Houses normally creak a little, but banging noises can be outright alarming. The good news is that even though banging sounds from your roof are loud, they're very rarely a sign of any serious problems. While generally harmless, however, these sounds are usually something you should investigate just to be on the safe side.
1. Shifting Wood and Metal
If it sounds like the ghost of a carpenter comes to your house every winter, this is actually somewhat normal. Once cold weather hits, the difference between warm air inside and cold air outside can cause some beams and plates to expand and contract. The good news is that your house was designed to be able to move a little, so there's nothing wrong with this occurring. Part of the reason why the sound is so loud is simply because it reverberates throughout the attic, and your home's air ducts can also carry the noise.
While there isn't very much you can do to minimize the noise, you could install attic vents to help decrease the difference in temperature and pressure inside and outside your attic. It's also a good idea to perform a routine inspection to look for any loose or damaged parts, just in case.
2. Air Pressure In Water Pipes
If air gets trapped in your water pipes, it can cause your pipes to "shudder" when water is turned on or off anywhere in the house, which can cause them to bang against nearby wood or metal. Since many appliances run water automatically, they don't need human input to cause the pipes to bang – and the reason it may sound like it's coming from your roof is because the sound can come from wherever the air pressure is, not where the water is exiting. Depending on where your water heater is installed, this could also be a cause. An easy fix for this is to shut off all water to your house, then open every tap and faucet to drain all the water in your pipes. Wait for all the water to drain from the pipes, then turn the water back on.
3. Animals Seeking Shelter
Your attic might not seem like much to you, but to an animal looking for refuge from the elements, it can be a perfect home. Most creatures who make their way into attics are simply looking for a home and will mind their own business, but they can also cause loud noises by walking over ducts or knocking things over. If you think you have an animal in your attic of any kind, call pest control so they can be dealt with safely. In the meantime, keep the entrance to the attic closed so the pest doesn't decide to check out the rest of your home.
For more help, talk to a roofing contractor from a company like JSI Roofing.