3 years old, 6 districts and 7 attics: roof, abnormal sound

Brother: Your situation is exactly the same as mine. Mine is a house seven years ago with a garden property. I often wake up in the middle of the night. Sounds like hitting the roof with a sledgehammer (I am the top floor). The sound direction is coming from above. The greater the temperature change, the greater the noise. There is a 4-5 cm thick benzene insulation layer on my wall. I went to see the roof this morning. Only snow, no human footprints, excluding human factors. ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

I am from Shenyang, QQ:206 14336.