system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why did thatched roofs not rot and collapse from the rain and damp? Or if they did rot, how frequently were they replaced?
gpt
They did rot, but because of how they are layered on the roof, it sheds water pretty efficiently (that's how they didn't rot quickly, water shedding ability and tight layering protecting lower layers) and a well thatched roof in modern times can last 50 years before it's beyond use. Historically, at least in parts of England, a new layer of thatch was added to the aging/weathered layer and some houses have been found to have seven feet of thatch on them with the oldest layers being 500 years old.