds, everything is developing very rapidly. Appear technical solutions, allowing you to perform work faster, better and more efficiently than a couple of decades ago. The construction industry also boasts many innovations that have significantly increased the speed of construction projects. If earlier, for example, when asked whether it is possible to pour the foundation in winter, the developer would have heard a clear “no,” today the answer will not be so categorical. Let's figure out how to carry out this work without loss of quality.
Pouring concrete in winter - some nuances
The question of constructing the foundation of the structure in winter divided the builders into two diametrically opposed camps. The first - adherents of classical technology - believe that no innovations can provide high-quality hydration of the solution. Without it, the strength characteristics of the base may be reduced. The second, supporters of various know-how, argue that it is possible to fill the foundation in winter, providing the required foundation parameters.
Both views on resolving this issue have the right to life. Traditional foundation pouring at above-zero temperatures is described in detail in many sources. Let's try to figure out how to carry out work during the cold season. At sub-zero temperatures, the water in the solution begins to crystallize, which ultimately leads to an increase in the porosity of the concrete mass. The main problem when pouring the base in winter is ensuring high-quality hydration of the concrete solution.
Not so long ago, with the onset of frosts, it was customary to “freeze” construction in our latitudes.
Hydration - educational program for novice builders
The solidification process at above-zero temperatures occurs in stages:
- a thin shell of acidic salt forms on the surface;
- in the upper layers, cement particles are bound with water;
- the outer layer, losing moisture due to evaporation, slowly contracts;
- the cement is bound by water at the next level.
The process gradually covers all layers. Within a month, the concrete gains the necessary strength, sufficient for the next stages of work.
When pouring a foundation in winter, it is difficult to evaporate moisture, which gradually freezes. This leads to an increase in the porosity of the concrete mass and a significant decrease in its strength. Therefore, the main rule for concreting in winter is to ensure normal temperature conditions that prevent the formation of ice crystals during hardening.
Pouring the foundation in winter - technological features
To reduce the hardening time, several methods are used that are aimed at maintaining the temperature of the concrete mass within limits that ensure normal hydration conditions.
The length of the winter breaks in construction forced residents of the northern country to look for methods that would allow them to continue concrete work in the cold
Heat is retained using:
- pair;
- electricity;
- infrared or induction radiation;
- thermal tent;
- thermal insulation around the formwork.
Let's look briefly at each of the methods.
Heating with steam
Heating the concrete mass with steam significantly accelerates hardening. By maintaining the temperature within 70 degrees Celsius for 1–1.5 days, the concrete reaches a strength corresponding to the solidification of the mass for 15 days at above-zero temperatures.
The duration of steam heating depends on:
- required strength;
- type of cement used;
- warm-up temperature.
Steam heating is carried out by arranging a steam jacket, which is mounted at a distance of no more than 15 cm from the formwork. This parameter ensures free steam flow around the array.
Owners, puzzled by the problem of whether it is possible to fill the foundation in winter, receive a clear affirmative answer, but with many variations
Heating by electric carriers
Create favorable conditions for hardening concrete, you can use electrical energy. The most common heating methods are:
- electrodes;
- PNSV wires.
Heating with electrodes is a fairly cheap method. Various types of electrodes are used for work:
- strings The main area of application is pouring vertical structures (pillars, columns, beams);
- rod-shaped To maintain the required temperature, metal fittings with a diameter of 8–12 mm are used;
- lamellar. When using plates, they are placed on opposite planes of the formwork.
More effective way warming up - using the PNSV wire. The high efficiency is explained by the fact that the heat source is not the concrete mass, but the wire itself, the temperature of which is much easier to regulate.
A type of electrical treatment of a concrete mass is the effect of infrared or induction radiation on it. Due to the complexity and uneven heating of large volumes, these methods are rarely used.
The electrodes are connected at one end to the transformer, at the other end to the fittings in increments of about half a meter
Arrangement of a thermal tent
Construction of a foundation in winter is quite labor-intensive and troublesome, but doable. It is believed that the time from April to November is the most favorable period for installing the foundation of any structure. But there are situations when work occurs in winter. Thanks to modern construction technologies, it is possible to build a reliable foundation that will not be inferior in its characteristics to the foundation laid in the warm season. From this article you can find out what pouring a foundation in winter is, whether it can be poured and how to make such a foundation.
When is winter foundation pouring necessary?
With careful adherence to all construction rules, the construction of a strong foundation is quite feasible even in severe frosts and, as a result, frozen soil. Pouring the foundation in winter is not always necessary, it all depends on the project. Most often, the decision to start construction in cold period related to the characteristics of the soil. There are areas where the soil crumbles in summer, and only in winter, when the ground is well frozen, can you dig a good pit. In this case, it is an excellent solution to accomplish the task. In many regions of Russia, winter is the main season of the year, and summer practically does not exist. Therefore, there is simply no other period for the construction of the foundation. In addition, it is believed that the costs of materials and labor in winter are much lower than in the summer months, although serious savings are unlikely to be counted on. Sometimes pouring a foundation in winter is necessary when the construction process needs to be completed as quickly as possible.
in winter
To arrange the foundation of any structure in winter, there are several types of foundations. Let's look at them in more detail:
1. The most common among developers is a strip foundation. In this case, experts advise reducing the so-called “wet” operations, for example, using ready-made ones for laying them in a pit.
