Construction and repair is hard to imagine without ceramic products. Before you start buying a ceramic material, you must make sure that its integrity and quality of manufacture. First you need to visually make sure that there are no oil spots and dark spots on the surface of the material. Dark spots indicate the possible inclusion of Mergel in the mixture from which a block or brick was made. Also, white lumps of silt on the surface of the material may indicate the inclusion of Mergel.
Such lumps absorb moisture under the influence of water and expand several times in the diameter, thus, the monolithic structure spoils, and cracks in the block may also occur. Some manufacturers neutralize Mergel using an additional heat or drying, such additional processing deactivates measurements and allows them to absorb moisture in the future. But the material obtained using such an additional technological process has an unattractive appearance and can only be used for the purpose of further coating with a layer of plaster or insulation. Producers do not throw mechels with mirgel intersperses into scraps, they are also launched on the market, but they are much cheaper.