Concrete cracks are nearly always referenced in my home inspection reports. Here in Oklahoma, and I would imagine nation wide, cracks in walkways, driveways and patios are common. Most of the time they are not related to any structural problem but simply a result of the expansion and contraction of the concrete itself or the soil it sits on and is surrounded by.
I have noticed from personal experience and from other home owners who have made it a point to perform regular maintenance around their home, that applying the appropriate sealant when the cracks are noticed, can go a long way in preventing further deterioration. Sealing cracks quickly will prevent expansion through ice and snow entry in the winter and soil and vegetation entry the rest of the year.
So the next time you are at your favorite home improvement store, spend a few bucks and put a reminder on your phone for your next day off to seal up those cracks you have noticed. Long term they could avoid costly replacement cost and trip hazards. Also, you will avoid having to deal with it when you sell your home and the buyers inspector calls it out as a defect.
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