Sage Journals: Discover world-class research

Abstract

The influence of a humidity dependent vapour retarder on the annual moisture distribution in thermally insulated flat roof constructions has been investigated by means of long term in situ measurements and two numerical simulation methods. It is shown that the simple Glaser method is not suitable to predict the moisture distribution in this type of construction under real climatic conditions and that only a transient hygrothermal analysis is able to reproduce the measured temperature and relative humidity. Based on both measurements and transient numerical simulations, the role of the vapour retarders for this type of constructions has been evaluated.

Keywords

Flat roof humidity dependent Moisture diffusion Transient behaviour Vapour retarder Wood construction

Get full access to this article

View all access options for this article.

References

Feuchtehaushalt und sommerlicher Wärmeschutz im Massivholzbau, Swiss Agency for the Environment, Forests and Landscape SAEFL, Project 2571.BUW, Report 643, February 2001.

Kuenzel HM : Moisture risk assessment of roof constructions by computer simulation in comparison to the standard Glaser-method , International Building Physics Conference, Eindhoven, September 2000, pp. 225-232 .

Glaser H: Graphisches Verfahren zur Untersuchung von Diffusionsvorgängen. Kältetechnik 1959;10:345-355.

European Standard EN ISO 13788: Hygrothermal performance of building components and building elements - Internal surface temperature to avoid critical surface humidity and interstitial condensation - Calculation methods, July 2001.

WUFI® PC-Program for calculating the coupled heat and moisture transfer in building components, www.wufi.de.

Kuenzel HM, Kasper FJ: Von der Idee einer feuchteadaptiven Dampfbremse bis zur Markteinführung. Bauphysik 1998;6:257-260.

Galbraith GH , McLean RC , Guo J , Kelly D : A system of permeability specification for use in moisture simulation models . Indoor Built Environ 1998;7: 216-223 .

Sekino N, Asakura N: Humidity control efficiency of low-density particleboards for interior Walls II. Measurement of EMC and calculation of moisture capacities. Mokuzai Gakkaishi 1993;39:1146-1151.

10.

Holm AH , Kuenzel HM : Practical application of an uncertainty approach for hygrothermal building simulations - drying of an AAC flat roof . Building Environ 2002;37: 883-889 .

11.

CEN TC 89 Item 29.3: Assessment of moisture transfer by numerical simulation. Approved draft standard. Sent for CEN Enquiry in May 2003.

A Humidity Dependent Vapour Retarder in Non-ventilated Flat Roofs. In Situ Measurements and Numerical Analysis

Abstract

Keywords

Get full access to this article

References