I bought a house that was built in 1948 and moved in 3 month ago. Now I notice nails popping from all the walls around my house and new cracks around all windows and doors. I noticed walls joints are showing.

I feel so disturbed, is it foundation issue?

I also hear dripping noise in my vents
( *now heat is on.* )

I checked the crawl space I found an additional piece of wood added to the foundation, is that normal?

[![enter image description here](https://i.stack.imgur.com/FiBWQ.jpg)](https://i.stack.imgur.com/FiBWQ.jpg)

[![enter image description here](https://i.stack.imgur.com/ozW2T.jpg)](https://i.stack.imgur.com/ozW2T.jpg)

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[![enter image description here](https://i.stack.imgur.com/4yRlv.jpg)](https://i.stack.imgur.com/4yRlv.jpg)

[![enter image description here](https://i.stack.imgur.com/2yk8S.jpg)](https://i.stack.imgur.com/2yk8S.jpg)

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[6]: [https://i.stack.imgur.com/QN7Cq.jpg![enter](https://i.stack.imgur.com/QN7Cq.jpg!%5Benter) image description here](<https://i.stack.imgur.com/NzSmX.jpg>)![enter image description here](https://i.stack.imgur.com/2hrpW.jpg)