Q. Our home inspector said that parts of our sidewalk are a potential trip hazard. We think that he is being too picky and splitting hairs. What do think about cracks in sidewalks?

A. Simple cracks in a concrete sidewalk are not necessarily a problem unless they become large enough to catch the heel or toe of a shoe or the tip of a cane. Cracks normally indicate movement in the sidewalk, and are fairly normal. Most sidewalks that are more than 20 years old will have some cracks. On the other hand, upheavals in sections of the sidewalk can be a liability. Concrete sidewalks typically will have expansion joints at regular intervals. These individual sections of concrete can rise or fall as much as three inches in some extreme cases. The most common reason for upheaval is tree roots. The opposite problem is caused by subsidence where the ground beneath the slab sinks. An upheaval of more than one inch can become a dangerous trip hazard, and a liability to you as the home owner. This type of trip hazard is particularly dangerous at night. In my practice, I always explain this to the client, and encourage them to make repairs.