Normally not. Ancient thatched houses were built with "Chongju grass", a tough and smooth grass that is very suitable for building houses.
After the ancients spread the rush grass on the house, they would use mud and polished building materials to spread it on the grass, and then spread a layer of rush grass on top. In this cycle, the house can be A solid "protective umbrella".
On rainy days, when raindrops fall on the thatched house, the rainwater will flow underground along the lines of the grass. Although it is not ruled out that a small amount of rainwater will seep into the grass, there are still multiple layers of materials underneath. Protection, therefore, the thatched houses that ancient people lived in generally did not leak when it rained.
In addition, the ancients would also conduct regular inspections and repairs on the house. If a leaky roof or grass material was found to be missing, it would be repaired immediately. The lifespan of this kind of thatched house can generally be as long as ten years.