What is considered a marriage in the production of ceramic bricks?
According to GOST, overburning and underburning are considered marriage, and this brick is not recommended for use. But the presence of lime inclusions GOST allows, although this does not make it easier for the buyer of such a brick. Don’t worry if the brick has a more intense color core.
How to understand if the red general building brick is burned correctly? If the middle of the brick is a more saturated color than the “body”, and when struck it gives a ringing sound, then this is a brick of decent quality.
1. Unburned, unburned brick Unburned brick has a characteristic mustard color, and when struck it makes a dull, not sonorous sound. Unburned ceramic bricks have low frost resistance; they are “afraid” of moisture. At one enterprise, they heard the following story. One winter, when prices for building materials are below seasonal, a greedy customer bought a brick at a low price. Then he delivered and dumped it on his site and began to calculate how much he could save. The construction season has come, the snow has melted, our buyer has looked at his construction site. And I saw… piles of crumbling bricks. This brick turned out to be defective – with an underburnt.
2. Burnt, burnt brick. It turns out, from very high temperatures. Such a brick turns black, melts, loses its clear geometric dimensions, and “inflates” it from the inside. But experts say that if the brick has not broken its shape, and only the middle has turned black, on the contrary, it becomes very strong, strong as if reinforced concrete.
3. Lime inclusions (often called “dutiks”). How do they appear? Clay raw materials from which bricks are made contain limestone. During the preparation of the clay, the limestone is crushed. But they may remain, at least small half-millimeter blotches, expect a catch. They absorb moisture and “swell”, breaking off pieces of brick, making it brittle. If the cleavage depth is more than 5-6 mm, this OTC brick is rejected, if it is less, it is put on sale. The facades of houses built from this brick come out pockmarked, as if “infested with flies”. By the way, lime inclusions are not purely our problem. For Europe, this is also a big problem.
4. Efflorescence on a brick. The most common brick marriage is efflorescence. Efflorescence appears on brick walls in the form of whitish spots and streaks (that is, already on the laid brick). And when buying, you can’t predict whether there will be efflorescence on a brick or not. They appear as a result of the migration of salts from masonry mortar, brick, groundwater and even air. It is recommended to use cement with a minimum content of salt-forming impurities and inclusions.
How to protect yourself from efflorescence on a brick?
1. Use a thick, non-shrinking mortar.
2. Do not smear (dirty) the solution on the facade of the brick.
3. Do not lay brick during precipitation: rain, sleet and cover fresh masonry at night.
4. Roof the house as soon as possible.
5. Cover the facade with a protective compound (water repellent). But if, after all the measures taken, the efflorescence still appeared, do not worry. Experts assure that most of the efflorescence is washed away by rain within a year or two. If you don’t want to wait, you can use folk remedies: a solution of acetic acid, a 5% solution of hydrochloric acid or a solution of ammonia (a vial for one bucket of water). Or purchase special tools in hardware stores. Or ask for help from an enterprise that will “wash” your facade, house from salt and cover the masonry with a protective agent.