Sorry in advance for the long post but I want to give as much detail as possible.
Recently moved into a 35 year old home back in January. Had a home inspection from a reputable company we've used before, and then moved in right before all the snow hit. This is up in New England and we had quite a brutal winter this year.
The home had fairly underrrated/spotty insulation in the attic and none in the basement, and lots of air leaks, so during the winter had an energy audit done, and between myself and a company got the attic up to R49 and insulated my basement. Filled air gaps before and during audit, which helped a lot with the winter air leaking in.
Now that spring has arrived and the mountains of snow are gone, I'm noticing a lot of nail pops in many rooms of the house. I know they are generally considered cosmetic, but some are in the middle of walls, some are running from ceiling edge in a line out across ceiling, etc. I'd say I have anywhere from 4 to 5 new nail pops in each room. Also, in one of my bathrooms, I replaced a piece of greenboard on an exterior bathroom wall (previous known damage) and the drywall screws I used even popped a little bit near the tub. All nailpops are convex, but few if any are actually breaking the paper.
I'm also noticing a lot of new tape seams I didn't before that are running horizontally across the walls in a few rooms and my staircase. They all seem to be at the midline joint of the walls where the sheetrock was taped.
None of the drywall flexes back on the nailpops or tape joints when I push on it. I occasionally hear a slight creak but that's it.
I'm also seeing some moulding around the ceilings move away a little. Honestly, it was a DIY job from the prior owner and I don't think it was done well or correctly, but I think it may have bowed/moved and had some trim nails pop over winter. Pics included of ceiling pops traveling out towards fan.
Here's what worries me. I discovered this crack in my foundation that appears to be from settlement once the snow melted. It's where an addition was built on the home years ago. Main structure is basement, addition is slab that steps down. I believe this may have been at a "cold joint"? Crack is about 1/8" inch wide and I marked it to monitor for movement. It wasn't on my HI report, but from pics you can see it's under my deck and somewhat obscured by the trellising. I honestly don't know if it was missed, or it's new, so I'm just monitoring.
The prior nailpop/moulding pics are of the room where the addition meets the main structure; in the vicinity of the slab crack.
I have some efflorescence in the basement, and low graded areas around the foundation, so I'm working on re-grading, gutter extensions, etc to try and move water further out. I think the water table in my neighborhood may be a bit on the high side.
I haven't noticed any cracks in my drywall, nor do I have any windows or interior doors sticking (besides a little bit from humidity here and there). Also roof is rafters and ties, so besides normal creaks and pops I didn't have any sort of truss uplift or anything of that nature.
So my question is are these fairly normal things to happen to a 35 year old home that got exacerbated from a really bad winter? I've lived in newer homes and apts that were "still settling" and drying out, but I'd expect a house this old to have already gotten past that stage of its life.
Should I just be getting out some caulk and hydraulic cement and keep mytape measure handy, or would this potentially warrant a call to a structural engineer since it all seems to have happened over the course of about 8-10 weeks.
Thanks in advance.