The main purpose of exterior sandwich walls of buildings is the protection rooms from adverse external influences - precipitation, temperature differences, direct sunlight, noise, dust, etc. However, apart from external influences, the walls can be influence by indoor temperature and humidity conditions, which in particular are subject to the wall of a technical floor. The impact of such destructive factors in particular exposes technical floor walls. Therefore, the projecting stage is necessary to consider all kinds of destructive influences. The purpose of this article is to describe some of the causes of the damage the facing layer of exterior walls technical floor and exhaust shafts influenced of negative factors such as a breach of moisture conditions on the floor, temperature and sunlight. In addition, separately considered defect prevention technologies suchas a ventilation system of the naturally driven type or forced ventilation, vapor barrier into walls and ceilings, and the use of brick with a lower void and more frost-resistance quality.