I would like to seal the join between these two layers and stop this happening, but the fix is made more complicated by the fact that the curves of the corrugated iron on the house and verandah levels are not perfectly aligned, so the shape of the space between the two roofs varies, making the weatherproof foam and rubber inserts that are usually suitable for this purpose, unsuitable.
I have considered using some kind of weatherproof tape but due to the misaligned corrugations, I am not sure that I would be able to make the tape curve as necessary and make a good seal. I have also considered some kind of waterproofing membrane treatment but I don't know much about them. Does anyone have any suggestions?
![Think :th:](./images/smilies/think.gif)