ABSTRACT
The paper shows results from two moisture loads in a Moisture Design. The primary results concern calculations of moisture transfer of vapour diffusion, in combination with or without pelting rain, for three different locations in Sweden. The construction is an apartment wall with south and north facings. Hourly values of the outer climatic data have been used for the time-period 1961 - 1990. The effects of solar and long wave radiation are considered and a simplified method for calculation of the pelting rain is used. Following primarily three results from the study: 1) The occurrences of high relative humidity at the surface radically increase if rain is included. The highest is for the south-west location and for the south facing. 2) The permitted moisture supply is given by drying out potential and it is lowest in the south of Sweden and the north facing. 3) The “dose” (relative humidity multiplied by the time of its occurrence) gives a design year that differs from year to year. A brittle facing material may have a different design year concerning the risk of frost damage compared to a firmer material. The worst case may be the southern parts of Sweden for locations with large amounts of rain.
