Investigation Of The Hygrothermal PerformanceOf Wooden Beam Ends Embedded In InsideInsulated Outside Walls

Abstract

The inside insulation has been investigated in the past by means of scientific institutions as a necessary method in connection with the thermal improvement of worth-preserving facades of architectonic heritage. In the case of fair faced brickwork it is established on homogenous areas of the wall, for instance as a variant of capillary active systems or as a classical version with a humid-dependent vapor barrier. With regard to the insulation of special details, e.g. embedded wooden beam ends within areas of outside walls, the opinion of experts differs considerably. Both the total ventilation of the beam ends and complete air tightness are proposed. In line with the new European directive on the energy efficiency of buildings, innovative ideas should also be developed in the field of building physics in order to realize the restrictions without damage to building envelope parts. The main point of this paper is the investigation of the hygrothermal situation of embedded beam ends in inside insulated outside walls, dependent on time and climate boundary conditions. The topics are treated by means of in situ measurements in two test houses in the eastern part of Germany under condition of use and by experiments in connection with an erected test stand. A comprehensive numerical simulation of the coupled heatand mass transfer supports the measurements to reduce the experimental work. In principle there are several options to avoid the effects of the hygrothermal deficiencies of the structure caused or intensified by inside insulation. Hygrothermal effects are quantified and solutions are found for workmanship without damage.