2. Foundation made of concrete piles. This type of foundation is ideal for light buildings, in particular wooden houses. Observing construction technology and by adhering to the basic rules, you can get a strong pile foundation that is not inferior in quality to other types. Further from the article you can learn everything about pouring the foundation in winter.
How to pour a foundation using piles? First of all, you need to distinguish between their types. Concrete piles are either bored or drilled. Foundation from screw piles ideal for winter work. Suitable for any difficult soil.
Preparation of concrete mixture
When arranging the foundation, the question often arises: “Is it possible to pour a foundation in winter using ordinary concrete?” No, you can't. For these purposes, one that contains special modifiers is suitable. Thanks to additives, concrete has time to gain the necessary qualities; it does not set ahead of time. In addition, modifying additives make it much easier to pour concrete into the formwork.
When choosing modifiers, you should pay attention to frost resistance indicators and the rate of hardening of concrete. Required quantity substances are determined according to the scale indicated on the packaging.
How to apply modifiers?
When using modified additives, it is necessary to focus on some basic points:
The use of frost-resistant substances allows you to reduce the amount of water consumed by 10-15% when making concrete mortar.
The minimum temperature at which the use of modifiers is acceptable is 25 degrees below zero.
When air humidity reaches 60%, the use of additives is prohibited.
It is necessary to take into account factors in which individual components of modifiers interact with certain metals.
The use of additives does not negate some additional measures when arranging the foundation during the cold period. When the air temperature is low, additives alone that affect the frost resistance of concrete are not enough. It is necessary to warm up the concrete and install additional thermal insulation to maintain a certain temperature of the finished structure.
The use of additional means that make it possible to fill the foundation in winter
Another way in which the answer to the question of whether it is possible to fill a foundation in winter will be positive is to ensure that the foundation is warmed up. It is known that concrete gains its highest strength during the first two days. It is during this period that the foundation especially needs protection from low temperatures. To heat the base along the entire perimeter, special equipment is used - a thermal gun. With its help, the temperature required for hardening of the concrete solution is ensured and maintained. The larger the foundation, the higher the power of the device should be
You can also heat the foundation electron current. This method allows you to maintain the temperature required for hardening by transferring heat (from hot to cool). The concrete is heated by reinforcement rods, to which an electric current (380 V) is supplied.
Negative aspects of pouring a foundation in winter
So, the answer to the question “is it possible to pour a foundation in winter” is obvious. However, despite many positive arguments in favor of this process, there are also some negative aspects:
Although the savings in the cost of building materials are obvious, at the same time, the price of excavation work in frosty weather increases greatly. You will also incur additional costs for heating the concrete solution and structures, so in general, the savings in construction in winter are very doubtful.
The efficiency of work in winter is much lower than in summer, since working in cold weather is much more difficult.
The price of additives and modifying substances that affect the properties of concrete is low, but to build even a small foundation, quite a lot of them are required. And therefore the price building material increases significantly.
Sometimes it is necessary to use special equipment, in particular for digging a pit.
Therefore, before thinking about whether it is possible to fill the foundation in winter, you need to calculate all the costs and consider all the pros and cons of this idea.
List of basic materials and tools for creating a foundation
To arrange and pour the foundation, the following materials and tools are required:
- shovel;
- sawdust;
- building level;
- hacksaw;
- trowel;
- cement and concrete mortars;
- modifying additives;
- thermal insulation;
- reinforcing mesh;
- crushed stone
How to properly pour a foundation in winter?
Is it possible and is it worth doing? These questions often bother newcomers to construction. After all, it is very difficult to carry out any work in the cold; snow and frost can interfere. Expert advice will tell you how to properly fill the foundation in winter with your own hands. The rules of work are as follows:
First of all, a trench or pit is dug, while the ground moisture that will collect at the bottom is controlled. At sub-zero temperatures, water freezes and ice forms, which must be removed, since nothing can be placed on such a base.
The next step is the installation of formwork and reinforcement frame. The formwork is filled with concrete mixture. The required positive temperature must be maintained for a certain period of time (to accelerate the setting process) using heating equipment. Immediately after pouring, the foundation can be insulated using roofing material or polyethylene film. You can sprinkle a layer of sawdust (20-30 cm) on top. As a result, we have a ready-made foundation in winter.
Is it possible to fill it for the winter? The answer is yes. But it is still recommended to build walls on such foundations at above-zero temperatures, since the concrete solution needs a certain time to acquire strength. By preparing the foundation in winter (taking into account all the rules and nuances), you can get a strong and durable structure.