This paper is concerned with selected defects and failures of timber buildings. The paper is based on the findings of theoretical, implementation and realization work of loadbearing systems used for timber houses.
Due to the fact that the load-bearing capacity and deflections of timber structures are considerably affected by the load-bearing capacity of joints, it is desirable to verify the influence of structural design of connectors on the overall behaviour of structural systems.Findings from behaviour of structures after their rehabilitation are crucial for further research into real behaviour of timber structures. The paper contains authors, conclusions from designing, realization and exploration of selected building structures.

The article deals with the properties of concrete with two natural zeolites as a the supplementary cementitious material. The determined parameters bring the findings of basic mechanical propeties and frost resistance of aerated concretes with zeolites. The results of properties of concrete with two different kind of zeolite are compared to reference concrete without zeolite. Concrete with zeolite Z2 showed worse properties due to finer particles.

Stairs are part of construction. It is important to solve geometrical tolerances of stairs as of other parts of constructions. The most important tolerances of stairs which should be measured are steps (their high and width), because their dimensions could affect safety of stairs.

Acoustic design brings a new perspective to acoustics. Acoustic design tries to solve our uncomfortable noise conditions at any stage of the building. The easiest way is to solve at design and implementation stage. Situation at the stage of final inspection (stage to prepare to use) is more difficult. The most difficult path to the real solution is in using phase. Acoustic design focuses on the layout of dwellings to each other, the position of rooms within a house or apartments. Acoustic design solves issues of additional installations of suspended ceilings, primary plus secondary (added) walls and other acoustic absorbing elements that reduce reverberation time. Acoustic design also deals with a newly and additionally installed technologies such as modern air-condition units, new lifts, special heat pumps etc. The main point is to get the right balance between acoustic comfort of living and system of building construction using new technologies.

This contribution deal with the testing of thermal resistance and derived thermal transmittance of timbered wall from spruce wood beams 300 mm thick according to the standard EN ISO 8990 by Hot Guarded Box method. Thermal conductivity tests of individual layers made from the tested wall were carried out according to the standard ISO 8302 by Guarded Hot Plate method after the test according to the standard EN ISO 8990. These thermal conductivity tests were carried out for the average thermal resistance determination of the wall from the equivalent thermal conductivity and also for the comparison with the value founded by Hot Guarded Box method. The part of the tests was also the determination of mass moisture of individual layers and then the equivalent mass moisture of the wall. The contribution contains the maximal requirement values of thermal transmittance of the exterior walls according to the national standard ČSN 73 0540-2. The contribution contains also informative table of thermal conductivities of the plates of different wood profiles founded by tests or from literature.

The paper summarizes important information related to the field of design of wooden buildings from the point of view of the sound reduction index. The text is focused on wooden structures (both massive wood systems and wood frame systems) as well as on particularities of an acoustic behaviour of wooden floor structures with fillings. General principles are described which may serve as useful hints for architects and project engineers when designing structures with wooden elements. Emphasis is primarily put on the specific acoustic behaviour of wooden buildings in comparison with masonry and concrete structures.

The main purpose of this paper is to show how the different structural details affect the airborne sound insulation of lightweight building elements. The sound reduction index of such structures depends on several phenomena like the cavity attenuation, the mass-air-mass resonance, standing waves resonance, sound transmission via sound bridges etc. This paper describes their effect on sound insulation and gives the initiative information for optimized acoustic design.

The heat transfer between apartments operated on various internal temperatures objectively exists and under certain circumstances this may represent an important proportion of the total heat loss of the apartment. Is it possible to quantify the financial impact of the heat parasitism?

The article describes sensor system for increased moisture detection in construction materials, especially in the wood. The assumption is that a sensor network is built-in into the construction elements of the building and it is connected to a central unit. The goal is to develop a sensor suitable for permanent installation in the construction during realization of the building. The sensor network enables early warning and fast detection of increasing moisture in the building and alert building owner or operator. The sensors will be placed at critical building’s locations with high risk of plumbing accidents. Using the installed sensor system it is possible approximately locate the place of failure, shorten detection time and substantially reduce damage and reconstruction costs.

There is a significant possibility of improving the load bearing capacities calculated according to the existing Standards of spatial connections with thin walled metal nailing plates. The reason is that the design of these connecting elements has inadequate support in the existing Standards and Technical Reports. The improvement can make them more consistent with the results from tests. Therefore, research has been called to improve this state of the art. The paper presents the whole experimental study of angle brackets which consists of full-scale experiments, numerical models of the connections, current analytical calculation approaches and proposals how to improve them.

