I'm having a problem that I think might be due to settling, but I'm not sure. There are several (all new) cracks between the walls and ceiling and maybe one between two vertical walls. I moved into this 9 year old house at the end of October, and the inspection was clean. There were no other cracks like this that I noticed, and they also are getting worse.
I'll describe the house first. It's a 9 year old split level. All walls are drywall.
The "right" side has the LR, Kit, and DR over the basement. It is about 20' wide by 22' deep. The basement is mostly below grade with cinder block walls. There is a wood beam that runs left to right. I think it's 3 2x10's (maybe 2x12's). There are 2 steel posts under the beam, roughly a third of the way apart. They aren't adjustable. The area above the basement is vaulted to about 12' in the center. The vault line runs parallel and over the beam.
The "left" side has the Bedrooms and baths over the garage and family room, about 20' wide and 32' deep (guess). The left side is at grade.
As I said, the inspection was clean, and there were no cracks - at least not the ones I'm concerned about. A few weeks after moving in (in Nov), the floor above the beam started to creak - I'm sure it didn't before because my last house creaked and I loved my new silent floor. Then I noticed a crack in the basement floor - about 8ft long - no wider than 1/16th. It may have been there - don't know. Then, the wall/ceiling cracks started showing up. First and worst is the 1/4" wide at the wall/ceiling above the beam (and centered) at the highest point of the vault. Now the ceiling is beginning to crack away from that. Also, several cracks have appeared in 2 bedrooms (on the left side of the house) and it looks like more are coming - the joints are looking strained, but I can't describe it. Also, the vertical walls in the bath seem to be strained the same way. All of these are on the side furthest from the right side of the house. I can provide a quick drawing if this doesn't make sense.
I'm not sure what to do. I thought about jacks under the beam, but was afraid of making things worse or cracking the basement floor more. Plus, I wasn't sure where to put them. In the next year or two, I'd like to finish the basement and didn't really relish having extra posts in the way, but if it helps. Things seemed to get worse recently, and I'd like to stop the progression so I can fix the cracks. Any ideas are very much appreciated.