Since the appearance of concrete, the world of construction has not told anything: reinforced concrete, gas and foam concrete, expanded clay concrete and many other building materials. And the brick has remained practically unchanged for centuries. It remains a durable, comfortable and aesthetically pleasing building material. Only the possibility of choice was added - corpulent or with cavities, masonry or decorative. However, the real nightmare for the owner of brick buildings (in addition to direct physical destruction) can be efflorescence on the brick.
The reasons for their appearance can be different, the ways of elimination - too. But one thing is certain - this is not a norm, but an undesirable phenomenon, and one cannot simply not pay attention to it.
An unpleasant-looking white coating that seriously spoils the appearance - these are salt crystals that have been dissolved in water. This water is used to prepare mortar and is also contained in the brick blocks themselves. The composition of the white bloom may include a mixture of alkaline elements.
When the brick is wet and the mortar is fresh, the presence of salts and alkalis is invisible to the naked eye. Accordingly, any material is used, often in violation of masonry technology and solution preparation. When water dries, the liquid evaporates, and the dry substances that were dissolved in it remain. This process is called crystallization. You can see it if you leave cool salted water to dry in some kind of dish.
Over time, the water will simply evaporate, and at the bottom of the container there will be a white coating, which will mainly contain sodium chloride.
It is also present in efflorescence on brick, but besides it, there are many water-soluble compounds in the white bloom. There are several reasons for the appearance of this misfortune:
The most commonplace reason is too much water in building mixture. It is known that the thicker and steeper the cement-sand mixture, the more difficult it is to distribute it over the surface of the brickwork. Many inexperienced or unscrupulous bricklayers add more water to the mortar to make it more fluid, plastic.
Also, the reason may be a consideration of economy: after all, the liquid solution lays down in a thinner layer, respectively, its consumption will be less.
However, there are rules for masonry , along which the seams between the wall bricks should be 7 - 10 mm. The liquid solution intensively loses moisture, giving it to the brick, and on that, in turn, salt deposits appear.
The least of all claims for cement in the mixture is a factory product, the content of substances in which is regulated in production. When stored properly, it will not deliver any surprises.
But a lot depends on the quality of the sand. If unwashed quarry sand is used, it contains many impurities. So, clay particles in it are an excellent moisture-retaining agent, it accumulates water, and then gives it to the brick and promotes efflorescence. The best option for masonry mortar is river washed sand. True, he is expensive, and not every foreman will conscientiously point out the difference in quality to an ignorant customer.
Increased salt content in water is reflected in such indicator as hardness. High hardness means a lot of dry matter per 1 liter of water. When evaporated, all of them will be either in solution or in brick. In regions with hard water, special filtration systems with softeners are installed. Again, this affects the cost of construction, since not every customer will agree to use filtered water to prepare the solution.
Among many builders, there is an idea that if a brick is soaked before laying it, it will then dry more evenly without drawing water out of the solution. After all, a quickly drying solution can become cracked - it can "break", as the experienced say. For this purpose, the brick is kept in a container with water from several minutes to an hour. In fact, is an erroneous statement, and "tears" the solution more often from incorrect proportions. A brick, having collected a huge amount of moisture, becomes a container of dissolved salts.
The owners of the buildings then suffer from the manufacturer's mistakes. The most common example of a violation is improper drying. For example, as a result of malfunctions or simply due to a large load of equipment, bricks do not fall into the drying oven during time and dry directly in the open air. Bottom line: the whole batch is then salted out six months after the walls were erected.
Construction work is a common thing in Russia.
An attempt to comply with unrealistic deadlines, uneven distribution of time, general construction illiteracy lead to a situation where construction is carried out at an arbitrary time, without observing the relevant conditions. In rainy weather, it is better to refrain from laying bricks so that it does not collect excess moisture. Also, do not carry out any work with mortar at an ambient temperature below five degrees. In modern construction, chemical antifreezes are used - additives that optimize the behavior of the solution at low temperatures, ensure its adhesion and drying.But there is also a downside - the increased content of such additives causes salt concentration, which then spoils the facade of a beautiful house.
