It happens that the construction of a house is delayed so much that cold comes. Or when you need to erect 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 freeze
When the weather is cold outside, it significantly slows down the solidification of the solution. When the temperature drops to zero, the process generally stops. The whole mixture becomes divided 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 horizontal joints are absolutely not sealed.
What may thaw cement
When during the day, thawing occurs, under the influence of sunlight, the walls begin to settle, because the ice turns back into water. The worst thing is that such a winter bricklaying shrinks unevenly. As a result, structures lose their stability and strength.
In such conditions, when the masonry freezes, then thaws, 28 days must pass before everything is set. Then the solution becomes only half solid, from the hardness declared by the manufacturer. And this is if there is still the possibility of thawing, and not when frost is around the clock. For these reasons, solutions have been invented that can, even at low temperatures, preserve the strength of the masonry declared by the manufacturer.
Winter masonry methods
To ensure that the winter brickwork is durable, there are several ways to achieve this:
- antifrosty components are added to the solution;
- electric heating;
- create greenhouses.
Professional builders apply bricklaying in winter, however, it should 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 he could freeze, he was gaining strength. After that, everything freezes, and thawing, hardens again and so on. These processes calculate and predict the final result.
Types of mixtures used in winter
Technological brick laying in winter provides a solution:
- cement;
- lime-cement;
- clay-cement;
- a solution is also used, where the base is quicklime.
Based on weather conditions, the grade of the solution is determined. If climatic temperature is not taken into account, then they take a mixture that is two orders of magnitude higher than that designed for use in the summer.
Temperature and mixture selection
If on the street -3 and a little lower, use a summer mixture. When the temperature is from -4 to -20 ° C, then in this case the brand increases by two points. For example, replacing No. 10 by No. 25. If the frost is even stronger, then increase by another two steps.
In order for bricklaying to be successful in the winter, masons are delivered warm mortar using special containers. They are able to maintain the required temperature of the solution.
If the solution is frozen
If the street is windy, then you need to warm the mixture five degrees stronger. The bricklayer has 25 minutes until the mortar has solidified. If, nevertheless, ice has appeared in it, in no case can you add boiling water. This will create pores in which water will also freeze, this will significantly impair the quality of the masonry. It is necessary to send the frozen mixture back to warm up, and to take warm. For convenience, the required amount of solution is discharged into the insulated container, and scooping out of it, do the work. Only observing these rules, you can get the correct brick laying in the cold season.
Features of winter masonry
The peculiarity of winter masonry is that you need to do everything very quickly, putting the mortar on the bed, you should immediately cover it with brick, continuing throughout the row. The growth rate of the wall up is also very important, because for a more solid structure, it is necessary that the upper tiers press on the lower. Only so tightly compressed seams and solidified in this position will give the necessary stability to the walls.
Despite the fact that the masonry is carried out in the winter, the thickness of the seams should not be wider than the summer. If the volume of mortar in the joints is exceeded, this can lead to severe shrinkage after thawing. This is very undesirable and can even lead to collapse. Therefore, you must comply with these standards for bricklaying in the winter. Even during breaks, you need to cover the buildings with roofing materials, cloth, polyethylene, in general, keep the heat as long as possible. After all, the solution during curing also emits its own heat, it is not much, but it will also help hardening. It is also necessary to ensure that all seams are filled, and there are no voids in them. After all, they can lead to uneven shrinkage, mowing or even collapsing the entire structure.
Walls, ceilings and beams
When walls or poles are being erected, it is necessary to do the laying of the entire building, as a border, a seam may appear, 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 put 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 support the weight of the plates, pressing on top. Runs are fixed with twists, or if they are wooden, then with the help of overlays. Only the correct brick laying and competent fixing will give a positive final result.
They lay the foundation for the foundation, protecting everything from freezing, both during and after work. This is necessary so that the foundation does not begin to quickly sink during thawing, thereby exposing the masonry to deformations that can lead to collapse. In winter, roofing sheets are laid with roofing felt, roofing felt, or polyethylene, directly on a lined concrete bed. They are put in three layers and more can be, most importantly, to restrain the effects of frost.
Controlled shrinkage
When laying in winter, reinforced concrete lintels are used , and if the spans are no more than 1.5 m, then ordinary lintels to suspended formwork can be used. This is daily practice. Also, brick laying standards provide for the support of the formwork on racks that are installed on wedges, and when the thaw sets in, they are weakened. Thus, allowing the entire structure to evenly settle. All racks and jumpers are installed in the central parts of the walls, their displacement should not be allowed. After everything has thawed, formwork is removed from the jumpers only after 15 days.
Winter masonry is also distinguished by the fact that the height of the window and doorways, when they are laid out from brick, should be 5 mm higher than with similar work in the summer. In any case, the solution is mixed only in heated water.
Heating joints with electricity
There is also a technology for laying brick with heating. To do this, lay the wire in horizontal seams. Its thickness can be 0.3-6 mm, and you need to leave long enough ends to be able to conveniently connect to a current source. They can be a welding machine. When laying the wire, you need to ensure that there are no voids in the solution, because heating in this case will be slower and may become ineffective.
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 choosing a device that is capable of stably delivering the required amount of electricity. Such brickwork, the scheme of which is described here, is the most technologically advanced, and much more modern than the one where you need to build greenhouses.
Chemical way
There is also a way to prevent the solution from freezing by using 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, in this method of creating masonry there is a significant minus, many experts argue that it can not be used for the construction of residential buildings. After all, where a person will live, it is unreasonable to use chemicals: they can be poisonous and affect the health of residents in the future.
It is important to remember, resorting to this method, that you can not interfere too much with these additives, since the solution can set much faster than expected. Optimally enough 1-3% of the total mass of the mixture. Learn in more detail how much it costs to add them, you can only empirically.
Here we examined what brickwork is, 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. Of course, they require practice and some experience in order to understand exactly how the materials will behave.