This article is focused on design optimization in naturally ventilated facades. Ventilated facade constructions are designed according to ETAG 034. Thickness of the cavity is defined at least 20 mm. This distance can be reduced locally to 5 mm to 10 mm. In this case, it has to be verified that it does not affect the ventilated function. The minimum cross-sections of ventilation openings at the inlet and at the outlet are also determined at least 50 cm² per linear meter. The influences of local reductions at inlet and outlet openings are analyzed. Air temperatures and velocities are monitored in the cavity with thickness 20, 40 and 60 mm. Results show that the influence of local reduction increases with increasing cavity thickness.

A test of frost resistance of a building material belongs to standard methods of an evaluation of its durability, it expresses a resistance of a building material to a substantial change of temperature and an influence of atmospheric effects regarding to its functionality and utilization in a long-term horizon. The test of frost resistance is time demanding as well as it lays demands on a test equipment of a testing laboratory. This paper describes results of a project, which evaluated a possibility of using a quick indicative test enabling a quick evaluation of a tested concrete regarding its frost resistance. The used indicative test is derived from the standard ČSN 73 73 25 Determination of frost resistance by shorten tests, which has been cancelled without refundation. This method could be beneficial for a quick evaluation of a new designed concrete mixture non-proven in a laboratory. This paper was elaborated with the institutional support for long-term development of research organizations by the Ministry of Industry and Trade of the Czech Republic.

In the last article on the regeneration of residential buildings, I said that additional contributions will be more focused on topics that are crucial for the effective functioning of the heating system, or which are controversial perception among the general public. The first topic that fully meets the two criteria is the heat transfer between the different flats in apartment houses.

The article deals with the issue of economic accessibility of energy-saving buildings; respecting the possibility of financial support from the National programme “Nová zelená úsporám” (New green savings programme, abbr. NZÚ). The purpose of the article is to disprove some of the incorrect interpretations and myths connected with this topic. It point out the good practice examples of a high-quality projects preparation, their successful submission into “New green savings programme” and following realization. Article aims either at lay or professional reader.

This paper deals with additional moisture protection of the building structures on the contact with the ground. The presented remedial work is based on the WTA guidelines, which recommend the optimal material and technology. Low and high pressure injections are mentioned, as well as additional horizontal waterproofing. It is underlined that important role plays the suitable materials and compliance with the prescribed technology. We cannot forget on effect of splash water and effect of condensing moisture. The success of remediation is conditioned on the highly professional realization of details. Specific solutions are illustrated in the appended figures.

Basic principles of designing and realization of radon remedial measure in existing buildings are presented. Typical effectiveness of particular measures is summarized and schematic drawings of measures used most frequently are provided.

Many various physical, mechanical and deformation properties have to be designed, tested and observed during life of concrete because of possible failures in given service load and climatic conditions. Apart from basic strength characteristics, it is necessary to keep in view water tightness, capillarity, water absorbing capacity, frost resistance, volumetric changes or thermal expansion. Preventing of these failures during the whole life of concrete structures in various exposure classes is the basic condition of achieving required long-term durability. The text below describes several important properties of concrete connected with flaws and failures.
The crucial mechanical properties of concrete are compressive strength, splitting tensile strength, tensile strength, tensile bending strength and shear strength. Deformation properties are connected with volumetric changes and action of external and internal strength; the characteristic mechanical property is defined by static or dynamic elasticity modulus. As regards durability of concrete, the concept is relative and limited depending on the time of action of physical and chemical influences. Corrosion of concrete is the process leading to disintegration of the material by means of chemical processes or physical influences. Durability also includes fire resistance, frost resistance and abrasive quality of concrete.

If you ask hygienist, how to define the term " indoor environment quality", the aswer will be: A set of physical, chemical and biological environmental factors. All of these factors should have - if possible, and the current state of knowledge it allows - hygienic limits as insurmountable values, protecting human health.

The exact determination of emissivity and the following determination of surface temperature of glossy materials can be carried out e. g. after applying a material with a known value of emissivity on the surface (e. g. self-adhesive foil or spray tint). The contribution deals with other possibility of determination of surface temperature and the influence of emissivity of glossy materials using a metal shield that reduces the negative influence of the reflected radiation during the termographical measurement.