Insulation of the house, part 2

The temperature-keeping property is different for different materials. Porous materials, containing a lot of air, they conduct heat badly and are therefore good insulation. Still air is practically the best insulator, what you can get. In walls with large free spaces, it is always in motion, especially in winter. The internal decking transfers heat to the air in the free space, which rises and moves towards the external formwork, where it cools down and descends. Thus, it constantly circulates through the wall. In the case of filling with mineral wool, air movements are inhibited yes, that it practically stands still. Therefore, the insulating properties of such a wall are much better. Mineral wool, however, is not very resistant to blowing winds, therefore, in the case of low temperature and strong winds, the situation changes radically. The same is true, when in the mountains we walk in strong winds and cold, wearing only a sweater. We'll get cold quickly, unless we wear a jacket. In the same way, roofing felt or a windproof board must be laid over the mineral wool layer. The edges of the asphalt roofing felt must be protected to increase the effectiveness of the wall thermal insulation.

Mineral wool is also attacked from the inside. We know now, that warm air contains more water vapor than cold air from outside. When steam gets inside the insulation, it cools down and condenses. This has the known consequences of icing and mold formation in the wood (gnicia). Therefore, we need to build a vapor barrier in the form of a sealed layer (diffusion).