Even if everything is done correctly - both mortar and brick, and laying in warm, dry weather - you can still encounter efflorescence. The fact is that atmospheric precipitation, especially in large cities and in areas of large industrial facilities, are saturated with various chemical compounds. When it rains, brick walls are saturated with this moisture, and then it evaporates, leaving stains. Although they come from the surface and are considered less dangerous than deep ones, nevertheless, in an aggressive chemical environment, it is recommended to protect the facade with modern facing materials.
This is just a basic list of reasons that cause salting out on bricks.
There are many individual factors that can unpleasantly affect the situation with the appearance of a brick facade.
The fact that whitish stains spoil the appearance of the facade, faced with red facade brick, is beyond doubt. But is it worth worrying if efflorescence only affects the cosmetic effect?
In fact, the appearance of a brick wall with efflorescence is only a visible part of the disorder in brickwork. The real trouble lies deeper - after all, salts, crystallizing, appear not only on the surface, but also in the thickness of the brick, in its very inner structure. The area of formation of such crystals is the pores of the brick, cavities in its volume.
Growing up, the crystal destroys, corrodes the smallest particles, enlarging the pores.
This is how the process of breaking the brick begins, slow, invisible, and therefore doubly dangerous. You may have seen the result: a brick oversaturated with salt crystals, even if it was recently laid out, begins to exfoliate, fall off in pieces, thinning the brick wall.
Fortunately, in order to achieve this state, several factors must combine besides salting out. But in any case, even the aesthetic moment is already enough to spoil the mood of the homeowner.
After all, the facade is the face of the entire building.
All efflorescence control measures can be divided into two large groups. The first group includes a set of actions to prevent and prevent the appearance of efflorescence. They relate to the rules and regulations in the field of brickwork and its features. However, it so happens that a building has already been built, and a white coating on it is perceived as a given.
In this case, efflorescence will be removed and an attempt will be made to stop their appearance. Let's start with the first group.
If you follow the rules for the construction of structures from bricks, as well as their acquisition and storage, with a high degree of probability it will be possible to avoid further troubles with crystallization of salt solutions.
Purchase bricks only from a trusted supplier. This will compensate for possible violations in the production of this building material.
In a bona fide business, a breach of technology is more an accident than willful intent. Feel free to purchase a small test batch and test it "in the field". After all, it will be much more expensive to eliminate troubles in an already erected house.
Store brick in dry conditions, in the shade. Ideal - under a canopy.
If the pallets are damaged in production, do not unpack them ahead of time. If the brick constantly gets wet, and then dries in natural conditions, this leads to its saturation with salts.
Make a calendar of construction works. Build on the climatic characteristics of your region. Usually the end of spring, the second half of summer and the beginning of autumn is the most favorable time for construction, usually at this time it is quite warm and dry.
Keep track of the weather forecast and its current state. Do not masonry in the rain and do not require it from your workers. Sometimes it is better to wait a bit for the work to be of better quality.
Important! Do not soak brick before laying. Under the specified storage conditions, it does not dry out in such a way that it requires moisture.
Pay special attention to the preparation of the mortar:
Carefully measure the amount of sand and cement so that you do not have to add water to the ready mixture later. The mortar must be fresh and strong so that it does not run off the trowel or trowel.
This also minimizes the amount of water injected, improving the performance of the solution.
After the stage of wall construction a break has been erected from bricks and is planned, the structures must be properly "preserved", especially for the winter. Sections of the walls built up to the current level are covered with plastic wrap. If you plan to finish building the house in one season, include the roof construction so that the box hibernates under the roof. This will reduce the risk of efflorescence and brick failure in the future.
