Like in a relationship, the foundation of a house is integral, and must be strong. There are many reasons why a house's foundation might crack or shift – including temperature variances in the soil surrounding it, since earth expands in heat and contracts in cold. But whatever the reason, there are certain steps to follow when addressing concerns about your house's foundation.
Prevent The Problem, If Possible
First, whenever possible act to prevent problems before they arise. Make it a habit to check for foundational stress by taking a walk through your basement and around the outside of your home. Signs of a problem include cracks in the foundation itself (particularly horizontal ones larger than a hairline), uneven or sloping floors, doors or windows that won't open or close properly anymore, and water damage (puddles or moisture in the wood) that signals improper drainage.
Confirm The Problem, If There's Time
If you find a crack that has you worried, but isn't an insurmountable gap, take the time to coat it with concrete waterproofing paint. Then keep an eye on it. If the crack reappears after the paint has dried, it means the gap that produced the crack is growing and should be addressed. If you suspect water drainage problems, try shutting down all water-using appliances in your home. Then watch the water meter for 6 to 12 hours. If the levels change in that time, your water is finding another way out of the house. Finally, if you suspect a sloping floor, rest a tennis ball on it and look for rolling.
Fix The Problem, If It's Small
Sometimes DIY methods can be used to address small issues, like little cracks (ones not in the foundation itself, but in walls or floors). Fill them with a vinyl concrete patch, or a similar product. Be sure the material you use is flexible and can move a little, because the concrete will – it slightly expands and contracts to keep stable.
Call For Reinforcements!
That said, the absolute best method of dealing with foundation problems is to call in reinforcements, because even successful DIY fixes are temporary. And because, even though it will cost a little more, the money is worth it to prevent your house from collapsing! Reach out to a foundational specialist or a structural engineer if there are any signs that have you worried about a shifting or crumbling foundation.
If you have more in-depth questions, or want advice on a foundational specialist, talk to your trusted local real estate agent.