WUFI

I am trying to simulate a sloped white and dark roofs (35° Inclination,north-south) in different location but my problem is that total water content in each side of the roof is so much different (always south side has higher than north)
would you please tell me the reason of this difference ?
Tnx

Do you try to simulate the roof assemblies in WUFI Pro or in WUFI Plus?
Without your input file it is not possible to assess why you get such different total water contents.