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Microwaves are electromagnetic waves of frequencies from 300 MHz to 300 GHz, corresponding to wavelengths from 1 m to 1 mm. For industrial application is allowed more frequencies, but we are mainly interested in the frequency 2 450 MHz, a wavelength of 12,2 cm, which we use in our applications. The heating occurs so that the electric field in the water molecules orient themselves according to polarization. Microwaves are a classical electromagnetic radiation with frequency lower than the solar radiation and therefore leave no residual radiation harmful to health. Using the device is completely safe, damage to health can occur only by direct irradiation of a few cm for several minutes, either intentionally or careless handling of the machine.

The publication introduces results of experimental measurements which were carried out for the transport of humidity in porous composite concrete in non-stationary conditions to express the moisture profiles with the help of measuring apparatus working on the non-destructive model of electromagnetic microwave radiation. The aim is to verify the mentioned method of measurement for the description of moisture parameters of the composite building materials in practice. It is experimentally made material from more substance with different characteristics which together arrange resulting new feature, and which is not any from single composite (like the example composite building material-concrete, stone, cement, ceramics etc). These materials are developed by Institute of Technology of Building Materials and Components by Brno University of Technology and represents insulating mass with fibrous filling of specific gravity. The usage of the mentioned materials in building activities is based on the material characteristics and attributes. These materials are as subject for the following examination. We deal with the samples of materials, based on the products usage. Characteristic material is porous structure as well as composite building material, which includes aggregate gradation in range 0 up to 8 mm or possible in range 4 up to 8 mm.

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The main subjects of the thesis are new materials and assessment of ventilation efficiency floors. As we are working with old buildings most of all, in most cases waterproofing is not working and simply it is missing. The rising humidity can, without any problems, penetrate higher to the brickwork or flooring above. Therefore we need a suitable solution. Software CFD is capable of flow visualisation which is then used as the base for the ventilation efficiency assessment.