What’s the point of cracking and leaking tiles in the main beam of a house?

The research on the cracking and leakage of tiles in the main beam of the house is as follows:

The cracks in the roof tiles leaked. That was when the house was built, and the wall builder did not pay attention when building the tiles. , the distance between the two tiles is a bit too big (the saying goes, the tiles are sparsely covered), then you can only ask a mason (commonly known as a wall builder) to go up to the roof and insert a few tiles for you, and make them tighter, so there will be no leakage. .