If you spent a lot of money in order to impose a facade decorative brick on the house, salting out will violate the main idea of this action - aesthetics of appearance and protection from adverse environmental conditions, because over time, bricks can begin to exfoliate, crumble and fall apart. Unfortunately, the appearance of efflorescence is an alarming consequence of some miscalculations made during the construction phase. However, because of this, you will not dismantle the cladding. It remains to look for means to remove this unpleasant effect.
Today, the construction chemistry industry offers a worried owner a whole arsenal of ready-made products to remove efflorescence.
These substances are usually packed in plastic canisters with a volume of from 1 to 5 liters. All are supplied in concentrated form and must be pre-diluted with water. Look on the shelves of building supermarkets for canisters labeled "antisalt", "efflorescence remover" and the like. Pay attention to the composition. It is similar for all such drugs - mainly diluted acid and surfactants.
The higher the percentage of active ingredients, the stronger the effect can be obtained from the application.
After purchasing the mixture, simply mix it with water in proportion, indicated on the label. The water must be clean. If it is not possible to use filtered water, it should at least be defended. Apply "antisalt" to the surface of a brick wall in different ways: with a roller, a brush, and a brush.
If the volume of work is large, then you can use a garden sprayer: pour the solution into the tank, pump it into the tank and spray over the surface. For small areas, even a garden spray will do. Well, for those who have a pressure washer, applying the composition will generally be an easy task.
Important! Means against efflorescence contain chemically active substances. Work with protective clothing, gloves and goggles.
If there is a high percentage of acid in the composition, a respirator will come in handy.
After processing, you need to wait a few hours after disappearing white traces, and then wash the facade with a garden hose or the same sink. This is done so that the active substances do not remain in the brick and the medicine does not become poison.
If the wall section is small, you can try to remove it manually by mechanical means - take a hard brush, you can bristles, and shedding water, rub until efflorescence is removed. The work is not easy and also destroys the brick, so it can be advised at the peril and risk of the homeowner.
Combined physical and chemical treatment works best of all. By the way, you can do it yourself, if you are not afraid of work, and there is no hardware store nearby where you can buy a factory product. Traditional methods will come to the rescue, just adhere to the following instructions:
Table 1. Step-by-step instructions for a folk remedy for removing efflorescence.
| Step 1.
Perform a thorough visual inspection of the walls. If you see that efflorescence has collected in a crystalline coating, do not be too lazy to walk through these places with a brush with a hard and short synthetic bristle.
Clean the surface
| Step 2. Prepare your brick mortar. To do this, dissolve 1 - 2 bottles of ammonia from the nearest pharmacy in a bucket of clean water.
Preparing the solution
| Step 3. Test the product on a small section of the wall. If the effect is weak, you need to make the solution stronger. For this you need to take hydrochloric acid. A 10 liter bucket will require about 150 ml of pure HCl.
If there is no hydrochloric acid, you can take sulfuric acid, just be careful with it. There is no need for pure acid; it is enough to pour into a bucket a little electrolyte for car batteries, which every motorist has.
We check the solution, if necessary, add concentrations
| Step 4. Apply the composition with a wide brush or a brush, as if you are rubbing it into the pores of the brickwork. Salts will drain together with the solution.
Rub in the solution
|Step 5. After treatment, water the wall with a garden hose over time to remove any residues.||
Wash off the residues
After efflorescence is removed , the question arises of what to do when they appear again. This process can be slowed down and even stopped completely. For this, such preparations are used as:
Hydrophobizator - creates a film with water-repellent properties on the surface of the brickwork.
The water does not wet the brick surface and efflorescence does not appear. True, it needs to be updated at regular intervals.
This process is discussed in more detail in our article - Hydrophobization facades.
Acrylic impregnation - this substance creates a waterproof film on the facing brick. This product is expensive, but it actually waterproofs the masonry for a long time.
Although efflorescence on the brick and spoil the view and affect the integrity of the brick, they can and should be successfully dealt with. By combining factory formulations with folk remedies, you can achieve complete removal of efflorescence. Well, for the future, be careful and control every process of erection and facing of brick walls.
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