It happens that the construction of a house is delayed so much that the cold comes. Or when you need to build a building right now, and not wait until the summer. But cement at zero temperature ceases to harden, so how is bricklaying carried out in winter at sub-zero temperatures?
Why the solution does not harden
When the weather is cold outside, it significantly slows down the solidification of the solution. When the temperature drops to zero, the process stops altogether. The whole mixture becomes separated into sand, cement or other binders. And the partition between them is water that has become ice. This reaction leads to the fact that there is no plasticity in the cement, which is why the horizontal joints are not sealed at all.
What threatens the thawing of cement
When the thaw occurs during the day, under the influence of sunlight, the walls begin to settle, because the ice turns back into water. The worst thing is that such winter bricklaying shrinks unevenly. As a result,structures lose stability and strength.
In such conditions, when the masonry freezes and thaws, it takes 28 days for everything to set. Then the solution becomes only half strong, from the hardness declared by the manufacturer. And this is in the event that there is still the possibility of thawing, and not when frosts are around the clock. For these reasons, solutions have been invented that can maintain the strength of the masonry declared by the manufacturer even at low temperatures.
Winter laying methods
To make winter bricklaying strong, there are several ways to achieve this:
- antifreeze components are added to the solution;
- electric heating;
- create greenhouses.
Bricklaying in winter is acceptable by professional builders, however, it must be planned initially in the project. Then everything is thoroughly calculated so that the process is controlled and gives the best possible results. Bricks are laid on a heated mortar. And before it has time to freeze, it is gaining strength. After that, everything freezes, and when it thaws, it hardens again, and so on. These processes calculate and predict the final result.
Types of mixtures that are used in winter
Technological bricklaying in winter provides for mortar:
- cement;
- lime-cement;
- clay-cement;
- also use a solution where the base is quicklime.
Based on the weather conditions, the grade of the solution is determined. If we do not take into account the climatic temperature, then they take a mixture that is two orders of magnitude higher than that designed for use in the summer.
Temperatures and mixture selection
If it's -3 outside and a little lower, use a summer mix. When the temperature is from -4 to -20 ° C, then in this case the mark increases by two points. For example, replacing 10 with 25. If the frost is even stronger, then they increase by two more steps.
In order for bricklaying to be successful in winter, warm mortar is delivered to masons using special containers. They are able to maintain the required solution temperature.
If the solution is frozen
If it's windy outside, then you need to heat the mixture five degrees more. The bricklayer has 25 minutes until the mortar has hardened. If, nevertheless, ice managed to appear in it, in no case should boiling water be added. This will create pores in which water will also freeze, this will significantly worsen the quality of the masonry. It is necessary to send the frozen mixture back for heating, and for work, take a warm one. For convenience, the required amount of solution is unloaded into an insulated container, and scooping from it, they do the work. Only by observing these rules, you can get the correct laying of bricks in the cold season.
Features of winter masonry
The peculiarity of winter masonry is that you need to do everything very quickly, putting mortar on the bed, you should immediately cover it with a brick, so continuing along the entire row. The upward growth rate of the wall is also very important, because for a more durable structure it is necessary thatthe upper tiers pressed on the lower ones. Only in this way tightly compressed seams and frozen in this position will give the necessary stability to the walls.
Despite the fact that laying is carried out in winter, the thickness of the joints should not be wider than summer. If the volume of mortar in the joints is exceeded, this can lead to severe shrinkage after thawing. This is highly undesirable and may even lead to collapse. Therefore, these norms for laying bricks in winter must also be observed. Even during breaks, you need to cover the buildings with roofing paper, cloth, polyethylene, in general, keep the heat in for as long as possible. After all, the solution during solidification also emits its own heat, it is not much, but it will also help solidification. You also need to make sure that all the seams are filled, and there are no voids in them. After all, they can lead to uneven shrinkage, squinting or even bringing down the entire structure.
Walls, floors and beams
When walls or pillars are erected, it is necessary to masonry the entire building, as a border, a seam may protrude, which is sedimentary. The height of the structure in such conditions should not be more than 4 m. When the masonry is ready, it is immediately necessary to hoist floor slabs on it. All beams, as well as girders that rest on the walls, must be connected using metal anchors. So, the whole structure will be able to withstand the weight of the plates pressing from above. The runs are fixed with twists, or if they are wooden, then with the help of overlays. Only the correct laying of bricks and proper fixing will give a positive end result.
The foundation for the foundation is laid out, protectingeverything from freezing, both during and after work. This is necessary so that the foundation does not begin to sag rapidly during thawing, thereby exposing the masonry to deformations that can lead to collapse. In winter, roofing felt, roofing felt, or polyethylene are laid on the plinths, directly on a leveled concrete bed. They are put in three layers or more, the main thing is to contain the effects of frost.
Controlled shrinkage
When laying in winter, reinforced concrete lintels are used, and if the spans are not more than 1.5 m, then ordinary lintels can be used to suspended formwork. This is a daily practice. Also, the norms of bricklaying provide for the formwork to be supported on racks that are installed on wedges, and when a thaw occurs, they are weakened. Thus, allowing the entire structure to settle evenly. All racks and lintels are installed in the central parts of the walls; they must not be allowed to move. After everything has thawed, formwork is removed from the lintels only after 15 days.
Winter masonry is also different in that the height of window and door openings, when they are laid out of brick, should be 5 mm higher than during similar work in the summer. In any case, the solution is mixed only in heated water.
Heating seams with electricity
There is also a technology for laying bricks with heating. To do this, you need to lay the wire in the horizontal seams. Its thickness can be 0.3-6 mm, and long enough ends must be left,so that it can be conveniently connected to a power source. They can be a welding machine. When laying the wire, care must be taken to ensure that there are no voids in the solution, because heating in this case will be slower and may become inefficient.
Only 25% is spent on heating the mixture itself, the rest of the energy is spent on heating the brick and the surrounding air. Therefore, it is worth carefully choosing a device that is capable of consistently delivering the required amount of electricity. Such bricklaying, the scheme of which is presented here, is the most technologically advanced, and much more modern than the one where it is necessary to build greenhouses.
Chemical method
There is also a way to keep the solution from freezing by applying chemicals. They are added to the solution, and they lower the temperature at which the mixture would freeze. Among these substances, the most effective and widely used are: sodium chloride, calcium nitrite, calcium nitrite in combination with urea and potash.
However, there is a significant disadvantage in this method of creating masonry, many experts argue that it cannot be used to build residential buildings. After all, where a person will live, it is unwise to use chemicals: they can be poisonous and affect the he alth of residents in the future.
An important thing to remember when using this method is not to mix these additives too much, as the solution can set much faster than expected. Optimally enough 1-3% of the total mass of the mixture. To find out in more detail how much it costs to add them, you can only empirically.
Here we looked at what isbricklaying, how to properly carry it out in the cold season, and materials that may be needed. As you can see, even in such a seemingly hopeless situation, there are several solutions. They certainly take practice and some experience to know exactly how the materials will behave.
