Recently purchased a 1920s 2-story rowhome and now have a horrible feeling. I've noticed that the slab had lots of cracks and i expected this in such an old home but today i saw a hole the size of a dime in it. Maybe i dropped something at some point to make this hole but i saw that it was hollow for a good 3 or 4 inches. I grabbed a hammer and made the hole larger and poked around with a stick to see how far it goes. The stick was a foot long and i could only find an edge in one direction. So i grabbed an 80 pound bag of mason mix i had and used half of the bag filling this hole.
1. Should I be worried? Because i really don't have the money to pay for a whole new slab and im afraid one day im going to take a step and go right through!
2. Is this common?
3. What would cause this since its an older house I would think it wouldn't need to settle any more.
4. What are my options here?