My home is on the top floor, but why can I always hear the sound of "dong, dong" upstairs at night?

Let me tell you, because heat expands and contracts, especially in summer, some materials will expand or soften after the sun shines on the roof during the day, and the average temperature of the roof at night is much lower than that when the sun shines! Some materials will shrink and harden after cooling! Probably linoleum because there will be residual asphalt under the linoleum, and there will be adhesion in one day! Drag away a catty when it's cold at night! If you really don't want any movement, you can re-vote and stick it firmly!