The back bedroom in our house creaks and pops. It is not just a creaking board sound, but a loud firecracker sound that sometimes travels the whole length of the room. It wakes me up at night from time to time because of how loud it is. That portion of the house is on cender blocks and the blocks are on a rock foundation. Can you tell me what is causing this. We live in Prescott, AZ which is at 5,500 ft in elevation. The nights are quite cold 25-35 degrees f and it warms up to 55-70 during the day.