Historical Overview of the Laboratory Measurements of Moisture Dependent Thermal Conductivity and the Integration of these Measurement Results into the Design of Hungarian Building Structures

Abstract

The thermal conductivity of installed building materials can differ from the declared value, which is determined under specific laboratory conditions given in standards (Fülöp, 2007; MSZ EN ISO 10456, 2008). In this article, the author investigates moisture as a thermal conductivity modifying effect and the design of building structures in relation to this effect. In the first chapter, the international and Hungarian results of laboratory measurements of the value of moisture dependent thermal conductivity factors are summarized. In the next section, the application of these results in the design of Hungarian building structures is discussed, especially with regard to the flat roof, due to its increased exposure. With the framework of a historical overview, the most important flat roof layer combinations are described from the perspective of how thermal insulation material was protected against the different routes of moisture penetration. Concluding the article, a terrace restoration (a building constructed in the early 1900s originally without separate thermal insulation material) of Dr Zsuzsanna Fülöp is described to illustrate the points referred above.