[wingnut60]

I suggest using the tape where possible...the self-leveling is for use only on horizontal surfaces, don't use on vertical surface. Take a look at the YouTube vids on how to use it, then follow them exactly. Once placed on a surface, it isn't coming back off. Cleaning before placing is critical, then using a roller to push it down evenly works well.
If there is a window near the wet spot, check around it carefully for full seal, clean drain holes in bottom of frame.