I have lived in 2 story house in Northern California since 1999. This house was built in 1989. Basic stucco over frame type building. I do have a large attic that was not finished. In 2007 I decided to use the space and we put down some ply-wood just for storage purposes. Recently I have noticed some real LOUD popping noises coming from the northwest side of my house. Sounds like closer to the outer walls or roof line. It is loud. Usually the pops come at night, or in the morning. I have been reading about the "temperature change" possibility. We don't have "extreme" weather conditions here. I live right outside of San Francisco. It gets warm here during the summer on occasion but its not constant. Mid 70's- mid 80's... I just never heard it this loud or this often. I have noticed the creaks in other parts of the house, but like I said not coming from this one location or certainly not this loud. Should I be worried about structural issues? I am the second resident and I am not sure about the builder if they were good and bad. I remember initial house inspection said the house had an excellent solid concrete foundation, so not too sure about the "settling" factor. Any suggestions or directions would be greatly appreciated.

How did you attach the plywood in the attic? Most homes move ever so slightly even from the wind. Wood structure can absorb some movement but enough movement will actually make a wood connection, like wall stud to raft) actually slip just a hair. A slip will sound like a pop or a creak

We only put down a couple of pieces of ply wood and secured it with wood screws into the joists. I had my then boyfriend do it, so I am not completely sure how secure or at what points he screwed them in. The majority of the loud pops seem to be coming from the outerwall/roof of the house. I have heard a couple from the attic area, but not very loud.

I would not worry about the noises. Sounds like the sound started after you installed the ply and its likely the cause. Flooring, even attic flooring, should be glued and screwed to prevent creeking.

Thanks for your responses. It's been awhile now since I have heard the pops... maybe they are subsiding. Appreciate your time!